Integrated Ableton/link library

config.mk

@@ -12,7 +12,8 @@ endif
 VERSION := $(MAJOR).$(MINOR).$(PATCH)-dev+$(COMMIT)
 
 CXXFLAGS:=$(CXXFLAGS) -std=c++20 -Wall -Wextra -Werror=switch -Werror=return-type -Werror=unused-result
-CPPFLAGS:=$(CPPFLAGS) -Ilib/expected/ -I. -Ilib/bestline/ -Ilib/rtmidi/ -DMusique_Version='"$(VERSION)"'
+CPPFLAGS:=$(CPPFLAGS) -DMusique_Version='"$(VERSION)"' \
+	-Ilib/expected/ -I. -Ilib/bestline/ -Ilib/rtmidi/ -Ilib/link/include -Ilib/asio/include/
 LDFLAGS=-flto
 LDLIBS= -lpthread
 

lib/asio/COPYING

@@ -0,0 +1,4 @@
+Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+
+Distributed under the Boost Software License, Version 1.0. (See accompanying
+file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)

lib/asio/LICENSE_1_0.txt

@@ -0,0 +1,23 @@
+Boost Software License - Version 1.0 - August 17th, 2003
+
+Permission is hereby granted, free of charge, to any person or organization
+obtaining a copy of the software and accompanying documentation covered by
+this license (the "Software") to use, reproduce, display, distribute,
+execute, and transmit the Software, and to prepare derivative works of the
+Software, and to permit third-parties to whom the Software is furnished to
+do so, all subject to the following:
+
+The copyright notices in the Software and this entire statement, including
+the above license grant, this restriction and the following disclaimer,
+must be included in all copies of the Software, in whole or in part, and
+all derivative works of the Software, unless such copies or derivative
+works are solely in the form of machine-executable object code generated by
+a source language processor.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
+SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
+FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
+ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.

lib/asio/include/.gitignore

@@ -0,0 +1,2 @@
+Makefile
+Makefile.in

lib/asio/include/Makefile.am

@@ -0,0 +1,658 @@
+# find . -name "*.*pp" | sed -e 's/^\.\///' | sed -e 's/^.*$/  & \\/' | sort
+nobase_include_HEADERS = \
+	asio/any_io_executor.hpp \
+	asio/associated_allocator.hpp \
+	asio/associated_cancellation_slot.hpp \
+	asio/associated_executor.hpp \
+	asio/associator.hpp \
+	asio/async_result.hpp \
+	asio/awaitable.hpp \
+	asio/basic_datagram_socket.hpp \
+	asio/basic_deadline_timer.hpp \
+	asio/basic_file.hpp \
+	asio/basic_io_object.hpp \
+	asio/basic_random_access_file.hpp \
+	asio/basic_raw_socket.hpp \
+	asio/basic_readable_pipe.hpp \
+	asio/basic_seq_packet_socket.hpp \
+	asio/basic_serial_port.hpp \
+	asio/basic_signal_set.hpp \
+	asio/basic_socket_acceptor.hpp \
+	asio/basic_socket.hpp \
+	asio/basic_socket_iostream.hpp \
+	asio/basic_socket_streambuf.hpp \
+	asio/basic_streambuf_fwd.hpp \
+	asio/basic_streambuf.hpp \
+	asio/basic_stream_file.hpp \
+	asio/basic_stream_socket.hpp \
+	asio/basic_waitable_timer.hpp \
+	asio/basic_writable_pipe.hpp \
+	asio/bind_allocator.hpp \
+	asio/bind_cancellation_slot.hpp \
+	asio/bind_executor.hpp \
+	asio/buffered_read_stream_fwd.hpp \
+	asio/buffered_read_stream.hpp \
+	asio/buffered_stream_fwd.hpp \
+	asio/buffered_stream.hpp \
+	asio/buffered_write_stream_fwd.hpp \
+	asio/buffered_write_stream.hpp \
+	asio/buffer.hpp \
+	asio/buffer_registration.hpp \
+	asio/buffers_iterator.hpp \
+	asio/cancellation_signal.hpp \
+	asio/cancellation_state.hpp \
+	asio/cancellation_type.hpp \
+	asio/co_spawn.hpp \
+	asio/completion_condition.hpp \
+	asio/compose.hpp \
+	asio/connect.hpp \
+	asio/connect_pipe.hpp \
+	asio/coroutine.hpp \
+	asio/deadline_timer.hpp \
+	asio/defer.hpp \
+	asio/detached.hpp \
+	asio/detail/array_fwd.hpp \
+	asio/detail/array.hpp \
+	asio/detail/assert.hpp \
+	asio/detail/atomic_count.hpp \
+	asio/detail/base_from_cancellation_state.hpp \
+	asio/detail/base_from_completion_cond.hpp \
+	asio/detail/bind_handler.hpp \
+	asio/detail/blocking_executor_op.hpp \
+	asio/detail/buffered_stream_storage.hpp \
+	asio/detail/buffer_resize_guard.hpp \
+	asio/detail/buffer_sequence_adapter.hpp \
+	asio/detail/bulk_executor_op.hpp \
+	asio/detail/call_stack.hpp \
+	asio/detail/chrono.hpp \
+	asio/detail/chrono_time_traits.hpp \
+	asio/detail/completion_handler.hpp \
+	asio/detail/concurrency_hint.hpp \
+	asio/detail/conditionally_enabled_event.hpp \
+	asio/detail/conditionally_enabled_mutex.hpp \
+	asio/detail/config.hpp \
+	asio/detail/consuming_buffers.hpp \
+	asio/detail/cstddef.hpp \
+	asio/detail/cstdint.hpp \
+	asio/detail/date_time_fwd.hpp \
+	asio/detail/deadline_timer_service.hpp \
+	asio/detail/dependent_type.hpp \
+	asio/detail/descriptor_ops.hpp \
+	asio/detail/descriptor_read_op.hpp \
+	asio/detail/descriptor_write_op.hpp \
+	asio/detail/dev_poll_reactor.hpp \
+	asio/detail/epoll_reactor.hpp \
+	asio/detail/eventfd_select_interrupter.hpp \
+	asio/detail/event.hpp \
+	asio/detail/executor_function.hpp \
+	asio/detail/executor_op.hpp \
+	asio/detail/fd_set_adapter.hpp \
+	asio/detail/fenced_block.hpp \
+	asio/detail/functional.hpp \
+	asio/detail/future.hpp \
+	asio/detail/gcc_arm_fenced_block.hpp \
+	asio/detail/gcc_hppa_fenced_block.hpp \
+	asio/detail/gcc_sync_fenced_block.hpp \
+	asio/detail/gcc_x86_fenced_block.hpp \
+	asio/detail/global.hpp \
+	asio/detail/handler_alloc_helpers.hpp \
+	asio/detail/handler_cont_helpers.hpp \
+	asio/detail/handler_invoke_helpers.hpp \
+	asio/detail/handler_tracking.hpp \
+	asio/detail/handler_type_requirements.hpp \
+	asio/detail/handler_work.hpp \
+	asio/detail/hash_map.hpp \
+	asio/detail/impl/buffer_sequence_adapter.ipp \
+	asio/detail/impl/descriptor_ops.ipp \
+	asio/detail/impl/dev_poll_reactor.hpp \
+	asio/detail/impl/dev_poll_reactor.ipp \
+	asio/detail/impl/epoll_reactor.hpp \
+	asio/detail/impl/epoll_reactor.ipp \
+	asio/detail/impl/eventfd_select_interrupter.ipp \
+	asio/detail/impl/handler_tracking.ipp \
+	asio/detail/impl/io_uring_descriptor_service.ipp \
+	asio/detail/impl/io_uring_file_service.ipp \
+	asio/detail/impl/io_uring_service.hpp \
+	asio/detail/impl/io_uring_service.ipp \
+	asio/detail/impl/io_uring_socket_service_base.ipp \
+	asio/detail/impl/kqueue_reactor.hpp \
+	asio/detail/impl/kqueue_reactor.ipp \
+	asio/detail/impl/null_event.ipp \
+	asio/detail/impl/pipe_select_interrupter.ipp \
+	asio/detail/impl/posix_event.ipp \
+	asio/detail/impl/posix_mutex.ipp \
+	asio/detail/impl/posix_serial_port_service.ipp \
+	asio/detail/impl/posix_thread.ipp \
+	asio/detail/impl/posix_tss_ptr.ipp \
+	asio/detail/impl/reactive_descriptor_service.ipp \
+	asio/detail/impl/reactive_socket_service_base.ipp \
+	asio/detail/impl/resolver_service_base.ipp \
+	asio/detail/impl/scheduler.ipp \
+	asio/detail/impl/select_reactor.hpp \
+	asio/detail/impl/select_reactor.ipp \
+	asio/detail/impl/service_registry.hpp \
+	asio/detail/impl/service_registry.ipp \
+	asio/detail/impl/signal_set_service.ipp \
+	asio/detail/impl/socket_ops.ipp \
+	asio/detail/impl/socket_select_interrupter.ipp \
+	asio/detail/impl/strand_executor_service.hpp \
+	asio/detail/impl/strand_executor_service.ipp \
+	asio/detail/impl/strand_service.hpp \
+	asio/detail/impl/strand_service.ipp \
+	asio/detail/impl/thread_context.ipp \
+	asio/detail/impl/throw_error.ipp \
+	asio/detail/impl/timer_queue_ptime.ipp \
+	asio/detail/impl/timer_queue_set.ipp \
+	asio/detail/impl/win_event.ipp \
+	asio/detail/impl/win_iocp_file_service.ipp \
+	asio/detail/impl/win_iocp_handle_service.ipp \
+	asio/detail/impl/win_iocp_io_context.hpp \
+	asio/detail/impl/win_iocp_io_context.ipp \
+	asio/detail/impl/win_iocp_serial_port_service.ipp \
+	asio/detail/impl/win_iocp_socket_service_base.ipp \
+	asio/detail/impl/win_mutex.ipp \
+	asio/detail/impl/win_object_handle_service.ipp \
+	asio/detail/impl/winrt_ssocket_service_base.ipp \
+	asio/detail/impl/winrt_timer_scheduler.hpp \
+	asio/detail/impl/winrt_timer_scheduler.ipp \
+	asio/detail/impl/winsock_init.ipp \
+	asio/detail/impl/win_static_mutex.ipp \
+	asio/detail/impl/win_thread.ipp \
+	asio/detail/impl/win_tss_ptr.ipp \
+	asio/detail/io_control.hpp \
+	asio/detail/io_object_impl.hpp \
+	asio/detail/io_uring_descriptor_read_at_op.hpp \
+	asio/detail/io_uring_descriptor_read_op.hpp \
+	asio/detail/io_uring_descriptor_service.hpp \
+	asio/detail/io_uring_descriptor_write_at_op.hpp \
+	asio/detail/io_uring_descriptor_write_op.hpp \
+	asio/detail/io_uring_file_service.hpp \
+	asio/detail/io_uring_null_buffers_op.hpp \
+	asio/detail/io_uring_operation.hpp \
+	asio/detail/io_uring_service.hpp \
+	asio/detail/io_uring_socket_accept_op.hpp \
+	asio/detail/io_uring_socket_connect_op.hpp \
+	asio/detail/io_uring_socket_recvfrom_op.hpp \
+	asio/detail/io_uring_socket_recvmsg_op.hpp \
+	asio/detail/io_uring_socket_recv_op.hpp \
+	asio/detail/io_uring_socket_send_op.hpp \
+	asio/detail/io_uring_socket_sendto_op.hpp \
+	asio/detail/io_uring_socket_service_base.hpp \
+	asio/detail/io_uring_socket_service.hpp \
+	asio/detail/io_uring_wait_op.hpp \
+	asio/detail/is_buffer_sequence.hpp \
+	asio/detail/is_executor.hpp \
+	asio/detail/keyword_tss_ptr.hpp \
+	asio/detail/kqueue_reactor.hpp \
+	asio/detail/limits.hpp \
+	asio/detail/local_free_on_block_exit.hpp \
+	asio/detail/macos_fenced_block.hpp \
+	asio/detail/memory.hpp \
+	asio/detail/mutex.hpp \
+	asio/detail/non_const_lvalue.hpp \
+	asio/detail/noncopyable.hpp \
+	asio/detail/null_event.hpp \
+	asio/detail/null_fenced_block.hpp \
+	asio/detail/null_global.hpp \
+	asio/detail/null_mutex.hpp \
+	asio/detail/null_reactor.hpp \
+	asio/detail/null_signal_blocker.hpp \
+	asio/detail/null_socket_service.hpp \
+	asio/detail/null_static_mutex.hpp \
+	asio/detail/null_thread.hpp \
+	asio/detail/null_tss_ptr.hpp \
+	asio/detail/object_pool.hpp \
+	asio/detail/old_win_sdk_compat.hpp \
+	asio/detail/operation.hpp \
+	asio/detail/op_queue.hpp \
+	asio/detail/pipe_select_interrupter.hpp \
+	asio/detail/pop_options.hpp \
+	asio/detail/posix_event.hpp \
+	asio/detail/posix_fd_set_adapter.hpp \
+	asio/detail/posix_global.hpp \
+	asio/detail/posix_mutex.hpp \
+	asio/detail/posix_serial_port_service.hpp \
+	asio/detail/posix_signal_blocker.hpp \
+	asio/detail/posix_static_mutex.hpp \
+	asio/detail/posix_thread.hpp \
+	asio/detail/posix_tss_ptr.hpp \
+	asio/detail/push_options.hpp \
+	asio/detail/reactive_descriptor_service.hpp \
+	asio/detail/reactive_null_buffers_op.hpp \
+	asio/detail/reactive_socket_accept_op.hpp \
+	asio/detail/reactive_socket_connect_op.hpp \
+	asio/detail/reactive_socket_recvfrom_op.hpp \
+	asio/detail/reactive_socket_recvmsg_op.hpp \
+	asio/detail/reactive_socket_recv_op.hpp \
+	asio/detail/reactive_socket_send_op.hpp \
+	asio/detail/reactive_socket_sendto_op.hpp \
+	asio/detail/reactive_socket_service_base.hpp \
+	asio/detail/reactive_socket_service.hpp \
+	asio/detail/reactive_wait_op.hpp \
+	asio/detail/reactor.hpp \
+	asio/detail/reactor_op.hpp \
+	asio/detail/reactor_op_queue.hpp \
+	asio/detail/recycling_allocator.hpp \
+	asio/detail/regex_fwd.hpp \
+	asio/detail/resolve_endpoint_op.hpp \
+	asio/detail/resolve_op.hpp \
+	asio/detail/resolve_query_op.hpp \
+	asio/detail/resolver_service_base.hpp \
+	asio/detail/resolver_service.hpp \
+	asio/detail/scheduler.hpp \
+	asio/detail/scheduler_operation.hpp \
+	asio/detail/scheduler_task.hpp \
+	asio/detail/scheduler_thread_info.hpp \
+	asio/detail/scoped_lock.hpp \
+	asio/detail/scoped_ptr.hpp \
+	asio/detail/select_interrupter.hpp \
+	asio/detail/select_reactor.hpp \
+	asio/detail/service_registry.hpp \
+	asio/detail/signal_blocker.hpp \
+	asio/detail/signal_handler.hpp \
+	asio/detail/signal_init.hpp \
+	asio/detail/signal_op.hpp \
+	asio/detail/signal_set_service.hpp \
+	asio/detail/socket_holder.hpp \
+	asio/detail/socket_ops.hpp \
+	asio/detail/socket_option.hpp \
+	asio/detail/socket_select_interrupter.hpp \
+	asio/detail/socket_types.hpp \
+	asio/detail/solaris_fenced_block.hpp \
+	asio/detail/source_location.hpp \
+	asio/detail/static_mutex.hpp \
+	asio/detail/std_event.hpp \
+	asio/detail/std_fenced_block.hpp \
+	asio/detail/std_global.hpp \
+	asio/detail/std_mutex.hpp \
+	asio/detail/std_static_mutex.hpp \
+	asio/detail/std_thread.hpp \
+	asio/detail/strand_executor_service.hpp \
+	asio/detail/strand_service.hpp \
+	asio/detail/string_view.hpp \
+	asio/detail/thread_context.hpp \
+	asio/detail/thread_group.hpp \
+	asio/detail/thread.hpp \
+	asio/detail/thread_info_base.hpp \
+	asio/detail/throw_error.hpp \
+	asio/detail/throw_exception.hpp \
+	asio/detail/timer_queue_base.hpp \
+	asio/detail/timer_queue.hpp \
+	asio/detail/timer_queue_ptime.hpp \
+	asio/detail/timer_queue_set.hpp \
+	asio/detail/timer_scheduler_fwd.hpp \
+	asio/detail/timer_scheduler.hpp \
+	asio/detail/tss_ptr.hpp \
+	asio/detail/type_traits.hpp \
+	asio/detail/variadic_templates.hpp \
+	asio/detail/wait_handler.hpp \
+	asio/detail/wait_op.hpp \
+	asio/detail/winapp_thread.hpp \
+	asio/detail/wince_thread.hpp \
+	asio/detail/win_event.hpp \
+	asio/detail/win_fd_set_adapter.hpp \
+	asio/detail/win_fenced_block.hpp \
+	asio/detail/win_global.hpp \
+	asio/detail/win_iocp_file_service.hpp \
+	asio/detail/win_iocp_handle_read_op.hpp \
+	asio/detail/win_iocp_handle_service.hpp \
+	asio/detail/win_iocp_handle_write_op.hpp \
+	asio/detail/win_iocp_io_context.hpp \
+	asio/detail/win_iocp_null_buffers_op.hpp \
+	asio/detail/win_iocp_operation.hpp \
+	asio/detail/win_iocp_overlapped_op.hpp \
+	asio/detail/win_iocp_overlapped_ptr.hpp \
+	asio/detail/win_iocp_serial_port_service.hpp \
+	asio/detail/win_iocp_socket_accept_op.hpp \
+	asio/detail/win_iocp_socket_connect_op.hpp \
+	asio/detail/win_iocp_socket_recvfrom_op.hpp \
+	asio/detail/win_iocp_socket_recvmsg_op.hpp \
+	asio/detail/win_iocp_socket_recv_op.hpp \
+	asio/detail/win_iocp_socket_send_op.hpp \
+	asio/detail/win_iocp_socket_service_base.hpp \
+	asio/detail/win_iocp_socket_service.hpp \
+	asio/detail/win_iocp_thread_info.hpp \
+	asio/detail/win_iocp_wait_op.hpp \
+	asio/detail/win_mutex.hpp \
+	asio/detail/win_object_handle_service.hpp \
+	asio/detail/winrt_async_manager.hpp \
+	asio/detail/winrt_async_op.hpp \
+	asio/detail/winrt_resolve_op.hpp \
+	asio/detail/winrt_resolver_service.hpp \
+	asio/detail/winrt_socket_connect_op.hpp \
+	asio/detail/winrt_socket_recv_op.hpp \
+	asio/detail/winrt_socket_send_op.hpp \
+	asio/detail/winrt_ssocket_service_base.hpp \
+	asio/detail/winrt_ssocket_service.hpp \
+	asio/detail/winrt_timer_scheduler.hpp \
+	asio/detail/winrt_utils.hpp \
+	asio/detail/winsock_init.hpp \
+	asio/detail/win_static_mutex.hpp \
+	asio/detail/win_thread.hpp \
+	asio/detail/win_tss_ptr.hpp \
+	asio/detail/work_dispatcher.hpp \
+	asio/detail/wrapped_handler.hpp \
+	asio/dispatch.hpp \
+	asio/error_code.hpp \
+	asio/error.hpp \
+	asio/execution.hpp \
+	asio/execution_context.hpp \
+	asio/execution/allocator.hpp \
+	asio/execution/any_executor.hpp \
+	asio/execution/bad_executor.hpp \
+	asio/execution/blocking.hpp \
+	asio/execution/blocking_adaptation.hpp \
+	asio/execution/bulk_execute.hpp \
+	asio/execution/bulk_guarantee.hpp \
+	asio/execution/connect.hpp \
+	asio/execution/context.hpp \
+	asio/execution/context_as.hpp \
+	asio/execution/detail/as_invocable.hpp \
+	asio/execution/detail/as_operation.hpp \
+	asio/execution/detail/as_receiver.hpp \
+	asio/execution/detail/bulk_sender.hpp \
+	asio/execution/detail/submit_receiver.hpp \
+	asio/execution/detail/void_receiver.hpp \
+	asio/execution/execute.hpp \
+	asio/execution/executor.hpp \
+	asio/execution/impl/bad_executor.ipp \
+	asio/execution/impl/receiver_invocation_error.ipp \
+	asio/execution/invocable_archetype.hpp \
+	asio/execution/mapping.hpp \
+	asio/execution/occupancy.hpp \
+	asio/execution/operation_state.hpp \
+	asio/execution/outstanding_work.hpp \
+	asio/execution/prefer_only.hpp \
+	asio/execution/receiver.hpp \
+	asio/execution/receiver_invocation_error.hpp \
+	asio/execution/relationship.hpp \
+	asio/execution/schedule.hpp \
+	asio/execution/scheduler.hpp \
+	asio/execution/sender.hpp \
+	asio/execution/set_done.hpp \
+	asio/execution/set_error.hpp \
+	asio/execution/set_value.hpp \
+	asio/execution/start.hpp \
+	asio/execution/submit.hpp \
+	asio/executor.hpp \
+	asio/executor_work_guard.hpp \
+	asio/experimental/append.hpp \
+	asio/experimental/as_single.hpp \
+	asio/experimental/as_tuple.hpp \
+	asio/experimental/awaitable_operators.hpp \
+	asio/experimental/basic_channel.hpp \
+	asio/experimental/basic_concurrent_channel.hpp \
+	asio/experimental/cancellation_condition.hpp \
+	asio/experimental/channel.hpp \
+	asio/experimental/channel_error.hpp \
+	asio/experimental/channel_traits.hpp \
+	asio/experimental/co_spawn.hpp \
+	asio/experimental/concurrent_channel.hpp \
+	asio/experimental/coro.hpp \
+	asio/experimental/coro_traits.hpp \
+	asio/experimental/deferred.hpp \
+	asio/experimental/detail/channel_handler.hpp \
+	asio/experimental/detail/channel_message.hpp \
+	asio/experimental/detail/channel_operation.hpp \
+	asio/experimental/detail/channel_payload.hpp \
+	asio/experimental/detail/channel_receive_op.hpp \
+	asio/experimental/detail/channel_send_functions.hpp \
+	asio/experimental/detail/channel_send_op.hpp \
+	asio/experimental/detail/channel_service.hpp \
+	asio/experimental/detail/completion_handler_erasure.hpp \
+	asio/experimental/detail/coro_promise_allocator.hpp \
+	asio/experimental/detail/has_signature.hpp \
+	asio/experimental/detail/impl/channel_service.hpp \
+	asio/experimental/detail/partial_promise.hpp \
+	asio/experimental/impl/append.hpp \
+	asio/experimental/impl/as_single.hpp \
+	asio/experimental/impl/as_tuple.hpp \
+	asio/experimental/impl/channel_error.ipp \
+	asio/experimental/impl/coro.hpp \
+	asio/experimental/impl/deferred.hpp \
+	asio/experimental/impl/parallel_group.hpp \
+	asio/experimental/impl/prepend.hpp \
+	asio/experimental/impl/promise.hpp \
+	asio/experimental/impl/use_coro.hpp \
+	asio/experimental/parallel_group.hpp \
+	asio/experimental/prepend.hpp \
+	asio/experimental/promise.hpp \
+	asio/experimental/use_coro.hpp \
+	asio/file_base.hpp \
+	asio/generic/basic_endpoint.hpp \
+	asio/generic/datagram_protocol.hpp \
+	asio/generic/detail/endpoint.hpp \
+	asio/generic/detail/impl/endpoint.ipp \
+	asio/generic/raw_protocol.hpp \
+	asio/generic/seq_packet_protocol.hpp \
+	asio/generic/stream_protocol.hpp \
+	asio/handler_alloc_hook.hpp \
+	asio/handler_continuation_hook.hpp \
+	asio/handler_invoke_hook.hpp \
+	asio/high_resolution_timer.hpp \
+	asio.hpp \
+	asio/impl/any_io_executor.ipp \
+	asio/impl/awaitable.hpp \
+	asio/impl/buffered_read_stream.hpp \
+	asio/impl/buffered_write_stream.hpp \
+	asio/impl/cancellation_signal.ipp \
+	asio/impl/co_spawn.hpp \
+	asio/impl/compose.hpp \
+	asio/impl/connect.hpp \
+	asio/impl/connect_pipe.hpp \
+	asio/impl/connect_pipe.ipp \
+	asio/impl/defer.hpp \
+	asio/impl/detached.hpp \
+	asio/impl/dispatch.hpp \
+	asio/impl/error_code.ipp \
+	asio/impl/error.ipp \
+	asio/impl/execution_context.hpp \
+	asio/impl/execution_context.ipp \
+	asio/impl/executor.hpp \
+	asio/impl/executor.ipp \
+	asio/impl/handler_alloc_hook.ipp \
+	asio/impl/io_context.hpp \
+	asio/impl/io_context.ipp \
+	asio/impl/multiple_exceptions.ipp \
+	asio/impl/post.hpp \
+	asio/impl/read_at.hpp \
+	asio/impl/read.hpp \
+	asio/impl/read_until.hpp \
+	asio/impl/redirect_error.hpp \
+	asio/impl/serial_port_base.hpp \
+	asio/impl/serial_port_base.ipp \
+	asio/impl/spawn.hpp \
+	asio/impl/src.hpp \
+	asio/impl/system_context.hpp \
+	asio/impl/system_context.ipp \
+	asio/impl/system_executor.hpp \
+	asio/impl/thread_pool.hpp \
+	asio/impl/thread_pool.ipp \
+	asio/impl/use_awaitable.hpp \
+	asio/impl/use_future.hpp \
+	asio/impl/write_at.hpp \
+	asio/impl/write.hpp \
+	asio/io_context.hpp \
+	asio/io_context_strand.hpp \
+	asio/io_service.hpp \
+	asio/io_service_strand.hpp \
+	asio/ip/address.hpp \
+	asio/ip/address_v4.hpp \
+	asio/ip/address_v4_iterator.hpp \
+	asio/ip/address_v4_range.hpp \
+	asio/ip/address_v6.hpp \
+	asio/ip/address_v6_iterator.hpp \
+	asio/ip/address_v6_range.hpp \
+	asio/ip/bad_address_cast.hpp \
+	asio/ip/basic_endpoint.hpp \
+	asio/ip/basic_resolver_entry.hpp \
+	asio/ip/basic_resolver.hpp \
+	asio/ip/basic_resolver_iterator.hpp \
+	asio/ip/basic_resolver_query.hpp \
+	asio/ip/basic_resolver_results.hpp \
+	asio/ip/detail/endpoint.hpp \
+	asio/ip/detail/impl/endpoint.ipp \
+	asio/ip/detail/socket_option.hpp \
+	asio/ip/host_name.hpp \
+	asio/ip/icmp.hpp \
+	asio/ip/impl/address.hpp \
+	asio/ip/impl/address.ipp \
+	asio/ip/impl/address_v4.hpp \
+	asio/ip/impl/address_v4.ipp \
+	asio/ip/impl/address_v6.hpp \
+	asio/ip/impl/address_v6.ipp \
+	asio/ip/impl/basic_endpoint.hpp \
+	asio/ip/impl/host_name.ipp \
+	asio/ip/impl/network_v4.hpp \
+	asio/ip/impl/network_v4.ipp \
+	asio/ip/impl/network_v6.hpp \
+	asio/ip/impl/network_v6.ipp \
+	asio/ip/multicast.hpp \
+	asio/ip/network_v4.hpp \
+	asio/ip/network_v6.hpp \
+	asio/ip/resolver_base.hpp \
+	asio/ip/resolver_query_base.hpp \
+	asio/ip/tcp.hpp \
+	asio/ip/udp.hpp \
+	asio/ip/unicast.hpp \
+	asio/ip/v6_only.hpp \
+	asio/is_applicable_property.hpp \
+	asio/is_executor.hpp \
+	asio/is_read_buffered.hpp \
+	asio/is_write_buffered.hpp \
+	asio/local/basic_endpoint.hpp \
+	asio/local/connect_pair.hpp \
+	asio/local/datagram_protocol.hpp \
+	asio/local/detail/endpoint.hpp \
+	asio/local/detail/impl/endpoint.ipp \
+	asio/local/stream_protocol.hpp \
+	asio/multiple_exceptions.hpp \
+	asio/packaged_task.hpp \
+	asio/placeholders.hpp \
+	asio/posix/basic_descriptor.hpp \
+	asio/posix/basic_stream_descriptor.hpp \
+	asio/posix/descriptor_base.hpp \
+	asio/posix/descriptor.hpp \
+	asio/posix/stream_descriptor.hpp \
+	asio/post.hpp \
+	asio/prefer.hpp \
+	asio/query.hpp \
+	asio/random_access_file.hpp \
+	asio/read_at.hpp \
+	asio/read.hpp \
+	asio/read_until.hpp \
+	asio/readable_pipe.hpp \
+	asio/recycling_allocator.hpp \
+	asio/redirect_error.hpp \
+	asio/registered_buffer.hpp \
+	asio/require.hpp \
+	asio/require_concept.hpp \
+	asio/serial_port_base.hpp \
+	asio/serial_port.hpp \
+	asio/signal_set.hpp \
+	asio/socket_base.hpp \
+	asio/spawn.hpp \
+	asio/ssl/context_base.hpp \
+	asio/ssl/context.hpp \
+	asio/ssl/detail/buffered_handshake_op.hpp \
+	asio/ssl/detail/engine.hpp \
+	asio/ssl/detail/handshake_op.hpp \
+	asio/ssl/detail/impl/engine.ipp \
+	asio/ssl/detail/impl/openssl_init.ipp \
+	asio/ssl/detail/io.hpp \
+	asio/ssl/detail/openssl_init.hpp \
+	asio/ssl/detail/openssl_types.hpp \
+	asio/ssl/detail/password_callback.hpp \
+	asio/ssl/detail/read_op.hpp \
+	asio/ssl/detail/shutdown_op.hpp \
+	asio/ssl/detail/stream_core.hpp \
+	asio/ssl/detail/verify_callback.hpp \
+	asio/ssl/detail/write_op.hpp \
+	asio/ssl/error.hpp \
+	asio/ssl.hpp \
+	asio/ssl/host_name_verification.hpp \
+	asio/ssl/impl/context.hpp \
+	asio/ssl/impl/context.ipp \
+	asio/ssl/impl/error.ipp \
+	asio/ssl/impl/host_name_verification.ipp \
+	asio/ssl/impl/rfc2818_verification.ipp \
+	asio/ssl/impl/src.hpp \
+	asio/ssl/rfc2818_verification.hpp \
+	asio/ssl/stream_base.hpp \
+	asio/ssl/stream.hpp \
+	asio/ssl/verify_context.hpp \
+	asio/ssl/verify_mode.hpp \
+	asio/static_thread_pool.hpp \
+	asio/steady_timer.hpp \
+	asio/strand.hpp \
+	asio/streambuf.hpp \
+	asio/stream_file.hpp \
+	asio/system_context.hpp \
+	asio/system_error.hpp \
+	asio/system_executor.hpp \
+	asio/system_timer.hpp \
+	asio/this_coro.hpp \
+	asio/thread.hpp \
+	asio/thread_pool.hpp \
+	asio/time_traits.hpp \
+	asio/traits/bulk_execute_free.hpp \
+	asio/traits/bulk_execute_member.hpp \
+	asio/traits/connect_free.hpp \
+	asio/traits/connect_member.hpp \
+	asio/traits/equality_comparable.hpp \
+	asio/traits/execute_free.hpp \
+	asio/traits/execute_member.hpp \
+	asio/traits/prefer_free.hpp \
+	asio/traits/prefer_member.hpp \
+	asio/traits/query_free.hpp \
+	asio/traits/query_member.hpp \
+	asio/traits/query_static_constexpr_member.hpp \
+	asio/traits/require_concept_free.hpp \
+	asio/traits/require_concept_member.hpp \
+	asio/traits/require_free.hpp \
+	asio/traits/require_member.hpp \
+	asio/traits/schedule_free.hpp \
+	asio/traits/schedule_member.hpp \
+	asio/traits/set_done_free.hpp \
+	asio/traits/set_done_member.hpp \
+	asio/traits/set_error_free.hpp \
+	asio/traits/set_error_member.hpp \
+	asio/traits/set_value_free.hpp \
+	asio/traits/set_value_member.hpp \
+	asio/traits/start_free.hpp \
+	asio/traits/start_member.hpp \
+	asio/traits/static_query.hpp \
+	asio/traits/static_require.hpp \
+	asio/traits/static_require_concept.hpp \
+	asio/traits/submit_free.hpp \
+	asio/traits/submit_member.hpp \
+	asio/ts/buffer.hpp \
+	asio/ts/executor.hpp \
+	asio/ts/internet.hpp \
+	asio/ts/io_context.hpp \
+	asio/ts/netfwd.hpp \
+	asio/ts/net.hpp \
+	asio/ts/socket.hpp \
+	asio/ts/timer.hpp \
+	asio/unyield.hpp \
+	asio/use_awaitable.hpp \
+	asio/use_future.hpp \
+	asio/uses_executor.hpp \
+	asio/version.hpp \
+	asio/wait_traits.hpp \
+	asio/windows/basic_object_handle.hpp \
+	asio/windows/basic_overlapped_handle.hpp \
+	asio/windows/basic_random_access_handle.hpp \
+	asio/windows/basic_stream_handle.hpp \
+	asio/windows/object_handle.hpp \
+	asio/windows/overlapped_handle.hpp \
+	asio/windows/overlapped_ptr.hpp \
+	asio/windows/random_access_handle.hpp \
+	asio/windows/stream_handle.hpp \
+	asio/writable_pipe.hpp \
+	asio/write_at.hpp \
+	asio/write.hpp \
+	asio/yield.hpp
+
+MAINTAINERCLEANFILES = \
+	$(srcdir)/Makefile.in

lib/asio/include/asio.hpp

@@ -0,0 +1,203 @@
+//
+// asio.hpp
+// ~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_HPP
+#define ASIO_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/associated_allocator.hpp"
+#include "asio/associated_executor.hpp"
+#include "asio/associated_cancellation_slot.hpp"
+#include "asio/associator.hpp"
+#include "asio/async_result.hpp"
+#include "asio/awaitable.hpp"
+#include "asio/basic_datagram_socket.hpp"
+#include "asio/basic_deadline_timer.hpp"
+#include "asio/basic_file.hpp"
+#include "asio/basic_io_object.hpp"
+#include "asio/basic_random_access_file.hpp"
+#include "asio/basic_raw_socket.hpp"
+#include "asio/basic_readable_pipe.hpp"
+#include "asio/basic_seq_packet_socket.hpp"
+#include "asio/basic_serial_port.hpp"
+#include "asio/basic_signal_set.hpp"
+#include "asio/basic_socket.hpp"
+#include "asio/basic_socket_acceptor.hpp"
+#include "asio/basic_socket_iostream.hpp"
+#include "asio/basic_socket_streambuf.hpp"
+#include "asio/basic_stream_file.hpp"
+#include "asio/basic_stream_socket.hpp"
+#include "asio/basic_streambuf.hpp"
+#include "asio/basic_waitable_timer.hpp"
+#include "asio/basic_writable_pipe.hpp"
+#include "asio/bind_allocator.hpp"
+#include "asio/bind_cancellation_slot.hpp"
+#include "asio/bind_executor.hpp"
+#include "asio/buffer.hpp"
+#include "asio/buffer_registration.hpp"
+#include "asio/buffered_read_stream_fwd.hpp"
+#include "asio/buffered_read_stream.hpp"
+#include "asio/buffered_stream_fwd.hpp"
+#include "asio/buffered_stream.hpp"
+#include "asio/buffered_write_stream_fwd.hpp"
+#include "asio/buffered_write_stream.hpp"
+#include "asio/buffers_iterator.hpp"
+#include "asio/cancellation_signal.hpp"
+#include "asio/cancellation_state.hpp"
+#include "asio/cancellation_type.hpp"
+#include "asio/co_spawn.hpp"
+#include "asio/completion_condition.hpp"
+#include "asio/compose.hpp"
+#include "asio/connect.hpp"
+#include "asio/connect_pipe.hpp"
+#include "asio/coroutine.hpp"
+#include "asio/deadline_timer.hpp"
+#include "asio/defer.hpp"
+#include "asio/detached.hpp"
+#include "asio/dispatch.hpp"
+#include "asio/error.hpp"
+#include "asio/error_code.hpp"
+#include "asio/execution.hpp"
+#include "asio/execution/allocator.hpp"
+#include "asio/execution/any_executor.hpp"
+#include "asio/execution/blocking.hpp"
+#include "asio/execution/blocking_adaptation.hpp"
+#include "asio/execution/bulk_execute.hpp"
+#include "asio/execution/bulk_guarantee.hpp"
+#include "asio/execution/connect.hpp"
+#include "asio/execution/context.hpp"
+#include "asio/execution/context_as.hpp"
+#include "asio/execution/execute.hpp"
+#include "asio/execution/executor.hpp"
+#include "asio/execution/invocable_archetype.hpp"
+#include "asio/execution/mapping.hpp"
+#include "asio/execution/occupancy.hpp"
+#include "asio/execution/operation_state.hpp"
+#include "asio/execution/outstanding_work.hpp"
+#include "asio/execution/prefer_only.hpp"
+#include "asio/execution/receiver.hpp"
+#include "asio/execution/receiver_invocation_error.hpp"
+#include "asio/execution/relationship.hpp"
+#include "asio/execution/schedule.hpp"
+#include "asio/execution/scheduler.hpp"
+#include "asio/execution/sender.hpp"
+#include "asio/execution/set_done.hpp"
+#include "asio/execution/set_error.hpp"
+#include "asio/execution/set_value.hpp"
+#include "asio/execution/start.hpp"
+#include "asio/execution_context.hpp"
+#include "asio/executor.hpp"
+#include "asio/executor_work_guard.hpp"
+#include "asio/file_base.hpp"
+#include "asio/generic/basic_endpoint.hpp"
+#include "asio/generic/datagram_protocol.hpp"
+#include "asio/generic/raw_protocol.hpp"
+#include "asio/generic/seq_packet_protocol.hpp"
+#include "asio/generic/stream_protocol.hpp"
+#include "asio/handler_alloc_hook.hpp"
+#include "asio/handler_continuation_hook.hpp"
+#include "asio/handler_invoke_hook.hpp"
+#include "asio/high_resolution_timer.hpp"
+#include "asio/io_context.hpp"
+#include "asio/io_context_strand.hpp"
+#include "asio/io_service.hpp"
+#include "asio/io_service_strand.hpp"
+#include "asio/ip/address.hpp"
+#include "asio/ip/address_v4.hpp"
+#include "asio/ip/address_v4_iterator.hpp"
+#include "asio/ip/address_v4_range.hpp"
+#include "asio/ip/address_v6.hpp"
+#include "asio/ip/address_v6_iterator.hpp"
+#include "asio/ip/address_v6_range.hpp"
+#include "asio/ip/network_v4.hpp"
+#include "asio/ip/network_v6.hpp"
+#include "asio/ip/bad_address_cast.hpp"
+#include "asio/ip/basic_endpoint.hpp"
+#include "asio/ip/basic_resolver.hpp"
+#include "asio/ip/basic_resolver_entry.hpp"
+#include "asio/ip/basic_resolver_iterator.hpp"
+#include "asio/ip/basic_resolver_query.hpp"
+#include "asio/ip/host_name.hpp"
+#include "asio/ip/icmp.hpp"
+#include "asio/ip/multicast.hpp"
+#include "asio/ip/resolver_base.hpp"
+#include "asio/ip/resolver_query_base.hpp"
+#include "asio/ip/tcp.hpp"
+#include "asio/ip/udp.hpp"
+#include "asio/ip/unicast.hpp"
+#include "asio/ip/v6_only.hpp"
+#include "asio/is_applicable_property.hpp"
+#include "asio/is_executor.hpp"
+#include "asio/is_read_buffered.hpp"
+#include "asio/is_write_buffered.hpp"
+#include "asio/local/basic_endpoint.hpp"
+#include "asio/local/connect_pair.hpp"
+#include "asio/local/datagram_protocol.hpp"
+#include "asio/local/stream_protocol.hpp"
+#include "asio/multiple_exceptions.hpp"
+#include "asio/packaged_task.hpp"
+#include "asio/placeholders.hpp"
+#include "asio/posix/basic_descriptor.hpp"
+#include "asio/posix/basic_stream_descriptor.hpp"
+#include "asio/posix/descriptor.hpp"
+#include "asio/posix/descriptor_base.hpp"
+#include "asio/posix/stream_descriptor.hpp"
+#include "asio/post.hpp"
+#include "asio/prefer.hpp"
+#include "asio/query.hpp"
+#include "asio/random_access_file.hpp"
+#include "asio/read.hpp"
+#include "asio/read_at.hpp"
+#include "asio/read_until.hpp"
+#include "asio/readable_pipe.hpp"
+#include "asio/recycling_allocator.hpp"
+#include "asio/redirect_error.hpp"
+#include "asio/registered_buffer.hpp"
+#include "asio/require.hpp"
+#include "asio/require_concept.hpp"
+#include "asio/serial_port.hpp"
+#include "asio/serial_port_base.hpp"
+#include "asio/signal_set.hpp"
+#include "asio/socket_base.hpp"
+#include "asio/static_thread_pool.hpp"
+#include "asio/steady_timer.hpp"
+#include "asio/strand.hpp"
+#include "asio/stream_file.hpp"
+#include "asio/streambuf.hpp"
+#include "asio/system_context.hpp"
+#include "asio/system_error.hpp"
+#include "asio/system_executor.hpp"
+#include "asio/system_timer.hpp"
+#include "asio/this_coro.hpp"
+#include "asio/thread.hpp"
+#include "asio/thread_pool.hpp"
+#include "asio/time_traits.hpp"
+#include "asio/use_awaitable.hpp"
+#include "asio/use_future.hpp"
+#include "asio/uses_executor.hpp"
+#include "asio/version.hpp"
+#include "asio/wait_traits.hpp"
+#include "asio/windows/basic_object_handle.hpp"
+#include "asio/windows/basic_overlapped_handle.hpp"
+#include "asio/windows/basic_random_access_handle.hpp"
+#include "asio/windows/basic_stream_handle.hpp"
+#include "asio/windows/object_handle.hpp"
+#include "asio/windows/overlapped_handle.hpp"
+#include "asio/windows/overlapped_ptr.hpp"
+#include "asio/windows/random_access_handle.hpp"
+#include "asio/windows/stream_handle.hpp"
+#include "asio/writable_pipe.hpp"
+#include "asio/write.hpp"
+#include "asio/write_at.hpp"
+
+#endif // ASIO_HPP

lib/asio/include/asio/any_io_executor.hpp

@@ -0,0 +1,303 @@
+//
+// any_io_executor.hpp
+// ~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_ANY_IO_EXECUTOR_HPP
+#define ASIO_ANY_IO_EXECUTOR_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+#if defined(ASIO_USE_TS_EXECUTOR_AS_DEFAULT)
+# include "asio/executor.hpp"
+#else // defined(ASIO_USE_TS_EXECUTOR_AS_DEFAULT)
+# include "asio/execution.hpp"
+# include "asio/execution_context.hpp"
+#endif // defined(ASIO_USE_TS_EXECUTOR_AS_DEFAULT)
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+
+#if defined(ASIO_USE_TS_EXECUTOR_AS_DEFAULT)
+
+typedef executor any_io_executor;
+
+#else // defined(ASIO_USE_TS_EXECUTOR_AS_DEFAULT)
+
+/// Polymorphic executor type for use with I/O objects.
+/**
+ * The @c any_io_executor type is a polymorphic executor that supports the set
+ * of properties required by I/O objects. It is defined as the
+ * execution::any_executor class template parameterised as follows:
+ * @code execution::any_executor<
+ *   execution::context_as_t<execution_context&>,
+ *   execution::blocking_t::never_t,
+ *   execution::prefer_only<execution::blocking_t::possibly_t>,
+ *   execution::prefer_only<execution::outstanding_work_t::tracked_t>,
+ *   execution::prefer_only<execution::outstanding_work_t::untracked_t>,
+ *   execution::prefer_only<execution::relationship_t::fork_t>,
+ *   execution::prefer_only<execution::relationship_t::continuation_t>
+ * > @endcode
+ */
+class any_io_executor :
+#if defined(GENERATING_DOCUMENTATION)
+  public execution::any_executor<...>
+#else // defined(GENERATING_DOCUMENTATION)
+  public execution::any_executor<
+      execution::context_as_t<execution_context&>,
+      execution::blocking_t::never_t,
+      execution::prefer_only<execution::blocking_t::possibly_t>,
+      execution::prefer_only<execution::outstanding_work_t::tracked_t>,
+      execution::prefer_only<execution::outstanding_work_t::untracked_t>,
+      execution::prefer_only<execution::relationship_t::fork_t>,
+      execution::prefer_only<execution::relationship_t::continuation_t>
+    >
+#endif // defined(GENERATING_DOCUMENTATION)
+{
+public:
+#if !defined(GENERATING_DOCUMENTATION)
+  typedef execution::any_executor<
+      execution::context_as_t<execution_context&>,
+      execution::blocking_t::never_t,
+      execution::prefer_only<execution::blocking_t::possibly_t>,
+      execution::prefer_only<execution::outstanding_work_t::tracked_t>,
+      execution::prefer_only<execution::outstanding_work_t::untracked_t>,
+      execution::prefer_only<execution::relationship_t::fork_t>,
+      execution::prefer_only<execution::relationship_t::continuation_t>
+    > base_type;
+
+  typedef void supportable_properties_type(
+      execution::context_as_t<execution_context&>,
+      execution::blocking_t::never_t,
+      execution::prefer_only<execution::blocking_t::possibly_t>,
+      execution::prefer_only<execution::outstanding_work_t::tracked_t>,
+      execution::prefer_only<execution::outstanding_work_t::untracked_t>,
+      execution::prefer_only<execution::relationship_t::fork_t>,
+      execution::prefer_only<execution::relationship_t::continuation_t>
+    );
+#endif // !defined(GENERATING_DOCUMENTATION)
+
+  /// Default constructor.
+  ASIO_DECL any_io_executor() ASIO_NOEXCEPT;
+
+  /// Construct in an empty state. Equivalent effects to default constructor.
+  ASIO_DECL any_io_executor(nullptr_t) ASIO_NOEXCEPT;
+
+  /// Copy constructor.
+  ASIO_DECL any_io_executor(const any_io_executor& e) ASIO_NOEXCEPT;
+
+#if defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+  /// Move constructor.
+  ASIO_DECL any_io_executor(any_io_executor&& e) ASIO_NOEXCEPT;
+#endif // defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+
+  /// Construct to point to the same target as another any_executor.
+#if defined(GENERATING_DOCUMENTATION)
+  template <class... OtherSupportableProperties>
+    any_io_executor(execution::any_executor<OtherSupportableProperties...> e);
+#else // defined(GENERATING_DOCUMENTATION)
+  template <typename OtherAnyExecutor>
+  any_io_executor(OtherAnyExecutor e,
+      typename constraint<
+        conditional<
+          !is_same<OtherAnyExecutor, any_io_executor>::value
+            && is_base_of<execution::detail::any_executor_base,
+              OtherAnyExecutor>::value,
+          typename execution::detail::supportable_properties<
+            0, supportable_properties_type>::template
+              is_valid_target<OtherAnyExecutor>,
+          false_type
+        >::type::value
+      >::type = 0)
+    : base_type(ASIO_MOVE_CAST(OtherAnyExecutor)(e))
+  {
+  }
+#endif // defined(GENERATING_DOCUMENTATION)
+
+  /// Construct a polymorphic wrapper for the specified executor.
+#if defined(GENERATING_DOCUMENTATION)
+  template <ASIO_EXECUTION_EXECUTOR Executor>
+  any_io_executor(Executor e);
+#else // defined(GENERATING_DOCUMENTATION)
+  template <ASIO_EXECUTION_EXECUTOR Executor>
+  any_io_executor(Executor e,
+      typename constraint<
+        conditional<
+          !is_same<Executor, any_io_executor>::value
+            && !is_base_of<execution::detail::any_executor_base,
+              Executor>::value,
+          execution::detail::is_valid_target_executor<
+            Executor, supportable_properties_type>,
+          false_type
+        >::type::value
+      >::type = 0)
+    : base_type(ASIO_MOVE_CAST(Executor)(e))
+  {
+  }
+#endif // defined(GENERATING_DOCUMENTATION)
+
+  /// Assignment operator.
+  ASIO_DECL any_io_executor& operator=(
+      const any_io_executor& e) ASIO_NOEXCEPT;
+
+#if defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+  /// Move assignment operator.
+  ASIO_DECL any_io_executor& operator=(
+      any_io_executor&& e) ASIO_NOEXCEPT;
+#endif // defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+
+  /// Assignment operator that sets the polymorphic wrapper to the empty state.
+  ASIO_DECL any_io_executor& operator=(nullptr_t);
+
+  /// Destructor.
+  ASIO_DECL ~any_io_executor();
+
+  /// Swap targets with another polymorphic wrapper.
+  ASIO_DECL void swap(any_io_executor& other) ASIO_NOEXCEPT;
+
+  /// Obtain a polymorphic wrapper with the specified property.
+  /**
+   * Do not call this function directly. It is intended for use with the
+   * asio::require and asio::prefer customisation points.
+   *
+   * For example:
+   * @code any_io_executor ex = ...;
+   * auto ex2 = asio::require(ex, execution::blocking.possibly); @endcode
+   */
+  template <typename Property>
+  any_io_executor require(const Property& p,
+      typename constraint<
+        traits::require_member<const base_type&, const Property&>::is_valid
+      >::type = 0) const
+  {
+    return static_cast<const base_type&>(*this).require(p);
+  }
+
+  /// Obtain a polymorphic wrapper with the specified property.
+  /**
+   * Do not call this function directly. It is intended for use with the
+   * asio::prefer customisation point.
+   *
+   * For example:
+   * @code any_io_executor ex = ...;
+   * auto ex2 = asio::prefer(ex, execution::blocking.possibly); @endcode
+   */
+  template <typename Property>
+  any_io_executor prefer(const Property& p,
+      typename constraint<
+        traits::prefer_member<const base_type&, const Property&>::is_valid
+      >::type = 0) const
+  {
+    return static_cast<const base_type&>(*this).prefer(p);
+  }
+};
+
+#if !defined(GENERATING_DOCUMENTATION)
+
+template <>
+ASIO_DECL any_io_executor any_io_executor::require(
+    const execution::blocking_t::never_t&, int) const;
+
+template <>
+ASIO_DECL any_io_executor any_io_executor::prefer(
+    const execution::blocking_t::possibly_t&, int) const;
+
+template <>
+ASIO_DECL any_io_executor any_io_executor::prefer(
+    const execution::outstanding_work_t::tracked_t&, int) const;
+
+template <>
+ASIO_DECL any_io_executor any_io_executor::prefer(
+    const execution::outstanding_work_t::untracked_t&, int) const;
+
+template <>
+ASIO_DECL any_io_executor any_io_executor::prefer(
+    const execution::relationship_t::fork_t&, int) const;
+
+template <>
+ASIO_DECL any_io_executor any_io_executor::prefer(
+    const execution::relationship_t::continuation_t&, int) const;
+
+namespace traits {
+
+#if !defined(ASIO_HAS_DEDUCED_EQUALITY_COMPARABLE_TRAIT)
+
+template <>
+struct equality_comparable<any_io_executor>
+{
+  static const bool is_valid = true;
+  static const bool is_noexcept = true;
+};
+
+#endif // !defined(ASIO_HAS_DEDUCED_EQUALITY_COMPARABLE_TRAIT)
+
+#if !defined(ASIO_HAS_DEDUCED_EXECUTE_MEMBER_TRAIT)
+
+template <typename F>
+struct execute_member<any_io_executor, F>
+{
+  static const bool is_valid = true;
+  static const bool is_noexcept = false;
+  typedef void result_type;
+};
+
+#endif // !defined(ASIO_HAS_DEDUCED_EXECUTE_MEMBER_TRAIT)
+
+#if !defined(ASIO_HAS_DEDUCED_QUERY_MEMBER_TRAIT)
+
+template <typename Prop>
+struct query_member<any_io_executor, Prop> :
+  query_member<any_io_executor::base_type, Prop>
+{
+};
+
+#endif // !defined(ASIO_HAS_DEDUCED_QUERY_MEMBER_TRAIT)
+
+#if !defined(ASIO_HAS_DEDUCED_REQUIRE_MEMBER_TRAIT)
+
+template <typename Prop>
+struct require_member<any_io_executor, Prop> :
+  require_member<any_io_executor::base_type, Prop>
+{
+  typedef any_io_executor result_type;
+};
+
+#endif // !defined(ASIO_HAS_DEDUCED_REQUIRE_MEMBER_TRAIT)
+
+#if !defined(ASIO_HAS_DEDUCED_PREFER_MEMBER_TRAIT)
+
+template <typename Prop>
+struct prefer_member<any_io_executor, Prop> :
+  prefer_member<any_io_executor::base_type, Prop>
+{
+  typedef any_io_executor result_type;
+};
+
+#endif // !defined(ASIO_HAS_DEDUCED_PREFER_MEMBER_TRAIT)
+
+} // namespace traits
+
+#endif // !defined(GENERATING_DOCUMENTATION)
+
+#endif // defined(ASIO_USE_TS_EXECUTOR_AS_DEFAULT)
+
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#if defined(ASIO_HEADER_ONLY) \
+  && !defined(ASIO_USE_TS_EXECUTOR_AS_DEFAULT)
+# include "asio/impl/any_io_executor.ipp"
+#endif // defined(ASIO_HEADER_ONLY)
+       //   && !defined(ASIO_USE_TS_EXECUTOR_AS_DEFAULT)
+
+#endif // ASIO_ANY_IO_EXECUTOR_HPP

lib/asio/include/asio/associated_allocator.hpp

@@ -0,0 +1,177 @@
+//
+// associated_allocator.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_ASSOCIATED_ALLOCATOR_HPP
+#define ASIO_ASSOCIATED_ALLOCATOR_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+#include <memory>
+#include "asio/associator.hpp"
+#include "asio/detail/functional.hpp"
+#include "asio/detail/type_traits.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+
+template <typename T, typename Allocator>
+struct associated_allocator;
+
+namespace detail {
+
+template <typename T, typename = void>
+struct has_allocator_type : false_type
+{
+};
+
+template <typename T>
+struct has_allocator_type<T,
+  typename void_type<typename T::allocator_type>::type>
+    : true_type
+{
+};
+
+template <typename T, typename E, typename = void, typename = void>
+struct associated_allocator_impl
+{
+  typedef E type;
+
+  static type get(const T&, const E& e) ASIO_NOEXCEPT
+  {
+    return e;
+  }
+};
+
+template <typename T, typename E>
+struct associated_allocator_impl<T, E,
+  typename void_type<typename T::allocator_type>::type>
+{
+  typedef typename T::allocator_type type;
+
+  static type get(const T& t, const E&) ASIO_NOEXCEPT
+  {
+    return t.get_allocator();
+  }
+};
+
+template <typename T, typename E>
+struct associated_allocator_impl<T, E,
+  typename enable_if<
+    !has_allocator_type<T>::value
+  >::type,
+  typename void_type<
+    typename associator<associated_allocator, T, E>::type
+  >::type> : associator<associated_allocator, T, E>
+{
+};
+
+} // namespace detail
+
+/// Traits type used to obtain the allocator associated with an object.
+/**
+ * A program may specialise this traits type if the @c T template parameter in
+ * the specialisation is a user-defined type. The template parameter @c
+ * Allocator shall be a type meeting the Allocator requirements.
+ *
+ * Specialisations shall meet the following requirements, where @c t is a const
+ * reference to an object of type @c T, and @c a is an object of type @c
+ * Allocator.
+ *
+ * @li Provide a nested typedef @c type that identifies a type meeting the
+ * Allocator requirements.
+ *
+ * @li Provide a noexcept static member function named @c get, callable as @c
+ * get(t) and with return type @c type.
+ *
+ * @li Provide a noexcept static member function named @c get, callable as @c
+ * get(t,a) and with return type @c type.
+ */
+template <typename T, typename Allocator = std::allocator<void> >
+struct associated_allocator
+{
+  /// If @c T has a nested type @c allocator_type, <tt>T::allocator_type</tt>.
+  /// Otherwise @c Allocator.
+#if defined(GENERATING_DOCUMENTATION)
+  typedef see_below type;
+#else // defined(GENERATING_DOCUMENTATION)
+  typedef typename detail::associated_allocator_impl<T, Allocator>::type type;
+#endif // defined(GENERATING_DOCUMENTATION)
+
+  /// If @c T has a nested type @c allocator_type, returns
+  /// <tt>t.get_allocator()</tt>. Otherwise returns @c a.
+  static type get(const T& t,
+      const Allocator& a = Allocator()) ASIO_NOEXCEPT
+  {
+    return detail::associated_allocator_impl<T, Allocator>::get(t, a);
+  }
+};
+
+/// Helper function to obtain an object's associated allocator.
+/**
+ * @returns <tt>associated_allocator<T>::get(t)</tt>
+ */
+template <typename T>
+ASIO_NODISCARD inline typename associated_allocator<T>::type
+get_associated_allocator(const T& t) ASIO_NOEXCEPT
+{
+  return associated_allocator<T>::get(t);
+}
+
+/// Helper function to obtain an object's associated allocator.
+/**
+ * @returns <tt>associated_allocator<T, Allocator>::get(t, a)</tt>
+ */
+template <typename T, typename Allocator>
+ASIO_NODISCARD inline typename associated_allocator<T, Allocator>::type
+get_associated_allocator(const T& t, const Allocator& a) ASIO_NOEXCEPT
+{
+  return associated_allocator<T, Allocator>::get(t, a);
+}
+
+#if defined(ASIO_HAS_ALIAS_TEMPLATES)
+
+template <typename T, typename Allocator = std::allocator<void> >
+using associated_allocator_t
+  = typename associated_allocator<T, Allocator>::type;
+
+#endif // defined(ASIO_HAS_ALIAS_TEMPLATES)
+
+#if defined(ASIO_HAS_STD_REFERENCE_WRAPPER) \
+  || defined(GENERATING_DOCUMENTATION)
+
+/// Specialisation of associated_allocator for @c std::reference_wrapper.
+template <typename T, typename Allocator>
+struct associated_allocator<reference_wrapper<T>, Allocator>
+{
+  /// Forwards @c type to the associator specialisation for the unwrapped type
+  /// @c T.
+  typedef typename associated_allocator<T, Allocator>::type type;
+
+  /// Forwards the request to get the allocator to the associator specialisation
+  /// for the unwrapped type @c T.
+  static type get(reference_wrapper<T> t,
+      const Allocator& a = Allocator()) ASIO_NOEXCEPT
+  {
+    return associated_allocator<T, Allocator>::get(t.get(), a);
+  }
+};
+
+#endif // defined(ASIO_HAS_STD_REFERENCE_WRAPPER)
+       //   || defined(GENERATING_DOCUMENTATION)
+
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // ASIO_ASSOCIATED_ALLOCATOR_HPP

lib/asio/include/asio/associated_cancellation_slot.hpp

@@ -0,0 +1,178 @@
+//
+// associated_cancellation_slot.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_ASSOCIATED_CANCELLATION_SLOT_HPP
+#define ASIO_ASSOCIATED_CANCELLATION_SLOT_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+#include "asio/associator.hpp"
+#include "asio/cancellation_signal.hpp"
+#include "asio/detail/type_traits.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+
+template <typename T, typename CancellationSlot>
+struct associated_cancellation_slot;
+
+namespace detail {
+
+template <typename T, typename = void>
+struct has_cancellation_slot_type : false_type
+{
+};
+
+template <typename T>
+struct has_cancellation_slot_type<T,
+  typename void_type<typename T::cancellation_slot_type>::type>
+    : true_type
+{
+};
+
+template <typename T, typename S, typename = void, typename = void>
+struct associated_cancellation_slot_impl
+{
+  typedef void asio_associated_cancellation_slot_is_unspecialised;
+
+  typedef S type;
+
+  static type get(const T&, const S& s = S()) ASIO_NOEXCEPT
+  {
+    return s;
+  }
+};
+
+template <typename T, typename S>
+struct associated_cancellation_slot_impl<T, S,
+  typename void_type<typename T::cancellation_slot_type>::type>
+{
+  typedef typename T::cancellation_slot_type type;
+
+  static type get(const T& t, const S& = S()) ASIO_NOEXCEPT
+  {
+    return t.get_cancellation_slot();
+  }
+};
+
+template <typename T, typename S>
+struct associated_cancellation_slot_impl<T, S,
+  typename enable_if<
+    !has_cancellation_slot_type<T>::value
+  >::type,
+  typename void_type<
+    typename associator<associated_cancellation_slot, T, S>::type
+  >::type> : associator<associated_cancellation_slot, T, S>
+{
+};
+
+} // namespace detail
+
+/// Traits type used to obtain the cancellation_slot associated with an object.
+/**
+ * A program may specialise this traits type if the @c T template parameter in
+ * the specialisation is a user-defined type. The template parameter @c
+ * CancellationSlot shall be a type meeting the CancellationSlot requirements.
+ *
+ * Specialisations shall meet the following requirements, where @c t is a const
+ * reference to an object of type @c T, and @c s is an object of type @c
+ * CancellationSlot.
+ *
+ * @li Provide a nested typedef @c type that identifies a type meeting the
+ * CancellationSlot requirements.
+ *
+ * @li Provide a noexcept static member function named @c get, callable as @c
+ * get(t) and with return type @c type.
+ *
+ * @li Provide a noexcept static member function named @c get, callable as @c
+ * get(t,s) and with return type @c type.
+ */
+template <typename T, typename CancellationSlot = cancellation_slot>
+struct associated_cancellation_slot
+#if !defined(GENERATING_DOCUMENTATION)
+  : detail::associated_cancellation_slot_impl<T, CancellationSlot>
+#endif // !defined(GENERATING_DOCUMENTATION)
+{
+#if defined(GENERATING_DOCUMENTATION)
+  /// If @c T has a nested type @c cancellation_slot_type,
+  /// <tt>T::cancellation_slot_type</tt>. Otherwise
+  /// @c CancellationSlot.
+  typedef see_below type;
+
+  /// If @c T has a nested type @c cancellation_slot_type, returns
+  /// <tt>t.get_cancellation_slot()</tt>. Otherwise returns @c s.
+  static type get(const T& t,
+      const CancellationSlot& s = CancellationSlot()) ASIO_NOEXCEPT;
+#endif // defined(GENERATING_DOCUMENTATION)
+};
+
+/// Helper function to obtain an object's associated cancellation_slot.
+/**
+ * @returns <tt>associated_cancellation_slot<T>::get(t)</tt>
+ */
+template <typename T>
+ASIO_NODISCARD inline typename associated_cancellation_slot<T>::type
+get_associated_cancellation_slot(const T& t) ASIO_NOEXCEPT
+{
+  return associated_cancellation_slot<T>::get(t);
+}
+
+/// Helper function to obtain an object's associated cancellation_slot.
+/**
+ * @returns <tt>associated_cancellation_slot<T,
+ * CancellationSlot>::get(t, st)</tt>
+ */
+template <typename T, typename CancellationSlot>
+ASIO_NODISCARD inline
+typename associated_cancellation_slot<T, CancellationSlot>::type
+get_associated_cancellation_slot(const T& t,
+    const CancellationSlot& st) ASIO_NOEXCEPT
+{
+  return associated_cancellation_slot<T, CancellationSlot>::get(t, st);
+}
+
+#if defined(ASIO_HAS_ALIAS_TEMPLATES)
+
+template <typename T, typename CancellationSlot = cancellation_slot>
+using associated_cancellation_slot_t =
+  typename associated_cancellation_slot<T, CancellationSlot>::type;
+
+#endif // defined(ASIO_HAS_ALIAS_TEMPLATES)
+
+namespace detail {
+
+template <typename T, typename S, typename = void>
+struct associated_cancellation_slot_forwarding_base
+{
+};
+
+template <typename T, typename S>
+struct associated_cancellation_slot_forwarding_base<T, S,
+    typename enable_if<
+      is_same<
+        typename associated_cancellation_slot<T,
+          S>::asio_associated_cancellation_slot_is_unspecialised,
+        void
+      >::value
+    >::type>
+{
+  typedef void asio_associated_cancellation_slot_is_unspecialised;
+};
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // ASIO_ASSOCIATED_CANCELLATION_SLOT_HPP

lib/asio/include/asio/associated_executor.hpp

@@ -0,0 +1,222 @@
+//
+// associated_executor.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_ASSOCIATED_EXECUTOR_HPP
+#define ASIO_ASSOCIATED_EXECUTOR_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+#include "asio/associator.hpp"
+#include "asio/detail/functional.hpp"
+#include "asio/detail/type_traits.hpp"
+#include "asio/execution/executor.hpp"
+#include "asio/is_executor.hpp"
+#include "asio/system_executor.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+
+template <typename T, typename Executor>
+struct associated_executor;
+
+namespace detail {
+
+template <typename T, typename = void>
+struct has_executor_type : false_type
+{
+};
+
+template <typename T>
+struct has_executor_type<T,
+  typename void_type<typename T::executor_type>::type>
+    : true_type
+{
+};
+
+template <typename T, typename E, typename = void, typename = void>
+struct associated_executor_impl
+{
+  typedef void asio_associated_executor_is_unspecialised;
+
+  typedef E type;
+
+  static type get(const T&, const E& e = E()) ASIO_NOEXCEPT
+  {
+    return e;
+  }
+};
+
+template <typename T, typename E>
+struct associated_executor_impl<T, E,
+  typename void_type<typename T::executor_type>::type>
+{
+  typedef typename T::executor_type type;
+
+  static type get(const T& t, const E& = E()) ASIO_NOEXCEPT
+  {
+    return t.get_executor();
+  }
+};
+
+template <typename T, typename E>
+struct associated_executor_impl<T, E,
+  typename enable_if<
+    !has_executor_type<T>::value
+  >::type,
+  typename void_type<
+    typename associator<associated_executor, T, E>::type
+  >::type> : associator<associated_executor, T, E>
+{
+};
+
+} // namespace detail
+
+/// Traits type used to obtain the executor associated with an object.
+/**
+ * A program may specialise this traits type if the @c T template parameter in
+ * the specialisation is a user-defined type. The template parameter @c
+ * Executor shall be a type meeting the Executor requirements.
+ *
+ * Specialisations shall meet the following requirements, where @c t is a const
+ * reference to an object of type @c T, and @c e is an object of type @c
+ * Executor.
+ *
+ * @li Provide a nested typedef @c type that identifies a type meeting the
+ * Executor requirements.
+ *
+ * @li Provide a noexcept static member function named @c get, callable as @c
+ * get(t) and with return type @c type.
+ *
+ * @li Provide a noexcept static member function named @c get, callable as @c
+ * get(t,e) and with return type @c type.
+ */
+template <typename T, typename Executor = system_executor>
+struct associated_executor
+#if !defined(GENERATING_DOCUMENTATION)
+  : detail::associated_executor_impl<T, Executor>
+#endif // !defined(GENERATING_DOCUMENTATION)
+{
+#if defined(GENERATING_DOCUMENTATION)
+  /// If @c T has a nested type @c executor_type, <tt>T::executor_type</tt>.
+  /// Otherwise @c Executor.
+  typedef see_below type;
+
+  /// If @c T has a nested type @c executor_type, returns
+  /// <tt>t.get_executor()</tt>. Otherwise returns @c ex.
+  static type get(const T& t,
+      const Executor& ex = Executor()) ASIO_NOEXCEPT;
+#endif // defined(GENERATING_DOCUMENTATION)
+};
+
+/// Helper function to obtain an object's associated executor.
+/**
+ * @returns <tt>associated_executor<T>::get(t)</tt>
+ */
+template <typename T>
+ASIO_NODISCARD inline typename associated_executor<T>::type
+get_associated_executor(const T& t) ASIO_NOEXCEPT
+{
+  return associated_executor<T>::get(t);
+}
+
+/// Helper function to obtain an object's associated executor.
+/**
+ * @returns <tt>associated_executor<T, Executor>::get(t, ex)</tt>
+ */
+template <typename T, typename Executor>
+ASIO_NODISCARD inline typename associated_executor<T, Executor>::type
+get_associated_executor(const T& t, const Executor& ex,
+    typename constraint<
+      is_executor<Executor>::value || execution::is_executor<Executor>::value
+    >::type = 0) ASIO_NOEXCEPT
+{
+  return associated_executor<T, Executor>::get(t, ex);
+}
+
+/// Helper function to obtain an object's associated executor.
+/**
+ * @returns <tt>associated_executor<T, typename
+ * ExecutionContext::executor_type>::get(t, ctx.get_executor())</tt>
+ */
+template <typename T, typename ExecutionContext>
+ASIO_NODISCARD inline typename associated_executor<T,
+  typename ExecutionContext::executor_type>::type
+get_associated_executor(const T& t, ExecutionContext& ctx,
+    typename constraint<is_convertible<ExecutionContext&,
+      execution_context&>::value>::type = 0) ASIO_NOEXCEPT
+{
+  return associated_executor<T,
+    typename ExecutionContext::executor_type>::get(t, ctx.get_executor());
+}
+
+#if defined(ASIO_HAS_ALIAS_TEMPLATES)
+
+template <typename T, typename Executor = system_executor>
+using associated_executor_t = typename associated_executor<T, Executor>::type;
+
+#endif // defined(ASIO_HAS_ALIAS_TEMPLATES)
+
+namespace detail {
+
+template <typename T, typename E, typename = void>
+struct associated_executor_forwarding_base
+{
+};
+
+template <typename T, typename E>
+struct associated_executor_forwarding_base<T, E,
+    typename enable_if<
+      is_same<
+        typename associated_executor<T,
+          E>::asio_associated_executor_is_unspecialised,
+        void
+      >::value
+    >::type>
+{
+  typedef void asio_associated_executor_is_unspecialised;
+};
+
+} // namespace detail
+
+#if defined(ASIO_HAS_STD_REFERENCE_WRAPPER) \
+  || defined(GENERATING_DOCUMENTATION)
+
+/// Specialisation of associated_executor for @c std::reference_wrapper.
+template <typename T, typename Executor>
+struct associated_executor<reference_wrapper<T>, Executor>
+#if !defined(GENERATING_DOCUMENTATION)
+  : detail::associated_executor_forwarding_base<T, Executor>
+#endif // !defined(GENERATING_DOCUMENTATION)
+{
+  /// Forwards @c type to the associator specialisation for the unwrapped type
+  /// @c T.
+  typedef typename associated_executor<T, Executor>::type type;
+
+  /// Forwards the request to get the executor to the associator specialisation
+  /// for the unwrapped type @c T.
+  static type get(reference_wrapper<T> t,
+      const Executor& ex = Executor()) ASIO_NOEXCEPT
+  {
+    return associated_executor<T, Executor>::get(t.get(), ex);
+  }
+};
+
+#endif // defined(ASIO_HAS_STD_REFERENCE_WRAPPER)
+       //   || defined(GENERATING_DOCUMENTATION)
+
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // ASIO_ASSOCIATED_EXECUTOR_HPP

lib/asio/include/asio/associator.hpp

@@ -0,0 +1,35 @@
+//
+// associator.hpp
+// ~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_ASSOCIATOR_HPP
+#define ASIO_ASSOCIATOR_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+
+/// Used to generically specialise associators for a type.
+template <template <typename, typename> class Associator,
+    typename T, typename DefaultCandidate>
+struct associator
+{
+};
+
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // ASIO_ASSOCIATOR_HPP

lib/asio/include/asio/awaitable.hpp

@@ -0,0 +1,142 @@
+//
+// awaitable.hpp
+// ~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_AWAITABLE_HPP
+#define ASIO_AWAITABLE_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_HAS_CO_AWAIT) || defined(GENERATING_DOCUMENTATION)
+
+#if defined(ASIO_HAS_STD_COROUTINE)
+# include <coroutine>
+#else // defined(ASIO_HAS_STD_COROUTINE)
+# include <experimental/coroutine>
+#endif // defined(ASIO_HAS_STD_COROUTINE)
+
+#include <utility>
+#include "asio/any_io_executor.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+#if defined(ASIO_HAS_STD_COROUTINE)
+using std::coroutine_handle;
+using std::suspend_always;
+#else // defined(ASIO_HAS_STD_COROUTINE)
+using std::experimental::coroutine_handle;
+using std::experimental::suspend_always;
+#endif // defined(ASIO_HAS_STD_COROUTINE)
+
+template <typename> class awaitable_thread;
+template <typename, typename> class awaitable_frame;
+
+} // namespace detail
+
+/// The return type of a coroutine or asynchronous operation.
+template <typename T, typename Executor = any_io_executor>
+class ASIO_NODISCARD awaitable
+{
+public:
+  /// The type of the awaited value.
+  typedef T value_type;
+
+  /// The executor type that will be used for the coroutine.
+  typedef Executor executor_type;
+
+  /// Default constructor.
+  constexpr awaitable() noexcept
+    : frame_(nullptr)
+  {
+  }
+
+  /// Move constructor.
+  awaitable(awaitable&& other) noexcept
+    : frame_(std::exchange(other.frame_, nullptr))
+  {
+  }
+
+  /// Destructor
+  ~awaitable()
+  {
+    if (frame_)
+      frame_->destroy();
+  }
+
+  /// Move assignment.
+  awaitable& operator=(awaitable&& other) noexcept
+  {
+    if (this != &other)
+      frame_ = std::exchange(other.frame_, nullptr);
+    return *this;
+  }
+
+  /// Checks if the awaitable refers to a future result.
+  bool valid() const noexcept
+  {
+    return !!frame_;
+  }
+
+#if !defined(GENERATING_DOCUMENTATION)
+
+  // Support for co_await keyword.
+  bool await_ready() const noexcept
+  {
+    return false;
+  }
+
+  // Support for co_await keyword.
+  template <class U>
+  void await_suspend(
+      detail::coroutine_handle<detail::awaitable_frame<U, Executor>> h)
+  {
+    frame_->push_frame(&h.promise());
+  }
+
+  // Support for co_await keyword.
+  T await_resume()
+  {
+    return awaitable(static_cast<awaitable&&>(*this)).frame_->get();
+  }
+
+#endif // !defined(GENERATING_DOCUMENTATION)
+
+private:
+  template <typename> friend class detail::awaitable_thread;
+  template <typename, typename> friend class detail::awaitable_frame;
+
+  // Not copy constructible or copy assignable.
+  awaitable(const awaitable&) = delete;
+  awaitable& operator=(const awaitable&) = delete;
+
+  // Construct the awaitable from a coroutine's frame object.
+  explicit awaitable(detail::awaitable_frame<T, Executor>* a)
+    : frame_(a)
+  {
+  }
+
+  detail::awaitable_frame<T, Executor>* frame_;
+};
+
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#include "asio/impl/awaitable.hpp"
+
+#endif // defined(ASIO_HAS_CO_AWAIT) || defined(GENERATING_DOCUMENTATION)
+
+#endif // ASIO_AWAITABLE_HPP

lib/asio/include/asio/basic_deadline_timer.hpp

@@ -0,0 +1,709 @@
+//
+// basic_deadline_timer.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_BASIC_DEADLINE_TIMER_HPP
+#define ASIO_BASIC_DEADLINE_TIMER_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_HAS_BOOST_DATE_TIME) \
+  || defined(GENERATING_DOCUMENTATION)
+
+#include <cstddef>
+#include "asio/any_io_executor.hpp"
+#include "asio/detail/deadline_timer_service.hpp"
+#include "asio/detail/handler_type_requirements.hpp"
+#include "asio/detail/io_object_impl.hpp"
+#include "asio/detail/non_const_lvalue.hpp"
+#include "asio/detail/throw_error.hpp"
+#include "asio/error.hpp"
+#include "asio/execution_context.hpp"
+#include "asio/time_traits.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+
+/// Provides waitable timer functionality.
+/**
+ * The basic_deadline_timer class template provides the ability to perform a
+ * blocking or asynchronous wait for a timer to expire.
+ *
+ * A deadline timer is always in one of two states: "expired" or "not expired".
+ * If the wait() or async_wait() function is called on an expired timer, the
+ * wait operation will complete immediately.
+ *
+ * Most applications will use the asio::deadline_timer typedef.
+ *
+ * @par Thread Safety
+ * @e Distinct @e objects: Safe.@n
+ * @e Shared @e objects: Unsafe.
+ *
+ * @par Examples
+ * Performing a blocking wait:
+ * @code
+ * // Construct a timer without setting an expiry time.
+ * asio::deadline_timer timer(my_context);
+ *
+ * // Set an expiry time relative to now.
+ * timer.expires_from_now(boost::posix_time::seconds(5));
+ *
+ * // Wait for the timer to expire.
+ * timer.wait();
+ * @endcode
+ *
+ * @par 
+ * Performing an asynchronous wait:
+ * @code
+ * void handler(const asio::error_code& error)
+ * {
+ *   if (!error)
+ *   {
+ *     // Timer expired.
+ *   }
+ * }
+ *
+ * ...
+ *
+ * // Construct a timer with an absolute expiry time.
+ * asio::deadline_timer timer(my_context,
+ *     boost::posix_time::time_from_string("2005-12-07 23:59:59.000"));
+ *
+ * // Start an asynchronous wait.
+ * timer.async_wait(handler);
+ * @endcode
+ *
+ * @par Changing an active deadline_timer's expiry time
+ *
+ * Changing the expiry time of a timer while there are pending asynchronous
+ * waits causes those wait operations to be cancelled. To ensure that the action
+ * associated with the timer is performed only once, use something like this:
+ * used:
+ *
+ * @code
+ * void on_some_event()
+ * {
+ *   if (my_timer.expires_from_now(seconds(5)) > 0)
+ *   {
+ *     // We managed to cancel the timer. Start new asynchronous wait.
+ *     my_timer.async_wait(on_timeout);
+ *   }
+ *   else
+ *   {
+ *     // Too late, timer has already expired!
+ *   }
+ * }
+ *
+ * void on_timeout(const asio::error_code& e)
+ * {
+ *   if (e != asio::error::operation_aborted)
+ *   {
+ *     // Timer was not cancelled, take necessary action.
+ *   }
+ * }
+ * @endcode
+ *
+ * @li The asio::basic_deadline_timer::expires_from_now() function
+ * cancels any pending asynchronous waits, and returns the number of
+ * asynchronous waits that were cancelled. If it returns 0 then you were too
+ * late and the wait handler has already been executed, or will soon be
+ * executed. If it returns 1 then the wait handler was successfully cancelled.
+ *
+ * @li If a wait handler is cancelled, the asio::error_code passed to
+ * it contains the value asio::error::operation_aborted.
+ */
+template <typename Time,
+    typename TimeTraits = asio::time_traits<Time>,
+    typename Executor = any_io_executor>
+class basic_deadline_timer
+{
+public:
+  /// The type of the executor associated with the object.
+  typedef Executor executor_type;
+
+  /// Rebinds the timer type to another executor.
+  template <typename Executor1>
+  struct rebind_executor
+  {
+    /// The timer type when rebound to the specified executor.
+    typedef basic_deadline_timer<Time, TimeTraits, Executor1> other;
+  };
+
+  /// The time traits type.
+  typedef TimeTraits traits_type;
+
+  /// The time type.
+  typedef typename traits_type::time_type time_type;
+
+  /// The duration type.
+  typedef typename traits_type::duration_type duration_type;
+
+  /// Constructor.
+  /**
+   * This constructor creates a timer without setting an expiry time. The
+   * expires_at() or expires_from_now() functions must be called to set an
+   * expiry time before the timer can be waited on.
+   *
+   * @param ex The I/O executor that the timer will use, by default, to
+   * dispatch handlers for any asynchronous operations performed on the timer.
+   */
+  explicit basic_deadline_timer(const executor_type& ex)
+    : impl_(0, ex)
+  {
+  }
+
+  /// Constructor.
+  /**
+   * This constructor creates a timer without setting an expiry time. The
+   * expires_at() or expires_from_now() functions must be called to set an
+   * expiry time before the timer can be waited on.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the timer will use, by default, to dispatch handlers for any asynchronous
+   * operations performed on the timer.
+   */
+  template <typename ExecutionContext>
+  explicit basic_deadline_timer(ExecutionContext& context,
+      typename constraint<
+        is_convertible<ExecutionContext&, execution_context&>::value
+      >::type = 0)
+    : impl_(0, 0, context)
+  {
+  }
+
+  /// Constructor to set a particular expiry time as an absolute time.
+  /**
+   * This constructor creates a timer and sets the expiry time.
+   *
+   * @param ex The I/O executor that the timer will use, by default, to
+   * dispatch handlers for any asynchronous operations performed on the timer.
+   *
+   * @param expiry_time The expiry time to be used for the timer, expressed
+   * as an absolute time.
+   */
+  basic_deadline_timer(const executor_type& ex, const time_type& expiry_time)
+    : impl_(0, ex)
+  {
+    asio::error_code ec;
+    impl_.get_service().expires_at(impl_.get_implementation(), expiry_time, ec);
+    asio::detail::throw_error(ec, "expires_at");
+  }
+
+  /// Constructor to set a particular expiry time as an absolute time.
+  /**
+   * This constructor creates a timer and sets the expiry time.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the timer will use, by default, to dispatch handlers for any asynchronous
+   * operations performed on the timer.
+   *
+   * @param expiry_time The expiry time to be used for the timer, expressed
+   * as an absolute time.
+   */
+  template <typename ExecutionContext>
+  basic_deadline_timer(ExecutionContext& context, const time_type& expiry_time,
+      typename constraint<
+        is_convertible<ExecutionContext&, execution_context&>::value
+      >::type = 0)
+    : impl_(0, 0, context)
+  {
+    asio::error_code ec;
+    impl_.get_service().expires_at(impl_.get_implementation(), expiry_time, ec);
+    asio::detail::throw_error(ec, "expires_at");
+  }
+
+  /// Constructor to set a particular expiry time relative to now.
+  /**
+   * This constructor creates a timer and sets the expiry time.
+   *
+   * @param ex The I/O executor that the timer will use, by default, to
+   * dispatch handlers for any asynchronous operations performed on the timer.
+   *
+   * @param expiry_time The expiry time to be used for the timer, relative to
+   * now.
+   */
+  basic_deadline_timer(const executor_type& ex,
+      const duration_type& expiry_time)
+    : impl_(0, ex)
+  {
+    asio::error_code ec;
+    impl_.get_service().expires_from_now(
+        impl_.get_implementation(), expiry_time, ec);
+    asio::detail::throw_error(ec, "expires_from_now");
+  }
+
+  /// Constructor to set a particular expiry time relative to now.
+  /**
+   * This constructor creates a timer and sets the expiry time.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the timer will use, by default, to dispatch handlers for any asynchronous
+   * operations performed on the timer.
+   *
+   * @param expiry_time The expiry time to be used for the timer, relative to
+   * now.
+   */
+  template <typename ExecutionContext>
+  basic_deadline_timer(ExecutionContext& context,
+      const duration_type& expiry_time,
+      typename constraint<
+        is_convertible<ExecutionContext&, execution_context&>::value
+      >::type = 0)
+    : impl_(0, 0, context)
+  {
+    asio::error_code ec;
+    impl_.get_service().expires_from_now(
+        impl_.get_implementation(), expiry_time, ec);
+    asio::detail::throw_error(ec, "expires_from_now");
+  }
+
+#if defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+  /// Move-construct a basic_deadline_timer from another.
+  /**
+   * This constructor moves a timer from one object to another.
+   *
+   * @param other The other basic_deadline_timer object from which the move will
+   * occur.
+   *
+   * @note Following the move, the moved-from object is in the same state as if
+   * constructed using the @c basic_deadline_timer(const executor_type&)
+   * constructor.
+   */
+  basic_deadline_timer(basic_deadline_timer&& other)
+    : impl_(std::move(other.impl_))
+  {
+  }
+
+  /// Move-assign a basic_deadline_timer from another.
+  /**
+   * This assignment operator moves a timer from one object to another. Cancels
+   * any outstanding asynchronous operations associated with the target object.
+   *
+   * @param other The other basic_deadline_timer object from which the move will
+   * occur.
+   *
+   * @note Following the move, the moved-from object is in the same state as if
+   * constructed using the @c basic_deadline_timer(const executor_type&)
+   * constructor.
+   */
+  basic_deadline_timer& operator=(basic_deadline_timer&& other)
+  {
+    impl_ = std::move(other.impl_);
+    return *this;
+  }
+#endif // defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+
+  /// Destroys the timer.
+  /**
+   * This function destroys the timer, cancelling any outstanding asynchronous
+   * wait operations associated with the timer as if by calling @c cancel.
+   */
+  ~basic_deadline_timer()
+  {
+  }
+
+  /// Get the executor associated with the object.
+  executor_type get_executor() ASIO_NOEXCEPT
+  {
+    return impl_.get_executor();
+  }
+
+  /// Cancel any asynchronous operations that are waiting on the timer.
+  /**
+   * This function forces the completion of any pending asynchronous wait
+   * operations against the timer. The handler for each cancelled operation will
+   * be invoked with the asio::error::operation_aborted error code.
+   *
+   * Cancelling the timer does not change the expiry time.
+   *
+   * @return The number of asynchronous operations that were cancelled.
+   *
+   * @throws asio::system_error Thrown on failure.
+   *
+   * @note If the timer has already expired when cancel() is called, then the
+   * handlers for asynchronous wait operations will:
+   *
+   * @li have already been invoked; or
+   *
+   * @li have been queued for invocation in the near future.
+   *
+   * These handlers can no longer be cancelled, and therefore are passed an
+   * error code that indicates the successful completion of the wait operation.
+   */
+  std::size_t cancel()
+  {
+    asio::error_code ec;
+    std::size_t s = impl_.get_service().cancel(impl_.get_implementation(), ec);
+    asio::detail::throw_error(ec, "cancel");
+    return s;
+  }
+
+  /// Cancel any asynchronous operations that are waiting on the timer.
+  /**
+   * This function forces the completion of any pending asynchronous wait
+   * operations against the timer. The handler for each cancelled operation will
+   * be invoked with the asio::error::operation_aborted error code.
+   *
+   * Cancelling the timer does not change the expiry time.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @return The number of asynchronous operations that were cancelled.
+   *
+   * @note If the timer has already expired when cancel() is called, then the
+   * handlers for asynchronous wait operations will:
+   *
+   * @li have already been invoked; or
+   *
+   * @li have been queued for invocation in the near future.
+   *
+   * These handlers can no longer be cancelled, and therefore are passed an
+   * error code that indicates the successful completion of the wait operation.
+   */
+  std::size_t cancel(asio::error_code& ec)
+  {
+    return impl_.get_service().cancel(impl_.get_implementation(), ec);
+  }
+
+  /// Cancels one asynchronous operation that is waiting on the timer.
+  /**
+   * This function forces the completion of one pending asynchronous wait
+   * operation against the timer. Handlers are cancelled in FIFO order. The
+   * handler for the cancelled operation will be invoked with the
+   * asio::error::operation_aborted error code.
+   *
+   * Cancelling the timer does not change the expiry time.
+   *
+   * @return The number of asynchronous operations that were cancelled. That is,
+   * either 0 or 1.
+   *
+   * @throws asio::system_error Thrown on failure.
+   *
+   * @note If the timer has already expired when cancel_one() is called, then
+   * the handlers for asynchronous wait operations will:
+   *
+   * @li have already been invoked; or
+   *
+   * @li have been queued for invocation in the near future.
+   *
+   * These handlers can no longer be cancelled, and therefore are passed an
+   * error code that indicates the successful completion of the wait operation.
+   */
+  std::size_t cancel_one()
+  {
+    asio::error_code ec;
+    std::size_t s = impl_.get_service().cancel_one(
+        impl_.get_implementation(), ec);
+    asio::detail::throw_error(ec, "cancel_one");
+    return s;
+  }
+
+  /// Cancels one asynchronous operation that is waiting on the timer.
+  /**
+   * This function forces the completion of one pending asynchronous wait
+   * operation against the timer. Handlers are cancelled in FIFO order. The
+   * handler for the cancelled operation will be invoked with the
+   * asio::error::operation_aborted error code.
+   *
+   * Cancelling the timer does not change the expiry time.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @return The number of asynchronous operations that were cancelled. That is,
+   * either 0 or 1.
+   *
+   * @note If the timer has already expired when cancel_one() is called, then
+   * the handlers for asynchronous wait operations will:
+   *
+   * @li have already been invoked; or
+   *
+   * @li have been queued for invocation in the near future.
+   *
+   * These handlers can no longer be cancelled, and therefore are passed an
+   * error code that indicates the successful completion of the wait operation.
+   */
+  std::size_t cancel_one(asio::error_code& ec)
+  {
+    return impl_.get_service().cancel_one(impl_.get_implementation(), ec);
+  }
+
+  /// Get the timer's expiry time as an absolute time.
+  /**
+   * This function may be used to obtain the timer's current expiry time.
+   * Whether the timer has expired or not does not affect this value.
+   */
+  time_type expires_at() const
+  {
+    return impl_.get_service().expires_at(impl_.get_implementation());
+  }
+
+  /// Set the timer's expiry time as an absolute time.
+  /**
+   * This function sets the expiry time. Any pending asynchronous wait
+   * operations will be cancelled. The handler for each cancelled operation will
+   * be invoked with the asio::error::operation_aborted error code.
+   *
+   * @param expiry_time The expiry time to be used for the timer.
+   *
+   * @return The number of asynchronous operations that were cancelled.
+   *
+   * @throws asio::system_error Thrown on failure.
+   *
+   * @note If the timer has already expired when expires_at() is called, then
+   * the handlers for asynchronous wait operations will:
+   *
+   * @li have already been invoked; or
+   *
+   * @li have been queued for invocation in the near future.
+   *
+   * These handlers can no longer be cancelled, and therefore are passed an
+   * error code that indicates the successful completion of the wait operation.
+   */
+  std::size_t expires_at(const time_type& expiry_time)
+  {
+    asio::error_code ec;
+    std::size_t s = impl_.get_service().expires_at(
+        impl_.get_implementation(), expiry_time, ec);
+    asio::detail::throw_error(ec, "expires_at");
+    return s;
+  }
+
+  /// Set the timer's expiry time as an absolute time.
+  /**
+   * This function sets the expiry time. Any pending asynchronous wait
+   * operations will be cancelled. The handler for each cancelled operation will
+   * be invoked with the asio::error::operation_aborted error code.
+   *
+   * @param expiry_time The expiry time to be used for the timer.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @return The number of asynchronous operations that were cancelled.
+   *
+   * @note If the timer has already expired when expires_at() is called, then
+   * the handlers for asynchronous wait operations will:
+   *
+   * @li have already been invoked; or
+   *
+   * @li have been queued for invocation in the near future.
+   *
+   * These handlers can no longer be cancelled, and therefore are passed an
+   * error code that indicates the successful completion of the wait operation.
+   */
+  std::size_t expires_at(const time_type& expiry_time,
+      asio::error_code& ec)
+  {
+    return impl_.get_service().expires_at(
+        impl_.get_implementation(), expiry_time, ec);
+  }
+
+  /// Get the timer's expiry time relative to now.
+  /**
+   * This function may be used to obtain the timer's current expiry time.
+   * Whether the timer has expired or not does not affect this value.
+   */
+  duration_type expires_from_now() const
+  {
+    return impl_.get_service().expires_from_now(impl_.get_implementation());
+  }
+
+  /// Set the timer's expiry time relative to now.
+  /**
+   * This function sets the expiry time. Any pending asynchronous wait
+   * operations will be cancelled. The handler for each cancelled operation will
+   * be invoked with the asio::error::operation_aborted error code.
+   *
+   * @param expiry_time The expiry time to be used for the timer.
+   *
+   * @return The number of asynchronous operations that were cancelled.
+   *
+   * @throws asio::system_error Thrown on failure.
+   *
+   * @note If the timer has already expired when expires_from_now() is called,
+   * then the handlers for asynchronous wait operations will:
+   *
+   * @li have already been invoked; or
+   *
+   * @li have been queued for invocation in the near future.
+   *
+   * These handlers can no longer be cancelled, and therefore are passed an
+   * error code that indicates the successful completion of the wait operation.
+   */
+  std::size_t expires_from_now(const duration_type& expiry_time)
+  {
+    asio::error_code ec;
+    std::size_t s = impl_.get_service().expires_from_now(
+        impl_.get_implementation(), expiry_time, ec);
+    asio::detail::throw_error(ec, "expires_from_now");
+    return s;
+  }
+
+  /// Set the timer's expiry time relative to now.
+  /**
+   * This function sets the expiry time. Any pending asynchronous wait
+   * operations will be cancelled. The handler for each cancelled operation will
+   * be invoked with the asio::error::operation_aborted error code.
+   *
+   * @param expiry_time The expiry time to be used for the timer.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @return The number of asynchronous operations that were cancelled.
+   *
+   * @note If the timer has already expired when expires_from_now() is called,
+   * then the handlers for asynchronous wait operations will:
+   *
+   * @li have already been invoked; or
+   *
+   * @li have been queued for invocation in the near future.
+   *
+   * These handlers can no longer be cancelled, and therefore are passed an
+   * error code that indicates the successful completion of the wait operation.
+   */
+  std::size_t expires_from_now(const duration_type& expiry_time,
+      asio::error_code& ec)
+  {
+    return impl_.get_service().expires_from_now(
+        impl_.get_implementation(), expiry_time, ec);
+  }
+
+  /// Perform a blocking wait on the timer.
+  /**
+   * This function is used to wait for the timer to expire. This function
+   * blocks and does not return until the timer has expired.
+   *
+   * @throws asio::system_error Thrown on failure.
+   */
+  void wait()
+  {
+    asio::error_code ec;
+    impl_.get_service().wait(impl_.get_implementation(), ec);
+    asio::detail::throw_error(ec, "wait");
+  }
+
+  /// Perform a blocking wait on the timer.
+  /**
+   * This function is used to wait for the timer to expire. This function
+   * blocks and does not return until the timer has expired.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   */
+  void wait(asio::error_code& ec)
+  {
+    impl_.get_service().wait(impl_.get_implementation(), ec);
+  }
+
+  /// Start an asynchronous wait on the timer.
+  /**
+   * This function may be used to initiate an asynchronous wait against the
+   * timer. It is an initiating function for an @ref asynchronous_operation,
+   * and always returns immediately.
+   *
+   * For each call to async_wait(), the completion handler will be called
+   * exactly once. The completion handler will be called when:
+   *
+   * @li The timer has expired.
+   *
+   * @li The timer was cancelled, in which case the handler is passed the error
+   * code asio::error::operation_aborted.
+   *
+   * @param token The @ref completion_token that will be used to produce a
+   * completion handler, which will be called when the timer expires. Potential
+   * completion tokens include @ref use_future, @ref use_awaitable, @ref
+   * yield_context, or a function object with the correct completion signature.
+   * The function signature of the completion handler must be:
+   * @code void handler(
+   *   const asio::error_code& error // Result of operation.
+   * ); @endcode
+   * Regardless of whether the asynchronous operation completes immediately or
+   * not, the completion handler will not be invoked from within this function.
+   * On immediate completion, invocation of the handler will be performed in a
+   * manner equivalent to using asio::post().
+   *
+   * @par Completion Signature
+   * @code void(asio::error_code) @endcode
+   *
+   * @par Per-Operation Cancellation
+   * This asynchronous operation supports cancellation for the following
+   * asio::cancellation_type values:
+   *
+   * @li @c cancellation_type::terminal
+   *
+   * @li @c cancellation_type::partial
+   *
+   * @li @c cancellation_type::total
+   */
+  template <
+      ASIO_COMPLETION_TOKEN_FOR(void (asio::error_code))
+        WaitToken ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(executor_type)>
+  ASIO_INITFN_AUTO_RESULT_TYPE(WaitToken,
+      void (asio::error_code))
+  async_wait(
+      ASIO_MOVE_ARG(WaitToken) token
+        ASIO_DEFAULT_COMPLETION_TOKEN(executor_type))
+  {
+    return async_initiate<WaitToken, void (asio::error_code)>(
+        initiate_async_wait(this), token);
+  }
+
+private:
+  // Disallow copying and assignment.
+  basic_deadline_timer(const basic_deadline_timer&) ASIO_DELETED;
+  basic_deadline_timer& operator=(
+      const basic_deadline_timer&) ASIO_DELETED;
+
+  class initiate_async_wait
+  {
+  public:
+    typedef Executor executor_type;
+
+    explicit initiate_async_wait(basic_deadline_timer* self)
+      : self_(self)
+    {
+    }
+
+    executor_type get_executor() const ASIO_NOEXCEPT
+    {
+      return self_->get_executor();
+    }
+
+    template <typename WaitHandler>
+    void operator()(ASIO_MOVE_ARG(WaitHandler) handler) const
+    {
+      // If you get an error on the following line it means that your handler
+      // does not meet the documented type requirements for a WaitHandler.
+      ASIO_WAIT_HANDLER_CHECK(WaitHandler, handler) type_check;
+
+      detail::non_const_lvalue<WaitHandler> handler2(handler);
+      self_->impl_.get_service().async_wait(
+          self_->impl_.get_implementation(),
+          handler2.value, self_->impl_.get_executor());
+    }
+
+  private:
+    basic_deadline_timer* self_;
+  };
+
+  detail::io_object_impl<
+    detail::deadline_timer_service<TimeTraits>, Executor> impl_;
+};
+
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // defined(ASIO_HAS_BOOST_DATE_TIME)
+       // || defined(GENERATING_DOCUMENTATION)
+
+#endif // ASIO_BASIC_DEADLINE_TIMER_HPP

lib/asio/include/asio/basic_file.hpp

@@ -0,0 +1,829 @@
+//
+// basic_file.hpp
+// ~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_BASIC_FILE_HPP
+#define ASIO_BASIC_FILE_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_HAS_FILE) \
+  || defined(GENERATING_DOCUMENTATION)
+
+#include <string>
+#include "asio/any_io_executor.hpp"
+#include "asio/async_result.hpp"
+#include "asio/detail/cstdint.hpp"
+#include "asio/detail/handler_type_requirements.hpp"
+#include "asio/detail/io_object_impl.hpp"
+#include "asio/detail/non_const_lvalue.hpp"
+#include "asio/detail/throw_error.hpp"
+#include "asio/detail/type_traits.hpp"
+#include "asio/error.hpp"
+#include "asio/execution_context.hpp"
+#include "asio/post.hpp"
+#include "asio/file_base.hpp"
+#if defined(ASIO_HAS_IOCP)
+# include "asio/detail/win_iocp_file_service.hpp"
+#elif defined(ASIO_HAS_IO_URING)
+# include "asio/detail/io_uring_file_service.hpp"
+#endif
+
+#if defined(ASIO_HAS_MOVE)
+# include <utility>
+#endif // defined(ASIO_HAS_MOVE)
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+
+#if !defined(ASIO_BASIC_FILE_FWD_DECL)
+#define ASIO_BASIC_FILE_FWD_DECL
+
+// Forward declaration with defaulted arguments.
+template <typename Executor = any_io_executor>
+class basic_file;
+
+#endif // !defined(ASIO_BASIC_FILE_FWD_DECL)
+
+/// Provides file functionality.
+/**
+ * The basic_file class template provides functionality that is common to both
+ * stream-oriented and random-access files.
+ *
+ * @par Thread Safety
+ * @e Distinct @e objects: Safe.@n
+ * @e Shared @e objects: Unsafe.
+ */
+template <typename Executor>
+class basic_file
+  : public file_base
+{
+public:
+  /// The type of the executor associated with the object.
+  typedef Executor executor_type;
+
+  /// Rebinds the file type to another executor.
+  template <typename Executor1>
+  struct rebind_executor
+  {
+    /// The file type when rebound to the specified executor.
+    typedef basic_file<Executor1> other;
+  };
+
+  /// The native representation of a file.
+#if defined(GENERATING_DOCUMENTATION)
+  typedef implementation_defined native_handle_type;
+#elif defined(ASIO_HAS_IOCP)
+  typedef detail::win_iocp_file_service::native_handle_type native_handle_type;
+#elif defined(ASIO_HAS_IO_URING)
+  typedef detail::io_uring_file_service::native_handle_type native_handle_type;
+#endif
+
+  /// Construct a basic_file without opening it.
+  /**
+   * This constructor initialises a file without opening it.
+   *
+   * @param ex The I/O executor that the file will use, by default, to
+   * dispatch handlers for any asynchronous operations performed on the file.
+   */
+  explicit basic_file(const executor_type& ex)
+    : impl_(0, ex)
+  {
+  }
+
+  /// Construct a basic_file without opening it.
+  /**
+   * This constructor initialises a file without opening it.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the file will use, by default, to dispatch handlers for any asynchronous
+   * operations performed on the file.
+   */
+  template <typename ExecutionContext>
+  explicit basic_file(ExecutionContext& context,
+      typename constraint<
+        is_convertible<ExecutionContext&, execution_context&>::value,
+        defaulted_constraint
+      >::type = defaulted_constraint())
+    : impl_(0, 0, context)
+  {
+  }
+
+  /// Construct and open a basic_file.
+  /**
+   * This constructor initialises a file and opens it.
+   *
+   * @param ex The I/O executor that the file will use, by default, to
+   * dispatch handlers for any asynchronous operations performed on the file.
+   *
+   * @param path The path name identifying the file to be opened.
+   *
+   * @param open_flags A set of flags that determine how the file should be
+   * opened.
+   */
+  explicit basic_file(const executor_type& ex,
+      const char* path, file_base::flags open_flags)
+    : impl_(0, ex)
+  {
+    asio::error_code ec;
+    impl_.get_service().open(impl_.get_implementation(), path, open_flags, ec);
+    asio::detail::throw_error(ec, "open");
+  }
+
+  /// Construct a basic_file without opening it.
+  /**
+   * This constructor initialises a file and opens it.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the file will use, by default, to dispatch handlers for any asynchronous
+   * operations performed on the file.
+   *
+   * @param path The path name identifying the file to be opened.
+   *
+   * @param open_flags A set of flags that determine how the file should be
+   * opened.
+   */
+  template <typename ExecutionContext>
+  explicit basic_file(ExecutionContext& context,
+      const char* path, file_base::flags open_flags,
+      typename constraint<
+        is_convertible<ExecutionContext&, execution_context&>::value,
+        defaulted_constraint
+      >::type = defaulted_constraint())
+    : impl_(0, 0, context)
+  {
+    asio::error_code ec;
+    impl_.get_service().open(impl_.get_implementation(), path, open_flags, ec);
+    asio::detail::throw_error(ec, "open");
+  }
+
+  /// Construct and open a basic_file.
+  /**
+   * This constructor initialises a file and opens it.
+   *
+   * @param ex The I/O executor that the file will use, by default, to
+   * dispatch handlers for any asynchronous operations performed on the file.
+   *
+   * @param path The path name identifying the file to be opened.
+   *
+   * @param open_flags A set of flags that determine how the file should be
+   * opened.
+   */
+  explicit basic_file(const executor_type& ex,
+      const std::string& path, file_base::flags open_flags)
+    : impl_(0, ex)
+  {
+    asio::error_code ec;
+    impl_.get_service().open(impl_.get_implementation(),
+        path.c_str(), open_flags, ec);
+    asio::detail::throw_error(ec, "open");
+  }
+
+  /// Construct a basic_file without opening it.
+  /**
+   * This constructor initialises a file and opens it.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the file will use, by default, to dispatch handlers for any asynchronous
+   * operations performed on the file.
+   *
+   * @param path The path name identifying the file to be opened.
+   *
+   * @param open_flags A set of flags that determine how the file should be
+   * opened.
+   */
+  template <typename ExecutionContext>
+  explicit basic_file(ExecutionContext& context,
+      const std::string& path, file_base::flags open_flags,
+      typename constraint<
+        is_convertible<ExecutionContext&, execution_context&>::value,
+        defaulted_constraint
+      >::type = defaulted_constraint())
+    : impl_(0, 0, context)
+  {
+    asio::error_code ec;
+    impl_.get_service().open(impl_.get_implementation(),
+        path.c_str(), open_flags, ec);
+    asio::detail::throw_error(ec, "open");
+  }
+
+  /// Construct a basic_file on an existing native file handle.
+  /**
+   * This constructor initialises a file object to hold an existing native file.
+   *
+   * @param ex The I/O executor that the file will use, by default, to
+   * dispatch handlers for any asynchronous operations performed on the file.
+   *
+   * @param native_file A native file handle.
+   *
+   * @throws asio::system_error Thrown on failure.
+   */
+  basic_file(const executor_type& ex, const native_handle_type& native_file)
+    : impl_(0, ex)
+  {
+    asio::error_code ec;
+    impl_.get_service().assign(
+        impl_.get_implementation(), native_file, ec);
+    asio::detail::throw_error(ec, "assign");
+  }
+
+  /// Construct a basic_file on an existing native file.
+  /**
+   * This constructor initialises a file object to hold an existing native file.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the file will use, by default, to dispatch handlers for any asynchronous
+   * operations performed on the file.
+   *
+   * @param native_file A native file.
+   *
+   * @throws asio::system_error Thrown on failure.
+   */
+  template <typename ExecutionContext>
+  basic_file(ExecutionContext& context, const native_handle_type& native_file,
+      typename constraint<
+        is_convertible<ExecutionContext&, execution_context&>::value,
+        defaulted_constraint
+      >::type = defaulted_constraint())
+    : impl_(0, 0, context)
+  {
+    asio::error_code ec;
+    impl_.get_service().assign(
+        impl_.get_implementation(), native_file, ec);
+    asio::detail::throw_error(ec, "assign");
+  }
+
+#if defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+  /// Move-construct a basic_file from another.
+  /**
+   * This constructor moves a file from one object to another.
+   *
+   * @param other The other basic_file object from which the move will
+   * occur.
+   *
+   * @note Following the move, the moved-from object is in the same state as if
+   * constructed using the @c basic_file(const executor_type&) constructor.
+   */
+  basic_file(basic_file&& other) ASIO_NOEXCEPT
+    : impl_(std::move(other.impl_))
+  {
+  }
+
+  /// Move-assign a basic_file from another.
+  /**
+   * This assignment operator moves a file from one object to another.
+   *
+   * @param other The other basic_file object from which the move will
+   * occur.
+   *
+   * @note Following the move, the moved-from object is in the same state as if
+   * constructed using the @c basic_file(const executor_type&) constructor.
+   */
+  basic_file& operator=(basic_file&& other)
+  {
+    impl_ = std::move(other.impl_);
+    return *this;
+  }
+
+  // All files have access to each other's implementations.
+  template <typename Executor1>
+  friend class basic_file;
+
+  /// Move-construct a basic_file from a file of another executor type.
+  /**
+   * This constructor moves a file from one object to another.
+   *
+   * @param other The other basic_file object from which the move will
+   * occur.
+   *
+   * @note Following the move, the moved-from object is in the same state as if
+   * constructed using the @c basic_file(const executor_type&) constructor.
+   */
+  template <typename Executor1>
+  basic_file(basic_file<Executor1>&& other,
+      typename constraint<
+        is_convertible<Executor1, Executor>::value,
+        defaulted_constraint
+      >::type = defaulted_constraint())
+    : impl_(std::move(other.impl_))
+  {
+  }
+
+  /// Move-assign a basic_file from a file of another executor type.
+  /**
+   * This assignment operator moves a file from one object to another.
+   *
+   * @param other The other basic_file object from which the move will
+   * occur.
+   *
+   * @note Following the move, the moved-from object is in the same state as if
+   * constructed using the @c basic_file(const executor_type&) constructor.
+   */
+  template <typename Executor1>
+  typename constraint<
+    is_convertible<Executor1, Executor>::value,
+    basic_file&
+  >::type operator=(basic_file<Executor1> && other)
+  {
+    basic_file tmp(std::move(other));
+    impl_ = std::move(tmp.impl_);
+    return *this;
+  }
+#endif // defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+
+  /// Get the executor associated with the object.
+  executor_type get_executor() ASIO_NOEXCEPT
+  {
+    return impl_.get_executor();
+  }
+
+  /// Open the file using the specified path.
+  /**
+   * This function opens the file so that it will use the specified path.
+   *
+   * @param path The path name identifying the file to be opened.
+   *
+   * @param open_flags A set of flags that determine how the file should be
+   * opened.
+   *
+   * @throws asio::system_error Thrown on failure.
+   *
+   * @par Example
+   * @code
+   * asio::stream_file file(my_context);
+   * file.open("/path/to/my/file", asio::stream_file::read_only);
+   * @endcode
+   */
+  void open(const char* path, file_base::flags open_flags)
+  {
+    asio::error_code ec;
+    impl_.get_service().open(impl_.get_implementation(), path, open_flags, ec);
+    asio::detail::throw_error(ec, "open");
+  }
+
+  /// Open the file using the specified path.
+  /**
+   * This function opens the file so that it will use the specified path.
+   *
+   * @param path The path name identifying the file to be opened.
+   *
+   * @param open_flags A set of flags that determine how the file should be
+   * opened.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @par Example
+   * @code
+   * asio::stream_file file(my_context);
+   * asio::error_code ec;
+   * file.open("/path/to/my/file", asio::stream_file::read_only, ec);
+   * if (ec)
+   * {
+   *   // An error occurred.
+   * }
+   * @endcode
+   */
+  ASIO_SYNC_OP_VOID open(const char* path,
+      file_base::flags open_flags, asio::error_code& ec)
+  {
+    impl_.get_service().open(impl_.get_implementation(), path, open_flags, ec);
+    ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Open the file using the specified path.
+  /**
+   * This function opens the file so that it will use the specified path.
+   *
+   * @param path The path name identifying the file to be opened.
+   *
+   * @param open_flags A set of flags that determine how the file should be
+   * opened.
+   *
+   * @throws asio::system_error Thrown on failure.
+   *
+   * @par Example
+   * @code
+   * asio::stream_file file(my_context);
+   * file.open("/path/to/my/file", asio::stream_file::read_only);
+   * @endcode
+   */
+  void open(const std::string& path, file_base::flags open_flags)
+  {
+    asio::error_code ec;
+    impl_.get_service().open(impl_.get_implementation(),
+        path.c_str(), open_flags, ec);
+    asio::detail::throw_error(ec, "open");
+  }
+
+  /// Open the file using the specified path.
+  /**
+   * This function opens the file so that it will use the specified path.
+   *
+   * @param path The path name identifying the file to be opened.
+   *
+   * @param open_flags A set of flags that determine how the file should be
+   * opened.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @par Example
+   * @code
+   * asio::stream_file file(my_context);
+   * asio::error_code ec;
+   * file.open("/path/to/my/file", asio::stream_file::read_only, ec);
+   * if (ec)
+   * {
+   *   // An error occurred.
+   * }
+   * @endcode
+   */
+  ASIO_SYNC_OP_VOID open(const std::string& path,
+      file_base::flags open_flags, asio::error_code& ec)
+  {
+    impl_.get_service().open(impl_.get_implementation(),
+        path.c_str(), open_flags, ec);
+    ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Assign an existing native file to the file.
+  /*
+   * This function opens the file to hold an existing native file.
+   *
+   * @param native_file A native file.
+   *
+   * @throws asio::system_error Thrown on failure.
+   */
+  void assign(const native_handle_type& native_file)
+  {
+    asio::error_code ec;
+    impl_.get_service().assign(
+        impl_.get_implementation(), native_file, ec);
+    asio::detail::throw_error(ec, "assign");
+  }
+
+  /// Assign an existing native file to the file.
+  /*
+   * This function opens the file to hold an existing native file.
+   *
+   * @param native_file A native file.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   */
+  ASIO_SYNC_OP_VOID assign(const native_handle_type& native_file,
+      asio::error_code& ec)
+  {
+    impl_.get_service().assign(
+        impl_.get_implementation(), native_file, ec);
+    ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Determine whether the file is open.
+  bool is_open() const
+  {
+    return impl_.get_service().is_open(impl_.get_implementation());
+  }
+
+  /// Close the file.
+  /**
+   * This function is used to close the file. Any asynchronous read or write
+   * operations will be cancelled immediately, and will complete with the
+   * asio::error::operation_aborted error.
+   *
+   * @throws asio::system_error Thrown on failure. Note that, even if
+   * the function indicates an error, the underlying descriptor is closed.
+   */
+  void close()
+  {
+    asio::error_code ec;
+    impl_.get_service().close(impl_.get_implementation(), ec);
+    asio::detail::throw_error(ec, "close");
+  }
+
+  /// Close the file.
+  /**
+   * This function is used to close the file. Any asynchronous read or write
+   * operations will be cancelled immediately, and will complete with the
+   * asio::error::operation_aborted error.
+   *
+   * @param ec Set to indicate what error occurred, if any. Note that, even if
+   * the function indicates an error, the underlying descriptor is closed.
+   *
+   * @par Example
+   * @code
+   * asio::stream_file file(my_context);
+   * ...
+   * asio::error_code ec;
+   * file.close(ec);
+   * if (ec)
+   * {
+   *   // An error occurred.
+   * }
+   * @endcode
+   */
+  ASIO_SYNC_OP_VOID close(asio::error_code& ec)
+  {
+    impl_.get_service().close(impl_.get_implementation(), ec);
+    ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Release ownership of the underlying native file.
+  /**
+   * This function causes all outstanding asynchronous read and write
+   * operations to finish immediately, and the handlers for cancelled
+   * operations will be passed the asio::error::operation_aborted error.
+   * Ownership of the native file is then transferred to the caller.
+   *
+   * @throws asio::system_error Thrown on failure.
+   *
+   * @note This function is unsupported on Windows versions prior to Windows
+   * 8.1, and will fail with asio::error::operation_not_supported on
+   * these platforms.
+   */
+#if defined(ASIO_MSVC) && (ASIO_MSVC >= 1400) \
+  && (!defined(_WIN32_WINNT) || _WIN32_WINNT < 0x0603)
+  __declspec(deprecated("This function always fails with "
+        "operation_not_supported when used on Windows versions "
+        "prior to Windows 8.1."))
+#endif
+  native_handle_type release()
+  {
+    asio::error_code ec;
+    native_handle_type s = impl_.get_service().release(
+        impl_.get_implementation(), ec);
+    asio::detail::throw_error(ec, "release");
+    return s;
+  }
+
+  /// Release ownership of the underlying native file.
+  /**
+   * This function causes all outstanding asynchronous read and write
+   * operations to finish immediately, and the handlers for cancelled
+   * operations will be passed the asio::error::operation_aborted error.
+   * Ownership of the native file is then transferred to the caller.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @note This function is unsupported on Windows versions prior to Windows
+   * 8.1, and will fail with asio::error::operation_not_supported on
+   * these platforms.
+   */
+#if defined(ASIO_MSVC) && (ASIO_MSVC >= 1400) \
+  && (!defined(_WIN32_WINNT) || _WIN32_WINNT < 0x0603)
+  __declspec(deprecated("This function always fails with "
+        "operation_not_supported when used on Windows versions "
+        "prior to Windows 8.1."))
+#endif
+  native_handle_type release(asio::error_code& ec)
+  {
+    return impl_.get_service().release(impl_.get_implementation(), ec);
+  }
+
+  /// Get the native file representation.
+  /**
+   * This function may be used to obtain the underlying representation of the
+   * file. This is intended to allow access to native file functionality
+   * that is not otherwise provided.
+   */
+  native_handle_type native_handle()
+  {
+    return impl_.get_service().native_handle(impl_.get_implementation());
+  }
+
+  /// Cancel all asynchronous operations associated with the file.
+  /**
+   * This function causes all outstanding asynchronous read and write
+   * operations to finish immediately, and the handlers for cancelled
+   * operations will be passed the asio::error::operation_aborted error.
+   *
+   * @throws asio::system_error Thrown on failure.
+   *
+   * @note Calls to cancel() will always fail with
+   * asio::error::operation_not_supported when run on Windows XP, Windows
+   * Server 2003, and earlier versions of Windows, unless
+   * ASIO_ENABLE_CANCELIO is defined. However, the CancelIo function has
+   * two issues that should be considered before enabling its use:
+   *
+   * @li It will only cancel asynchronous operations that were initiated in the
+   * current thread.
+   *
+   * @li It can appear to complete without error, but the request to cancel the
+   * unfinished operations may be silently ignored by the operating system.
+   * Whether it works or not seems to depend on the drivers that are installed.
+   *
+   * For portable cancellation, consider using the close() function to
+   * simultaneously cancel the outstanding operations and close the file.
+   *
+   * When running on Windows Vista, Windows Server 2008, and later, the
+   * CancelIoEx function is always used. This function does not have the
+   * problems described above.
+   */
+#if defined(ASIO_MSVC) && (ASIO_MSVC >= 1400) \
+  && (!defined(_WIN32_WINNT) || _WIN32_WINNT < 0x0600) \
+  && !defined(ASIO_ENABLE_CANCELIO)
+  __declspec(deprecated("By default, this function always fails with "
+        "operation_not_supported when used on Windows XP, Windows Server 2003, "
+        "or earlier. Consult documentation for details."))
+#endif
+  void cancel()
+  {
+    asio::error_code ec;
+    impl_.get_service().cancel(impl_.get_implementation(), ec);
+    asio::detail::throw_error(ec, "cancel");
+  }
+
+  /// Cancel all asynchronous operations associated with the file.
+  /**
+   * This function causes all outstanding asynchronous read and write
+   * operations to finish immediately, and the handlers for cancelled
+   * operations will be passed the asio::error::operation_aborted error.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @note Calls to cancel() will always fail with
+   * asio::error::operation_not_supported when run on Windows XP, Windows
+   * Server 2003, and earlier versions of Windows, unless
+   * ASIO_ENABLE_CANCELIO is defined. However, the CancelIo function has
+   * two issues that should be considered before enabling its use:
+   *
+   * @li It will only cancel asynchronous operations that were initiated in the
+   * current thread.
+   *
+   * @li It can appear to complete without error, but the request to cancel the
+   * unfinished operations may be silently ignored by the operating system.
+   * Whether it works or not seems to depend on the drivers that are installed.
+   *
+   * For portable cancellation, consider using the close() function to
+   * simultaneously cancel the outstanding operations and close the file.
+   *
+   * When running on Windows Vista, Windows Server 2008, and later, the
+   * CancelIoEx function is always used. This function does not have the
+   * problems described above.
+   */
+#if defined(ASIO_MSVC) && (ASIO_MSVC >= 1400) \
+  && (!defined(_WIN32_WINNT) || _WIN32_WINNT < 0x0600) \
+  && !defined(ASIO_ENABLE_CANCELIO)
+  __declspec(deprecated("By default, this function always fails with "
+        "operation_not_supported when used on Windows XP, Windows Server 2003, "
+        "or earlier. Consult documentation for details."))
+#endif
+  ASIO_SYNC_OP_VOID cancel(asio::error_code& ec)
+  {
+    impl_.get_service().cancel(impl_.get_implementation(), ec);
+    ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Get the size of the file.
+  /**
+   * This function determines the size of the file, in bytes.
+   *
+   * @throws asio::system_error Thrown on failure.
+   */
+  uint64_t size() const
+  {
+    asio::error_code ec;
+    uint64_t s = impl_.get_service().size(impl_.get_implementation(), ec);
+    asio::detail::throw_error(ec, "size");
+    return s;
+  }
+
+  /// Get the size of the file.
+  /**
+   * This function determines the size of the file, in bytes.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   */
+  uint64_t size(asio::error_code& ec) const
+  {
+    return impl_.get_service().size(impl_.get_implementation(), ec);
+  }
+
+  /// Alter the size of the file.
+  /**
+   * This function resizes the file to the specified size, in bytes. If the
+   * current file size exceeds @c n then any extra data is discarded. If the
+   * current size is less than @c n then the file is extended and filled with
+   * zeroes.
+   *
+   * @param n The new size for the file.
+   *
+   * @throws asio::system_error Thrown on failure.
+   */
+  void resize(uint64_t n)
+  {
+    asio::error_code ec;
+    impl_.get_service().resize(impl_.get_implementation(), n, ec);
+    asio::detail::throw_error(ec, "resize");
+  }
+
+  /// Alter the size of the file.
+  /**
+   * This function resizes the file to the specified size, in bytes. If the
+   * current file size exceeds @c n then any extra data is discarded. If the
+   * current size is less than @c n then the file is extended and filled with
+   * zeroes.
+   *
+   * @param n The new size for the file.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   */
+  ASIO_SYNC_OP_VOID resize(uint64_t n, asio::error_code& ec)
+  {
+    impl_.get_service().resize(impl_.get_implementation(), n, ec);
+    ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Synchronise the file to disk.
+  /**
+   * This function synchronises the file data and metadata to disk. Note that
+   * the semantics of this synchronisation vary between operation systems.
+   *
+   * @throws asio::system_error Thrown on failure.
+   */
+  void sync_all()
+  {
+    asio::error_code ec;
+    impl_.get_service().sync_all(impl_.get_implementation(), ec);
+    asio::detail::throw_error(ec, "sync_all");
+  }
+
+  /// Synchronise the file to disk.
+  /**
+   * This function synchronises the file data and metadata to disk. Note that
+   * the semantics of this synchronisation vary between operation systems.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   */
+  ASIO_SYNC_OP_VOID sync_all(asio::error_code& ec)
+  {
+    impl_.get_service().sync_all(impl_.get_implementation(), ec);
+    ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Synchronise the file data to disk.
+  /**
+   * This function synchronises the file data to disk. Note that the semantics
+   * of this synchronisation vary between operation systems.
+   *
+   * @throws asio::system_error Thrown on failure.
+   */
+  void sync_data()
+  {
+    asio::error_code ec;
+    impl_.get_service().sync_data(impl_.get_implementation(), ec);
+    asio::detail::throw_error(ec, "sync_data");
+  }
+
+  /// Synchronise the file data to disk.
+  /**
+   * This function synchronises the file data to disk. Note that the semantics
+   * of this synchronisation vary between operation systems.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   */
+  ASIO_SYNC_OP_VOID sync_data(asio::error_code& ec)
+  {
+    impl_.get_service().sync_data(impl_.get_implementation(), ec);
+    ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+protected:
+  /// Protected destructor to prevent deletion through this type.
+  /**
+   * This function destroys the file, cancelling any outstanding asynchronous
+   * operations associated with the file as if by calling @c cancel.
+   */
+  ~basic_file()
+  {
+  }
+
+#if defined(ASIO_HAS_IOCP)
+  detail::io_object_impl<detail::win_iocp_file_service, Executor> impl_;
+#elif defined(ASIO_HAS_IO_URING)
+  detail::io_object_impl<detail::io_uring_file_service, Executor> impl_;
+#endif
+
+private:
+  // Disallow copying and assignment.
+  basic_file(const basic_file&) ASIO_DELETED;
+  basic_file& operator=(const basic_file&) ASIO_DELETED;
+};
+
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // defined(ASIO_HAS_FILE)
+       //   || defined(GENERATING_DOCUMENTATION)
+
+#endif // ASIO_BASIC_FILE_HPP

lib/asio/include/asio/basic_io_object.hpp

@@ -0,0 +1,290 @@
+//
+// basic_io_object.hpp
+// ~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_BASIC_IO_OBJECT_HPP
+#define ASIO_BASIC_IO_OBJECT_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+#include "asio/io_context.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+
+#if defined(ASIO_HAS_MOVE)
+namespace detail
+{
+  // Type trait used to determine whether a service supports move.
+  template <typename IoObjectService>
+  class service_has_move
+  {
+  private:
+    typedef IoObjectService service_type;
+    typedef typename service_type::implementation_type implementation_type;
+
+    template <typename T, typename U>
+    static auto asio_service_has_move_eval(T* t, U* u)
+      -> decltype(t->move_construct(*u, *u), char());
+    static char (&asio_service_has_move_eval(...))[2];
+
+  public:
+    static const bool value =
+      sizeof(asio_service_has_move_eval(
+        static_cast<service_type*>(0),
+        static_cast<implementation_type*>(0))) == 1;
+  };
+}
+#endif // defined(ASIO_HAS_MOVE)
+
+/// Base class for all I/O objects.
+/**
+ * @note All I/O objects are non-copyable. However, when using C++0x, certain
+ * I/O objects do support move construction and move assignment.
+ */
+#if !defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+template <typename IoObjectService>
+#else
+template <typename IoObjectService,
+    bool Movable = detail::service_has_move<IoObjectService>::value>
+#endif
+class basic_io_object
+{
+public:
+  /// The type of the service that will be used to provide I/O operations.
+  typedef IoObjectService service_type;
+
+  /// The underlying implementation type of I/O object.
+  typedef typename service_type::implementation_type implementation_type;
+
+#if !defined(ASIO_NO_DEPRECATED)
+  /// (Deprecated: Use get_executor().) Get the io_context associated with the
+  /// object.
+  /**
+   * This function may be used to obtain the io_context object that the I/O
+   * object uses to dispatch handlers for asynchronous operations.
+   *
+   * @return A reference to the io_context object that the I/O object will use
+   * to dispatch handlers. Ownership is not transferred to the caller.
+   */
+  asio::io_context& get_io_context()
+  {
+    return service_.get_io_context();
+  }
+
+  /// (Deprecated: Use get_executor().) Get the io_context associated with the
+  /// object.
+  /**
+   * This function may be used to obtain the io_context object that the I/O
+   * object uses to dispatch handlers for asynchronous operations.
+   *
+   * @return A reference to the io_context object that the I/O object will use
+   * to dispatch handlers. Ownership is not transferred to the caller.
+   */
+  asio::io_context& get_io_service()
+  {
+    return service_.get_io_context();
+  }
+#endif // !defined(ASIO_NO_DEPRECATED)
+
+  /// The type of the executor associated with the object.
+  typedef asio::io_context::executor_type executor_type;
+
+  /// Get the executor associated with the object.
+  executor_type get_executor() ASIO_NOEXCEPT
+  {
+    return service_.get_io_context().get_executor();
+  }
+
+protected:
+  /// Construct a basic_io_object.
+  /**
+   * Performs:
+   * @code get_service().construct(get_implementation()); @endcode
+   */
+  explicit basic_io_object(asio::io_context& io_context)
+    : service_(asio::use_service<IoObjectService>(io_context))
+  {
+    service_.construct(implementation_);
+  }
+
+#if defined(GENERATING_DOCUMENTATION)
+  /// Move-construct a basic_io_object.
+  /**
+   * Performs:
+   * @code get_service().move_construct(
+   *     get_implementation(), other.get_implementation()); @endcode
+   *
+   * @note Available only for services that support movability,
+   */
+  basic_io_object(basic_io_object&& other);
+
+  /// Move-assign a basic_io_object.
+  /**
+   * Performs:
+   * @code get_service().move_assign(get_implementation(),
+   *     other.get_service(), other.get_implementation()); @endcode
+   *
+   * @note Available only for services that support movability,
+   */
+  basic_io_object& operator=(basic_io_object&& other);
+
+  /// Perform a converting move-construction of a basic_io_object.
+  template <typename IoObjectService1>
+  basic_io_object(IoObjectService1& other_service,
+      typename IoObjectService1::implementation_type& other_implementation);
+#endif // defined(GENERATING_DOCUMENTATION)
+
+  /// Protected destructor to prevent deletion through this type.
+  /**
+   * Performs:
+   * @code get_service().destroy(get_implementation()); @endcode
+   */
+  ~basic_io_object()
+  {
+    service_.destroy(implementation_);
+  }
+
+  /// Get the service associated with the I/O object.
+  service_type& get_service()
+  {
+    return service_;
+  }
+
+  /// Get the service associated with the I/O object.
+  const service_type& get_service() const
+  {
+    return service_;
+  }
+
+  /// Get the underlying implementation of the I/O object.
+  implementation_type& get_implementation()
+  {
+    return implementation_;
+  }
+
+  /// Get the underlying implementation of the I/O object.
+  const implementation_type& get_implementation() const
+  {
+    return implementation_;
+  }
+
+private:
+  basic_io_object(const basic_io_object&);
+  basic_io_object& operator=(const basic_io_object&);
+
+  // The service associated with the I/O object.
+  service_type& service_;
+
+  /// The underlying implementation of the I/O object.
+  implementation_type implementation_;
+};
+
+#if defined(ASIO_HAS_MOVE)
+// Specialisation for movable objects.
+template <typename IoObjectService>
+class basic_io_object<IoObjectService, true>
+{
+public:
+  typedef IoObjectService service_type;
+  typedef typename service_type::implementation_type implementation_type;
+
+#if !defined(ASIO_NO_DEPRECATED)
+  asio::io_context& get_io_context()
+  {
+    return service_->get_io_context();
+  }
+
+  asio::io_context& get_io_service()
+  {
+    return service_->get_io_context();
+  }
+#endif // !defined(ASIO_NO_DEPRECATED)
+
+  typedef asio::io_context::executor_type executor_type;
+
+  executor_type get_executor() ASIO_NOEXCEPT
+  {
+    return service_->get_io_context().get_executor();
+  }
+
+protected:
+  explicit basic_io_object(asio::io_context& io_context)
+    : service_(&asio::use_service<IoObjectService>(io_context))
+  {
+    service_->construct(implementation_);
+  }
+
+  basic_io_object(basic_io_object&& other)
+    : service_(&other.get_service())
+  {
+    service_->move_construct(implementation_, other.implementation_);
+  }
+
+  template <typename IoObjectService1>
+  basic_io_object(IoObjectService1& other_service,
+      typename IoObjectService1::implementation_type& other_implementation)
+    : service_(&asio::use_service<IoObjectService>(
+          other_service.get_io_context()))
+  {
+    service_->converting_move_construct(implementation_,
+        other_service, other_implementation);
+  }
+
+  ~basic_io_object()
+  {
+    service_->destroy(implementation_);
+  }
+
+  basic_io_object& operator=(basic_io_object&& other)
+  {
+    service_->move_assign(implementation_,
+        *other.service_, other.implementation_);
+    service_ = other.service_;
+    return *this;
+  }
+
+  service_type& get_service()
+  {
+    return *service_;
+  }
+
+  const service_type& get_service() const
+  {
+    return *service_;
+  }
+
+  implementation_type& get_implementation()
+  {
+    return implementation_;
+  }
+
+  const implementation_type& get_implementation() const
+  {
+    return implementation_;
+  }
+
+private:
+  basic_io_object(const basic_io_object&);
+  void operator=(const basic_io_object&);
+
+  IoObjectService* service_;
+  implementation_type implementation_;
+};
+#endif // defined(ASIO_HAS_MOVE)
+
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // ASIO_BASIC_IO_OBJECT_HPP

lib/asio/include/asio/basic_random_access_file.hpp

@@ -0,0 +1,689 @@
+//
+// basic_random_access_file.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_BASIC_RANDOM_ACCESS_FILE_HPP
+#define ASIO_BASIC_RANDOM_ACCESS_FILE_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_HAS_FILE) \
+  || defined(GENERATING_DOCUMENTATION)
+
+#include <cstddef>
+#include "asio/async_result.hpp"
+#include "asio/basic_file.hpp"
+#include "asio/detail/handler_type_requirements.hpp"
+#include "asio/detail/non_const_lvalue.hpp"
+#include "asio/detail/throw_error.hpp"
+#include "asio/error.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+
+#if !defined(ASIO_BASIC_RANDOM_ACCESS_FILE_FWD_DECL)
+#define ASIO_BASIC_RANDOM_ACCESS_FILE_FWD_DECL
+
+// Forward declaration with defaulted arguments.
+template <typename Executor = any_io_executor>
+class basic_random_access_file;
+
+#endif // !defined(ASIO_BASIC_RANDOM_ACCESS_FILE_FWD_DECL)
+
+/// Provides random-access file functionality.
+/**
+ * The basic_random_access_file class template provides asynchronous and
+ * blocking random-access file functionality.
+ *
+ * @par Thread Safety
+ * @e Distinct @e objects: Safe.@n
+ * @e Shared @e objects: Unsafe.
+ *
+ * Synchronous @c read_some_at and @c write_some_at operations are thread safe
+ * with respect to each other, if the underlying operating system calls are
+ * also thread safe. This means that it is permitted to perform concurrent
+ * calls to these synchronous operations on a single file object. Other
+ * synchronous operations, such as @c open or @c close, are not thread safe.
+ */
+template <typename Executor>
+class basic_random_access_file
+  : public basic_file<Executor>
+{
+public:
+  /// The type of the executor associated with the object.
+  typedef Executor executor_type;
+
+  /// Rebinds the file type to another executor.
+  template <typename Executor1>
+  struct rebind_executor
+  {
+    /// The file type when rebound to the specified executor.
+    typedef basic_random_access_file<Executor1> other;
+  };
+
+  /// The native representation of a file.
+#if defined(GENERATING_DOCUMENTATION)
+  typedef implementation_defined native_handle_type;
+#else
+  typedef typename basic_file<Executor>::native_handle_type native_handle_type;
+#endif
+
+  /// Construct a basic_random_access_file without opening it.
+  /**
+   * This constructor initialises a file without opening it. The file needs to
+   * be opened before data can be read from or or written to it.
+   *
+   * @param ex The I/O executor that the file will use, by default, to
+   * dispatch handlers for any asynchronous operations performed on the file.
+   */
+  explicit basic_random_access_file(const executor_type& ex)
+    : basic_file<Executor>(ex)
+  {
+  }
+
+  /// Construct a basic_random_access_file without opening it.
+  /**
+   * This constructor initialises a file without opening it. The file needs to
+   * be opened before data can be read from or or written to it.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the file will use, by default, to dispatch handlers for any asynchronous
+   * operations performed on the file.
+   */
+  template <typename ExecutionContext>
+  explicit basic_random_access_file(ExecutionContext& context,
+      typename constraint<
+        is_convertible<ExecutionContext&, execution_context&>::value,
+        defaulted_constraint
+      >::type = defaulted_constraint())
+    : basic_file<Executor>(context)
+  {
+  }
+
+  /// Construct and open a basic_random_access_file.
+  /**
+   * This constructor initialises and opens a file.
+   *
+   * @param ex The I/O executor that the file will use, by default, to
+   * dispatch handlers for any asynchronous operations performed on the file.
+   *
+   * @param path The path name identifying the file to be opened.
+   *
+   * @param open_flags A set of flags that determine how the file should be
+   * opened.
+   *
+   * @throws asio::system_error Thrown on failure.
+   */
+  basic_random_access_file(const executor_type& ex,
+      const char* path, file_base::flags open_flags)
+    : basic_file<Executor>(ex, path, open_flags)
+  {
+  }
+
+  /// Construct and open a basic_random_access_file.
+  /**
+   * This constructor initialises and opens a file.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the file will use, by default, to dispatch handlers for any asynchronous
+   * operations performed on the file.
+   *
+   * @param path The path name identifying the file to be opened.
+   *
+   * @param open_flags A set of flags that determine how the file should be
+   * opened.
+   *
+   * @throws asio::system_error Thrown on failure.
+   */
+  template <typename ExecutionContext>
+  basic_random_access_file(ExecutionContext& context,
+      const char* path, file_base::flags open_flags,
+      typename constraint<
+        is_convertible<ExecutionContext&, execution_context&>::value,
+        defaulted_constraint
+      >::type = defaulted_constraint())
+    : basic_file<Executor>(context, path, open_flags)
+  {
+  }
+
+  /// Construct and open a basic_random_access_file.
+  /**
+   * This constructor initialises and opens a file.
+   *
+   * @param ex The I/O executor that the file will use, by default, to
+   * dispatch handlers for any asynchronous operations performed on the file.
+   *
+   * @param path The path name identifying the file to be opened.
+   *
+   * @param open_flags A set of flags that determine how the file should be
+   * opened.
+   *
+   * @throws asio::system_error Thrown on failure.
+   */
+  basic_random_access_file(const executor_type& ex,
+      const std::string& path, file_base::flags open_flags)
+    : basic_file<Executor>(ex, path, open_flags)
+  {
+  }
+
+  /// Construct and open a basic_random_access_file.
+  /**
+   * This constructor initialises and opens a file.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the file will use, by default, to dispatch handlers for any asynchronous
+   * operations performed on the file.
+   *
+   * @param path The path name identifying the file to be opened.
+   *
+   * @param open_flags A set of flags that determine how the file should be
+   * opened.
+   *
+   * @throws asio::system_error Thrown on failure.
+   */
+  template <typename ExecutionContext>
+  basic_random_access_file(ExecutionContext& context,
+      const std::string& path, file_base::flags open_flags,
+      typename constraint<
+        is_convertible<ExecutionContext&, execution_context&>::value,
+        defaulted_constraint
+      >::type = defaulted_constraint())
+    : basic_file<Executor>(context, path, open_flags)
+  {
+  }
+
+  /// Construct a basic_random_access_file on an existing native file.
+  /**
+   * This constructor initialises a random-access file object to hold an
+   * existing native file.
+   *
+   * @param ex The I/O executor that the file will use, by default, to
+   * dispatch handlers for any asynchronous operations performed on the file.
+   *
+   * @param native_file The new underlying file implementation.
+   *
+   * @throws asio::system_error Thrown on failure.
+   */
+  basic_random_access_file(const executor_type& ex,
+      const native_handle_type& native_file)
+    : basic_file<Executor>(ex, native_file)
+  {
+  }
+
+  /// Construct a basic_random_access_file on an existing native file.
+  /**
+   * This constructor initialises a random-access file object to hold an
+   * existing native file.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the file will use, by default, to dispatch handlers for any asynchronous
+   * operations performed on the file.
+   *
+   * @param native_file The new underlying file implementation.
+   *
+   * @throws asio::system_error Thrown on failure.
+   */
+  template <typename ExecutionContext>
+  basic_random_access_file(ExecutionContext& context,
+      const native_handle_type& native_file,
+      typename constraint<
+        is_convertible<ExecutionContext&, execution_context&>::value,
+        defaulted_constraint
+      >::type = defaulted_constraint())
+    : basic_file<Executor>(context, native_file)
+  {
+  }
+
+#if defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+  /// Move-construct a basic_random_access_file from another.
+  /**
+   * This constructor moves a random-access file from one object to another.
+   *
+   * @param other The other basic_random_access_file object from which the move
+   * will occur.
+   *
+   * @note Following the move, the moved-from object is in the same state as if
+   * constructed using the @c basic_random_access_file(const executor_type&)
+   * constructor.
+   */
+  basic_random_access_file(basic_random_access_file&& other) ASIO_NOEXCEPT
+    : basic_file<Executor>(std::move(other))
+  {
+  }
+
+  /// Move-assign a basic_random_access_file from another.
+  /**
+   * This assignment operator moves a random-access file from one object to
+   * another.
+   *
+   * @param other The other basic_random_access_file object from which the move
+   * will occur.
+   *
+   * @note Following the move, the moved-from object is in the same state as if
+   * constructed using the @c basic_random_access_file(const executor_type&)
+   * constructor.
+   */
+  basic_random_access_file& operator=(basic_random_access_file&& other)
+  {
+    basic_file<Executor>::operator=(std::move(other));
+    return *this;
+  }
+
+  /// Move-construct a basic_random_access_file from a file of another executor
+  /// type.
+  /**
+   * This constructor moves a random-access file from one object to another.
+   *
+   * @param other The other basic_random_access_file object from which the move
+   * will occur.
+   *
+   * @note Following the move, the moved-from object is in the same state as if
+   * constructed using the @c basic_random_access_file(const executor_type&)
+   * constructor.
+   */
+  template <typename Executor1>
+  basic_random_access_file(basic_random_access_file<Executor1>&& other,
+      typename constraint<
+        is_convertible<Executor1, Executor>::value,
+        defaulted_constraint
+      >::type = defaulted_constraint())
+    : basic_file<Executor>(std::move(other))
+  {
+  }
+
+  /// Move-assign a basic_random_access_file from a file of another executor
+  /// type.
+  /**
+   * This assignment operator moves a random-access file from one object to
+   * another.
+   *
+   * @param other The other basic_random_access_file object from which the move
+   * will occur.
+   *
+   * @note Following the move, the moved-from object is in the same state as if
+   * constructed using the @c basic_random_access_file(const executor_type&)
+   * constructor.
+   */
+  template <typename Executor1>
+  typename constraint<
+    is_convertible<Executor1, Executor>::value,
+    basic_random_access_file&
+  >::type operator=(basic_random_access_file<Executor1>&& other)
+  {
+    basic_file<Executor>::operator=(std::move(other));
+    return *this;
+  }
+#endif // defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+
+  /// Destroys the file.
+  /**
+   * This function destroys the file, cancelling any outstanding asynchronous
+   * operations associated with the file as if by calling @c cancel.
+   */
+  ~basic_random_access_file()
+  {
+  }
+
+  /// Write some data to the handle at the specified offset.
+  /**
+   * This function is used to write data to the random-access handle. The
+   * function call will block until one or more bytes of the data has been
+   * written successfully, or until an error occurs.
+   *
+   * @param offset The offset at which the data will be written.
+   *
+   * @param buffers One or more data buffers to be written to the handle.
+   *
+   * @returns The number of bytes written.
+   *
+   * @throws asio::system_error Thrown on failure. An error code of
+   * asio::error::eof indicates that the end of the file was reached.
+   *
+   * @note The write_some_at operation may not write all of the data. Consider
+   * using the @ref write_at function if you need to ensure that all data is
+   * written before the blocking operation completes.
+   *
+   * @par Example
+   * To write a single data buffer use the @ref buffer function as follows:
+   * @code
+   * handle.write_some_at(42, asio::buffer(data, size));
+   * @endcode
+   * See the @ref buffer documentation for information on writing multiple
+   * buffers in one go, and how to use it with arrays, boost::array or
+   * std::vector.
+   */
+  template <typename ConstBufferSequence>
+  std::size_t write_some_at(uint64_t offset,
+      const ConstBufferSequence& buffers)
+  {
+    asio::error_code ec;
+    std::size_t s = this->impl_.get_service().write_some_at(
+        this->impl_.get_implementation(), offset, buffers, ec);
+    asio::detail::throw_error(ec, "write_some_at");
+    return s;
+  }
+
+  /// Write some data to the handle at the specified offset.
+  /**
+   * This function is used to write data to the random-access handle. The
+   * function call will block until one or more bytes of the data has been
+   * written successfully, or until an error occurs.
+   *
+   * @param offset The offset at which the data will be written.
+   *
+   * @param buffers One or more data buffers to be written to the handle.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @returns The number of bytes written. Returns 0 if an error occurred.
+   *
+   * @note The write_some operation may not write all of the data to the
+   * file. Consider using the @ref write_at function if you need to ensure that
+   * all data is written before the blocking operation completes.
+   */
+  template <typename ConstBufferSequence>
+  std::size_t write_some_at(uint64_t offset,
+      const ConstBufferSequence& buffers, asio::error_code& ec)
+  {
+    return this->impl_.get_service().write_some_at(
+        this->impl_.get_implementation(), offset, buffers, ec);
+  }
+
+  /// Start an asynchronous write at the specified offset.
+  /**
+   * This function is used to asynchronously write data to the random-access
+   * handle. It is an initiating function for an @ref asynchronous_operation,
+   * and always returns immediately.
+   *
+   * @param offset The offset at which the data will be written.
+   *
+   * @param buffers One or more data buffers to be written to the handle.
+   * Although the buffers object may be copied as necessary, ownership of the
+   * underlying memory blocks is retained by the caller, which must guarantee
+   * that they remain valid until the completion handler is called.
+   *
+   * @param token The @ref completion_token that will be used to produce a
+   * completion handler, which will be called when the write completes.
+   * Potential completion tokens include @ref use_future, @ref use_awaitable,
+   * @ref yield_context, or a function object with the correct completion
+   * signature. The function signature of the completion handler must be:
+   * @code void handler(
+   *   const asio::error_code& error, // Result of operation.
+   *   std::size_t bytes_transferred // Number of bytes written.
+   * ); @endcode
+   * Regardless of whether the asynchronous operation completes immediately or
+   * not, the completion handler will not be invoked from within this function.
+   * On immediate completion, invocation of the handler will be performed in a
+   * manner equivalent to using asio::post().
+   *
+   * @par Completion Signature
+   * @code void(asio::error_code, std::size_t) @endcode
+   *
+   * @note The write operation may not write all of the data to the file.
+   * Consider using the @ref async_write_at function if you need to ensure that
+   * all data is written before the asynchronous operation completes.
+   *
+   * @par Example
+   * To write a single data buffer use the @ref buffer function as follows:
+   * @code
+   * handle.async_write_some_at(42, asio::buffer(data, size), handler);
+   * @endcode
+   * See the @ref buffer documentation for information on writing multiple
+   * buffers in one go, and how to use it with arrays, boost::array or
+   * std::vector.
+   *
+   * @par Per-Operation Cancellation
+   * This asynchronous operation supports cancellation for the following
+   * asio::cancellation_type values:
+   *
+   * @li @c cancellation_type::terminal
+   *
+   * @li @c cancellation_type::partial
+   *
+   * @li @c cancellation_type::total
+   */
+  template <typename ConstBufferSequence,
+      ASIO_COMPLETION_TOKEN_FOR(void (asio::error_code,
+        std::size_t)) WriteToken
+          ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(executor_type)>
+  ASIO_INITFN_AUTO_RESULT_TYPE(WriteToken,
+      void (asio::error_code, std::size_t))
+  async_write_some_at(uint64_t offset,
+      const ConstBufferSequence& buffers,
+      ASIO_MOVE_ARG(WriteToken) token
+        ASIO_DEFAULT_COMPLETION_TOKEN(executor_type))
+  {
+    return async_initiate<WriteToken,
+      void (asio::error_code, std::size_t)>(
+        initiate_async_write_some_at(this), token, offset, buffers);
+  }
+
+  /// Read some data from the handle at the specified offset.
+  /**
+   * This function is used to read data from the random-access handle. The
+   * function call will block until one or more bytes of data has been read
+   * successfully, or until an error occurs.
+   *
+   * @param offset The offset at which the data will be read.
+   *
+   * @param buffers One or more buffers into which the data will be read.
+   *
+   * @returns The number of bytes read.
+   *
+   * @throws asio::system_error Thrown on failure. An error code of
+   * asio::error::eof indicates that the end of the file was reached.
+   *
+   * @note The read_some operation may not read all of the requested number of
+   * bytes. Consider using the @ref read_at function if you need to ensure that
+   * the requested amount of data is read before the blocking operation
+   * completes.
+   *
+   * @par Example
+   * To read into a single data buffer use the @ref buffer function as follows:
+   * @code
+   * handle.read_some_at(42, asio::buffer(data, size));
+   * @endcode
+   * See the @ref buffer documentation for information on reading into multiple
+   * buffers in one go, and how to use it with arrays, boost::array or
+   * std::vector.
+   */
+  template <typename MutableBufferSequence>
+  std::size_t read_some_at(uint64_t offset,
+      const MutableBufferSequence& buffers)
+  {
+    asio::error_code ec;
+    std::size_t s = this->impl_.get_service().read_some_at(
+        this->impl_.get_implementation(), offset, buffers, ec);
+    asio::detail::throw_error(ec, "read_some_at");
+    return s;
+  }
+
+  /// Read some data from the handle at the specified offset.
+  /**
+   * This function is used to read data from the random-access handle. The
+   * function call will block until one or more bytes of data has been read
+   * successfully, or until an error occurs.
+   *
+   * @param offset The offset at which the data will be read.
+   *
+   * @param buffers One or more buffers into which the data will be read.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @returns The number of bytes read. Returns 0 if an error occurred.
+   *
+   * @note The read_some operation may not read all of the requested number of
+   * bytes. Consider using the @ref read_at function if you need to ensure that
+   * the requested amount of data is read before the blocking operation
+   * completes.
+   */
+  template <typename MutableBufferSequence>
+  std::size_t read_some_at(uint64_t offset,
+      const MutableBufferSequence& buffers, asio::error_code& ec)
+  {
+    return this->impl_.get_service().read_some_at(
+        this->impl_.get_implementation(), offset, buffers, ec);
+  }
+
+  /// Start an asynchronous read at the specified offset.
+  /**
+   * This function is used to asynchronously read data from the random-access
+   * handle. It is an initiating function for an @ref asynchronous_operation,
+   * and always returns immediately.
+   *
+   * @param offset The offset at which the data will be read.
+   *
+   * @param buffers One or more buffers into which the data will be read.
+   * Although the buffers object may be copied as necessary, ownership of the
+   * underlying memory blocks is retained by the caller, which must guarantee
+   * that they remain valid until the completion handler is called.
+   *
+   * @param token The @ref completion_token that will be used to produce a
+   * completion handler, which will be called when the read completes.
+   * Potential completion tokens include @ref use_future, @ref use_awaitable,
+   * @ref yield_context, or a function object with the correct completion
+   * signature. The function signature of the completion handler must be:
+   * @code void handler(
+   *   const asio::error_code& error, // Result of operation.
+   *   std::size_t bytes_transferred // Number of bytes read.
+   * ); @endcode
+   * Regardless of whether the asynchronous operation completes immediately or
+   * not, the completion handler will not be invoked from within this function.
+   * On immediate completion, invocation of the handler will be performed in a
+   * manner equivalent to using asio::post().
+   *
+   * @par Completion Signature
+   * @code void(asio::error_code, std::size_t) @endcode
+   *
+   * @note The read operation may not read all of the requested number of bytes.
+   * Consider using the @ref async_read_at function if you need to ensure that
+   * the requested amount of data is read before the asynchronous operation
+   * completes.
+   *
+   * @par Example
+   * To read into a single data buffer use the @ref buffer function as follows:
+   * @code
+   * handle.async_read_some_at(42, asio::buffer(data, size), handler);
+   * @endcode
+   * See the @ref buffer documentation for information on reading into multiple
+   * buffers in one go, and how to use it with arrays, boost::array or
+   * std::vector.
+   *
+   * @par Per-Operation Cancellation
+   * This asynchronous operation supports cancellation for the following
+   * asio::cancellation_type values:
+   *
+   * @li @c cancellation_type::terminal
+   *
+   * @li @c cancellation_type::partial
+   *
+   * @li @c cancellation_type::total
+   */
+  template <typename MutableBufferSequence,
+      ASIO_COMPLETION_TOKEN_FOR(void (asio::error_code,
+        std::size_t)) ReadToken
+          ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(executor_type)>
+  ASIO_INITFN_AUTO_RESULT_TYPE(ReadToken,
+      void (asio::error_code, std::size_t))
+  async_read_some_at(uint64_t offset,
+      const MutableBufferSequence& buffers,
+      ASIO_MOVE_ARG(ReadToken) token
+        ASIO_DEFAULT_COMPLETION_TOKEN(executor_type))
+  {
+    return async_initiate<ReadToken,
+      void (asio::error_code, std::size_t)>(
+        initiate_async_read_some_at(this), token, offset, buffers);
+  }
+
+private:
+  // Disallow copying and assignment.
+  basic_random_access_file(const basic_random_access_file&) ASIO_DELETED;
+  basic_random_access_file& operator=(
+      const basic_random_access_file&) ASIO_DELETED;
+
+  class initiate_async_write_some_at
+  {
+  public:
+    typedef Executor executor_type;
+
+    explicit initiate_async_write_some_at(basic_random_access_file* self)
+      : self_(self)
+    {
+    }
+
+    executor_type get_executor() const ASIO_NOEXCEPT
+    {
+      return self_->get_executor();
+    }
+
+    template <typename WriteHandler, typename ConstBufferSequence>
+    void operator()(ASIO_MOVE_ARG(WriteHandler) handler,
+        uint64_t offset, const ConstBufferSequence& buffers) const
+    {
+      // If you get an error on the following line it means that your handler
+      // does not meet the documented type requirements for a WriteHandler.
+      ASIO_WRITE_HANDLER_CHECK(WriteHandler, handler) type_check;
+
+      detail::non_const_lvalue<WriteHandler> handler2(handler);
+      self_->impl_.get_service().async_write_some_at(
+          self_->impl_.get_implementation(), offset, buffers,
+          handler2.value, self_->impl_.get_executor());
+    }
+
+  private:
+    basic_random_access_file* self_;
+  };
+
+  class initiate_async_read_some_at
+  {
+  public:
+    typedef Executor executor_type;
+
+    explicit initiate_async_read_some_at(basic_random_access_file* self)
+      : self_(self)
+    {
+    }
+
+    executor_type get_executor() const ASIO_NOEXCEPT
+    {
+      return self_->get_executor();
+    }
+
+    template <typename ReadHandler, typename MutableBufferSequence>
+    void operator()(ASIO_MOVE_ARG(ReadHandler) handler,
+        uint64_t offset, const MutableBufferSequence& buffers) const
+    {
+      // If you get an error on the following line it means that your handler
+      // does not meet the documented type requirements for a ReadHandler.
+      ASIO_READ_HANDLER_CHECK(ReadHandler, handler) type_check;
+
+      detail::non_const_lvalue<ReadHandler> handler2(handler);
+      self_->impl_.get_service().async_read_some_at(
+          self_->impl_.get_implementation(), offset, buffers,
+          handler2.value, self_->impl_.get_executor());
+    }
+
+  private:
+    basic_random_access_file* self_;
+  };
+};
+
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // defined(ASIO_HAS_FILE)
+       //   || defined(GENERATING_DOCUMENTATION)
+
+#endif // ASIO_BASIC_RANDOM_ACCESS_FILE_HPP

lib/asio/include/asio/basic_readable_pipe.hpp

@@ -0,0 +1,529 @@
+//
+// basic_readable_pipe.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_BASIC_READABLE_PIPE_HPP
+#define ASIO_BASIC_READABLE_PIPE_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_HAS_PIPE) \
+  || defined(GENERATING_DOCUMENTATION)
+
+#include <string>
+#include "asio/any_io_executor.hpp"
+#include "asio/async_result.hpp"
+#include "asio/detail/handler_type_requirements.hpp"
+#include "asio/detail/io_object_impl.hpp"
+#include "asio/detail/non_const_lvalue.hpp"
+#include "asio/detail/throw_error.hpp"
+#include "asio/detail/type_traits.hpp"
+#include "asio/error.hpp"
+#include "asio/execution_context.hpp"
+#if defined(ASIO_HAS_IOCP)
+# include "asio/detail/win_iocp_handle_service.hpp"
+#elif defined(ASIO_HAS_IO_URING_AS_DEFAULT)
+# include "asio/detail/io_uring_descriptor_service.hpp"
+#else
+# include "asio/detail/reactive_descriptor_service.hpp"
+#endif
+
+#if defined(ASIO_HAS_MOVE)
+# include <utility>
+#endif // defined(ASIO_HAS_MOVE)
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+
+/// Provides pipe functionality.
+/**
+ * The basic_readable_pipe class provides a wrapper over pipe
+ * functionality.
+ *
+ * @par Thread Safety
+ * @e Distinct @e objects: Safe.@n
+ * @e Shared @e objects: Unsafe.
+ */
+template <typename Executor = any_io_executor>
+class basic_readable_pipe
+{
+public:
+  /// The type of the executor associated with the object.
+  typedef Executor executor_type;
+
+  /// Rebinds the pipe type to another executor.
+  template <typename Executor1>
+  struct rebind_executor
+  {
+    /// The pipe type when rebound to the specified executor.
+    typedef basic_readable_pipe<Executor1> other;
+  };
+
+  /// The native representation of a pipe.
+#if defined(GENERATING_DOCUMENTATION)
+  typedef implementation_defined native_handle_type;
+#elif defined(ASIO_HAS_IOCP)
+  typedef detail::win_iocp_handle_service::native_handle_type
+    native_handle_type;
+#elif defined(ASIO_HAS_IO_URING_AS_DEFAULT)
+  typedef detail::io_uring_descriptor_service::native_handle_type
+    native_handle_type;
+#else
+  typedef detail::reactive_descriptor_service::native_handle_type
+    native_handle_type;
+#endif
+
+  /// A basic_readable_pipe is always the lowest layer.
+  typedef basic_readable_pipe lowest_layer_type;
+
+  /// Construct a basic_readable_pipe without opening it.
+  /**
+   * This constructor creates a pipe without opening it.
+   *
+   * @param ex The I/O executor that the pipe will use, by default, to dispatch
+   * handlers for any asynchronous operations performed on the pipe.
+   */
+  explicit basic_readable_pipe(const executor_type& ex)
+    : impl_(0, ex)
+  {
+  }
+
+  /// Construct a basic_readable_pipe without opening it.
+  /**
+   * This constructor creates a pipe without opening it.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the pipe will use, by default, to dispatch handlers for any asynchronous
+   * operations performed on the pipe.
+   */
+  template <typename ExecutionContext>
+  explicit basic_readable_pipe(ExecutionContext& context,
+      typename constraint<
+        is_convertible<ExecutionContext&, execution_context&>::value,
+        defaulted_constraint
+      >::type = defaulted_constraint())
+    : impl_(0, 0, context)
+  {
+  }
+
+  /// Construct a basic_readable_pipe on an existing native pipe.
+  /**
+   * This constructor creates a pipe object to hold an existing native
+   * pipe.
+   *
+   * @param ex The I/O executor that the pipe will use, by default, to
+   * dispatch handlers for any asynchronous operations performed on the
+   * pipe.
+   *
+   * @param native_pipe A native pipe.
+   *
+   * @throws asio::system_error Thrown on failure.
+   */
+  basic_readable_pipe(const executor_type& ex,
+      const native_handle_type& native_pipe)
+    : impl_(0, ex)
+  {
+    asio::error_code ec;
+    impl_.get_service().assign(impl_.get_implementation(),
+        native_pipe, ec);
+    asio::detail::throw_error(ec, "assign");
+  }
+
+  /// Construct a basic_readable_pipe on an existing native pipe.
+  /**
+   * This constructor creates a pipe object to hold an existing native
+   * pipe.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the pipe will use, by default, to dispatch handlers for any
+   * asynchronous operations performed on the pipe.
+   *
+   * @param native_pipe A native pipe.
+   *
+   * @throws asio::system_error Thrown on failure.
+   */
+  template <typename ExecutionContext>
+  basic_readable_pipe(ExecutionContext& context,
+      const native_handle_type& native_pipe,
+      typename constraint<
+        is_convertible<ExecutionContext&, execution_context&>::value
+      >::type = 0)
+    : impl_(0, 0, context)
+  {
+    asio::error_code ec;
+    impl_.get_service().assign(impl_.get_implementation(),
+        native_pipe, ec);
+    asio::detail::throw_error(ec, "assign");
+  }
+
+#if defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+  /// Move-construct a basic_readable_pipe from another.
+  /**
+   * This constructor moves a pipe from one object to another.
+   *
+   * @param other The other basic_readable_pipe object from which the move will
+   * occur.
+   *
+   * @note Following the move, the moved-from object is in the same state as if
+   * constructed using the @c basic_readable_pipe(const executor_type&)
+   * constructor.
+   */
+  basic_readable_pipe(basic_readable_pipe&& other)
+    : impl_(std::move(other.impl_))
+  {
+  }
+
+  /// Move-assign a basic_readable_pipe from another.
+  /**
+   * This assignment operator moves a pipe from one object to another.
+   *
+   * @param other The other basic_readable_pipe object from which the move will
+   * occur.
+   *
+   * @note Following the move, the moved-from object is in the same state as if
+   * constructed using the @c basic_readable_pipe(const executor_type&)
+   * constructor.
+   */
+  basic_readable_pipe& operator=(basic_readable_pipe&& other)
+  {
+    impl_ = std::move(other.impl_);
+    return *this;
+  }
+#endif // defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+
+  /// Destroys the pipe.
+  /**
+   * This function destroys the pipe, cancelling any outstanding
+   * asynchronous wait operations associated with the pipe as if by
+   * calling @c cancel.
+   */
+  ~basic_readable_pipe()
+  {
+  }
+
+  /// Get the executor associated with the object.
+  executor_type get_executor() ASIO_NOEXCEPT
+  {
+    return impl_.get_executor();
+  }
+
+  /// Get a reference to the lowest layer.
+  /**
+   * This function returns a reference to the lowest layer in a stack of
+   * layers. Since a basic_readable_pipe cannot contain any further layers, it
+   * simply returns a reference to itself.
+   *
+   * @return A reference to the lowest layer in the stack of layers. Ownership
+   * is not transferred to the caller.
+   */
+  lowest_layer_type& lowest_layer()
+  {
+    return *this;
+  }
+
+  /// Get a const reference to the lowest layer.
+  /**
+   * This function returns a const reference to the lowest layer in a stack of
+   * layers. Since a basic_readable_pipe cannot contain any further layers, it
+   * simply returns a reference to itself.
+   *
+   * @return A const reference to the lowest layer in the stack of layers.
+   * Ownership is not transferred to the caller.
+   */
+  const lowest_layer_type& lowest_layer() const
+  {
+    return *this;
+  }
+
+  /// Assign an existing native pipe to the pipe.
+  /*
+   * This function opens the pipe to hold an existing native pipe.
+   *
+   * @param native_pipe A native pipe.
+   *
+   * @throws asio::system_error Thrown on failure.
+   */
+  void assign(const native_handle_type& native_pipe)
+  {
+    asio::error_code ec;
+    impl_.get_service().assign(impl_.get_implementation(), native_pipe, ec);
+    asio::detail::throw_error(ec, "assign");
+  }
+
+  /// Assign an existing native pipe to the pipe.
+  /*
+   * This function opens the pipe to hold an existing native pipe.
+   *
+   * @param native_pipe A native pipe.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   */
+  ASIO_SYNC_OP_VOID assign(const native_handle_type& native_pipe,
+      asio::error_code& ec)
+  {
+    impl_.get_service().assign(impl_.get_implementation(), native_pipe, ec);
+    ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Determine whether the pipe is open.
+  bool is_open() const
+  {
+    return impl_.get_service().is_open(impl_.get_implementation());
+  }
+
+  /// Close the pipe.
+  /**
+   * This function is used to close the pipe. Any asynchronous read operations
+   * will be cancelled immediately, and will complete with the
+   * asio::error::operation_aborted error.
+   *
+   * @throws asio::system_error Thrown on failure.
+   */
+  void close()
+  {
+    asio::error_code ec;
+    impl_.get_service().close(impl_.get_implementation(), ec);
+    asio::detail::throw_error(ec, "close");
+  }
+
+  /// Close the pipe.
+  /**
+   * This function is used to close the pipe. Any asynchronous read operations
+   * will be cancelled immediately, and will complete with the
+   * asio::error::operation_aborted error.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   */
+  ASIO_SYNC_OP_VOID close(asio::error_code& ec)
+  {
+    impl_.get_service().close(impl_.get_implementation(), ec);
+    ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Get the native pipe representation.
+  /**
+   * This function may be used to obtain the underlying representation of the
+   * pipe. This is intended to allow access to native pipe
+   * functionality that is not otherwise provided.
+   */
+  native_handle_type native_handle()
+  {
+    return impl_.get_service().native_handle(impl_.get_implementation());
+  }
+
+  /// Cancel all asynchronous operations associated with the pipe.
+  /**
+   * This function causes all outstanding asynchronous read operations to finish
+   * immediately, and the handlers for cancelled operations will be passed the
+   * asio::error::operation_aborted error.
+   *
+   * @throws asio::system_error Thrown on failure.
+   */
+  void cancel()
+  {
+    asio::error_code ec;
+    impl_.get_service().cancel(impl_.get_implementation(), ec);
+    asio::detail::throw_error(ec, "cancel");
+  }
+
+  /// Cancel all asynchronous operations associated with the pipe.
+  /**
+   * This function causes all outstanding asynchronous read operations to finish
+   * immediately, and the handlers for cancelled operations will be passed the
+   * asio::error::operation_aborted error.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   */
+  ASIO_SYNC_OP_VOID cancel(asio::error_code& ec)
+  {
+    impl_.get_service().cancel(impl_.get_implementation(), ec);
+    ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Read some data from the pipe.
+  /**
+   * This function is used to read data from the pipe. The function call will
+   * block until one or more bytes of data has been read successfully, or until
+   * an error occurs.
+   *
+   * @param buffers One or more buffers into which the data will be read.
+   *
+   * @returns The number of bytes read.
+   *
+   * @throws asio::system_error Thrown on failure. An error code of
+   * asio::error::eof indicates that the connection was closed by the
+   * peer.
+   *
+   * @note The read_some operation may not read all of the requested number of
+   * bytes. Consider using the @ref read function if you need to ensure that
+   * the requested amount of data is read before the blocking operation
+   * completes.
+   *
+   * @par Example
+   * To read into a single data buffer use the @ref buffer function as follows:
+   * @code
+   * basic_readable_pipe.read_some(asio::buffer(data, size));
+   * @endcode
+   * See the @ref buffer documentation for information on reading into multiple
+   * buffers in one go, and how to use it with arrays, boost::array or
+   * std::vector.
+   */
+  template <typename MutableBufferSequence>
+  std::size_t read_some(const MutableBufferSequence& buffers)
+  {
+    asio::error_code ec;
+    std::size_t s = impl_.get_service().read_some(
+        impl_.get_implementation(), buffers, ec);
+    asio::detail::throw_error(ec, "read_some");
+    return s;
+  }
+
+  /// Read some data from the pipe.
+  /**
+   * This function is used to read data from the pipe. The function call will
+   * block until one or more bytes of data has been read successfully, or until
+   * an error occurs.
+   *
+   * @param buffers One or more buffers into which the data will be read.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @returns The number of bytes read. Returns 0 if an error occurred.
+   *
+   * @note The read_some operation may not read all of the requested number of
+   * bytes. Consider using the @ref read function if you need to ensure that
+   * the requested amount of data is read before the blocking operation
+   * completes.
+   */
+  template <typename MutableBufferSequence>
+  std::size_t read_some(const MutableBufferSequence& buffers,
+      asio::error_code& ec)
+  {
+    return impl_.get_service().read_some(
+        impl_.get_implementation(), buffers, ec);
+  }
+
+  /// Start an asynchronous read.
+  /**
+   * This function is used to asynchronously read data from the pipe. It is an
+   * initiating function for an @ref asynchronous_operation, and always returns
+   * immediately.
+   *
+   * @param buffers One or more buffers into which the data will be read.
+   * Although the buffers object may be copied as necessary, ownership of the
+   * underlying memory blocks is retained by the caller, which must guarantee
+   * that they remain valid until the completion handler is called.
+   *
+   * @param token The @ref completion_token that will be used to produce a
+   * completion handler, which will be called when the read completes.
+   * Potential completion tokens include @ref use_future, @ref use_awaitable,
+   * @ref yield_context, or a function object with the correct completion
+   * signature. The function signature of the completion handler must be:
+   * @code void handler(
+   *   const asio::error_code& error, // Result of operation.
+   *   std::size_t bytes_transferred // Number of bytes read.
+   * ); @endcode
+   * Regardless of whether the asynchronous operation completes immediately or
+   * not, the completion handler will not be invoked from within this function.
+   * On immediate completion, invocation of the handler will be performed in a
+   * manner equivalent to using asio::post().
+   *
+   * @par Completion Signature
+   * @code void(asio::error_code, std::size_t) @endcode
+   *
+   * @note The read operation may not read all of the requested number of bytes.
+   * Consider using the @ref async_read function if you need to ensure that the
+   * requested amount of data is read before the asynchronous operation
+   * completes.
+   *
+   * @par Example
+   * To read into a single data buffer use the @ref buffer function as follows:
+   * @code
+   * basic_readable_pipe.async_read_some(
+   *     asio::buffer(data, size), handler);
+   * @endcode
+   * See the @ref buffer documentation for information on reading into multiple
+   * buffers in one go, and how to use it with arrays, boost::array or
+   * std::vector.
+   */
+  template <typename MutableBufferSequence,
+      ASIO_COMPLETION_TOKEN_FOR(void (asio::error_code,
+        std::size_t)) ReadToken
+          ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(executor_type)>
+  ASIO_INITFN_AUTO_RESULT_TYPE(ReadToken,
+      void (asio::error_code, std::size_t))
+  async_read_some(const MutableBufferSequence& buffers,
+      ASIO_MOVE_ARG(ReadToken) token
+        ASIO_DEFAULT_COMPLETION_TOKEN(executor_type))
+  {
+    return async_initiate<ReadToken,
+      void (asio::error_code, std::size_t)>(
+        initiate_async_read_some(this), token, buffers);
+  }
+
+private:
+  // Disallow copying and assignment.
+  basic_readable_pipe(const basic_readable_pipe&) ASIO_DELETED;
+  basic_readable_pipe& operator=(const basic_readable_pipe&) ASIO_DELETED;
+
+  class initiate_async_read_some
+  {
+  public:
+    typedef Executor executor_type;
+
+    explicit initiate_async_read_some(basic_readable_pipe* self)
+      : self_(self)
+    {
+    }
+
+    executor_type get_executor() const ASIO_NOEXCEPT
+    {
+      return self_->get_executor();
+    }
+
+    template <typename ReadHandler, typename MutableBufferSequence>
+    void operator()(ASIO_MOVE_ARG(ReadHandler) handler,
+        const MutableBufferSequence& buffers) const
+    {
+      // If you get an error on the following line it means that your handler
+      // does not meet the documented type requirements for a ReadHandler.
+      ASIO_READ_HANDLER_CHECK(ReadHandler, handler) type_check;
+
+      detail::non_const_lvalue<ReadHandler> handler2(handler);
+      self_->impl_.get_service().async_read_some(
+          self_->impl_.get_implementation(), buffers,
+          handler2.value, self_->impl_.get_executor());
+    }
+
+  private:
+    basic_readable_pipe* self_;
+  };
+
+#if defined(ASIO_HAS_IOCP)
+  detail::io_object_impl<detail::win_iocp_handle_service, Executor> impl_;
+#elif defined(ASIO_HAS_IO_URING_AS_DEFAULT)
+  detail::io_object_impl<detail::io_uring_descriptor_service, Executor> impl_;
+#else
+  detail::io_object_impl<detail::reactive_descriptor_service, Executor> impl_;
+#endif
+};
+
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // defined(ASIO_HAS_PIPE)
+       //   || defined(GENERATING_DOCUMENTATION)
+
+#endif // ASIO_BASIC_READABLE_PIPE_HPP

lib/asio/include/asio/basic_seq_packet_socket.hpp

@@ -0,0 +1,816 @@
+//
+// basic_seq_packet_socket.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_BASIC_SEQ_PACKET_SOCKET_HPP
+#define ASIO_BASIC_SEQ_PACKET_SOCKET_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+#include <cstddef>
+#include "asio/basic_socket.hpp"
+#include "asio/detail/handler_type_requirements.hpp"
+#include "asio/detail/throw_error.hpp"
+#include "asio/error.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+
+#if !defined(ASIO_BASIC_SEQ_PACKET_SOCKET_FWD_DECL)
+#define ASIO_BASIC_SEQ_PACKET_SOCKET_FWD_DECL
+
+// Forward declaration with defaulted arguments.
+template <typename Protocol, typename Executor = any_io_executor>
+class basic_seq_packet_socket;
+
+#endif // !defined(ASIO_BASIC_SEQ_PACKET_SOCKET_FWD_DECL)
+
+/// Provides sequenced packet socket functionality.
+/**
+ * The basic_seq_packet_socket class template provides asynchronous and blocking
+ * sequenced packet socket functionality.
+ *
+ * @par Thread Safety
+ * @e Distinct @e objects: Safe.@n
+ * @e Shared @e objects: Unsafe.
+ *
+ * Synchronous @c send, @c receive, and @c connect operations are thread safe
+ * with respect to each other, if the underlying operating system calls are
+ * also thread safe. This means that it is permitted to perform concurrent
+ * calls to these synchronous operations on a single socket object. Other
+ * synchronous operations, such as @c open or @c close, are not thread safe.
+ */
+template <typename Protocol, typename Executor>
+class basic_seq_packet_socket
+  : public basic_socket<Protocol, Executor>
+{
+public:
+  /// The type of the executor associated with the object.
+  typedef Executor executor_type;
+
+  /// Rebinds the socket type to another executor.
+  template <typename Executor1>
+  struct rebind_executor
+  {
+    /// The socket type when rebound to the specified executor.
+    typedef basic_seq_packet_socket<Protocol, Executor1> other;
+  };
+
+  /// The native representation of a socket.
+#if defined(GENERATING_DOCUMENTATION)
+  typedef implementation_defined native_handle_type;
+#else
+  typedef typename basic_socket<Protocol,
+    Executor>::native_handle_type native_handle_type;
+#endif
+
+  /// The protocol type.
+  typedef Protocol protocol_type;
+
+  /// The endpoint type.
+  typedef typename Protocol::endpoint endpoint_type;
+
+  /// Construct a basic_seq_packet_socket without opening it.
+  /**
+   * This constructor creates a sequenced packet socket without opening it. The
+   * socket needs to be opened and then connected or accepted before data can
+   * be sent or received on it.
+   *
+   * @param ex The I/O executor that the socket will use, by default, to
+   * dispatch handlers for any asynchronous operations performed on the socket.
+   */
+  explicit basic_seq_packet_socket(const executor_type& ex)
+    : basic_socket<Protocol, Executor>(ex)
+  {
+  }
+
+  /// Construct a basic_seq_packet_socket without opening it.
+  /**
+   * This constructor creates a sequenced packet socket without opening it. The
+   * socket needs to be opened and then connected or accepted before data can
+   * be sent or received on it.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the socket will use, by default, to dispatch handlers for any asynchronous
+   * operations performed on the socket.
+   */
+  template <typename ExecutionContext>
+  explicit basic_seq_packet_socket(ExecutionContext& context,
+      typename constraint<
+        is_convertible<ExecutionContext&, execution_context&>::value
+      >::type = 0)
+    : basic_socket<Protocol, Executor>(context)
+  {
+  }
+
+  /// Construct and open a basic_seq_packet_socket.
+  /**
+   * This constructor creates and opens a sequenced_packet socket. The socket
+   * needs to be connected or accepted before data can be sent or received on
+   * it.
+   *
+   * @param ex The I/O executor that the socket will use, by default, to
+   * dispatch handlers for any asynchronous operations performed on the socket.
+   *
+   * @param protocol An object specifying protocol parameters to be used.
+   *
+   * @throws asio::system_error Thrown on failure.
+   */
+  basic_seq_packet_socket(const executor_type& ex,
+      const protocol_type& protocol)
+    : basic_socket<Protocol, Executor>(ex, protocol)
+  {
+  }
+
+  /// Construct and open a basic_seq_packet_socket.
+  /**
+   * This constructor creates and opens a sequenced_packet socket. The socket
+   * needs to be connected or accepted before data can be sent or received on
+   * it.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the socket will use, by default, to dispatch handlers for any asynchronous
+   * operations performed on the socket.
+   *
+   * @param protocol An object specifying protocol parameters to be used.
+   *
+   * @throws asio::system_error Thrown on failure.
+   */
+  template <typename ExecutionContext>
+  basic_seq_packet_socket(ExecutionContext& context,
+      const protocol_type& protocol,
+      typename constraint<
+        is_convertible<ExecutionContext&, execution_context&>::value,
+        defaulted_constraint
+      >::type = defaulted_constraint())
+    : basic_socket<Protocol, Executor>(context, protocol)
+  {
+  }
+
+  /// Construct a basic_seq_packet_socket, opening it and binding it to the
+  /// given local endpoint.
+  /**
+   * This constructor creates a sequenced packet socket and automatically opens
+   * it bound to the specified endpoint on the local machine. The protocol used
+   * is the protocol associated with the given endpoint.
+   *
+   * @param ex The I/O executor that the socket will use, by default, to
+   * dispatch handlers for any asynchronous operations performed on the socket.
+   *
+   * @param endpoint An endpoint on the local machine to which the sequenced
+   * packet socket will be bound.
+   *
+   * @throws asio::system_error Thrown on failure.
+   */
+  basic_seq_packet_socket(const executor_type& ex,
+      const endpoint_type& endpoint)
+    : basic_socket<Protocol, Executor>(ex, endpoint)
+  {
+  }
+
+  /// Construct a basic_seq_packet_socket, opening it and binding it to the
+  /// given local endpoint.
+  /**
+   * This constructor creates a sequenced packet socket and automatically opens
+   * it bound to the specified endpoint on the local machine. The protocol used
+   * is the protocol associated with the given endpoint.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the socket will use, by default, to dispatch handlers for any asynchronous
+   * operations performed on the socket.
+   *
+   * @param endpoint An endpoint on the local machine to which the sequenced
+   * packet socket will be bound.
+   *
+   * @throws asio::system_error Thrown on failure.
+   */
+  template <typename ExecutionContext>
+  basic_seq_packet_socket(ExecutionContext& context,
+      const endpoint_type& endpoint,
+      typename constraint<
+        is_convertible<ExecutionContext&, execution_context&>::value
+      >::type = 0)
+    : basic_socket<Protocol, Executor>(context, endpoint)
+  {
+  }
+
+  /// Construct a basic_seq_packet_socket on an existing native socket.
+  /**
+   * This constructor creates a sequenced packet socket object to hold an
+   * existing native socket.
+   *
+   * @param ex The I/O executor that the socket will use, by default, to
+   * dispatch handlers for any asynchronous operations performed on the socket.
+   *
+   * @param protocol An object specifying protocol parameters to be used.
+   *
+   * @param native_socket The new underlying socket implementation.
+   *
+   * @throws asio::system_error Thrown on failure.
+   */
+  basic_seq_packet_socket(const executor_type& ex,
+      const protocol_type& protocol, const native_handle_type& native_socket)
+    : basic_socket<Protocol, Executor>(ex, protocol, native_socket)
+  {
+  }
+
+  /// Construct a basic_seq_packet_socket on an existing native socket.
+  /**
+   * This constructor creates a sequenced packet socket object to hold an
+   * existing native socket.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the socket will use, by default, to dispatch handlers for any asynchronous
+   * operations performed on the socket.
+   *
+   * @param protocol An object specifying protocol parameters to be used.
+   *
+   * @param native_socket The new underlying socket implementation.
+   *
+   * @throws asio::system_error Thrown on failure.
+   */
+  template <typename ExecutionContext>
+  basic_seq_packet_socket(ExecutionContext& context,
+      const protocol_type& protocol, const native_handle_type& native_socket,
+      typename constraint<
+        is_convertible<ExecutionContext&, execution_context&>::value
+      >::type = 0)
+    : basic_socket<Protocol, Executor>(context, protocol, native_socket)
+  {
+  }
+
+#if defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+  /// Move-construct a basic_seq_packet_socket from another.
+  /**
+   * This constructor moves a sequenced packet socket from one object to
+   * another.
+   *
+   * @param other The other basic_seq_packet_socket object from which the move
+   * will occur.
+   *
+   * @note Following the move, the moved-from object is in the same state as if
+   * constructed using the @c basic_seq_packet_socket(const executor_type&)
+   * constructor.
+   */
+  basic_seq_packet_socket(basic_seq_packet_socket&& other) ASIO_NOEXCEPT
+    : basic_socket<Protocol, Executor>(std::move(other))
+  {
+  }
+
+  /// Move-assign a basic_seq_packet_socket from another.
+  /**
+   * This assignment operator moves a sequenced packet socket from one object to
+   * another.
+   *
+   * @param other The other basic_seq_packet_socket object from which the move
+   * will occur.
+   *
+   * @note Following the move, the moved-from object is in the same state as if
+   * constructed using the @c basic_seq_packet_socket(const executor_type&)
+   * constructor.
+   */
+  basic_seq_packet_socket& operator=(basic_seq_packet_socket&& other)
+  {
+    basic_socket<Protocol, Executor>::operator=(std::move(other));
+    return *this;
+  }
+
+  /// Move-construct a basic_seq_packet_socket from a socket of another protocol
+  /// type.
+  /**
+   * This constructor moves a sequenced packet socket from one object to
+   * another.
+   *
+   * @param other The other basic_seq_packet_socket object from which the move
+   * will occur.
+   *
+   * @note Following the move, the moved-from object is in the same state as if
+   * constructed using the @c basic_seq_packet_socket(const executor_type&)
+   * constructor.
+   */
+  template <typename Protocol1, typename Executor1>
+  basic_seq_packet_socket(basic_seq_packet_socket<Protocol1, Executor1>&& other,
+      typename constraint<
+        is_convertible<Protocol1, Protocol>::value
+          && is_convertible<Executor1, Executor>::value
+      >::type = 0)
+    : basic_socket<Protocol, Executor>(std::move(other))
+  {
+  }
+
+  /// Move-assign a basic_seq_packet_socket from a socket of another protocol
+  /// type.
+  /**
+   * This assignment operator moves a sequenced packet socket from one object to
+   * another.
+   *
+   * @param other The other basic_seq_packet_socket object from which the move
+   * will occur.
+   *
+   * @note Following the move, the moved-from object is in the same state as if
+   * constructed using the @c basic_seq_packet_socket(const executor_type&)
+   * constructor.
+   */
+  template <typename Protocol1, typename Executor1>
+  typename constraint<
+    is_convertible<Protocol1, Protocol>::value
+      && is_convertible<Executor1, Executor>::value,
+    basic_seq_packet_socket&
+  >::type operator=(basic_seq_packet_socket<Protocol1, Executor1>&& other)
+  {
+    basic_socket<Protocol, Executor>::operator=(std::move(other));
+    return *this;
+  }
+#endif // defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+
+  /// Destroys the socket.
+  /**
+   * This function destroys the socket, cancelling any outstanding asynchronous
+   * operations associated with the socket as if by calling @c cancel.
+   */
+  ~basic_seq_packet_socket()
+  {
+  }
+
+  /// Send some data on the socket.
+  /**
+   * This function is used to send data on the sequenced packet socket. The
+   * function call will block until the data has been sent successfully, or an
+   * until error occurs.
+   *
+   * @param buffers One or more data buffers to be sent on the socket.
+   *
+   * @param flags Flags specifying how the send call is to be made.
+   *
+   * @returns The number of bytes sent.
+   *
+   * @throws asio::system_error Thrown on failure.
+   *
+   * @par Example
+   * To send a single data buffer use the @ref buffer function as follows:
+   * @code
+   * socket.send(asio::buffer(data, size), 0);
+   * @endcode
+   * See the @ref buffer documentation for information on sending multiple
+   * buffers in one go, and how to use it with arrays, boost::array or
+   * std::vector.
+   */
+  template <typename ConstBufferSequence>
+  std::size_t send(const ConstBufferSequence& buffers,
+      socket_base::message_flags flags)
+  {
+    asio::error_code ec;
+    std::size_t s = this->impl_.get_service().send(
+        this->impl_.get_implementation(), buffers, flags, ec);
+    asio::detail::throw_error(ec, "send");
+    return s;
+  }
+
+  /// Send some data on the socket.
+  /**
+   * This function is used to send data on the sequenced packet socket. The
+   * function call will block the data has been sent successfully, or an until
+   * error occurs.
+   *
+   * @param buffers One or more data buffers to be sent on the socket.
+   *
+   * @param flags Flags specifying how the send call is to be made.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @returns The number of bytes sent. Returns 0 if an error occurred.
+   *
+   * @note The send operation may not transmit all of the data to the peer.
+   * Consider using the @ref write function if you need to ensure that all data
+   * is written before the blocking operation completes.
+   */
+  template <typename ConstBufferSequence>
+  std::size_t send(const ConstBufferSequence& buffers,
+      socket_base::message_flags flags, asio::error_code& ec)
+  {
+    return this->impl_.get_service().send(
+        this->impl_.get_implementation(), buffers, flags, ec);
+  }
+
+  /// Start an asynchronous send.
+  /**
+   * This function is used to asynchronously send data on the sequenced packet
+   * socket. It is an initiating function for an @ref asynchronous_operation,
+   * and always returns immediately.
+   *
+   * @param buffers One or more data buffers to be sent on the socket. Although
+   * the buffers object may be copied as necessary, ownership of the underlying
+   * memory blocks is retained by the caller, which must guarantee that they
+   * remain valid until the completion handler is called.
+   *
+   * @param flags Flags specifying how the send call is to be made.
+   *
+   * @param token The @ref completion_token that will be used to produce a
+   * completion handler, which will be called when the send completes.
+   * Potential completion tokens include @ref use_future, @ref use_awaitable,
+   * @ref yield_context, or a function object with the correct completion
+   * signature. The function signature of the completion handler must be:
+   * @code void handler(
+   *   const asio::error_code& error, // Result of operation.
+   *   std::size_t bytes_transferred // Number of bytes sent.
+   * ); @endcode
+   * Regardless of whether the asynchronous operation completes immediately or
+   * not, the completion handler will not be invoked from within this function.
+   * On immediate completion, invocation of the handler will be performed in a
+   * manner equivalent to using asio::post().
+   *
+   * @par Completion Signature
+   * @code void(asio::error_code, std::size_t) @endcode
+   *
+   * @par Example
+   * To send a single data buffer use the @ref buffer function as follows:
+   * @code
+   * socket.async_send(asio::buffer(data, size), 0, handler);
+   * @endcode
+   * See the @ref buffer documentation for information on sending multiple
+   * buffers in one go, and how to use it with arrays, boost::array or
+   * std::vector.
+   *
+   * @par Per-Operation Cancellation
+   * On POSIX or Windows operating systems, this asynchronous operation supports
+   * cancellation for the following asio::cancellation_type values:
+   *
+   * @li @c cancellation_type::terminal
+   *
+   * @li @c cancellation_type::partial
+   *
+   * @li @c cancellation_type::total
+   */
+  template <typename ConstBufferSequence,
+      ASIO_COMPLETION_TOKEN_FOR(void (asio::error_code,
+        std::size_t)) WriteToken
+          ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(executor_type)>
+  ASIO_INITFN_AUTO_RESULT_TYPE(WriteToken,
+      void (asio::error_code, std::size_t))
+  async_send(const ConstBufferSequence& buffers,
+      socket_base::message_flags flags,
+      ASIO_MOVE_ARG(WriteToken) token
+        ASIO_DEFAULT_COMPLETION_TOKEN(executor_type))
+  {
+    return async_initiate<WriteToken,
+      void (asio::error_code, std::size_t)>(
+        initiate_async_send(this), token, buffers, flags);
+  }
+
+  /// Receive some data on the socket.
+  /**
+   * This function is used to receive data on the sequenced packet socket. The
+   * function call will block until data has been received successfully, or
+   * until an error occurs.
+   *
+   * @param buffers One or more buffers into which the data will be received.
+   *
+   * @param out_flags After the receive call completes, contains flags
+   * associated with the received data. For example, if the
+   * socket_base::message_end_of_record bit is set then the received data marks
+   * the end of a record.
+   *
+   * @returns The number of bytes received.
+   *
+   * @throws asio::system_error Thrown on failure. An error code of
+   * asio::error::eof indicates that the connection was closed by the
+   * peer.
+   *
+   * @par Example
+   * To receive into a single data buffer use the @ref buffer function as
+   * follows:
+   * @code
+   * socket.receive(asio::buffer(data, size), out_flags);
+   * @endcode
+   * See the @ref buffer documentation for information on receiving into
+   * multiple buffers in one go, and how to use it with arrays, boost::array or
+   * std::vector.
+   */
+  template <typename MutableBufferSequence>
+  std::size_t receive(const MutableBufferSequence& buffers,
+      socket_base::message_flags& out_flags)
+  {
+    asio::error_code ec;
+    std::size_t s = this->impl_.get_service().receive_with_flags(
+        this->impl_.get_implementation(), buffers, 0, out_flags, ec);
+    asio::detail::throw_error(ec, "receive");
+    return s;
+  }
+
+  /// Receive some data on the socket.
+  /**
+   * This function is used to receive data on the sequenced packet socket. The
+   * function call will block until data has been received successfully, or
+   * until an error occurs.
+   *
+   * @param buffers One or more buffers into which the data will be received.
+   *
+   * @param in_flags Flags specifying how the receive call is to be made.
+   *
+   * @param out_flags After the receive call completes, contains flags
+   * associated with the received data. For example, if the
+   * socket_base::message_end_of_record bit is set then the received data marks
+   * the end of a record.
+   *
+   * @returns The number of bytes received.
+   *
+   * @throws asio::system_error Thrown on failure. An error code of
+   * asio::error::eof indicates that the connection was closed by the
+   * peer.
+   *
+   * @note The receive operation may not receive all of the requested number of
+   * bytes. Consider using the @ref read function if you need to ensure that the
+   * requested amount of data is read before the blocking operation completes.
+   *
+   * @par Example
+   * To receive into a single data buffer use the @ref buffer function as
+   * follows:
+   * @code
+   * socket.receive(asio::buffer(data, size), 0, out_flags);
+   * @endcode
+   * See the @ref buffer documentation for information on receiving into
+   * multiple buffers in one go, and how to use it with arrays, boost::array or
+   * std::vector.
+   */
+  template <typename MutableBufferSequence>
+  std::size_t receive(const MutableBufferSequence& buffers,
+      socket_base::message_flags in_flags,
+      socket_base::message_flags& out_flags)
+  {
+    asio::error_code ec;
+    std::size_t s = this->impl_.get_service().receive_with_flags(
+        this->impl_.get_implementation(), buffers, in_flags, out_flags, ec);
+    asio::detail::throw_error(ec, "receive");
+    return s;
+  }
+
+  /// Receive some data on a connected socket.
+  /**
+   * This function is used to receive data on the sequenced packet socket. The
+   * function call will block until data has been received successfully, or
+   * until an error occurs.
+   *
+   * @param buffers One or more buffers into which the data will be received.
+   *
+   * @param in_flags Flags specifying how the receive call is to be made.
+   *
+   * @param out_flags After the receive call completes, contains flags
+   * associated with the received data. For example, if the
+   * socket_base::message_end_of_record bit is set then the received data marks
+   * the end of a record.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @returns The number of bytes received. Returns 0 if an error occurred.
+   *
+   * @note The receive operation may not receive all of the requested number of
+   * bytes. Consider using the @ref read function if you need to ensure that the
+   * requested amount of data is read before the blocking operation completes.
+   */
+  template <typename MutableBufferSequence>
+  std::size_t receive(const MutableBufferSequence& buffers,
+      socket_base::message_flags in_flags,
+      socket_base::message_flags& out_flags, asio::error_code& ec)
+  {
+    return this->impl_.get_service().receive_with_flags(
+        this->impl_.get_implementation(), buffers, in_flags, out_flags, ec);
+  }
+
+  /// Start an asynchronous receive.
+  /**
+   * This function is used to asynchronously receive data from the sequenced
+   * packet socket. It is an initiating function for an @ref
+   * asynchronous_operation, and always returns immediately.
+   *
+   * @param buffers One or more buffers into which the data will be received.
+   * Although the buffers object may be copied as necessary, ownership of the
+   * underlying memory blocks is retained by the caller, which must guarantee
+   * that they remain valid until the completion handler is called.
+   *
+   * @param out_flags Once the asynchronous operation completes, contains flags
+   * associated with the received data. For example, if the
+   * socket_base::message_end_of_record bit is set then the received data marks
+   * the end of a record. The caller must guarantee that the referenced
+   * variable remains valid until the completion handler is called.
+   *
+   * @param token The @ref completion_token that will be used to produce a
+   * completion handler, which will be called when the receive completes.
+   * Potential completion tokens include @ref use_future, @ref use_awaitable,
+   * @ref yield_context, or a function object with the correct completion
+   * signature. The function signature of the completion handler must be:
+   * @code void handler(
+   *   const asio::error_code& error, // Result of operation.
+   *   std::size_t bytes_transferred // Number of bytes received.
+   * ); @endcode
+   * Regardless of whether the asynchronous operation completes immediately or
+   * not, the completion handler will not be invoked from within this function.
+   * On immediate completion, invocation of the handler will be performed in a
+   * manner equivalent to using asio::post().
+   *
+   * @par Completion Signature
+   * @code void(asio::error_code, std::size_t) @endcode
+   *
+   * @par Example
+   * To receive into a single data buffer use the @ref buffer function as
+   * follows:
+   * @code
+   * socket.async_receive(asio::buffer(data, size), out_flags, handler);
+   * @endcode
+   * See the @ref buffer documentation for information on receiving into
+   * multiple buffers in one go, and how to use it with arrays, boost::array or
+   * std::vector.
+   *
+   * @par Per-Operation Cancellation
+   * On POSIX or Windows operating systems, this asynchronous operation supports
+   * cancellation for the following asio::cancellation_type values:
+   *
+   * @li @c cancellation_type::terminal
+   *
+   * @li @c cancellation_type::partial
+   *
+   * @li @c cancellation_type::total
+   */
+  template <typename MutableBufferSequence,
+      ASIO_COMPLETION_TOKEN_FOR(void (asio::error_code,
+        std::size_t)) ReadToken
+          ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(executor_type)>
+  ASIO_INITFN_AUTO_RESULT_TYPE(ReadToken,
+      void (asio::error_code, std::size_t))
+  async_receive(const MutableBufferSequence& buffers,
+      socket_base::message_flags& out_flags,
+      ASIO_MOVE_ARG(ReadToken) token
+        ASIO_DEFAULT_COMPLETION_TOKEN(executor_type))
+  {
+    return async_initiate<ReadToken,
+      void (asio::error_code, std::size_t)>(
+        initiate_async_receive_with_flags(this), token,
+        buffers, socket_base::message_flags(0), &out_flags);
+  }
+
+  /// Start an asynchronous receive.
+  /**
+   * This function is used to asynchronously receive data from the sequenced
+   * data socket. It is an initiating function for an @ref
+   * asynchronous_operation, and always returns immediately.
+   *
+   * @param buffers One or more buffers into which the data will be received.
+   * Although the buffers object may be copied as necessary, ownership of the
+   * underlying memory blocks is retained by the caller, which must guarantee
+   * that they remain valid until the completion handler is called.
+   *
+   * @param in_flags Flags specifying how the receive call is to be made.
+   *
+   * @param out_flags Once the asynchronous operation completes, contains flags
+   * associated with the received data. For example, if the
+   * socket_base::message_end_of_record bit is set then the received data marks
+   * the end of a record. The caller must guarantee that the referenced
+   * variable remains valid until the completion handler is called.
+   *
+   * @param token The @ref completion_token that will be used to produce a
+   * completion handler, which will be called when the receive completes.
+   * Potential completion tokens include @ref use_future, @ref use_awaitable,
+   * @ref yield_context, or a function object with the correct completion
+   * signature. The function signature of the completion handler must be:
+   * @code void handler(
+   *   const asio::error_code& error, // Result of operation.
+   *   std::size_t bytes_transferred // Number of bytes received.
+   * ); @endcode
+   * Regardless of whether the asynchronous operation completes immediately or
+   * not, the completion handler will not be invoked from within this function.
+   * On immediate completion, invocation of the handler will be performed in a
+   * manner equivalent to using asio::post().
+   *
+   * @par Completion Signature
+   * @code void(asio::error_code, std::size_t) @endcode
+   *
+   * @par Example
+   * To receive into a single data buffer use the @ref buffer function as
+   * follows:
+   * @code
+   * socket.async_receive(
+   *     asio::buffer(data, size),
+   *     0, out_flags, handler);
+   * @endcode
+   * See the @ref buffer documentation for information on receiving into
+   * multiple buffers in one go, and how to use it with arrays, boost::array or
+   * std::vector.
+   *
+   * @par Per-Operation Cancellation
+   * On POSIX or Windows operating systems, this asynchronous operation supports
+   * cancellation for the following asio::cancellation_type values:
+   *
+   * @li @c cancellation_type::terminal
+   *
+   * @li @c cancellation_type::partial
+   *
+   * @li @c cancellation_type::total
+   */
+  template <typename MutableBufferSequence,
+      ASIO_COMPLETION_TOKEN_FOR(void (asio::error_code,
+        std::size_t)) ReadToken
+          ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(executor_type)>
+  ASIO_INITFN_AUTO_RESULT_TYPE(ReadToken,
+      void (asio::error_code, std::size_t))
+  async_receive(const MutableBufferSequence& buffers,
+      socket_base::message_flags in_flags,
+      socket_base::message_flags& out_flags,
+      ASIO_MOVE_ARG(ReadToken) token
+        ASIO_DEFAULT_COMPLETION_TOKEN(executor_type))
+  {
+    return async_initiate<ReadToken,
+      void (asio::error_code, std::size_t)>(
+        initiate_async_receive_with_flags(this),
+        token, buffers, in_flags, &out_flags);
+  }
+
+private:
+  // Disallow copying and assignment.
+  basic_seq_packet_socket(const basic_seq_packet_socket&) ASIO_DELETED;
+  basic_seq_packet_socket& operator=(
+      const basic_seq_packet_socket&) ASIO_DELETED;
+
+  class initiate_async_send
+  {
+  public:
+    typedef Executor executor_type;
+
+    explicit initiate_async_send(basic_seq_packet_socket* self)
+      : self_(self)
+    {
+    }
+
+    executor_type get_executor() const ASIO_NOEXCEPT
+    {
+      return self_->get_executor();
+    }
+
+    template <typename WriteHandler, typename ConstBufferSequence>
+    void operator()(ASIO_MOVE_ARG(WriteHandler) handler,
+        const ConstBufferSequence& buffers,
+        socket_base::message_flags flags) const
+    {
+      // If you get an error on the following line it means that your handler
+      // does not meet the documented type requirements for a WriteHandler.
+      ASIO_WRITE_HANDLER_CHECK(WriteHandler, handler) type_check;
+
+      detail::non_const_lvalue<WriteHandler> handler2(handler);
+      self_->impl_.get_service().async_send(
+          self_->impl_.get_implementation(), buffers, flags,
+          handler2.value, self_->impl_.get_executor());
+    }
+
+  private:
+    basic_seq_packet_socket* self_;
+  };
+
+  class initiate_async_receive_with_flags
+  {
+  public:
+    typedef Executor executor_type;
+
+    explicit initiate_async_receive_with_flags(basic_seq_packet_socket* self)
+      : self_(self)
+    {
+    }
+
+    executor_type get_executor() const ASIO_NOEXCEPT
+    {
+      return self_->get_executor();
+    }
+
+    template <typename ReadHandler, typename MutableBufferSequence>
+    void operator()(ASIO_MOVE_ARG(ReadHandler) handler,
+        const MutableBufferSequence& buffers,
+        socket_base::message_flags in_flags,
+        socket_base::message_flags* out_flags) const
+    {
+      // If you get an error on the following line it means that your handler
+      // does not meet the documented type requirements for a ReadHandler.
+      ASIO_READ_HANDLER_CHECK(ReadHandler, handler) type_check;
+
+      detail::non_const_lvalue<ReadHandler> handler2(handler);
+      self_->impl_.get_service().async_receive_with_flags(
+          self_->impl_.get_implementation(), buffers, in_flags,
+          *out_flags, handler2.value, self_->impl_.get_executor());
+    }
+
+  private:
+    basic_seq_packet_socket* self_;
+  };
+};
+
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // ASIO_BASIC_SEQ_PACKET_SOCKET_HPP

lib/asio/include/asio/basic_serial_port.hpp

@@ -0,0 +1,939 @@
+//
+// basic_serial_port.hpp
+// ~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+// Copyright (c) 2008 Rep Invariant Systems, Inc. (info@repinvariant.com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_BASIC_SERIAL_PORT_HPP
+#define ASIO_BASIC_SERIAL_PORT_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_HAS_SERIAL_PORT) \
+  || defined(GENERATING_DOCUMENTATION)
+
+#include <string>
+#include "asio/any_io_executor.hpp"
+#include "asio/async_result.hpp"
+#include "asio/detail/handler_type_requirements.hpp"
+#include "asio/detail/io_object_impl.hpp"
+#include "asio/detail/non_const_lvalue.hpp"
+#include "asio/detail/throw_error.hpp"
+#include "asio/detail/type_traits.hpp"
+#include "asio/error.hpp"
+#include "asio/execution_context.hpp"
+#include "asio/serial_port_base.hpp"
+#if defined(ASIO_HAS_IOCP)
+# include "asio/detail/win_iocp_serial_port_service.hpp"
+#else
+# include "asio/detail/posix_serial_port_service.hpp"
+#endif
+
+#if defined(ASIO_HAS_MOVE)
+# include <utility>
+#endif // defined(ASIO_HAS_MOVE)
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+
+/// Provides serial port functionality.
+/**
+ * The basic_serial_port class provides a wrapper over serial port
+ * functionality.
+ *
+ * @par Thread Safety
+ * @e Distinct @e objects: Safe.@n
+ * @e Shared @e objects: Unsafe.
+ */
+template <typename Executor = any_io_executor>
+class basic_serial_port
+  : public serial_port_base
+{
+public:
+  /// The type of the executor associated with the object.
+  typedef Executor executor_type;
+
+  /// Rebinds the serial port type to another executor.
+  template <typename Executor1>
+  struct rebind_executor
+  {
+    /// The serial port type when rebound to the specified executor.
+    typedef basic_serial_port<Executor1> other;
+  };
+
+  /// The native representation of a serial port.
+#if defined(GENERATING_DOCUMENTATION)
+  typedef implementation_defined native_handle_type;
+#elif defined(ASIO_HAS_IOCP)
+  typedef detail::win_iocp_serial_port_service::native_handle_type
+    native_handle_type;
+#else
+  typedef detail::posix_serial_port_service::native_handle_type
+    native_handle_type;
+#endif
+
+  /// A basic_basic_serial_port is always the lowest layer.
+  typedef basic_serial_port lowest_layer_type;
+
+  /// Construct a basic_serial_port without opening it.
+  /**
+   * This constructor creates a serial port without opening it.
+   *
+   * @param ex The I/O executor that the serial port will use, by default, to
+   * dispatch handlers for any asynchronous operations performed on the
+   * serial port.
+   */
+  explicit basic_serial_port(const executor_type& ex)
+    : impl_(0, ex)
+  {
+  }
+
+  /// Construct a basic_serial_port without opening it.
+  /**
+   * This constructor creates a serial port without opening it.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the serial port will use, by default, to dispatch handlers for any
+   * asynchronous operations performed on the serial port.
+   */
+  template <typename ExecutionContext>
+  explicit basic_serial_port(ExecutionContext& context,
+      typename constraint<
+        is_convertible<ExecutionContext&, execution_context&>::value,
+        defaulted_constraint
+      >::type = defaulted_constraint())
+    : impl_(0, 0, context)
+  {
+  }
+
+  /// Construct and open a basic_serial_port.
+  /**
+   * This constructor creates and opens a serial port for the specified device
+   * name.
+   *
+   * @param ex The I/O executor that the serial port will use, by default, to
+   * dispatch handlers for any asynchronous operations performed on the
+   * serial port.
+   *
+   * @param device The platform-specific device name for this serial
+   * port.
+   */
+  basic_serial_port(const executor_type& ex, const char* device)
+    : impl_(0, ex)
+  {
+    asio::error_code ec;
+    impl_.get_service().open(impl_.get_implementation(), device, ec);
+    asio::detail::throw_error(ec, "open");
+  }
+
+  /// Construct and open a basic_serial_port.
+  /**
+   * This constructor creates and opens a serial port for the specified device
+   * name.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the serial port will use, by default, to dispatch handlers for any
+   * asynchronous operations performed on the serial port.
+   *
+   * @param device The platform-specific device name for this serial
+   * port.
+   */
+  template <typename ExecutionContext>
+  basic_serial_port(ExecutionContext& context, const char* device,
+      typename constraint<
+        is_convertible<ExecutionContext&, execution_context&>::value
+      >::type = 0)
+    : impl_(0, 0, context)
+  {
+    asio::error_code ec;
+    impl_.get_service().open(impl_.get_implementation(), device, ec);
+    asio::detail::throw_error(ec, "open");
+  }
+
+  /// Construct and open a basic_serial_port.
+  /**
+   * This constructor creates and opens a serial port for the specified device
+   * name.
+   *
+   * @param ex The I/O executor that the serial port will use, by default, to
+   * dispatch handlers for any asynchronous operations performed on the
+   * serial port.
+   *
+   * @param device The platform-specific device name for this serial
+   * port.
+   */
+  basic_serial_port(const executor_type& ex, const std::string& device)
+    : impl_(0, ex)
+  {
+    asio::error_code ec;
+    impl_.get_service().open(impl_.get_implementation(), device, ec);
+    asio::detail::throw_error(ec, "open");
+  }
+
+  /// Construct and open a basic_serial_port.
+  /**
+   * This constructor creates and opens a serial port for the specified device
+   * name.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the serial port will use, by default, to dispatch handlers for any
+   * asynchronous operations performed on the serial port.
+   *
+   * @param device The platform-specific device name for this serial
+   * port.
+   */
+  template <typename ExecutionContext>
+  basic_serial_port(ExecutionContext& context, const std::string& device,
+      typename constraint<
+        is_convertible<ExecutionContext&, execution_context&>::value
+      >::type = 0)
+    : impl_(0, 0, context)
+  {
+    asio::error_code ec;
+    impl_.get_service().open(impl_.get_implementation(), device, ec);
+    asio::detail::throw_error(ec, "open");
+  }
+
+  /// Construct a basic_serial_port on an existing native serial port.
+  /**
+   * This constructor creates a serial port object to hold an existing native
+   * serial port.
+   *
+   * @param ex The I/O executor that the serial port will use, by default, to
+   * dispatch handlers for any asynchronous operations performed on the
+   * serial port.
+   *
+   * @param native_serial_port A native serial port.
+   *
+   * @throws asio::system_error Thrown on failure.
+   */
+  basic_serial_port(const executor_type& ex,
+      const native_handle_type& native_serial_port)
+    : impl_(0, ex)
+  {
+    asio::error_code ec;
+    impl_.get_service().assign(impl_.get_implementation(),
+        native_serial_port, ec);
+    asio::detail::throw_error(ec, "assign");
+  }
+
+  /// Construct a basic_serial_port on an existing native serial port.
+  /**
+   * This constructor creates a serial port object to hold an existing native
+   * serial port.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the serial port will use, by default, to dispatch handlers for any
+   * asynchronous operations performed on the serial port.
+   *
+   * @param native_serial_port A native serial port.
+   *
+   * @throws asio::system_error Thrown on failure.
+   */
+  template <typename ExecutionContext>
+  basic_serial_port(ExecutionContext& context,
+      const native_handle_type& native_serial_port,
+      typename constraint<
+        is_convertible<ExecutionContext&, execution_context&>::value
+      >::type = 0)
+    : impl_(0, 0, context)
+  {
+    asio::error_code ec;
+    impl_.get_service().assign(impl_.get_implementation(),
+        native_serial_port, ec);
+    asio::detail::throw_error(ec, "assign");
+  }
+
+#if defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+  /// Move-construct a basic_serial_port from another.
+  /**
+   * This constructor moves a serial port from one object to another.
+   *
+   * @param other The other basic_serial_port object from which the move will
+   * occur.
+   *
+   * @note Following the move, the moved-from object is in the same state as if
+   * constructed using the @c basic_serial_port(const executor_type&)
+   * constructor.
+   */
+  basic_serial_port(basic_serial_port&& other)
+    : impl_(std::move(other.impl_))
+  {
+  }
+
+  /// Move-assign a basic_serial_port from another.
+  /**
+   * This assignment operator moves a serial port from one object to another.
+   *
+   * @param other The other basic_serial_port object from which the move will
+   * occur.
+   *
+   * @note Following the move, the moved-from object is in the same state as if
+   * constructed using the @c basic_serial_port(const executor_type&)
+   * constructor.
+   */
+  basic_serial_port& operator=(basic_serial_port&& other)
+  {
+    impl_ = std::move(other.impl_);
+    return *this;
+  }
+#endif // defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+
+  /// Destroys the serial port.
+  /**
+   * This function destroys the serial port, cancelling any outstanding
+   * asynchronous wait operations associated with the serial port as if by
+   * calling @c cancel.
+   */
+  ~basic_serial_port()
+  {
+  }
+
+  /// Get the executor associated with the object.
+  executor_type get_executor() ASIO_NOEXCEPT
+  {
+    return impl_.get_executor();
+  }
+
+  /// Get a reference to the lowest layer.
+  /**
+   * This function returns a reference to the lowest layer in a stack of
+   * layers. Since a basic_serial_port cannot contain any further layers, it
+   * simply returns a reference to itself.
+   *
+   * @return A reference to the lowest layer in the stack of layers. Ownership
+   * is not transferred to the caller.
+   */
+  lowest_layer_type& lowest_layer()
+  {
+    return *this;
+  }
+
+  /// Get a const reference to the lowest layer.
+  /**
+   * This function returns a const reference to the lowest layer in a stack of
+   * layers. Since a basic_serial_port cannot contain any further layers, it
+   * simply returns a reference to itself.
+   *
+   * @return A const reference to the lowest layer in the stack of layers.
+   * Ownership is not transferred to the caller.
+   */
+  const lowest_layer_type& lowest_layer() const
+  {
+    return *this;
+  }
+
+  /// Open the serial port using the specified device name.
+  /**
+   * This function opens the serial port for the specified device name.
+   *
+   * @param device The platform-specific device name.
+   *
+   * @throws asio::system_error Thrown on failure.
+   */
+  void open(const std::string& device)
+  {
+    asio::error_code ec;
+    impl_.get_service().open(impl_.get_implementation(), device, ec);
+    asio::detail::throw_error(ec, "open");
+  }
+
+  /// Open the serial port using the specified device name.
+  /**
+   * This function opens the serial port using the given platform-specific
+   * device name.
+   *
+   * @param device The platform-specific device name.
+   *
+   * @param ec Set the indicate what error occurred, if any.
+   */
+  ASIO_SYNC_OP_VOID open(const std::string& device,
+      asio::error_code& ec)
+  {
+    impl_.get_service().open(impl_.get_implementation(), device, ec);
+    ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Assign an existing native serial port to the serial port.
+  /*
+   * This function opens the serial port to hold an existing native serial port.
+   *
+   * @param native_serial_port A native serial port.
+   *
+   * @throws asio::system_error Thrown on failure.
+   */
+  void assign(const native_handle_type& native_serial_port)
+  {
+    asio::error_code ec;
+    impl_.get_service().assign(impl_.get_implementation(),
+        native_serial_port, ec);
+    asio::detail::throw_error(ec, "assign");
+  }
+
+  /// Assign an existing native serial port to the serial port.
+  /*
+   * This function opens the serial port to hold an existing native serial port.
+   *
+   * @param native_serial_port A native serial port.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   */
+  ASIO_SYNC_OP_VOID assign(const native_handle_type& native_serial_port,
+      asio::error_code& ec)
+  {
+    impl_.get_service().assign(impl_.get_implementation(),
+        native_serial_port, ec);
+    ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Determine whether the serial port is open.
+  bool is_open() const
+  {
+    return impl_.get_service().is_open(impl_.get_implementation());
+  }
+
+  /// Close the serial port.
+  /**
+   * This function is used to close the serial port. Any asynchronous read or
+   * write operations will be cancelled immediately, and will complete with the
+   * asio::error::operation_aborted error.
+   *
+   * @throws asio::system_error Thrown on failure.
+   */
+  void close()
+  {
+    asio::error_code ec;
+    impl_.get_service().close(impl_.get_implementation(), ec);
+    asio::detail::throw_error(ec, "close");
+  }
+
+  /// Close the serial port.
+  /**
+   * This function is used to close the serial port. Any asynchronous read or
+   * write operations will be cancelled immediately, and will complete with the
+   * asio::error::operation_aborted error.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   */
+  ASIO_SYNC_OP_VOID close(asio::error_code& ec)
+  {
+    impl_.get_service().close(impl_.get_implementation(), ec);
+    ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Get the native serial port representation.
+  /**
+   * This function may be used to obtain the underlying representation of the
+   * serial port. This is intended to allow access to native serial port
+   * functionality that is not otherwise provided.
+   */
+  native_handle_type native_handle()
+  {
+    return impl_.get_service().native_handle(impl_.get_implementation());
+  }
+
+  /// Cancel all asynchronous operations associated with the serial port.
+  /**
+   * This function causes all outstanding asynchronous read or write operations
+   * to finish immediately, and the handlers for cancelled operations will be
+   * passed the asio::error::operation_aborted error.
+   *
+   * @throws asio::system_error Thrown on failure.
+   */
+  void cancel()
+  {
+    asio::error_code ec;
+    impl_.get_service().cancel(impl_.get_implementation(), ec);
+    asio::detail::throw_error(ec, "cancel");
+  }
+
+  /// Cancel all asynchronous operations associated with the serial port.
+  /**
+   * This function causes all outstanding asynchronous read or write operations
+   * to finish immediately, and the handlers for cancelled operations will be
+   * passed the asio::error::operation_aborted error.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   */
+  ASIO_SYNC_OP_VOID cancel(asio::error_code& ec)
+  {
+    impl_.get_service().cancel(impl_.get_implementation(), ec);
+    ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Send a break sequence to the serial port.
+  /**
+   * This function causes a break sequence of platform-specific duration to be
+   * sent out the serial port.
+   *
+   * @throws asio::system_error Thrown on failure.
+   */
+  void send_break()
+  {
+    asio::error_code ec;
+    impl_.get_service().send_break(impl_.get_implementation(), ec);
+    asio::detail::throw_error(ec, "send_break");
+  }
+
+  /// Send a break sequence to the serial port.
+  /**
+   * This function causes a break sequence of platform-specific duration to be
+   * sent out the serial port.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   */
+  ASIO_SYNC_OP_VOID send_break(asio::error_code& ec)
+  {
+    impl_.get_service().send_break(impl_.get_implementation(), ec);
+    ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Set an option on the serial port.
+  /**
+   * This function is used to set an option on the serial port.
+   *
+   * @param option The option value to be set on the serial port.
+   *
+   * @throws asio::system_error Thrown on failure.
+   *
+   * @sa SettableSerialPortOption @n
+   * asio::serial_port_base::baud_rate @n
+   * asio::serial_port_base::flow_control @n
+   * asio::serial_port_base::parity @n
+   * asio::serial_port_base::stop_bits @n
+   * asio::serial_port_base::character_size
+   */
+  template <typename SettableSerialPortOption>
+  void set_option(const SettableSerialPortOption& option)
+  {
+    asio::error_code ec;
+    impl_.get_service().set_option(impl_.get_implementation(), option, ec);
+    asio::detail::throw_error(ec, "set_option");
+  }
+
+  /// Set an option on the serial port.
+  /**
+   * This function is used to set an option on the serial port.
+   *
+   * @param option The option value to be set on the serial port.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @sa SettableSerialPortOption @n
+   * asio::serial_port_base::baud_rate @n
+   * asio::serial_port_base::flow_control @n
+   * asio::serial_port_base::parity @n
+   * asio::serial_port_base::stop_bits @n
+   * asio::serial_port_base::character_size
+   */
+  template <typename SettableSerialPortOption>
+  ASIO_SYNC_OP_VOID set_option(const SettableSerialPortOption& option,
+      asio::error_code& ec)
+  {
+    impl_.get_service().set_option(impl_.get_implementation(), option, ec);
+    ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Get an option from the serial port.
+  /**
+   * This function is used to get the current value of an option on the serial
+   * port.
+   *
+   * @param option The option value to be obtained from the serial port.
+   *
+   * @throws asio::system_error Thrown on failure.
+   *
+   * @sa GettableSerialPortOption @n
+   * asio::serial_port_base::baud_rate @n
+   * asio::serial_port_base::flow_control @n
+   * asio::serial_port_base::parity @n
+   * asio::serial_port_base::stop_bits @n
+   * asio::serial_port_base::character_size
+   */
+  template <typename GettableSerialPortOption>
+  void get_option(GettableSerialPortOption& option) const
+  {
+    asio::error_code ec;
+    impl_.get_service().get_option(impl_.get_implementation(), option, ec);
+    asio::detail::throw_error(ec, "get_option");
+  }
+
+  /// Get an option from the serial port.
+  /**
+   * This function is used to get the current value of an option on the serial
+   * port.
+   *
+   * @param option The option value to be obtained from the serial port.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @sa GettableSerialPortOption @n
+   * asio::serial_port_base::baud_rate @n
+   * asio::serial_port_base::flow_control @n
+   * asio::serial_port_base::parity @n
+   * asio::serial_port_base::stop_bits @n
+   * asio::serial_port_base::character_size
+   */
+  template <typename GettableSerialPortOption>
+  ASIO_SYNC_OP_VOID get_option(GettableSerialPortOption& option,
+      asio::error_code& ec) const
+  {
+    impl_.get_service().get_option(impl_.get_implementation(), option, ec);
+    ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Write some data to the serial port.
+  /**
+   * This function is used to write data to the serial port. The function call
+   * will block until one or more bytes of the data has been written
+   * successfully, or until an error occurs.
+   *
+   * @param buffers One or more data buffers to be written to the serial port.
+   *
+   * @returns The number of bytes written.
+   *
+   * @throws asio::system_error Thrown on failure. An error code of
+   * asio::error::eof indicates that the connection was closed by the
+   * peer.
+   *
+   * @note The write_some operation may not transmit all of the data to the
+   * peer. Consider using the @ref write function if you need to ensure that
+   * all data is written before the blocking operation completes.
+   *
+   * @par Example
+   * To write a single data buffer use the @ref buffer function as follows:
+   * @code
+   * basic_serial_port.write_some(asio::buffer(data, size));
+   * @endcode
+   * See the @ref buffer documentation for information on writing multiple
+   * buffers in one go, and how to use it with arrays, boost::array or
+   * std::vector.
+   */
+  template <typename ConstBufferSequence>
+  std::size_t write_some(const ConstBufferSequence& buffers)
+  {
+    asio::error_code ec;
+    std::size_t s = impl_.get_service().write_some(
+        impl_.get_implementation(), buffers, ec);
+    asio::detail::throw_error(ec, "write_some");
+    return s;
+  }
+
+  /// Write some data to the serial port.
+  /**
+   * This function is used to write data to the serial port. The function call
+   * will block until one or more bytes of the data has been written
+   * successfully, or until an error occurs.
+   *
+   * @param buffers One or more data buffers to be written to the serial port.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @returns The number of bytes written. Returns 0 if an error occurred.
+   *
+   * @note The write_some operation may not transmit all of the data to the
+   * peer. Consider using the @ref write function if you need to ensure that
+   * all data is written before the blocking operation completes.
+   */
+  template <typename ConstBufferSequence>
+  std::size_t write_some(const ConstBufferSequence& buffers,
+      asio::error_code& ec)
+  {
+    return impl_.get_service().write_some(
+        impl_.get_implementation(), buffers, ec);
+  }
+
+  /// Start an asynchronous write.
+  /**
+   * This function is used to asynchronously write data to the serial port.
+   * It is an initiating function for an @ref asynchronous_operation, and always
+   * returns immediately.
+   *
+   * @param buffers One or more data buffers to be written to the serial port.
+   * Although the buffers object may be copied as necessary, ownership of the
+   * underlying memory blocks is retained by the caller, which must guarantee
+   * that they remain valid until the completion handler is called.
+   *
+   * @param token The @ref completion_token that will be used to produce a
+   * completion handler, which will be called when the write completes.
+   * Potential completion tokens include @ref use_future, @ref use_awaitable,
+   * @ref yield_context, or a function object with the correct completion
+   * signature. The function signature of the completion handler must be:
+   * @code void handler(
+   *   const asio::error_code& error, // Result of operation.
+   *   std::size_t bytes_transferred // Number of bytes written.
+   * ); @endcode
+   * Regardless of whether the asynchronous operation completes immediately or
+   * not, the completion handler will not be invoked from within this function.
+   * On immediate completion, invocation of the handler will be performed in a
+   * manner equivalent to using asio::post().
+   *
+   * @par Completion Signature
+   * @code void(asio::error_code, std::size_t) @endcode
+   *
+   * @note The write operation may not transmit all of the data to the peer.
+   * Consider using the @ref async_write function if you need to ensure that all
+   * data is written before the asynchronous operation completes.
+   *
+   * @par Example
+   * To write a single data buffer use the @ref buffer function as follows:
+   * @code
+   * basic_serial_port.async_write_some(
+   *     asio::buffer(data, size), handler);
+   * @endcode
+   * See the @ref buffer documentation for information on writing multiple
+   * buffers in one go, and how to use it with arrays, boost::array or
+   * std::vector.
+   *
+   * @par Per-Operation Cancellation
+   * On POSIX or Windows operating systems, this asynchronous operation supports
+   * cancellation for the following asio::cancellation_type values:
+   *
+   * @li @c cancellation_type::terminal
+   *
+   * @li @c cancellation_type::partial
+   *
+   * @li @c cancellation_type::total
+   */
+  template <typename ConstBufferSequence,
+      ASIO_COMPLETION_TOKEN_FOR(void (asio::error_code,
+        std::size_t)) WriteToken
+          ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(executor_type)>
+  ASIO_INITFN_AUTO_RESULT_TYPE(WriteToken,
+      void (asio::error_code, std::size_t))
+  async_write_some(const ConstBufferSequence& buffers,
+      ASIO_MOVE_ARG(WriteToken) token
+        ASIO_DEFAULT_COMPLETION_TOKEN(executor_type))
+  {
+    return async_initiate<WriteToken,
+      void (asio::error_code, std::size_t)>(
+        initiate_async_write_some(this), token, buffers);
+  }
+
+  /// Read some data from the serial port.
+  /**
+   * This function is used to read data from the serial port. The function
+   * call will block until one or more bytes of data has been read successfully,
+   * or until an error occurs.
+   *
+   * @param buffers One or more buffers into which the data will be read.
+   *
+   * @returns The number of bytes read.
+   *
+   * @throws asio::system_error Thrown on failure. An error code of
+   * asio::error::eof indicates that the connection was closed by the
+   * peer.
+   *
+   * @note The read_some operation may not read all of the requested number of
+   * bytes. Consider using the @ref read function if you need to ensure that
+   * the requested amount of data is read before the blocking operation
+   * completes.
+   *
+   * @par Example
+   * To read into a single data buffer use the @ref buffer function as follows:
+   * @code
+   * basic_serial_port.read_some(asio::buffer(data, size));
+   * @endcode
+   * See the @ref buffer documentation for information on reading into multiple
+   * buffers in one go, and how to use it with arrays, boost::array or
+   * std::vector.
+   */
+  template <typename MutableBufferSequence>
+  std::size_t read_some(const MutableBufferSequence& buffers)
+  {
+    asio::error_code ec;
+    std::size_t s = impl_.get_service().read_some(
+        impl_.get_implementation(), buffers, ec);
+    asio::detail::throw_error(ec, "read_some");
+    return s;
+  }
+
+  /// Read some data from the serial port.
+  /**
+   * This function is used to read data from the serial port. The function
+   * call will block until one or more bytes of data has been read successfully,
+   * or until an error occurs.
+   *
+   * @param buffers One or more buffers into which the data will be read.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @returns The number of bytes read. Returns 0 if an error occurred.
+   *
+   * @note The read_some operation may not read all of the requested number of
+   * bytes. Consider using the @ref read function if you need to ensure that
+   * the requested amount of data is read before the blocking operation
+   * completes.
+   */
+  template <typename MutableBufferSequence>
+  std::size_t read_some(const MutableBufferSequence& buffers,
+      asio::error_code& ec)
+  {
+    return impl_.get_service().read_some(
+        impl_.get_implementation(), buffers, ec);
+  }
+
+  /// Start an asynchronous read.
+  /**
+   * This function is used to asynchronously read data from the serial port.
+   * It is an initiating function for an @ref asynchronous_operation, and always
+   * returns immediately.
+   *
+   * @param buffers One or more buffers into which the data will be read.
+   * Although the buffers object may be copied as necessary, ownership of the
+   * underlying memory blocks is retained by the caller, which must guarantee
+   * that they remain valid until the completion handler is called.
+   *
+   * @param token The @ref completion_token that will be used to produce a
+   * completion handler, which will be called when the read completes.
+   * Potential completion tokens include @ref use_future, @ref use_awaitable,
+   * @ref yield_context, or a function object with the correct completion
+   * signature. The function signature of the completion handler must be:
+   * @code void handler(
+   *   const asio::error_code& error, // Result of operation.
+   *   std::size_t bytes_transferred // Number of bytes read.
+   * ); @endcode
+   * Regardless of whether the asynchronous operation completes immediately or
+   * not, the completion handler will not be invoked from within this function.
+   * On immediate completion, invocation of the handler will be performed in a
+   * manner equivalent to using asio::post().
+   *
+   * @par Completion Signature
+   * @code void(asio::error_code, std::size_t) @endcode
+   *
+   * @note The read operation may not read all of the requested number of bytes.
+   * Consider using the @ref async_read function if you need to ensure that the
+   * requested amount of data is read before the asynchronous operation
+   * completes.
+   *
+   * @par Example
+   * To read into a single data buffer use the @ref buffer function as follows:
+   * @code
+   * basic_serial_port.async_read_some(
+   *     asio::buffer(data, size), handler);
+   * @endcode
+   * See the @ref buffer documentation for information on reading into multiple
+   * buffers in one go, and how to use it with arrays, boost::array or
+   * std::vector.
+   *
+   * @par Per-Operation Cancellation
+   * On POSIX or Windows operating systems, this asynchronous operation supports
+   * cancellation for the following asio::cancellation_type values:
+   *
+   * @li @c cancellation_type::terminal
+   *
+   * @li @c cancellation_type::partial
+   *
+   * @li @c cancellation_type::total
+   */
+  template <typename MutableBufferSequence,
+      ASIO_COMPLETION_TOKEN_FOR(void (asio::error_code,
+        std::size_t)) ReadToken
+          ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(executor_type)>
+  ASIO_INITFN_AUTO_RESULT_TYPE(ReadToken,
+      void (asio::error_code, std::size_t))
+  async_read_some(const MutableBufferSequence& buffers,
+      ASIO_MOVE_ARG(ReadToken) token
+        ASIO_DEFAULT_COMPLETION_TOKEN(executor_type))
+  {
+    return async_initiate<ReadToken,
+      void (asio::error_code, std::size_t)>(
+        initiate_async_read_some(this), token, buffers);
+  }
+
+private:
+  // Disallow copying and assignment.
+  basic_serial_port(const basic_serial_port&) ASIO_DELETED;
+  basic_serial_port& operator=(const basic_serial_port&) ASIO_DELETED;
+
+  class initiate_async_write_some
+  {
+  public:
+    typedef Executor executor_type;
+
+    explicit initiate_async_write_some(basic_serial_port* self)
+      : self_(self)
+    {
+    }
+
+    executor_type get_executor() const ASIO_NOEXCEPT
+    {
+      return self_->get_executor();
+    }
+
+    template <typename WriteHandler, typename ConstBufferSequence>
+    void operator()(ASIO_MOVE_ARG(WriteHandler) handler,
+        const ConstBufferSequence& buffers) const
+    {
+      // If you get an error on the following line it means that your handler
+      // does not meet the documented type requirements for a WriteHandler.
+      ASIO_WRITE_HANDLER_CHECK(WriteHandler, handler) type_check;
+
+      detail::non_const_lvalue<WriteHandler> handler2(handler);
+      self_->impl_.get_service().async_write_some(
+          self_->impl_.get_implementation(), buffers,
+          handler2.value, self_->impl_.get_executor());
+    }
+
+  private:
+    basic_serial_port* self_;
+  };
+
+  class initiate_async_read_some
+  {
+  public:
+    typedef Executor executor_type;
+
+    explicit initiate_async_read_some(basic_serial_port* self)
+      : self_(self)
+    {
+    }
+
+    executor_type get_executor() const ASIO_NOEXCEPT
+    {
+      return self_->get_executor();
+    }
+
+    template <typename ReadHandler, typename MutableBufferSequence>
+    void operator()(ASIO_MOVE_ARG(ReadHandler) handler,
+        const MutableBufferSequence& buffers) const
+    {
+      // If you get an error on the following line it means that your handler
+      // does not meet the documented type requirements for a ReadHandler.
+      ASIO_READ_HANDLER_CHECK(ReadHandler, handler) type_check;
+
+      detail::non_const_lvalue<ReadHandler> handler2(handler);
+      self_->impl_.get_service().async_read_some(
+          self_->impl_.get_implementation(), buffers,
+          handler2.value, self_->impl_.get_executor());
+    }
+
+  private:
+    basic_serial_port* self_;
+  };
+
+#if defined(ASIO_HAS_IOCP)
+  detail::io_object_impl<detail::win_iocp_serial_port_service, Executor> impl_;
+#else
+  detail::io_object_impl<detail::posix_serial_port_service, Executor> impl_;
+#endif
+};
+
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // defined(ASIO_HAS_SERIAL_PORT)
+       //   || defined(GENERATING_DOCUMENTATION)
+
+#endif // ASIO_BASIC_SERIAL_PORT_HPP

lib/asio/include/asio/basic_signal_set.hpp

@@ -0,0 +1,592 @@
+//
+// basic_signal_set.hpp
+// ~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_BASIC_SIGNAL_SET_HPP
+#define ASIO_BASIC_SIGNAL_SET_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#include "asio/any_io_executor.hpp"
+#include "asio/async_result.hpp"
+#include "asio/detail/handler_type_requirements.hpp"
+#include "asio/detail/io_object_impl.hpp"
+#include "asio/detail/non_const_lvalue.hpp"
+#include "asio/detail/signal_set_service.hpp"
+#include "asio/detail/throw_error.hpp"
+#include "asio/detail/type_traits.hpp"
+#include "asio/error.hpp"
+#include "asio/execution_context.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+
+/// Provides signal functionality.
+/**
+ * The basic_signal_set class provides the ability to perform an asynchronous
+ * wait for one or more signals to occur.
+ *
+ * @par Thread Safety
+ * @e Distinct @e objects: Safe.@n
+ * @e Shared @e objects: Unsafe.
+ *
+ * @par Example
+ * Performing an asynchronous wait:
+ * @code
+ * void handler(
+ *     const asio::error_code& error,
+ *     int signal_number)
+ * {
+ *   if (!error)
+ *   {
+ *     // A signal occurred.
+ *   }
+ * }
+ *
+ * ...
+ *
+ * // Construct a signal set registered for process termination.
+ * asio::signal_set signals(my_context, SIGINT, SIGTERM);
+ *
+ * // Start an asynchronous wait for one of the signals to occur.
+ * signals.async_wait(handler);
+ * @endcode
+ *
+ * @par Queueing of signal notifications
+ *
+ * If a signal is registered with a signal_set, and the signal occurs when
+ * there are no waiting handlers, then the signal notification is queued. The
+ * next async_wait operation on that signal_set will dequeue the notification.
+ * If multiple notifications are queued, subsequent async_wait operations
+ * dequeue them one at a time. Signal notifications are dequeued in order of
+ * ascending signal number.
+ *
+ * If a signal number is removed from a signal_set (using the @c remove or @c
+ * erase member functions) then any queued notifications for that signal are
+ * discarded.
+ *
+ * @par Multiple registration of signals
+ *
+ * The same signal number may be registered with different signal_set objects.
+ * When the signal occurs, one handler is called for each signal_set object.
+ *
+ * Note that multiple registration only works for signals that are registered
+ * using Asio. The application must not also register a signal handler using
+ * functions such as @c signal() or @c sigaction().
+ *
+ * @par Signal masking on POSIX platforms
+ *
+ * POSIX allows signals to be blocked using functions such as @c sigprocmask()
+ * and @c pthread_sigmask(). For signals to be delivered, programs must ensure
+ * that any signals registered using signal_set objects are unblocked in at
+ * least one thread.
+ */
+template <typename Executor = any_io_executor>
+class basic_signal_set
+{
+public:
+  /// The type of the executor associated with the object.
+  typedef Executor executor_type;
+
+  /// Rebinds the signal set type to another executor.
+  template <typename Executor1>
+  struct rebind_executor
+  {
+    /// The signal set type when rebound to the specified executor.
+    typedef basic_signal_set<Executor1> other;
+  };
+
+  /// Construct a signal set without adding any signals.
+  /**
+   * This constructor creates a signal set without registering for any signals.
+   *
+   * @param ex The I/O executor that the signal set will use, by default, to
+   * dispatch handlers for any asynchronous operations performed on the
+   * signal set.
+   */
+  explicit basic_signal_set(const executor_type& ex)
+    : impl_(0, ex)
+  {
+  }
+
+  /// Construct a signal set without adding any signals.
+  /**
+   * This constructor creates a signal set without registering for any signals.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the signal set will use, by default, to dispatch handlers for any
+   * asynchronous operations performed on the signal set.
+   */
+  template <typename ExecutionContext>
+  explicit basic_signal_set(ExecutionContext& context,
+      typename constraint<
+        is_convertible<ExecutionContext&, execution_context&>::value,
+        defaulted_constraint
+      >::type = defaulted_constraint())
+    : impl_(0, 0, context)
+  {
+  }
+
+  /// Construct a signal set and add one signal.
+  /**
+   * This constructor creates a signal set and registers for one signal.
+   *
+   * @param ex The I/O executor that the signal set will use, by default, to
+   * dispatch handlers for any asynchronous operations performed on the
+   * signal set.
+   *
+   * @param signal_number_1 The signal number to be added.
+   *
+   * @note This constructor is equivalent to performing:
+   * @code asio::signal_set signals(ex);
+   * signals.add(signal_number_1); @endcode
+   */
+  basic_signal_set(const executor_type& ex, int signal_number_1)
+    : impl_(0, ex)
+  {
+    asio::error_code ec;
+    impl_.get_service().add(impl_.get_implementation(), signal_number_1, ec);
+    asio::detail::throw_error(ec, "add");
+  }
+
+  /// Construct a signal set and add one signal.
+  /**
+   * This constructor creates a signal set and registers for one signal.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the signal set will use, by default, to dispatch handlers for any
+   * asynchronous operations performed on the signal set.
+   *
+   * @param signal_number_1 The signal number to be added.
+   *
+   * @note This constructor is equivalent to performing:
+   * @code asio::signal_set signals(context);
+   * signals.add(signal_number_1); @endcode
+   */
+  template <typename ExecutionContext>
+  basic_signal_set(ExecutionContext& context, int signal_number_1,
+      typename constraint<
+        is_convertible<ExecutionContext&, execution_context&>::value,
+        defaulted_constraint
+      >::type = defaulted_constraint())
+    : impl_(0, 0, context)
+  {
+    asio::error_code ec;
+    impl_.get_service().add(impl_.get_implementation(), signal_number_1, ec);
+    asio::detail::throw_error(ec, "add");
+  }
+
+  /// Construct a signal set and add two signals.
+  /**
+   * This constructor creates a signal set and registers for two signals.
+   *
+   * @param ex The I/O executor that the signal set will use, by default, to
+   * dispatch handlers for any asynchronous operations performed on the
+   * signal set.
+   *
+   * @param signal_number_1 The first signal number to be added.
+   *
+   * @param signal_number_2 The second signal number to be added.
+   *
+   * @note This constructor is equivalent to performing:
+   * @code asio::signal_set signals(ex);
+   * signals.add(signal_number_1);
+   * signals.add(signal_number_2); @endcode
+   */
+  basic_signal_set(const executor_type& ex, int signal_number_1,
+      int signal_number_2)
+    : impl_(0, ex)
+  {
+    asio::error_code ec;
+    impl_.get_service().add(impl_.get_implementation(), signal_number_1, ec);
+    asio::detail::throw_error(ec, "add");
+    impl_.get_service().add(impl_.get_implementation(), signal_number_2, ec);
+    asio::detail::throw_error(ec, "add");
+  }
+
+  /// Construct a signal set and add two signals.
+  /**
+   * This constructor creates a signal set and registers for two signals.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the signal set will use, by default, to dispatch handlers for any
+   * asynchronous operations performed on the signal set.
+   *
+   * @param signal_number_1 The first signal number to be added.
+   *
+   * @param signal_number_2 The second signal number to be added.
+   *
+   * @note This constructor is equivalent to performing:
+   * @code asio::signal_set signals(context);
+   * signals.add(signal_number_1);
+   * signals.add(signal_number_2); @endcode
+   */
+  template <typename ExecutionContext>
+  basic_signal_set(ExecutionContext& context, int signal_number_1,
+      int signal_number_2,
+      typename constraint<
+        is_convertible<ExecutionContext&, execution_context&>::value,
+        defaulted_constraint
+      >::type = defaulted_constraint())
+    : impl_(0, 0, context)
+  {
+    asio::error_code ec;
+    impl_.get_service().add(impl_.get_implementation(), signal_number_1, ec);
+    asio::detail::throw_error(ec, "add");
+    impl_.get_service().add(impl_.get_implementation(), signal_number_2, ec);
+    asio::detail::throw_error(ec, "add");
+  }
+
+  /// Construct a signal set and add three signals.
+  /**
+   * This constructor creates a signal set and registers for three signals.
+   *
+   * @param ex The I/O executor that the signal set will use, by default, to
+   * dispatch handlers for any asynchronous operations performed on the
+   * signal set.
+   *
+   * @param signal_number_1 The first signal number to be added.
+   *
+   * @param signal_number_2 The second signal number to be added.
+   *
+   * @param signal_number_3 The third signal number to be added.
+   *
+   * @note This constructor is equivalent to performing:
+   * @code asio::signal_set signals(ex);
+   * signals.add(signal_number_1);
+   * signals.add(signal_number_2);
+   * signals.add(signal_number_3); @endcode
+   */
+  basic_signal_set(const executor_type& ex, int signal_number_1,
+      int signal_number_2, int signal_number_3)
+    : impl_(0, ex)
+  {
+    asio::error_code ec;
+    impl_.get_service().add(impl_.get_implementation(), signal_number_1, ec);
+    asio::detail::throw_error(ec, "add");
+    impl_.get_service().add(impl_.get_implementation(), signal_number_2, ec);
+    asio::detail::throw_error(ec, "add");
+    impl_.get_service().add(impl_.get_implementation(), signal_number_3, ec);
+    asio::detail::throw_error(ec, "add");
+  }
+
+  /// Construct a signal set and add three signals.
+  /**
+   * This constructor creates a signal set and registers for three signals.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the signal set will use, by default, to dispatch handlers for any
+   * asynchronous operations performed on the signal set.
+   *
+   * @param signal_number_1 The first signal number to be added.
+   *
+   * @param signal_number_2 The second signal number to be added.
+   *
+   * @param signal_number_3 The third signal number to be added.
+   *
+   * @note This constructor is equivalent to performing:
+   * @code asio::signal_set signals(context);
+   * signals.add(signal_number_1);
+   * signals.add(signal_number_2);
+   * signals.add(signal_number_3); @endcode
+   */
+  template <typename ExecutionContext>
+  basic_signal_set(ExecutionContext& context, int signal_number_1,
+      int signal_number_2, int signal_number_3,
+      typename constraint<
+        is_convertible<ExecutionContext&, execution_context&>::value,
+        defaulted_constraint
+      >::type = defaulted_constraint())
+    : impl_(0, 0, context)
+  {
+    asio::error_code ec;
+    impl_.get_service().add(impl_.get_implementation(), signal_number_1, ec);
+    asio::detail::throw_error(ec, "add");
+    impl_.get_service().add(impl_.get_implementation(), signal_number_2, ec);
+    asio::detail::throw_error(ec, "add");
+    impl_.get_service().add(impl_.get_implementation(), signal_number_3, ec);
+    asio::detail::throw_error(ec, "add");
+  }
+
+  /// Destroys the signal set.
+  /**
+   * This function destroys the signal set, cancelling any outstanding
+   * asynchronous wait operations associated with the signal set as if by
+   * calling @c cancel.
+   */
+  ~basic_signal_set()
+  {
+  }
+
+  /// Get the executor associated with the object.
+  executor_type get_executor() ASIO_NOEXCEPT
+  {
+    return impl_.get_executor();
+  }
+
+  /// Add a signal to a signal_set.
+  /**
+   * This function adds the specified signal to the set. It has no effect if the
+   * signal is already in the set.
+   *
+   * @param signal_number The signal to be added to the set.
+   *
+   * @throws asio::system_error Thrown on failure.
+   */
+  void add(int signal_number)
+  {
+    asio::error_code ec;
+    impl_.get_service().add(impl_.get_implementation(), signal_number, ec);
+    asio::detail::throw_error(ec, "add");
+  }
+
+  /// Add a signal to a signal_set.
+  /**
+   * This function adds the specified signal to the set. It has no effect if the
+   * signal is already in the set.
+   *
+   * @param signal_number The signal to be added to the set.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   */
+  ASIO_SYNC_OP_VOID add(int signal_number,
+      asio::error_code& ec)
+  {
+    impl_.get_service().add(impl_.get_implementation(), signal_number, ec);
+    ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Remove a signal from a signal_set.
+  /**
+   * This function removes the specified signal from the set. It has no effect
+   * if the signal is not in the set.
+   *
+   * @param signal_number The signal to be removed from the set.
+   *
+   * @throws asio::system_error Thrown on failure.
+   *
+   * @note Removes any notifications that have been queued for the specified
+   * signal number.
+   */
+  void remove(int signal_number)
+  {
+    asio::error_code ec;
+    impl_.get_service().remove(impl_.get_implementation(), signal_number, ec);
+    asio::detail::throw_error(ec, "remove");
+  }
+
+  /// Remove a signal from a signal_set.
+  /**
+   * This function removes the specified signal from the set. It has no effect
+   * if the signal is not in the set.
+   *
+   * @param signal_number The signal to be removed from the set.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @note Removes any notifications that have been queued for the specified
+   * signal number.
+   */
+  ASIO_SYNC_OP_VOID remove(int signal_number,
+      asio::error_code& ec)
+  {
+    impl_.get_service().remove(impl_.get_implementation(), signal_number, ec);
+    ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Remove all signals from a signal_set.
+  /**
+   * This function removes all signals from the set. It has no effect if the set
+   * is already empty.
+   *
+   * @throws asio::system_error Thrown on failure.
+   *
+   * @note Removes all queued notifications.
+   */
+  void clear()
+  {
+    asio::error_code ec;
+    impl_.get_service().clear(impl_.get_implementation(), ec);
+    asio::detail::throw_error(ec, "clear");
+  }
+
+  /// Remove all signals from a signal_set.
+  /**
+   * This function removes all signals from the set. It has no effect if the set
+   * is already empty.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @note Removes all queued notifications.
+   */
+  ASIO_SYNC_OP_VOID clear(asio::error_code& ec)
+  {
+    impl_.get_service().clear(impl_.get_implementation(), ec);
+    ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Cancel all operations associated with the signal set.
+  /**
+   * This function forces the completion of any pending asynchronous wait
+   * operations against the signal set. The handler for each cancelled
+   * operation will be invoked with the asio::error::operation_aborted
+   * error code.
+   *
+   * Cancellation does not alter the set of registered signals.
+   *
+   * @throws asio::system_error Thrown on failure.
+   *
+   * @note If a registered signal occurred before cancel() is called, then the
+   * handlers for asynchronous wait operations will:
+   *
+   * @li have already been invoked; or
+   *
+   * @li have been queued for invocation in the near future.
+   *
+   * These handlers can no longer be cancelled, and therefore are passed an
+   * error code that indicates the successful completion of the wait operation.
+   */
+  void cancel()
+  {
+    asio::error_code ec;
+    impl_.get_service().cancel(impl_.get_implementation(), ec);
+    asio::detail::throw_error(ec, "cancel");
+  }
+
+  /// Cancel all operations associated with the signal set.
+  /**
+   * This function forces the completion of any pending asynchronous wait
+   * operations against the signal set. The handler for each cancelled
+   * operation will be invoked with the asio::error::operation_aborted
+   * error code.
+   *
+   * Cancellation does not alter the set of registered signals.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @note If a registered signal occurred before cancel() is called, then the
+   * handlers for asynchronous wait operations will:
+   *
+   * @li have already been invoked; or
+   *
+   * @li have been queued for invocation in the near future.
+   *
+   * These handlers can no longer be cancelled, and therefore are passed an
+   * error code that indicates the successful completion of the wait operation.
+   */
+  ASIO_SYNC_OP_VOID cancel(asio::error_code& ec)
+  {
+    impl_.get_service().cancel(impl_.get_implementation(), ec);
+    ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Start an asynchronous operation to wait for a signal to be delivered.
+  /**
+   * This function may be used to initiate an asynchronous wait against the
+   * signal set. It is an initiating function for an @ref
+   * asynchronous_operation, and always returns immediately.
+   *
+   * For each call to async_wait(), the completion handler will be called
+   * exactly once. The completion handler will be called when:
+   *
+   * @li One of the registered signals in the signal set occurs; or
+   *
+   * @li The signal set was cancelled, in which case the handler is passed the
+   * error code asio::error::operation_aborted.
+   *
+   * @param token The @ref completion_token that will be used to produce a
+   * completion handler, which will be called when the wait completes.
+   * Potential completion tokens include @ref use_future, @ref use_awaitable,
+   * @ref yield_context, or a function object with the correct completion
+   * signature. The function signature of the completion handler must be:
+   * @code void handler(
+   *   const asio::error_code& error, // Result of operation.
+   *   int signal_number // Indicates which signal occurred.
+   * ); @endcode
+   * Regardless of whether the asynchronous operation completes immediately or
+   * not, the completion handler will not be invoked from within this function.
+   * On immediate completion, invocation of the handler will be performed in a
+   * manner equivalent to using asio::post().
+   *
+   * @par Completion Signature
+   * @code void(asio::error_code, int) @endcode
+   *
+   * @par Per-Operation Cancellation
+   * This asynchronous operation supports cancellation for the following
+   * asio::cancellation_type values:
+   *
+   * @li @c cancellation_type::terminal
+   *
+   * @li @c cancellation_type::partial
+   *
+   * @li @c cancellation_type::total
+   */
+  template <
+    ASIO_COMPLETION_TOKEN_FOR(void (asio::error_code, int))
+      SignalToken ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(executor_type)>
+  ASIO_INITFN_AUTO_RESULT_TYPE(SignalToken,
+      void (asio::error_code, int))
+  async_wait(
+      ASIO_MOVE_ARG(SignalToken) token
+        ASIO_DEFAULT_COMPLETION_TOKEN(executor_type))
+  {
+    return async_initiate<SignalToken, void (asio::error_code, int)>(
+        initiate_async_wait(this), token);
+  }
+
+private:
+  // Disallow copying and assignment.
+  basic_signal_set(const basic_signal_set&) ASIO_DELETED;
+  basic_signal_set& operator=(const basic_signal_set&) ASIO_DELETED;
+
+  class initiate_async_wait
+  {
+  public:
+    typedef Executor executor_type;
+
+    explicit initiate_async_wait(basic_signal_set* self)
+      : self_(self)
+    {
+    }
+
+    executor_type get_executor() const ASIO_NOEXCEPT
+    {
+      return self_->get_executor();
+    }
+
+    template <typename SignalHandler>
+    void operator()(ASIO_MOVE_ARG(SignalHandler) handler) const
+    {
+      // If you get an error on the following line it means that your handler
+      // does not meet the documented type requirements for a SignalHandler.
+      ASIO_SIGNAL_HANDLER_CHECK(SignalHandler, handler) type_check;
+
+      detail::non_const_lvalue<SignalHandler> handler2(handler);
+      self_->impl_.get_service().async_wait(
+          self_->impl_.get_implementation(),
+          handler2.value, self_->impl_.get_executor());
+    }
+
+  private:
+    basic_signal_set* self_;
+  };
+
+  detail::io_object_impl<detail::signal_set_service, Executor> impl_;
+};
+
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // ASIO_BASIC_SIGNAL_SET_HPP

lib/asio/include/asio/basic_socket_iostream.hpp

@@ -0,0 +1,407 @@
+//
+// basic_socket_iostream.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_BASIC_SOCKET_IOSTREAM_HPP
+#define ASIO_BASIC_SOCKET_IOSTREAM_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if !defined(ASIO_NO_IOSTREAM)
+
+#include <istream>
+#include <ostream>
+#include "asio/basic_socket_streambuf.hpp"
+
+#if !defined(ASIO_HAS_VARIADIC_TEMPLATES)
+
+# include "asio/detail/variadic_templates.hpp"
+
+// A macro that should expand to:
+//   template <typename T1, ..., typename Tn>
+//   explicit basic_socket_iostream(T1 x1, ..., Tn xn)
+//     : std::basic_iostream<char>(
+//         &this->detail::socket_iostream_base<
+//           Protocol, Clock, WaitTraits>::streambuf_)
+//   {
+//     if (rdbuf()->connect(x1, ..., xn) == 0)
+//       this->setstate(std::ios_base::failbit);
+//   }
+// This macro should only persist within this file.
+
+# define ASIO_PRIVATE_CTR_DEF(n) \
+  template <ASIO_VARIADIC_TPARAMS(n)> \
+  explicit basic_socket_iostream(ASIO_VARIADIC_BYVAL_PARAMS(n)) \
+    : std::basic_iostream<char>( \
+        &this->detail::socket_iostream_base< \
+          Protocol, Clock, WaitTraits>::streambuf_) \
+  { \
+    this->setf(std::ios_base::unitbuf); \
+    if (rdbuf()->connect(ASIO_VARIADIC_BYVAL_ARGS(n)) == 0) \
+      this->setstate(std::ios_base::failbit); \
+  } \
+  /**/
+
+// A macro that should expand to:
+//   template <typename T1, ..., typename Tn>
+//   void connect(T1 x1, ..., Tn xn)
+//   {
+//     if (rdbuf()->connect(x1, ..., xn) == 0)
+//       this->setstate(std::ios_base::failbit);
+//   }
+// This macro should only persist within this file.
+
+# define ASIO_PRIVATE_CONNECT_DEF(n) \
+  template <ASIO_VARIADIC_TPARAMS(n)> \
+  void connect(ASIO_VARIADIC_BYVAL_PARAMS(n)) \
+  { \
+    if (rdbuf()->connect(ASIO_VARIADIC_BYVAL_ARGS(n)) == 0) \
+      this->setstate(std::ios_base::failbit); \
+  } \
+  /**/
+
+#endif // !defined(ASIO_HAS_VARIADIC_TEMPLATES)
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+// A separate base class is used to ensure that the streambuf is initialised
+// prior to the basic_socket_iostream's basic_iostream base class.
+template <typename Protocol, typename Clock, typename WaitTraits>
+class socket_iostream_base
+{
+protected:
+  socket_iostream_base()
+  {
+  }
+
+#if defined(ASIO_HAS_MOVE)
+  socket_iostream_base(socket_iostream_base&& other)
+    : streambuf_(std::move(other.streambuf_))
+  {
+  }
+
+  socket_iostream_base(basic_stream_socket<Protocol> s)
+    : streambuf_(std::move(s))
+  {
+  }
+
+  socket_iostream_base& operator=(socket_iostream_base&& other)
+  {
+    streambuf_ = std::move(other.streambuf_);
+    return *this;
+  }
+#endif // defined(ASIO_HAS_MOVE)
+
+  basic_socket_streambuf<Protocol, Clock, WaitTraits> streambuf_;
+};
+
+} // namespace detail
+
+#if !defined(ASIO_BASIC_SOCKET_IOSTREAM_FWD_DECL)
+#define ASIO_BASIC_SOCKET_IOSTREAM_FWD_DECL
+
+// Forward declaration with defaulted arguments.
+template <typename Protocol,
+#if defined(ASIO_HAS_BOOST_DATE_TIME) \
+  && defined(ASIO_USE_BOOST_DATE_TIME_FOR_SOCKET_IOSTREAM)
+    typename Clock = boost::posix_time::ptime,
+    typename WaitTraits = time_traits<Clock> >
+#else // defined(ASIO_HAS_BOOST_DATE_TIME)
+      // && defined(ASIO_USE_BOOST_DATE_TIME_FOR_SOCKET_IOSTREAM)
+    typename Clock = chrono::steady_clock,
+    typename WaitTraits = wait_traits<Clock> >
+#endif // defined(ASIO_HAS_BOOST_DATE_TIME)
+       // && defined(ASIO_USE_BOOST_DATE_TIME_FOR_SOCKET_IOSTREAM)
+class basic_socket_iostream;
+
+#endif // !defined(ASIO_BASIC_SOCKET_IOSTREAM_FWD_DECL)
+
+/// Iostream interface for a socket.
+#if defined(GENERATING_DOCUMENTATION)
+template <typename Protocol,
+    typename Clock = chrono::steady_clock,
+    typename WaitTraits = wait_traits<Clock> >
+#else // defined(GENERATING_DOCUMENTATION)
+template <typename Protocol, typename Clock, typename WaitTraits>
+#endif // defined(GENERATING_DOCUMENTATION)
+class basic_socket_iostream
+  : private detail::socket_iostream_base<Protocol, Clock, WaitTraits>,
+    public std::basic_iostream<char>
+{
+private:
+  // These typedefs are intended keep this class's implementation independent
+  // of whether it's using Boost.DateClock, Boost.Chrono or std::chrono.
+#if defined(ASIO_HAS_BOOST_DATE_TIME) \
+  && defined(ASIO_USE_BOOST_DATE_TIME_FOR_SOCKET_IOSTREAM)
+  typedef WaitTraits traits_helper;
+#else // defined(ASIO_HAS_BOOST_DATE_TIME)
+      // && defined(ASIO_USE_BOOST_DATE_TIME_FOR_SOCKET_IOSTREAM)
+  typedef detail::chrono_time_traits<Clock, WaitTraits> traits_helper;
+#endif // defined(ASIO_HAS_BOOST_DATE_TIME)
+       // && defined(ASIO_USE_BOOST_DATE_TIME_FOR_SOCKET_IOSTREAM)
+
+public:
+  /// The protocol type.
+  typedef Protocol protocol_type;
+
+  /// The endpoint type.
+  typedef typename Protocol::endpoint endpoint_type;
+
+  /// The clock type.
+  typedef Clock clock_type;
+
+#if defined(GENERATING_DOCUMENTATION)
+  /// (Deprecated: Use time_point.) The time type.
+  typedef typename WaitTraits::time_type time_type;
+
+  /// The time type.
+  typedef typename WaitTraits::time_point time_point;
+
+  /// (Deprecated: Use duration.) The duration type.
+  typedef typename WaitTraits::duration_type duration_type;
+
+  /// The duration type.
+  typedef typename WaitTraits::duration duration;
+#else
+# if !defined(ASIO_NO_DEPRECATED)
+  typedef typename traits_helper::time_type time_type;
+  typedef typename traits_helper::duration_type duration_type;
+# endif // !defined(ASIO_NO_DEPRECATED)
+  typedef typename traits_helper::time_type time_point;
+  typedef typename traits_helper::duration_type duration;
+#endif
+
+  /// Construct a basic_socket_iostream without establishing a connection.
+  basic_socket_iostream()
+    : std::basic_iostream<char>(
+        &this->detail::socket_iostream_base<
+          Protocol, Clock, WaitTraits>::streambuf_)
+  {
+    this->setf(std::ios_base::unitbuf);
+  }
+
+#if defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+  /// Construct a basic_socket_iostream from the supplied socket.
+  explicit basic_socket_iostream(basic_stream_socket<protocol_type> s)
+    : detail::socket_iostream_base<
+        Protocol, Clock, WaitTraits>(std::move(s)),
+      std::basic_iostream<char>(
+        &this->detail::socket_iostream_base<
+          Protocol, Clock, WaitTraits>::streambuf_)
+  {
+    this->setf(std::ios_base::unitbuf);
+  }
+
+#if defined(ASIO_HAS_STD_IOSTREAM_MOVE) \
+  || defined(GENERATING_DOCUMENTATION)
+  /// Move-construct a basic_socket_iostream from another.
+  basic_socket_iostream(basic_socket_iostream&& other)
+    : detail::socket_iostream_base<
+        Protocol, Clock, WaitTraits>(std::move(other)),
+      std::basic_iostream<char>(std::move(other))
+  {
+    this->set_rdbuf(&this->detail::socket_iostream_base<
+          Protocol, Clock, WaitTraits>::streambuf_);
+  }
+
+  /// Move-assign a basic_socket_iostream from another.
+  basic_socket_iostream& operator=(basic_socket_iostream&& other)
+  {
+    std::basic_iostream<char>::operator=(std::move(other));
+    detail::socket_iostream_base<
+        Protocol, Clock, WaitTraits>::operator=(std::move(other));
+    return *this;
+  }
+#endif // defined(ASIO_HAS_STD_IOSTREAM_MOVE)
+       //   || defined(GENERATING_DOCUMENTATION)
+#endif // defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+
+#if defined(GENERATING_DOCUMENTATION)
+  /// Establish a connection to an endpoint corresponding to a resolver query.
+  /**
+   * This constructor automatically establishes a connection based on the
+   * supplied resolver query parameters. The arguments are used to construct
+   * a resolver query object.
+   */
+  template <typename T1, ..., typename TN>
+  explicit basic_socket_iostream(T1 t1, ..., TN tn);
+#elif defined(ASIO_HAS_VARIADIC_TEMPLATES)
+  template <typename... T>
+  explicit basic_socket_iostream(T... x)
+    : std::basic_iostream<char>(
+        &this->detail::socket_iostream_base<
+          Protocol, Clock, WaitTraits>::streambuf_)
+  {
+    this->setf(std::ios_base::unitbuf);
+    if (rdbuf()->connect(x...) == 0)
+      this->setstate(std::ios_base::failbit);
+  }
+#else
+  ASIO_VARIADIC_GENERATE(ASIO_PRIVATE_CTR_DEF)
+#endif
+
+#if defined(GENERATING_DOCUMENTATION)
+  /// Establish a connection to an endpoint corresponding to a resolver query.
+  /**
+   * This function automatically establishes a connection based on the supplied
+   * resolver query parameters. The arguments are used to construct a resolver
+   * query object.
+   */
+  template <typename T1, ..., typename TN>
+  void connect(T1 t1, ..., TN tn);
+#elif defined(ASIO_HAS_VARIADIC_TEMPLATES)
+  template <typename... T>
+  void connect(T... x)
+  {
+    if (rdbuf()->connect(x...) == 0)
+      this->setstate(std::ios_base::failbit);
+  }
+#else
+  ASIO_VARIADIC_GENERATE(ASIO_PRIVATE_CONNECT_DEF)
+#endif
+
+  /// Close the connection.
+  void close()
+  {
+    if (rdbuf()->close() == 0)
+      this->setstate(std::ios_base::failbit);
+  }
+
+  /// Return a pointer to the underlying streambuf.
+  basic_socket_streambuf<Protocol, Clock, WaitTraits>* rdbuf() const
+  {
+    return const_cast<basic_socket_streambuf<Protocol, Clock, WaitTraits>*>(
+        &this->detail::socket_iostream_base<
+          Protocol, Clock, WaitTraits>::streambuf_);
+  }
+
+  /// Get a reference to the underlying socket.
+  basic_socket<Protocol>& socket()
+  {
+    return rdbuf()->socket();
+  }
+
+  /// Get the last error associated with the stream.
+  /**
+   * @return An \c error_code corresponding to the last error from the stream.
+   *
+   * @par Example
+   * To print the error associated with a failure to establish a connection:
+   * @code tcp::iostream s("www.boost.org", "http");
+   * if (!s)
+   * {
+   *   std::cout << "Error: " << s.error().message() << std::endl;
+   * } @endcode
+   */
+  const asio::error_code& error() const
+  {
+    return rdbuf()->error();
+  }
+
+#if !defined(ASIO_NO_DEPRECATED)
+  /// (Deprecated: Use expiry().) Get the stream's expiry time as an absolute
+  /// time.
+  /**
+   * @return An absolute time value representing the stream's expiry time.
+   */
+  time_point expires_at() const
+  {
+    return rdbuf()->expires_at();
+  }
+#endif // !defined(ASIO_NO_DEPRECATED)
+
+  /// Get the stream's expiry time as an absolute time.
+  /**
+   * @return An absolute time value representing the stream's expiry time.
+   */
+  time_point expiry() const
+  {
+    return rdbuf()->expiry();
+  }
+
+  /// Set the stream's expiry time as an absolute time.
+  /**
+   * This function sets the expiry time associated with the stream. Stream
+   * operations performed after this time (where the operations cannot be
+   * completed using the internal buffers) will fail with the error
+   * asio::error::operation_aborted.
+   *
+   * @param expiry_time The expiry time to be used for the stream.
+   */
+  void expires_at(const time_point& expiry_time)
+  {
+    rdbuf()->expires_at(expiry_time);
+  }
+
+  /// Set the stream's expiry time relative to now.
+  /**
+   * This function sets the expiry time associated with the stream. Stream
+   * operations performed after this time (where the operations cannot be
+   * completed using the internal buffers) will fail with the error
+   * asio::error::operation_aborted.
+   *
+   * @param expiry_time The expiry time to be used for the timer.
+   */
+  void expires_after(const duration& expiry_time)
+  {
+    rdbuf()->expires_after(expiry_time);
+  }
+
+#if !defined(ASIO_NO_DEPRECATED)
+  /// (Deprecated: Use expiry().) Get the stream's expiry time relative to now.
+  /**
+   * @return A relative time value representing the stream's expiry time.
+   */
+  duration expires_from_now() const
+  {
+    return rdbuf()->expires_from_now();
+  }
+
+  /// (Deprecated: Use expires_after().) Set the stream's expiry time relative
+  /// to now.
+  /**
+   * This function sets the expiry time associated with the stream. Stream
+   * operations performed after this time (where the operations cannot be
+   * completed using the internal buffers) will fail with the error
+   * asio::error::operation_aborted.
+   *
+   * @param expiry_time The expiry time to be used for the timer.
+   */
+  void expires_from_now(const duration& expiry_time)
+  {
+    rdbuf()->expires_from_now(expiry_time);
+  }
+#endif // !defined(ASIO_NO_DEPRECATED)
+
+private:
+  // Disallow copying and assignment.
+  basic_socket_iostream(const basic_socket_iostream&) ASIO_DELETED;
+  basic_socket_iostream& operator=(
+      const basic_socket_iostream&) ASIO_DELETED;
+};
+
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#if !defined(ASIO_HAS_VARIADIC_TEMPLATES)
+# undef ASIO_PRIVATE_CTR_DEF
+# undef ASIO_PRIVATE_CONNECT_DEF
+#endif // !defined(ASIO_HAS_VARIADIC_TEMPLATES)
+
+#endif // !defined(ASIO_NO_IOSTREAM)
+
+#endif // ASIO_BASIC_SOCKET_IOSTREAM_HPP

lib/asio/include/asio/basic_socket_streambuf.hpp

@@ -0,0 +1,687 @@
+//
+// basic_socket_streambuf.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_BASIC_SOCKET_STREAMBUF_HPP
+#define ASIO_BASIC_SOCKET_STREAMBUF_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if !defined(ASIO_NO_IOSTREAM)
+
+#include <streambuf>
+#include <vector>
+#include "asio/basic_socket.hpp"
+#include "asio/basic_stream_socket.hpp"
+#include "asio/detail/buffer_sequence_adapter.hpp"
+#include "asio/detail/memory.hpp"
+#include "asio/detail/throw_error.hpp"
+#include "asio/io_context.hpp"
+
+#if defined(ASIO_HAS_BOOST_DATE_TIME) \
+  && defined(ASIO_USE_BOOST_DATE_TIME_FOR_SOCKET_IOSTREAM)
+# include "asio/detail/deadline_timer_service.hpp"
+#else // defined(ASIO_HAS_BOOST_DATE_TIME)
+      // && defined(ASIO_USE_BOOST_DATE_TIME_FOR_SOCKET_IOSTREAM)
+# include "asio/steady_timer.hpp"
+#endif // defined(ASIO_HAS_BOOST_DATE_TIME)
+       // && defined(ASIO_USE_BOOST_DATE_TIME_FOR_SOCKET_IOSTREAM)
+
+#if !defined(ASIO_HAS_VARIADIC_TEMPLATES)
+
+# include "asio/detail/variadic_templates.hpp"
+
+// A macro that should expand to:
+//   template <typename T1, ..., typename Tn>
+//   basic_socket_streambuf* connect(T1 x1, ..., Tn xn)
+//   {
+//     init_buffers();
+//     typedef typename Protocol::resolver resolver_type;
+//     resolver_type resolver(socket().get_executor());
+//     connect_to_endpoints(
+//         resolver.resolve(x1, ..., xn, ec_));
+//     return !ec_ ? this : 0;
+//   }
+// This macro should only persist within this file.
+
+# define ASIO_PRIVATE_CONNECT_DEF(n) \
+  template <ASIO_VARIADIC_TPARAMS(n)> \
+  basic_socket_streambuf* connect(ASIO_VARIADIC_BYVAL_PARAMS(n)) \
+  { \
+    init_buffers(); \
+    typedef typename Protocol::resolver resolver_type; \
+    resolver_type resolver(socket().get_executor()); \
+    connect_to_endpoints( \
+        resolver.resolve(ASIO_VARIADIC_BYVAL_ARGS(n), ec_)); \
+    return !ec_ ? this : 0; \
+  } \
+  /**/
+
+#endif // !defined(ASIO_HAS_VARIADIC_TEMPLATES)
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+// A separate base class is used to ensure that the io_context member is
+// initialised prior to the basic_socket_streambuf's basic_socket base class.
+class socket_streambuf_io_context
+{
+protected:
+  socket_streambuf_io_context(io_context* ctx)
+    : default_io_context_(ctx)
+  {
+  }
+
+  shared_ptr<io_context> default_io_context_;
+};
+
+// A separate base class is used to ensure that the dynamically allocated
+// buffers are constructed prior to the basic_socket_streambuf's basic_socket
+// base class. This makes moving the socket is the last potentially throwing
+// step in the streambuf's move constructor, giving the constructor a strong
+// exception safety guarantee.
+class socket_streambuf_buffers
+{
+protected:
+  socket_streambuf_buffers()
+    : get_buffer_(buffer_size),
+      put_buffer_(buffer_size)
+  {
+  }
+
+  enum { buffer_size = 512 };
+  std::vector<char> get_buffer_;
+  std::vector<char> put_buffer_;
+};
+
+} // namespace detail
+
+#if !defined(ASIO_BASIC_SOCKET_STREAMBUF_FWD_DECL)
+#define ASIO_BASIC_SOCKET_STREAMBUF_FWD_DECL
+
+// Forward declaration with defaulted arguments.
+template <typename Protocol,
+#if defined(ASIO_HAS_BOOST_DATE_TIME) \
+  && defined(ASIO_USE_BOOST_DATE_TIME_FOR_SOCKET_IOSTREAM)
+    typename Clock = boost::posix_time::ptime,
+    typename WaitTraits = time_traits<Clock> >
+#else // defined(ASIO_HAS_BOOST_DATE_TIME)
+      // && defined(ASIO_USE_BOOST_DATE_TIME_FOR_SOCKET_IOSTREAM)
+    typename Clock = chrono::steady_clock,
+    typename WaitTraits = wait_traits<Clock> >
+#endif // defined(ASIO_HAS_BOOST_DATE_TIME)
+       // && defined(ASIO_USE_BOOST_DATE_TIME_FOR_SOCKET_IOSTREAM)
+class basic_socket_streambuf;
+
+#endif // !defined(ASIO_BASIC_SOCKET_STREAMBUF_FWD_DECL)
+
+/// Iostream streambuf for a socket.
+#if defined(GENERATING_DOCUMENTATION)
+template <typename Protocol,
+    typename Clock = chrono::steady_clock,
+    typename WaitTraits = wait_traits<Clock> >
+#else // defined(GENERATING_DOCUMENTATION)
+template <typename Protocol, typename Clock, typename WaitTraits>
+#endif // defined(GENERATING_DOCUMENTATION)
+class basic_socket_streambuf
+  : public std::streambuf,
+    private detail::socket_streambuf_io_context,
+    private detail::socket_streambuf_buffers,
+#if defined(ASIO_NO_DEPRECATED) || defined(GENERATING_DOCUMENTATION)
+    private basic_socket<Protocol>
+#else // defined(ASIO_NO_DEPRECATED) || defined(GENERATING_DOCUMENTATION)
+    public basic_socket<Protocol>
+#endif // defined(ASIO_NO_DEPRECATED) || defined(GENERATING_DOCUMENTATION)
+{
+private:
+  // These typedefs are intended keep this class's implementation independent
+  // of whether it's using Boost.DateClock, Boost.Chrono or std::chrono.
+#if defined(ASIO_HAS_BOOST_DATE_TIME) \
+  && defined(ASIO_USE_BOOST_DATE_TIME_FOR_SOCKET_IOSTREAM)
+  typedef WaitTraits traits_helper;
+#else // defined(ASIO_HAS_BOOST_DATE_TIME)
+      // && defined(ASIO_USE_BOOST_DATE_TIME_FOR_SOCKET_IOSTREAM)
+  typedef detail::chrono_time_traits<Clock, WaitTraits> traits_helper;
+#endif // defined(ASIO_HAS_BOOST_DATE_TIME)
+       // && defined(ASIO_USE_BOOST_DATE_TIME_FOR_SOCKET_IOSTREAM)
+
+public:
+  /// The protocol type.
+  typedef Protocol protocol_type;
+
+  /// The endpoint type.
+  typedef typename Protocol::endpoint endpoint_type;
+
+  /// The clock type.
+  typedef Clock clock_type;
+
+#if defined(GENERATING_DOCUMENTATION)
+  /// (Deprecated: Use time_point.) The time type.
+  typedef typename WaitTraits::time_type time_type;
+
+  /// The time type.
+  typedef typename WaitTraits::time_point time_point;
+
+  /// (Deprecated: Use duration.) The duration type.
+  typedef typename WaitTraits::duration_type duration_type;
+
+  /// The duration type.
+  typedef typename WaitTraits::duration duration;
+#else
+# if !defined(ASIO_NO_DEPRECATED)
+  typedef typename traits_helper::time_type time_type;
+  typedef typename traits_helper::duration_type duration_type;
+# endif // !defined(ASIO_NO_DEPRECATED)
+  typedef typename traits_helper::time_type time_point;
+  typedef typename traits_helper::duration_type duration;
+#endif
+
+  /// Construct a basic_socket_streambuf without establishing a connection.
+  basic_socket_streambuf()
+    : detail::socket_streambuf_io_context(new io_context),
+      basic_socket<Protocol>(*default_io_context_),
+      expiry_time_(max_expiry_time())
+  {
+    init_buffers();
+  }
+
+#if defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+  /// Construct a basic_socket_streambuf from the supplied socket.
+  explicit basic_socket_streambuf(basic_stream_socket<protocol_type> s)
+    : detail::socket_streambuf_io_context(0),
+      basic_socket<Protocol>(std::move(s)),
+      expiry_time_(max_expiry_time())
+  {
+    init_buffers();
+  }
+
+  /// Move-construct a basic_socket_streambuf from another.
+  basic_socket_streambuf(basic_socket_streambuf&& other)
+    : detail::socket_streambuf_io_context(other),
+      basic_socket<Protocol>(std::move(other.socket())),
+      ec_(other.ec_),
+      expiry_time_(other.expiry_time_)
+  {
+    get_buffer_.swap(other.get_buffer_);
+    put_buffer_.swap(other.put_buffer_);
+    setg(other.eback(), other.gptr(), other.egptr());
+    setp(other.pptr(), other.epptr());
+    other.ec_ = asio::error_code();
+    other.expiry_time_ = max_expiry_time();
+    other.init_buffers();
+  }
+
+  /// Move-assign a basic_socket_streambuf from another.
+  basic_socket_streambuf& operator=(basic_socket_streambuf&& other)
+  {
+    this->close();
+    socket() = std::move(other.socket());
+    detail::socket_streambuf_io_context::operator=(other);
+    ec_ = other.ec_;
+    expiry_time_ = other.expiry_time_;
+    get_buffer_.swap(other.get_buffer_);
+    put_buffer_.swap(other.put_buffer_);
+    setg(other.eback(), other.gptr(), other.egptr());
+    setp(other.pptr(), other.epptr());
+    other.ec_ = asio::error_code();
+    other.expiry_time_ = max_expiry_time();
+    other.put_buffer_.resize(buffer_size);
+    other.init_buffers();
+    return *this;
+  }
+#endif // defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+
+  /// Destructor flushes buffered data.
+  virtual ~basic_socket_streambuf()
+  {
+    if (pptr() != pbase())
+      overflow(traits_type::eof());
+  }
+
+  /// Establish a connection.
+  /**
+   * This function establishes a connection to the specified endpoint.
+   *
+   * @return \c this if a connection was successfully established, a null
+   * pointer otherwise.
+   */
+  basic_socket_streambuf* connect(const endpoint_type& endpoint)
+  {
+    init_buffers();
+    ec_ = asio::error_code();
+    this->connect_to_endpoints(&endpoint, &endpoint + 1);
+    return !ec_ ? this : 0;
+  }
+
+#if defined(GENERATING_DOCUMENTATION)
+  /// Establish a connection.
+  /**
+   * This function automatically establishes a connection based on the supplied
+   * resolver query parameters. The arguments are used to construct a resolver
+   * query object.
+   *
+   * @return \c this if a connection was successfully established, a null
+   * pointer otherwise.
+   */
+  template <typename T1, ..., typename TN>
+  basic_socket_streambuf* connect(T1 t1, ..., TN tn);
+#elif defined(ASIO_HAS_VARIADIC_TEMPLATES)
+  template <typename... T>
+  basic_socket_streambuf* connect(T... x)
+  {
+    init_buffers();
+    typedef typename Protocol::resolver resolver_type;
+    resolver_type resolver(socket().get_executor());
+    connect_to_endpoints(resolver.resolve(x..., ec_));
+    return !ec_ ? this : 0;
+  }
+#else
+  ASIO_VARIADIC_GENERATE(ASIO_PRIVATE_CONNECT_DEF)
+#endif
+
+  /// Close the connection.
+  /**
+   * @return \c this if a connection was successfully established, a null
+   * pointer otherwise.
+   */
+  basic_socket_streambuf* close()
+  {
+    sync();
+    socket().close(ec_);
+    if (!ec_)
+      init_buffers();
+    return !ec_ ? this : 0;
+  }
+
+  /// Get a reference to the underlying socket.
+  basic_socket<Protocol>& socket()
+  {
+    return *this;
+  }
+
+  /// Get the last error associated with the stream buffer.
+  /**
+   * @return An \c error_code corresponding to the last error from the stream
+   * buffer.
+   */
+  const asio::error_code& error() const
+  {
+    return ec_;
+  }
+
+#if !defined(ASIO_NO_DEPRECATED)
+  /// (Deprecated: Use error().) Get the last error associated with the stream
+  /// buffer.
+  /**
+   * @return An \c error_code corresponding to the last error from the stream
+   * buffer.
+   */
+  const asio::error_code& puberror() const
+  {
+    return error();
+  }
+
+  /// (Deprecated: Use expiry().) Get the stream buffer's expiry time as an
+  /// absolute time.
+  /**
+   * @return An absolute time value representing the stream buffer's expiry
+   * time.
+   */
+  time_point expires_at() const
+  {
+    return expiry_time_;
+  }
+#endif // !defined(ASIO_NO_DEPRECATED)
+
+  /// Get the stream buffer's expiry time as an absolute time.
+  /**
+   * @return An absolute time value representing the stream buffer's expiry
+   * time.
+   */
+  time_point expiry() const
+  {
+    return expiry_time_;
+  }
+
+  /// Set the stream buffer's expiry time as an absolute time.
+  /**
+   * This function sets the expiry time associated with the stream. Stream
+   * operations performed after this time (where the operations cannot be
+   * completed using the internal buffers) will fail with the error
+   * asio::error::operation_aborted.
+   *
+   * @param expiry_time The expiry time to be used for the stream.
+   */
+  void expires_at(const time_point& expiry_time)
+  {
+    expiry_time_ = expiry_time;
+  }
+
+  /// Set the stream buffer's expiry time relative to now.
+  /**
+   * This function sets the expiry time associated with the stream. Stream
+   * operations performed after this time (where the operations cannot be
+   * completed using the internal buffers) will fail with the error
+   * asio::error::operation_aborted.
+   *
+   * @param expiry_time The expiry time to be used for the timer.
+   */
+  void expires_after(const duration& expiry_time)
+  {
+    expiry_time_ = traits_helper::add(traits_helper::now(), expiry_time);
+  }
+
+#if !defined(ASIO_NO_DEPRECATED)
+  /// (Deprecated: Use expiry().) Get the stream buffer's expiry time relative
+  /// to now.
+  /**
+   * @return A relative time value representing the stream buffer's expiry time.
+   */
+  duration expires_from_now() const
+  {
+    return traits_helper::subtract(expires_at(), traits_helper::now());
+  }
+
+  /// (Deprecated: Use expires_after().) Set the stream buffer's expiry time
+  /// relative to now.
+  /**
+   * This function sets the expiry time associated with the stream. Stream
+   * operations performed after this time (where the operations cannot be
+   * completed using the internal buffers) will fail with the error
+   * asio::error::operation_aborted.
+   *
+   * @param expiry_time The expiry time to be used for the timer.
+   */
+  void expires_from_now(const duration& expiry_time)
+  {
+    expiry_time_ = traits_helper::add(traits_helper::now(), expiry_time);
+  }
+#endif // !defined(ASIO_NO_DEPRECATED)
+
+protected:
+  int_type underflow()
+  {
+#if defined(ASIO_WINDOWS_RUNTIME)
+    ec_ = asio::error::operation_not_supported;
+    return traits_type::eof();
+#else // defined(ASIO_WINDOWS_RUNTIME)
+    if (gptr() != egptr())
+      return traits_type::eof();
+
+    for (;;)
+    {
+      // Check if we are past the expiry time.
+      if (traits_helper::less_than(expiry_time_, traits_helper::now()))
+      {
+        ec_ = asio::error::timed_out;
+        return traits_type::eof();
+      }
+
+      // Try to complete the operation without blocking.
+      if (!socket().native_non_blocking())
+        socket().native_non_blocking(true, ec_);
+      detail::buffer_sequence_adapter<mutable_buffer, mutable_buffer>
+        bufs(asio::buffer(get_buffer_) + putback_max);
+      detail::signed_size_type bytes = detail::socket_ops::recv(
+          socket().native_handle(), bufs.buffers(), bufs.count(), 0, ec_);
+
+      // Check if operation succeeded.
+      if (bytes > 0)
+      {
+        setg(&get_buffer_[0], &get_buffer_[0] + putback_max,
+            &get_buffer_[0] + putback_max + bytes);
+        return traits_type::to_int_type(*gptr());
+      }
+
+      // Check for EOF.
+      if (bytes == 0)
+      {
+        ec_ = asio::error::eof;
+        return traits_type::eof();
+      }
+
+      // Operation failed.
+      if (ec_ != asio::error::would_block
+          && ec_ != asio::error::try_again)
+        return traits_type::eof();
+
+      // Wait for socket to become ready.
+      if (detail::socket_ops::poll_read(
+            socket().native_handle(), 0, timeout(), ec_) < 0)
+        return traits_type::eof();
+    }
+#endif // defined(ASIO_WINDOWS_RUNTIME)
+  }
+
+  int_type overflow(int_type c)
+  {
+#if defined(ASIO_WINDOWS_RUNTIME)
+    ec_ = asio::error::operation_not_supported;
+    return traits_type::eof();
+#else // defined(ASIO_WINDOWS_RUNTIME)
+    char_type ch = traits_type::to_char_type(c);
+
+    // Determine what needs to be sent.
+    const_buffer output_buffer;
+    if (put_buffer_.empty())
+    {
+      if (traits_type::eq_int_type(c, traits_type::eof()))
+        return traits_type::not_eof(c); // Nothing to do.
+      output_buffer = asio::buffer(&ch, sizeof(char_type));
+    }
+    else
+    {
+      output_buffer = asio::buffer(pbase(),
+          (pptr() - pbase()) * sizeof(char_type));
+    }
+
+    while (output_buffer.size() > 0)
+    {
+      // Check if we are past the expiry time.
+      if (traits_helper::less_than(expiry_time_, traits_helper::now()))
+      {
+        ec_ = asio::error::timed_out;
+        return traits_type::eof();
+      }
+
+      // Try to complete the operation without blocking.
+      if (!socket().native_non_blocking())
+        socket().native_non_blocking(true, ec_);
+      detail::buffer_sequence_adapter<
+        const_buffer, const_buffer> bufs(output_buffer);
+      detail::signed_size_type bytes = detail::socket_ops::send(
+          socket().native_handle(), bufs.buffers(), bufs.count(), 0, ec_);
+
+      // Check if operation succeeded.
+      if (bytes > 0)
+      {
+        output_buffer += static_cast<std::size_t>(bytes);
+        continue;
+      }
+
+      // Operation failed.
+      if (ec_ != asio::error::would_block
+          && ec_ != asio::error::try_again)
+        return traits_type::eof();
+
+      // Wait for socket to become ready.
+      if (detail::socket_ops::poll_write(
+            socket().native_handle(), 0, timeout(), ec_) < 0)
+        return traits_type::eof();
+    }
+
+    if (!put_buffer_.empty())
+    {
+      setp(&put_buffer_[0], &put_buffer_[0] + put_buffer_.size());
+
+      // If the new character is eof then our work here is done.
+      if (traits_type::eq_int_type(c, traits_type::eof()))
+        return traits_type::not_eof(c);
+
+      // Add the new character to the output buffer.
+      *pptr() = ch;
+      pbump(1);
+    }
+
+    return c;
+#endif // defined(ASIO_WINDOWS_RUNTIME)
+  }
+
+  int sync()
+  {
+    return overflow(traits_type::eof());
+  }
+
+  std::streambuf* setbuf(char_type* s, std::streamsize n)
+  {
+    if (pptr() == pbase() && s == 0 && n == 0)
+    {
+      put_buffer_.clear();
+      setp(0, 0);
+      sync();
+      return this;
+    }
+
+    return 0;
+  }
+
+private:
+  // Disallow copying and assignment.
+  basic_socket_streambuf(const basic_socket_streambuf&) ASIO_DELETED;
+  basic_socket_streambuf& operator=(
+      const basic_socket_streambuf&) ASIO_DELETED;
+
+  void init_buffers()
+  {
+    setg(&get_buffer_[0],
+        &get_buffer_[0] + putback_max,
+        &get_buffer_[0] + putback_max);
+
+    if (put_buffer_.empty())
+      setp(0, 0);
+    else
+      setp(&put_buffer_[0], &put_buffer_[0] + put_buffer_.size());
+  }
+
+  int timeout() const
+  {
+    int64_t msec = traits_helper::to_posix_duration(
+        traits_helper::subtract(expiry_time_,
+          traits_helper::now())).total_milliseconds();
+    if (msec > (std::numeric_limits<int>::max)())
+      msec = (std::numeric_limits<int>::max)();
+    else if (msec < 0)
+      msec = 0;
+    return static_cast<int>(msec);
+  }
+
+  template <typename EndpointSequence>
+  void connect_to_endpoints(const EndpointSequence& endpoints)
+  {
+    this->connect_to_endpoints(endpoints.begin(), endpoints.end());
+  }
+
+  template <typename EndpointIterator>
+  void connect_to_endpoints(EndpointIterator begin, EndpointIterator end)
+  {
+#if defined(ASIO_WINDOWS_RUNTIME)
+    ec_ = asio::error::operation_not_supported;
+#else // defined(ASIO_WINDOWS_RUNTIME)
+    if (ec_)
+      return;
+
+    ec_ = asio::error::not_found;
+    for (EndpointIterator i = begin; i != end; ++i)
+    {
+      // Check if we are past the expiry time.
+      if (traits_helper::less_than(expiry_time_, traits_helper::now()))
+      {
+        ec_ = asio::error::timed_out;
+        return;
+      }
+
+      // Close and reopen the socket.
+      typename Protocol::endpoint ep(*i);
+      socket().close(ec_);
+      socket().open(ep.protocol(), ec_);
+      if (ec_)
+        continue;
+
+      // Try to complete the operation without blocking.
+      if (!socket().native_non_blocking())
+        socket().native_non_blocking(true, ec_);
+      detail::socket_ops::connect(socket().native_handle(),
+          ep.data(), ep.size(), ec_);
+
+      // Check if operation succeeded.
+      if (!ec_)
+        return;
+
+      // Operation failed.
+      if (ec_ != asio::error::in_progress
+          && ec_ != asio::error::would_block)
+        continue;
+
+      // Wait for socket to become ready.
+      if (detail::socket_ops::poll_connect(
+            socket().native_handle(), timeout(), ec_) < 0)
+        continue;
+
+      // Get the error code from the connect operation.
+      int connect_error = 0;
+      size_t connect_error_len = sizeof(connect_error);
+      if (detail::socket_ops::getsockopt(socket().native_handle(), 0,
+            SOL_SOCKET, SO_ERROR, &connect_error, &connect_error_len, ec_)
+          == detail::socket_error_retval)
+        return;
+
+      // Check the result of the connect operation.
+      ec_ = asio::error_code(connect_error,
+          asio::error::get_system_category());
+      if (!ec_)
+        return;
+    }
+#endif // defined(ASIO_WINDOWS_RUNTIME)
+  }
+
+  // Helper function to get the maximum expiry time.
+  static time_point max_expiry_time()
+  {
+#if defined(ASIO_HAS_BOOST_DATE_TIME) \
+  && defined(ASIO_USE_BOOST_DATE_TIME_FOR_SOCKET_IOSTREAM)
+    return boost::posix_time::pos_infin;
+#else // defined(ASIO_HAS_BOOST_DATE_TIME)
+      // && defined(ASIO_USE_BOOST_DATE_TIME_FOR_SOCKET_IOSTREAM)
+    return (time_point::max)();
+#endif // defined(ASIO_HAS_BOOST_DATE_TIME)
+       // && defined(ASIO_USE_BOOST_DATE_TIME_FOR_SOCKET_IOSTREAM)
+  }
+
+  enum { putback_max = 8 };
+  asio::error_code ec_;
+  time_point expiry_time_;
+};
+
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#if !defined(ASIO_HAS_VARIADIC_TEMPLATES)
+# undef ASIO_PRIVATE_CONNECT_DEF
+#endif // !defined(ASIO_HAS_VARIADIC_TEMPLATES)
+
+#endif // !defined(ASIO_NO_IOSTREAM)
+
+#endif // ASIO_BASIC_SOCKET_STREAMBUF_HPP

lib/asio/include/asio/basic_stream_file.hpp

@@ -0,0 +1,742 @@
+//
+// basic_stream_file.hpp
+// ~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_BASIC_STREAM_FILE_HPP
+#define ASIO_BASIC_STREAM_FILE_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_HAS_FILE) \
+  || defined(GENERATING_DOCUMENTATION)
+
+#include <cstddef>
+#include "asio/async_result.hpp"
+#include "asio/basic_file.hpp"
+#include "asio/detail/handler_type_requirements.hpp"
+#include "asio/detail/non_const_lvalue.hpp"
+#include "asio/detail/throw_error.hpp"
+#include "asio/error.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+
+#if !defined(ASIO_BASIC_STREAM_FILE_FWD_DECL)
+#define ASIO_BASIC_STREAM_FILE_FWD_DECL
+
+// Forward declaration with defaulted arguments.
+template <typename Executor = any_io_executor>
+class basic_stream_file;
+
+#endif // !defined(ASIO_BASIC_STREAM_FILE_FWD_DECL)
+
+/// Provides stream-oriented file functionality.
+/**
+ * The basic_stream_file class template provides asynchronous and blocking
+ * stream-oriented file functionality.
+ *
+ * @par Thread Safety
+ * @e Distinct @e objects: Safe.@n
+ * @e Shared @e objects: Unsafe.
+ *
+ * @par Concepts:
+ * AsyncReadStream, AsyncWriteStream, Stream, SyncReadStream, SyncWriteStream.
+ */
+template <typename Executor>
+class basic_stream_file
+  : public basic_file<Executor>
+{
+public:
+  /// The type of the executor associated with the object.
+  typedef Executor executor_type;
+
+  /// Rebinds the file type to another executor.
+  template <typename Executor1>
+  struct rebind_executor
+  {
+    /// The file type when rebound to the specified executor.
+    typedef basic_stream_file<Executor1> other;
+  };
+
+  /// The native representation of a file.
+#if defined(GENERATING_DOCUMENTATION)
+  typedef implementation_defined native_handle_type;
+#else
+  typedef typename basic_file<Executor>::native_handle_type native_handle_type;
+#endif
+
+  /// Construct a basic_stream_file without opening it.
+  /**
+   * This constructor initialises a file without opening it. The file needs to
+   * be opened before data can be read from or or written to it.
+   *
+   * @param ex The I/O executor that the file will use, by default, to
+   * dispatch handlers for any asynchronous operations performed on the file.
+   */
+  explicit basic_stream_file(const executor_type& ex)
+    : basic_file<Executor>(ex)
+  {
+    this->impl_.get_service().set_is_stream(
+        this->impl_.get_implementation(), true);
+  }
+
+  /// Construct a basic_stream_file without opening it.
+  /**
+   * This constructor initialises a file without opening it. The file needs to
+   * be opened before data can be read from or or written to it.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the file will use, by default, to dispatch handlers for any asynchronous
+   * operations performed on the file.
+   */
+  template <typename ExecutionContext>
+  explicit basic_stream_file(ExecutionContext& context,
+      typename constraint<
+        is_convertible<ExecutionContext&, execution_context&>::value,
+        defaulted_constraint
+      >::type = defaulted_constraint())
+    : basic_file<Executor>(context)
+  {
+    this->impl_.get_service().set_is_stream(
+        this->impl_.get_implementation(), true);
+  }
+
+  /// Construct and open a basic_stream_file.
+  /**
+   * This constructor initialises and opens a file.
+   *
+   * @param ex The I/O executor that the file will use, by default, to
+   * dispatch handlers for any asynchronous operations performed on the file.
+   *
+   * @param path The path name identifying the file to be opened.
+   *
+   * @param open_flags A set of flags that determine how the file should be
+   * opened.
+   *
+   * @throws asio::system_error Thrown on failure.
+   */
+  basic_stream_file(const executor_type& ex,
+      const char* path, file_base::flags open_flags)
+    : basic_file<Executor>(ex)
+  {
+    asio::error_code ec;
+    this->impl_.get_service().set_is_stream(
+        this->impl_.get_implementation(), true);
+    this->impl_.get_service().open(
+        this->impl_.get_implementation(),
+        path, open_flags, ec);
+    asio::detail::throw_error(ec, "open");
+  }
+
+  /// Construct and open a basic_stream_file.
+  /**
+   * This constructor initialises and opens a file.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the file will use, by default, to dispatch handlers for any asynchronous
+   * operations performed on the file.
+   *
+   * @param path The path name identifying the file to be opened.
+   *
+   * @param open_flags A set of flags that determine how the file should be
+   * opened.
+   *
+   * @throws asio::system_error Thrown on failure.
+   */
+  template <typename ExecutionContext>
+  basic_stream_file(ExecutionContext& context,
+      const char* path, file_base::flags open_flags,
+      typename constraint<
+        is_convertible<ExecutionContext&, execution_context&>::value,
+        defaulted_constraint
+      >::type = defaulted_constraint())
+    : basic_file<Executor>(context)
+  {
+    asio::error_code ec;
+    this->impl_.get_service().set_is_stream(
+        this->impl_.get_implementation(), true);
+    this->impl_.get_service().open(
+        this->impl_.get_implementation(),
+        path, open_flags, ec);
+    asio::detail::throw_error(ec, "open");
+  }
+
+  /// Construct and open a basic_stream_file.
+  /**
+   * This constructor initialises and opens a file.
+   *
+   * @param ex The I/O executor that the file will use, by default, to
+   * dispatch handlers for any asynchronous operations performed on the file.
+   *
+   * @param path The path name identifying the file to be opened.
+   *
+   * @param open_flags A set of flags that determine how the file should be
+   * opened.
+   *
+   * @throws asio::system_error Thrown on failure.
+   */
+  basic_stream_file(const executor_type& ex,
+      const std::string& path, file_base::flags open_flags)
+    : basic_file<Executor>(ex)
+  {
+    asio::error_code ec;
+    this->impl_.get_service().set_is_stream(
+        this->impl_.get_implementation(), true);
+    this->impl_.get_service().open(
+        this->impl_.get_implementation(),
+        path.c_str(), open_flags, ec);
+    asio::detail::throw_error(ec, "open");
+  }
+
+  /// Construct and open a basic_stream_file.
+  /**
+   * This constructor initialises and opens a file.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the file will use, by default, to dispatch handlers for any asynchronous
+   * operations performed on the file.
+   *
+   * @param path The path name identifying the file to be opened.
+   *
+   * @param open_flags A set of flags that determine how the file should be
+   * opened.
+   *
+   * @throws asio::system_error Thrown on failure.
+   */
+  template <typename ExecutionContext>
+  basic_stream_file(ExecutionContext& context,
+      const std::string& path, file_base::flags open_flags,
+      typename constraint<
+        is_convertible<ExecutionContext&, execution_context&>::value,
+        defaulted_constraint
+      >::type = defaulted_constraint())
+    : basic_file<Executor>(context)
+  {
+    asio::error_code ec;
+    this->impl_.get_service().set_is_stream(
+        this->impl_.get_implementation(), true);
+    this->impl_.get_service().open(
+        this->impl_.get_implementation(),
+        path.c_str(), open_flags, ec);
+    asio::detail::throw_error(ec, "open");
+  }
+
+  /// Construct a basic_stream_file on an existing native file.
+  /**
+   * This constructor initialises a stream file object to hold an existing
+   * native file.
+   *
+   * @param ex The I/O executor that the file will use, by default, to
+   * dispatch handlers for any asynchronous operations performed on the file.
+   *
+   * @param native_file The new underlying file implementation.
+   *
+   * @throws asio::system_error Thrown on failure.
+   */
+  basic_stream_file(const executor_type& ex,
+      const native_handle_type& native_file)
+    : basic_file<Executor>(ex, native_file)
+  {
+    this->impl_.get_service().set_is_stream(
+        this->impl_.get_implementation(), true);
+  }
+
+  /// Construct a basic_stream_file on an existing native file.
+  /**
+   * This constructor initialises a stream file object to hold an existing
+   * native file.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the file will use, by default, to dispatch handlers for any asynchronous
+   * operations performed on the file.
+   *
+   * @param native_file The new underlying file implementation.
+   *
+   * @throws asio::system_error Thrown on failure.
+   */
+  template <typename ExecutionContext>
+  basic_stream_file(ExecutionContext& context,
+      const native_handle_type& native_file,
+      typename constraint<
+        is_convertible<ExecutionContext&, execution_context&>::value,
+        defaulted_constraint
+      >::type = defaulted_constraint())
+    : basic_file<Executor>(context, native_file)
+  {
+    this->impl_.get_service().set_is_stream(
+        this->impl_.get_implementation(), true);
+  }
+
+#if defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+  /// Move-construct a basic_stream_file from another.
+  /**
+   * This constructor moves a stream file from one object to another.
+   *
+   * @param other The other basic_stream_file object from which the move
+   * will occur.
+   *
+   * @note Following the move, the moved-from object is in the same state as if
+   * constructed using the @c basic_stream_file(const executor_type&)
+   * constructor.
+   */
+  basic_stream_file(basic_stream_file&& other) ASIO_NOEXCEPT
+    : basic_file<Executor>(std::move(other))
+  {
+  }
+
+  /// Move-assign a basic_stream_file from another.
+  /**
+   * This assignment operator moves a stream file from one object to another.
+   *
+   * @param other The other basic_stream_file object from which the move
+   * will occur.
+   *
+   * @note Following the move, the moved-from object is in the same state as if
+   * constructed using the @c basic_stream_file(const executor_type&)
+   * constructor.
+   */
+  basic_stream_file& operator=(basic_stream_file&& other)
+  {
+    basic_file<Executor>::operator=(std::move(other));
+    return *this;
+  }
+
+  /// Move-construct a basic_stream_file from a file of another executor
+  /// type.
+  /**
+   * This constructor moves a stream file from one object to another.
+   *
+   * @param other The other basic_stream_file object from which the move
+   * will occur.
+   *
+   * @note Following the move, the moved-from object is in the same state as if
+   * constructed using the @c basic_stream_file(const executor_type&)
+   * constructor.
+   */
+  template <typename Executor1>
+  basic_stream_file(basic_stream_file<Executor1>&& other,
+      typename constraint<
+        is_convertible<Executor1, Executor>::value,
+        defaulted_constraint
+      >::type = defaulted_constraint())
+    : basic_file<Executor>(std::move(other))
+  {
+  }
+
+  /// Move-assign a basic_stream_file from a file of another executor type.
+  /**
+   * This assignment operator moves a stream file from one object to another.
+   *
+   * @param other The other basic_stream_file object from which the move
+   * will occur.
+   *
+   * @note Following the move, the moved-from object is in the same state as if
+   * constructed using the @c basic_stream_file(const executor_type&)
+   * constructor.
+   */
+  template <typename Executor1>
+  typename constraint<
+    is_convertible<Executor1, Executor>::value,
+    basic_stream_file&
+  >::type operator=(basic_stream_file<Executor1>&& other)
+  {
+    basic_file<Executor>::operator=(std::move(other));
+    return *this;
+  }
+#endif // defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+
+  /// Destroys the file.
+  /**
+   * This function destroys the file, cancelling any outstanding asynchronous
+   * operations associated with the file as if by calling @c cancel.
+   */
+  ~basic_stream_file()
+  {
+  }
+
+  /// Seek to a position in the file.
+  /**
+   * This function updates the current position in the file.
+   *
+   * @param offset The requested position in the file, relative to @c whence.
+   *
+   * @param whence One of @c seek_set, @c seek_cur or @c seek_end.
+   *
+   * @returns The new position relative to the beginning of the file.
+   *
+   * @throws asio::system_error Thrown on failure.
+   */
+  uint64_t seek(int64_t offset, file_base::seek_basis whence)
+  {
+    asio::error_code ec;
+    uint64_t n = this->impl_.get_service().seek(
+        this->impl_.get_implementation(), offset, whence, ec);
+    asio::detail::throw_error(ec, "seek");
+    return n;
+  }
+
+  /// Seek to a position in the file.
+  /**
+   * This function updates the current position in the file.
+   *
+   * @param offset The requested position in the file, relative to @c whence.
+   *
+   * @param whence One of @c seek_set, @c seek_cur or @c seek_end.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @returns The new position relative to the beginning of the file.
+   */
+  uint64_t seek(int64_t offset, file_base::seek_basis whence,
+      asio::error_code& ec)
+  {
+    return this->impl_.get_service().seek(
+        this->impl_.get_implementation(), offset, whence, ec);
+  }
+
+  /// Write some data to the file.
+  /**
+   * This function is used to write data to the stream file. The function call
+   * will block until one or more bytes of the data has been written
+   * successfully, or until an error occurs.
+   *
+   * @param buffers One or more data buffers to be written to the file.
+   *
+   * @returns The number of bytes written.
+   *
+   * @throws asio::system_error Thrown on failure. An error code of
+   * asio::error::eof indicates that the end of the file was reached.
+   *
+   * @note The write_some operation may not transmit all of the data to the
+   * peer. Consider using the @ref write function if you need to ensure that
+   * all data is written before the blocking operation completes.
+   *
+   * @par Example
+   * To write a single data buffer use the @ref buffer function as follows:
+   * @code
+   * file.write_some(asio::buffer(data, size));
+   * @endcode
+   * See the @ref buffer documentation for information on writing multiple
+   * buffers in one go, and how to use it with arrays, boost::array or
+   * std::vector.
+   */
+  template <typename ConstBufferSequence>
+  std::size_t write_some(const ConstBufferSequence& buffers)
+  {
+    asio::error_code ec;
+    std::size_t s = this->impl_.get_service().write_some(
+        this->impl_.get_implementation(), buffers, ec);
+    asio::detail::throw_error(ec, "write_some");
+    return s;
+  }
+
+  /// Write some data to the file.
+  /**
+   * This function is used to write data to the stream file. The function call
+   * will block until one or more bytes of the data has been written
+   * successfully, or until an error occurs.
+   *
+   * @param buffers One or more data buffers to be written to the file.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @returns The number of bytes written. Returns 0 if an error occurred.
+   *
+   * @note The write_some operation may not transmit all of the data to the
+   * peer. Consider using the @ref write function if you need to ensure that
+   * all data is written before the blocking operation completes.
+   */
+  template <typename ConstBufferSequence>
+  std::size_t write_some(const ConstBufferSequence& buffers,
+      asio::error_code& ec)
+  {
+    return this->impl_.get_service().write_some(
+        this->impl_.get_implementation(), buffers, ec);
+  }
+
+  /// Start an asynchronous write.
+  /**
+   * This function is used to asynchronously write data to the stream file.
+   * It is an initiating function for an @ref asynchronous_operation, and always
+   * returns immediately.
+   *
+   * @param buffers One or more data buffers to be written to the file.
+   * Although the buffers object may be copied as necessary, ownership of the
+   * underlying memory blocks is retained by the caller, which must guarantee
+   * that they remain valid until the completion handler is called.
+   *
+   * @param token The @ref completion_token that will be used to produce a
+   * completion handler, which will be called when the write completes.
+   * Potential completion tokens include @ref use_future, @ref use_awaitable,
+   * @ref yield_context, or a function object with the correct completion
+   * signature. The function signature of the completion handler must be:
+   * @code void handler(
+   *   const asio::error_code& error, // Result of operation.
+   *   std::size_t bytes_transferred // Number of bytes written.
+   * ); @endcode
+   * Regardless of whether the asynchronous operation completes immediately or
+   * not, the completion handler will not be invoked from within this function.
+   * On immediate completion, invocation of the handler will be performed in a
+   * manner equivalent to using asio::post().
+   *
+   * @par Completion Signature
+   * @code void(asio::error_code, std::size_t) @endcode
+   *
+   * @note The write operation may not transmit all of the data to the peer.
+   * Consider using the @ref async_write function if you need to ensure that all
+   * data is written before the asynchronous operation completes.
+   *
+   * @par Example
+   * To write a single data buffer use the @ref buffer function as follows:
+   * @code
+   * file.async_write_some(asio::buffer(data, size), handler);
+   * @endcode
+   * See the @ref buffer documentation for information on writing multiple
+   * buffers in one go, and how to use it with arrays, boost::array or
+   * std::vector.
+   *
+   * @par Per-Operation Cancellation
+   * On POSIX or Windows operating systems, this asynchronous operation supports
+   * cancellation for the following asio::cancellation_type values:
+   *
+   * @li @c cancellation_type::terminal
+   *
+   * @li @c cancellation_type::partial
+   *
+   * @li @c cancellation_type::total
+   */
+  template <typename ConstBufferSequence,
+      ASIO_COMPLETION_TOKEN_FOR(void (asio::error_code,
+        std::size_t)) WriteToken
+          ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(executor_type)>
+  ASIO_INITFN_AUTO_RESULT_TYPE(WriteToken,
+      void (asio::error_code, std::size_t))
+  async_write_some(const ConstBufferSequence& buffers,
+      ASIO_MOVE_ARG(WriteToken) token
+        ASIO_DEFAULT_COMPLETION_TOKEN(executor_type))
+  {
+    return async_initiate<WriteToken,
+      void (asio::error_code, std::size_t)>(
+        initiate_async_write_some(this), token, buffers);
+  }
+
+  /// Read some data from the file.
+  /**
+   * This function is used to read data from the stream file. The function
+   * call will block until one or more bytes of data has been read successfully,
+   * or until an error occurs.
+   *
+   * @param buffers One or more buffers into which the data will be read.
+   *
+   * @returns The number of bytes read.
+   *
+   * @throws asio::system_error Thrown on failure. An error code of
+   * asio::error::eof indicates that the end of the file was reached.
+   *
+   * @note The read_some operation may not read all of the requested number of
+   * bytes. Consider using the @ref read function if you need to ensure that
+   * the requested amount of data is read before the blocking operation
+   * completes.
+   *
+   * @par Example
+   * To read into a single data buffer use the @ref buffer function as follows:
+   * @code
+   * file.read_some(asio::buffer(data, size));
+   * @endcode
+   * See the @ref buffer documentation for information on reading into multiple
+   * buffers in one go, and how to use it with arrays, boost::array or
+   * std::vector.
+   */
+  template <typename MutableBufferSequence>
+  std::size_t read_some(const MutableBufferSequence& buffers)
+  {
+    asio::error_code ec;
+    std::size_t s = this->impl_.get_service().read_some(
+        this->impl_.get_implementation(), buffers, ec);
+    asio::detail::throw_error(ec, "read_some");
+    return s;
+  }
+
+  /// Read some data from the file.
+  /**
+   * This function is used to read data from the stream file. The function
+   * call will block until one or more bytes of data has been read successfully,
+   * or until an error occurs.
+   *
+   * @param buffers One or more buffers into which the data will be read.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @returns The number of bytes read. Returns 0 if an error occurred.
+   *
+   * @note The read_some operation may not read all of the requested number of
+   * bytes. Consider using the @ref read function if you need to ensure that
+   * the requested amount of data is read before the blocking operation
+   * completes.
+   */
+  template <typename MutableBufferSequence>
+  std::size_t read_some(const MutableBufferSequence& buffers,
+      asio::error_code& ec)
+  {
+    return this->impl_.get_service().read_some(
+        this->impl_.get_implementation(), buffers, ec);
+  }
+
+  /// Start an asynchronous read.
+  /**
+   * This function is used to asynchronously read data from the stream file.
+   * It is an initiating function for an @ref asynchronous_operation, and always
+   * returns immediately.
+   *
+   * @param buffers One or more buffers into which the data will be read.
+   * Although the buffers object may be copied as necessary, ownership of the
+   * underlying memory blocks is retained by the caller, which must guarantee
+   * that they remain valid until the completion handler is called.
+   *
+   * @param token The @ref completion_token that will be used to produce a
+   * completion handler, which will be called when the read completes.
+   * Potential completion tokens include @ref use_future, @ref use_awaitable,
+   * @ref yield_context, or a function object with the correct completion
+   * signature. The function signature of the completion handler must be:
+   * @code void handler(
+   *   const asio::error_code& error, // Result of operation.
+   *   std::size_t bytes_transferred // Number of bytes read.
+   * ); @endcode
+   * Regardless of whether the asynchronous operation completes immediately or
+   * not, the completion handler will not be invoked from within this function.
+   * On immediate completion, invocation of the handler will be performed in a
+   * manner equivalent to using asio::post().
+   *
+   * @par Completion Signature
+   * @code void(asio::error_code, std::size_t) @endcode
+   *
+   * @note The read operation may not read all of the requested number of bytes.
+   * Consider using the @ref async_read function if you need to ensure that the
+   * requested amount of data is read before the asynchronous operation
+   * completes.
+   *
+   * @par Example
+   * To read into a single data buffer use the @ref buffer function as follows:
+   * @code
+   * file.async_read_some(asio::buffer(data, size), handler);
+   * @endcode
+   * See the @ref buffer documentation for information on reading into multiple
+   * buffers in one go, and how to use it with arrays, boost::array or
+   * std::vector.
+   *
+   * @par Per-Operation Cancellation
+   * On POSIX or Windows operating systems, this asynchronous operation supports
+   * cancellation for the following asio::cancellation_type values:
+   *
+   * @li @c cancellation_type::terminal
+   *
+   * @li @c cancellation_type::partial
+   *
+   * @li @c cancellation_type::total
+   */
+  template <typename MutableBufferSequence,
+      ASIO_COMPLETION_TOKEN_FOR(void (asio::error_code,
+        std::size_t)) ReadToken
+          ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(executor_type)>
+  ASIO_INITFN_AUTO_RESULT_TYPE(ReadToken,
+      void (asio::error_code, std::size_t))
+  async_read_some(const MutableBufferSequence& buffers,
+      ASIO_MOVE_ARG(ReadToken) token
+        ASIO_DEFAULT_COMPLETION_TOKEN(executor_type))
+  {
+    return async_initiate<ReadToken,
+      void (asio::error_code, std::size_t)>(
+        initiate_async_read_some(this), token, buffers);
+  }
+
+private:
+  // Disallow copying and assignment.
+  basic_stream_file(const basic_stream_file&) ASIO_DELETED;
+  basic_stream_file& operator=(const basic_stream_file&) ASIO_DELETED;
+
+  class initiate_async_write_some
+  {
+  public:
+    typedef Executor executor_type;
+
+    explicit initiate_async_write_some(basic_stream_file* self)
+      : self_(self)
+    {
+    }
+
+    executor_type get_executor() const ASIO_NOEXCEPT
+    {
+      return self_->get_executor();
+    }
+
+    template <typename WriteHandler, typename ConstBufferSequence>
+    void operator()(ASIO_MOVE_ARG(WriteHandler) handler,
+        const ConstBufferSequence& buffers) const
+    {
+      // If you get an error on the following line it means that your handler
+      // does not meet the documented type requirements for a WriteHandler.
+      ASIO_WRITE_HANDLER_CHECK(WriteHandler, handler) type_check;
+
+      detail::non_const_lvalue<WriteHandler> handler2(handler);
+      self_->impl_.get_service().async_write_some(
+          self_->impl_.get_implementation(), buffers,
+          handler2.value, self_->impl_.get_executor());
+    }
+
+  private:
+    basic_stream_file* self_;
+  };
+
+  class initiate_async_read_some
+  {
+  public:
+    typedef Executor executor_type;
+
+    explicit initiate_async_read_some(basic_stream_file* self)
+      : self_(self)
+    {
+    }
+
+    executor_type get_executor() const ASIO_NOEXCEPT
+    {
+      return self_->get_executor();
+    }
+
+    template <typename ReadHandler, typename MutableBufferSequence>
+    void operator()(ASIO_MOVE_ARG(ReadHandler) handler,
+        const MutableBufferSequence& buffers) const
+    {
+      // If you get an error on the following line it means that your handler
+      // does not meet the documented type requirements for a ReadHandler.
+      ASIO_READ_HANDLER_CHECK(ReadHandler, handler) type_check;
+
+      detail::non_const_lvalue<ReadHandler> handler2(handler);
+      self_->impl_.get_service().async_read_some(
+          self_->impl_.get_implementation(), buffers,
+          handler2.value, self_->impl_.get_executor());
+    }
+
+  private:
+    basic_stream_file* self_;
+  };
+};
+
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // defined(ASIO_HAS_FILE)
+       //   || defined(GENERATING_DOCUMENTATION)
+
+#endif // ASIO_BASIC_STREAM_FILE_HPP

lib/asio/include/asio/basic_streambuf.hpp

@@ -0,0 +1,452 @@
+//
+// basic_streambuf.hpp
+// ~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_BASIC_STREAMBUF_HPP
+#define ASIO_BASIC_STREAMBUF_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if !defined(ASIO_NO_IOSTREAM)
+
+#include <algorithm>
+#include <cstring>
+#include <stdexcept>
+#include <streambuf>
+#include <vector>
+#include "asio/basic_streambuf_fwd.hpp"
+#include "asio/buffer.hpp"
+#include "asio/detail/limits.hpp"
+#include "asio/detail/noncopyable.hpp"
+#include "asio/detail/throw_exception.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+
+/// Automatically resizable buffer class based on std::streambuf.
+/**
+ * The @c basic_streambuf class is derived from @c std::streambuf to associate
+ * the streambuf's input and output sequences with one or more character
+ * arrays. These character arrays are internal to the @c basic_streambuf
+ * object, but direct access to the array elements is provided to permit them
+ * to be used efficiently with I/O operations. Characters written to the output
+ * sequence of a @c basic_streambuf object are appended to the input sequence
+ * of the same object.
+ *
+ * The @c basic_streambuf class's public interface is intended to permit the
+ * following implementation strategies:
+ *
+ * @li A single contiguous character array, which is reallocated as necessary
+ * to accommodate changes in the size of the character sequence. This is the
+ * implementation approach currently used in Asio.
+ *
+ * @li A sequence of one or more character arrays, where each array is of the
+ * same size. Additional character array objects are appended to the sequence
+ * to accommodate changes in the size of the character sequence.
+ *
+ * @li A sequence of one or more character arrays of varying sizes. Additional
+ * character array objects are appended to the sequence to accommodate changes
+ * in the size of the character sequence.
+ *
+ * The constructor for basic_streambuf accepts a @c size_t argument specifying
+ * the maximum of the sum of the sizes of the input sequence and output
+ * sequence. During the lifetime of the @c basic_streambuf object, the following
+ * invariant holds:
+ * @code size() <= max_size()@endcode
+ * Any member function that would, if successful, cause the invariant to be
+ * violated shall throw an exception of class @c std::length_error.
+ *
+ * The constructor for @c basic_streambuf takes an Allocator argument. A copy
+ * of this argument is used for any memory allocation performed, by the
+ * constructor and by all member functions, during the lifetime of each @c
+ * basic_streambuf object.
+ *
+ * @par Examples
+ * Writing directly from an streambuf to a socket:
+ * @code
+ * asio::streambuf b;
+ * std::ostream os(&b);
+ * os << "Hello, World!\n";
+ *
+ * // try sending some data in input sequence
+ * size_t n = sock.send(b.data());
+ *
+ * b.consume(n); // sent data is removed from input sequence
+ * @endcode
+ *
+ * Reading from a socket directly into a streambuf:
+ * @code
+ * asio::streambuf b;
+ *
+ * // reserve 512 bytes in output sequence
+ * asio::streambuf::mutable_buffers_type bufs = b.prepare(512);
+ *
+ * size_t n = sock.receive(bufs);
+ *
+ * // received data is "committed" from output sequence to input sequence
+ * b.commit(n);
+ *
+ * std::istream is(&b);
+ * std::string s;
+ * is >> s;
+ * @endcode
+ */
+#if defined(GENERATING_DOCUMENTATION)
+template <typename Allocator = std::allocator<char> >
+#else
+template <typename Allocator>
+#endif
+class basic_streambuf
+  : public std::streambuf,
+    private noncopyable
+{
+public:
+#if defined(GENERATING_DOCUMENTATION)
+  /// The type used to represent the input sequence as a list of buffers.
+  typedef implementation_defined const_buffers_type;
+
+  /// The type used to represent the output sequence as a list of buffers.
+  typedef implementation_defined mutable_buffers_type;
+#else
+  typedef ASIO_CONST_BUFFER const_buffers_type;
+  typedef ASIO_MUTABLE_BUFFER mutable_buffers_type;
+#endif
+
+  /// Construct a basic_streambuf object.
+  /**
+   * Constructs a streambuf with the specified maximum size. The initial size
+   * of the streambuf's input sequence is 0.
+   */
+  explicit basic_streambuf(
+      std::size_t maximum_size = (std::numeric_limits<std::size_t>::max)(),
+      const Allocator& allocator = Allocator())
+    : max_size_(maximum_size),
+      buffer_(allocator)
+  {
+    std::size_t pend = (std::min<std::size_t>)(max_size_, buffer_delta);
+    buffer_.resize((std::max<std::size_t>)(pend, 1));
+    setg(&buffer_[0], &buffer_[0], &buffer_[0]);
+    setp(&buffer_[0], &buffer_[0] + pend);
+  }
+
+  /// Get the size of the input sequence.
+  /**
+   * @returns The size of the input sequence. The value is equal to that
+   * calculated for @c s in the following code:
+   * @code
+   * size_t s = 0;
+   * const_buffers_type bufs = data();
+   * const_buffers_type::const_iterator i = bufs.begin();
+   * while (i != bufs.end())
+   * {
+   *   const_buffer buf(*i++);
+   *   s += buf.size();
+   * }
+   * @endcode
+   */
+  std::size_t size() const ASIO_NOEXCEPT
+  {
+    return pptr() - gptr();
+  }
+
+  /// Get the maximum size of the basic_streambuf.
+  /**
+   * @returns The allowed maximum of the sum of the sizes of the input sequence
+   * and output sequence.
+   */
+  std::size_t max_size() const ASIO_NOEXCEPT
+  {
+    return max_size_;
+  }
+
+  /// Get the current capacity of the basic_streambuf.
+  /**
+   * @returns The current total capacity of the streambuf, i.e. for both the
+   * input sequence and output sequence.
+   */
+  std::size_t capacity() const ASIO_NOEXCEPT
+  {
+    return buffer_.capacity();
+  }
+
+  /// Get a list of buffers that represents the input sequence.
+  /**
+   * @returns An object of type @c const_buffers_type that satisfies
+   * ConstBufferSequence requirements, representing all character arrays in the
+   * input sequence.
+   *
+   * @note The returned object is invalidated by any @c basic_streambuf member
+   * function that modifies the input sequence or output sequence.
+   */
+  const_buffers_type data() const ASIO_NOEXCEPT
+  {
+    return asio::buffer(asio::const_buffer(gptr(),
+          (pptr() - gptr()) * sizeof(char_type)));
+  }
+
+  /// Get a list of buffers that represents the output sequence, with the given
+  /// size.
+  /**
+   * Ensures that the output sequence can accommodate @c n characters,
+   * reallocating character array objects as necessary.
+   *
+   * @returns An object of type @c mutable_buffers_type that satisfies
+   * MutableBufferSequence requirements, representing character array objects
+   * at the start of the output sequence such that the sum of the buffer sizes
+   * is @c n.
+   *
+   * @throws std::length_error If <tt>size() + n > max_size()</tt>.
+   *
+   * @note The returned object is invalidated by any @c basic_streambuf member
+   * function that modifies the input sequence or output sequence.
+   */
+  mutable_buffers_type prepare(std::size_t n)
+  {
+    reserve(n);
+    return asio::buffer(asio::mutable_buffer(
+          pptr(), n * sizeof(char_type)));
+  }
+
+  /// Move characters from the output sequence to the input sequence.
+  /**
+   * Appends @c n characters from the start of the output sequence to the input
+   * sequence. The beginning of the output sequence is advanced by @c n
+   * characters.
+   *
+   * Requires a preceding call <tt>prepare(x)</tt> where <tt>x >= n</tt>, and
+   * no intervening operations that modify the input or output sequence.
+   *
+   * @note If @c n is greater than the size of the output sequence, the entire
+   * output sequence is moved to the input sequence and no error is issued.
+   */
+  void commit(std::size_t n)
+  {
+    n = std::min<std::size_t>(n, epptr() - pptr());
+    pbump(static_cast<int>(n));
+    setg(eback(), gptr(), pptr());
+  }
+
+  /// Remove characters from the input sequence.
+  /**
+   * Removes @c n characters from the beginning of the input sequence.
+   *
+   * @note If @c n is greater than the size of the input sequence, the entire
+   * input sequence is consumed and no error is issued.
+   */
+  void consume(std::size_t n)
+  {
+    if (egptr() < pptr())
+      setg(&buffer_[0], gptr(), pptr());
+    if (gptr() + n > pptr())
+      n = pptr() - gptr();
+    gbump(static_cast<int>(n));
+  }
+
+protected:
+  enum { buffer_delta = 128 };
+
+  /// Override std::streambuf behaviour.
+  /**
+   * Behaves according to the specification of @c std::streambuf::underflow().
+   */
+  int_type underflow()
+  {
+    if (gptr() < pptr())
+    {
+      setg(&buffer_[0], gptr(), pptr());
+      return traits_type::to_int_type(*gptr());
+    }
+    else
+    {
+      return traits_type::eof();
+    }
+  }
+
+  /// Override std::streambuf behaviour.
+  /**
+   * Behaves according to the specification of @c std::streambuf::overflow(),
+   * with the specialisation that @c std::length_error is thrown if appending
+   * the character to the input sequence would require the condition
+   * <tt>size() > max_size()</tt> to be true.
+   */
+  int_type overflow(int_type c)
+  {
+    if (!traits_type::eq_int_type(c, traits_type::eof()))
+    {
+      if (pptr() == epptr())
+      {
+        std::size_t buffer_size = pptr() - gptr();
+        if (buffer_size < max_size_ && max_size_ - buffer_size < buffer_delta)
+        {
+          reserve(max_size_ - buffer_size);
+        }
+        else
+        {
+          reserve(buffer_delta);
+        }
+      }
+
+      *pptr() = traits_type::to_char_type(c);
+      pbump(1);
+      return c;
+    }
+
+    return traits_type::not_eof(c);
+  }
+
+  void reserve(std::size_t n)
+  {
+    // Get current stream positions as offsets.
+    std::size_t gnext = gptr() - &buffer_[0];
+    std::size_t pnext = pptr() - &buffer_[0];
+    std::size_t pend = epptr() - &buffer_[0];
+
+    // Check if there is already enough space in the put area.
+    if (n <= pend - pnext)
+    {
+      return;
+    }
+
+    // Shift existing contents of get area to start of buffer.
+    if (gnext > 0)
+    {
+      pnext -= gnext;
+      std::memmove(&buffer_[0], &buffer_[0] + gnext, pnext);
+    }
+
+    // Ensure buffer is large enough to hold at least the specified size.
+    if (n > pend - pnext)
+    {
+      if (n <= max_size_ && pnext <= max_size_ - n)
+      {
+        pend = pnext + n;
+        buffer_.resize((std::max<std::size_t>)(pend, 1));
+      }
+      else
+      {
+        std::length_error ex("asio::streambuf too long");
+        asio::detail::throw_exception(ex);
+      }
+    }
+
+    // Update stream positions.
+    setg(&buffer_[0], &buffer_[0], &buffer_[0] + pnext);
+    setp(&buffer_[0] + pnext, &buffer_[0] + pend);
+  }
+
+private:
+  std::size_t max_size_;
+  std::vector<char_type, Allocator> buffer_;
+
+  // Helper function to get the preferred size for reading data.
+  friend std::size_t read_size_helper(
+      basic_streambuf& sb, std::size_t max_size)
+  {
+    return std::min<std::size_t>(
+        std::max<std::size_t>(512, sb.buffer_.capacity() - sb.size()),
+        std::min<std::size_t>(max_size, sb.max_size() - sb.size()));
+  }
+};
+
+/// Adapts basic_streambuf to the dynamic buffer sequence type requirements.
+#if defined(GENERATING_DOCUMENTATION)
+template <typename Allocator = std::allocator<char> >
+#else
+template <typename Allocator>
+#endif
+class basic_streambuf_ref
+{
+public:
+  /// The type used to represent the input sequence as a list of buffers.
+  typedef typename basic_streambuf<Allocator>::const_buffers_type
+    const_buffers_type;
+
+  /// The type used to represent the output sequence as a list of buffers.
+  typedef typename basic_streambuf<Allocator>::mutable_buffers_type
+    mutable_buffers_type;
+
+  /// Construct a basic_streambuf_ref for the given basic_streambuf object.
+  explicit basic_streambuf_ref(basic_streambuf<Allocator>& sb)
+    : sb_(sb)
+  {
+  }
+
+  /// Copy construct a basic_streambuf_ref.
+  basic_streambuf_ref(const basic_streambuf_ref& other) ASIO_NOEXCEPT
+    : sb_(other.sb_)
+  {
+  }
+
+#if defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+  /// Move construct a basic_streambuf_ref.
+  basic_streambuf_ref(basic_streambuf_ref&& other) ASIO_NOEXCEPT
+    : sb_(other.sb_)
+  {
+  }
+#endif // defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+
+  /// Get the size of the input sequence.
+  std::size_t size() const ASIO_NOEXCEPT
+  {
+    return sb_.size();
+  }
+
+  /// Get the maximum size of the dynamic buffer.
+  std::size_t max_size() const ASIO_NOEXCEPT
+  {
+    return sb_.max_size();
+  }
+
+  /// Get the current capacity of the dynamic buffer.
+  std::size_t capacity() const ASIO_NOEXCEPT
+  {
+    return sb_.capacity();
+  }
+
+  /// Get a list of buffers that represents the input sequence.
+  const_buffers_type data() const ASIO_NOEXCEPT
+  {
+    return sb_.data();
+  }
+
+  /// Get a list of buffers that represents the output sequence, with the given
+  /// size.
+  mutable_buffers_type prepare(std::size_t n)
+  {
+    return sb_.prepare(n);
+  }
+
+  /// Move bytes from the output sequence to the input sequence.
+  void commit(std::size_t n)
+  {
+    return sb_.commit(n);
+  }
+
+  /// Remove characters from the input sequence.
+  void consume(std::size_t n)
+  {
+    return sb_.consume(n);
+  }
+
+private:
+  basic_streambuf<Allocator>& sb_;
+};
+
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // !defined(ASIO_NO_IOSTREAM)
+
+#endif // ASIO_BASIC_STREAMBUF_HPP

lib/asio/include/asio/basic_streambuf_fwd.hpp

@@ -0,0 +1,36 @@
+//
+// basic_streambuf_fwd.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_BASIC_STREAMBUF_FWD_HPP
+#define ASIO_BASIC_STREAMBUF_FWD_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if !defined(ASIO_NO_IOSTREAM)
+
+#include <memory>
+
+namespace asio {
+
+template <typename Allocator = std::allocator<char> >
+class basic_streambuf;
+
+template <typename Allocator = std::allocator<char> >
+class basic_streambuf_ref;
+
+} // namespace asio
+
+#endif // !defined(ASIO_NO_IOSTREAM)
+
+#endif // ASIO_BASIC_STREAMBUF_FWD_HPP

lib/asio/include/asio/basic_waitable_timer.hpp

@@ -0,0 +1,827 @@
+//
+// basic_waitable_timer.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_BASIC_WAITABLE_TIMER_HPP
+#define ASIO_BASIC_WAITABLE_TIMER_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+#include <cstddef>
+#include "asio/any_io_executor.hpp"
+#include "asio/detail/chrono_time_traits.hpp"
+#include "asio/detail/deadline_timer_service.hpp"
+#include "asio/detail/handler_type_requirements.hpp"
+#include "asio/detail/io_object_impl.hpp"
+#include "asio/detail/non_const_lvalue.hpp"
+#include "asio/detail/throw_error.hpp"
+#include "asio/error.hpp"
+#include "asio/wait_traits.hpp"
+
+#if defined(ASIO_HAS_MOVE)
+# include <utility>
+#endif // defined(ASIO_HAS_MOVE)
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+
+#if !defined(ASIO_BASIC_WAITABLE_TIMER_FWD_DECL)
+#define ASIO_BASIC_WAITABLE_TIMER_FWD_DECL
+
+// Forward declaration with defaulted arguments.
+template <typename Clock,
+    typename WaitTraits = asio::wait_traits<Clock>,
+    typename Executor = any_io_executor>
+class basic_waitable_timer;
+
+#endif // !defined(ASIO_BASIC_WAITABLE_TIMER_FWD_DECL)
+
+/// Provides waitable timer functionality.
+/**
+ * The basic_waitable_timer class template provides the ability to perform a
+ * blocking or asynchronous wait for a timer to expire.
+ *
+ * A waitable timer is always in one of two states: "expired" or "not expired".
+ * If the wait() or async_wait() function is called on an expired timer, the
+ * wait operation will complete immediately.
+ *
+ * Most applications will use one of the asio::steady_timer,
+ * asio::system_timer or asio::high_resolution_timer typedefs.
+ *
+ * @note This waitable timer functionality is for use with the C++11 standard
+ * library's @c &lt;chrono&gt; facility, or with the Boost.Chrono library.
+ *
+ * @par Thread Safety
+ * @e Distinct @e objects: Safe.@n
+ * @e Shared @e objects: Unsafe.
+ *
+ * @par Examples
+ * Performing a blocking wait (C++11):
+ * @code
+ * // Construct a timer without setting an expiry time.
+ * asio::steady_timer timer(my_context);
+ *
+ * // Set an expiry time relative to now.
+ * timer.expires_after(std::chrono::seconds(5));
+ *
+ * // Wait for the timer to expire.
+ * timer.wait();
+ * @endcode
+ *
+ * @par 
+ * Performing an asynchronous wait (C++11):
+ * @code
+ * void handler(const asio::error_code& error)
+ * {
+ *   if (!error)
+ *   {
+ *     // Timer expired.
+ *   }
+ * }
+ *
+ * ...
+ *
+ * // Construct a timer with an absolute expiry time.
+ * asio::steady_timer timer(my_context,
+ *     std::chrono::steady_clock::now() + std::chrono::seconds(60));
+ *
+ * // Start an asynchronous wait.
+ * timer.async_wait(handler);
+ * @endcode
+ *
+ * @par Changing an active waitable timer's expiry time
+ *
+ * Changing the expiry time of a timer while there are pending asynchronous
+ * waits causes those wait operations to be cancelled. To ensure that the action
+ * associated with the timer is performed only once, use something like this:
+ * used:
+ *
+ * @code
+ * void on_some_event()
+ * {
+ *   if (my_timer.expires_after(seconds(5)) > 0)
+ *   {
+ *     // We managed to cancel the timer. Start new asynchronous wait.
+ *     my_timer.async_wait(on_timeout);
+ *   }
+ *   else
+ *   {
+ *     // Too late, timer has already expired!
+ *   }
+ * }
+ *
+ * void on_timeout(const asio::error_code& e)
+ * {
+ *   if (e != asio::error::operation_aborted)
+ *   {
+ *     // Timer was not cancelled, take necessary action.
+ *   }
+ * }
+ * @endcode
+ *
+ * @li The asio::basic_waitable_timer::expires_after() function
+ * cancels any pending asynchronous waits, and returns the number of
+ * asynchronous waits that were cancelled. If it returns 0 then you were too
+ * late and the wait handler has already been executed, or will soon be
+ * executed. If it returns 1 then the wait handler was successfully cancelled.
+ *
+ * @li If a wait handler is cancelled, the asio::error_code passed to
+ * it contains the value asio::error::operation_aborted.
+ */
+template <typename Clock, typename WaitTraits, typename Executor>
+class basic_waitable_timer
+{
+public:
+  /// The type of the executor associated with the object.
+  typedef Executor executor_type;
+
+  /// Rebinds the timer type to another executor.
+  template <typename Executor1>
+  struct rebind_executor
+  {
+    /// The timer type when rebound to the specified executor.
+    typedef basic_waitable_timer<Clock, WaitTraits, Executor1> other;
+  };
+
+  /// The clock type.
+  typedef Clock clock_type;
+
+  /// The duration type of the clock.
+  typedef typename clock_type::duration duration;
+
+  /// The time point type of the clock.
+  typedef typename clock_type::time_point time_point;
+
+  /// The wait traits type.
+  typedef WaitTraits traits_type;
+
+  /// Constructor.
+  /**
+   * This constructor creates a timer without setting an expiry time. The
+   * expires_at() or expires_after() functions must be called to set an expiry
+   * time before the timer can be waited on.
+   *
+   * @param ex The I/O executor that the timer will use, by default, to
+   * dispatch handlers for any asynchronous operations performed on the timer.
+   */
+  explicit basic_waitable_timer(const executor_type& ex)
+    : impl_(0, ex)
+  {
+  }
+
+  /// Constructor.
+  /**
+   * This constructor creates a timer without setting an expiry time. The
+   * expires_at() or expires_after() functions must be called to set an expiry
+   * time before the timer can be waited on.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the timer will use, by default, to dispatch handlers for any asynchronous
+   * operations performed on the timer.
+   */
+  template <typename ExecutionContext>
+  explicit basic_waitable_timer(ExecutionContext& context,
+      typename constraint<
+        is_convertible<ExecutionContext&, execution_context&>::value
+      >::type = 0)
+    : impl_(0, 0, context)
+  {
+  }
+
+  /// Constructor to set a particular expiry time as an absolute time.
+  /**
+   * This constructor creates a timer and sets the expiry time.
+   *
+   * @param ex The I/O executor object that the timer will use, by default, to
+   * dispatch handlers for any asynchronous operations performed on the timer.
+   *
+   * @param expiry_time The expiry time to be used for the timer, expressed
+   * as an absolute time.
+   */
+  basic_waitable_timer(const executor_type& ex, const time_point& expiry_time)
+    : impl_(0, ex)
+  {
+    asio::error_code ec;
+    impl_.get_service().expires_at(impl_.get_implementation(), expiry_time, ec);
+    asio::detail::throw_error(ec, "expires_at");
+  }
+
+  /// Constructor to set a particular expiry time as an absolute time.
+  /**
+   * This constructor creates a timer and sets the expiry time.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the timer will use, by default, to dispatch handlers for any asynchronous
+   * operations performed on the timer.
+   *
+   * @param expiry_time The expiry time to be used for the timer, expressed
+   * as an absolute time.
+   */
+  template <typename ExecutionContext>
+  explicit basic_waitable_timer(ExecutionContext& context,
+      const time_point& expiry_time,
+      typename constraint<
+        is_convertible<ExecutionContext&, execution_context&>::value
+      >::type = 0)
+    : impl_(0, 0, context)
+  {
+    asio::error_code ec;
+    impl_.get_service().expires_at(impl_.get_implementation(), expiry_time, ec);
+    asio::detail::throw_error(ec, "expires_at");
+  }
+
+  /// Constructor to set a particular expiry time relative to now.
+  /**
+   * This constructor creates a timer and sets the expiry time.
+   *
+   * @param ex The I/O executor that the timer will use, by default, to
+   * dispatch handlers for any asynchronous operations performed on the timer.
+   *
+   * @param expiry_time The expiry time to be used for the timer, relative to
+   * now.
+   */
+  basic_waitable_timer(const executor_type& ex, const duration& expiry_time)
+    : impl_(0, ex)
+  {
+    asio::error_code ec;
+    impl_.get_service().expires_after(
+        impl_.get_implementation(), expiry_time, ec);
+    asio::detail::throw_error(ec, "expires_after");
+  }
+
+  /// Constructor to set a particular expiry time relative to now.
+  /**
+   * This constructor creates a timer and sets the expiry time.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the timer will use, by default, to dispatch handlers for any asynchronous
+   * operations performed on the timer.
+   *
+   * @param expiry_time The expiry time to be used for the timer, relative to
+   * now.
+   */
+  template <typename ExecutionContext>
+  explicit basic_waitable_timer(ExecutionContext& context,
+      const duration& expiry_time,
+      typename constraint<
+        is_convertible<ExecutionContext&, execution_context&>::value
+      >::type = 0)
+    : impl_(0, 0, context)
+  {
+    asio::error_code ec;
+    impl_.get_service().expires_after(
+        impl_.get_implementation(), expiry_time, ec);
+    asio::detail::throw_error(ec, "expires_after");
+  }
+
+#if defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+  /// Move-construct a basic_waitable_timer from another.
+  /**
+   * This constructor moves a timer from one object to another.
+   *
+   * @param other The other basic_waitable_timer object from which the move will
+   * occur.
+   *
+   * @note Following the move, the moved-from object is in the same state as if
+   * constructed using the @c basic_waitable_timer(const executor_type&)
+   * constructor.
+   */
+  basic_waitable_timer(basic_waitable_timer&& other)
+    : impl_(std::move(other.impl_))
+  {
+  }
+
+  /// Move-assign a basic_waitable_timer from another.
+  /**
+   * This assignment operator moves a timer from one object to another. Cancels
+   * any outstanding asynchronous operations associated with the target object.
+   *
+   * @param other The other basic_waitable_timer object from which the move will
+   * occur.
+   *
+   * @note Following the move, the moved-from object is in the same state as if
+   * constructed using the @c basic_waitable_timer(const executor_type&)
+   * constructor.
+   */
+  basic_waitable_timer& operator=(basic_waitable_timer&& other)
+  {
+    impl_ = std::move(other.impl_);
+    return *this;
+  }
+
+  // All timers have access to each other's implementations.
+  template <typename Clock1, typename WaitTraits1, typename Executor1>
+  friend class basic_waitable_timer;
+
+  /// Move-construct a basic_waitable_timer from another.
+  /**
+   * This constructor moves a timer from one object to another.
+   *
+   * @param other The other basic_waitable_timer object from which the move will
+   * occur.
+   *
+   * @note Following the move, the moved-from object is in the same state as if
+   * constructed using the @c basic_waitable_timer(const executor_type&)
+   * constructor.
+   */
+  template <typename Executor1>
+  basic_waitable_timer(
+      basic_waitable_timer<Clock, WaitTraits, Executor1>&& other,
+      typename constraint<
+          is_convertible<Executor1, Executor>::value
+      >::type = 0)
+    : impl_(std::move(other.impl_))
+  {
+  }
+
+  /// Move-assign a basic_waitable_timer from another.
+  /**
+   * This assignment operator moves a timer from one object to another. Cancels
+   * any outstanding asynchronous operations associated with the target object.
+   *
+   * @param other The other basic_waitable_timer object from which the move will
+   * occur.
+   *
+   * @note Following the move, the moved-from object is in the same state as if
+   * constructed using the @c basic_waitable_timer(const executor_type&)
+   * constructor.
+   */
+  template <typename Executor1>
+  typename constraint<
+    is_convertible<Executor1, Executor>::value,
+    basic_waitable_timer&
+  >::type operator=(basic_waitable_timer<Clock, WaitTraits, Executor1>&& other)
+  {
+    basic_waitable_timer tmp(std::move(other));
+    impl_ = std::move(tmp.impl_);
+    return *this;
+  }
+#endif // defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+
+  /// Destroys the timer.
+  /**
+   * This function destroys the timer, cancelling any outstanding asynchronous
+   * wait operations associated with the timer as if by calling @c cancel.
+   */
+  ~basic_waitable_timer()
+  {
+  }
+
+  /// Get the executor associated with the object.
+  executor_type get_executor() ASIO_NOEXCEPT
+  {
+    return impl_.get_executor();
+  }
+
+  /// Cancel any asynchronous operations that are waiting on the timer.
+  /**
+   * This function forces the completion of any pending asynchronous wait
+   * operations against the timer. The handler for each cancelled operation will
+   * be invoked with the asio::error::operation_aborted error code.
+   *
+   * Cancelling the timer does not change the expiry time.
+   *
+   * @return The number of asynchronous operations that were cancelled.
+   *
+   * @throws asio::system_error Thrown on failure.
+   *
+   * @note If the timer has already expired when cancel() is called, then the
+   * handlers for asynchronous wait operations will:
+   *
+   * @li have already been invoked; or
+   *
+   * @li have been queued for invocation in the near future.
+   *
+   * These handlers can no longer be cancelled, and therefore are passed an
+   * error code that indicates the successful completion of the wait operation.
+   */
+  std::size_t cancel()
+  {
+    asio::error_code ec;
+    std::size_t s = impl_.get_service().cancel(impl_.get_implementation(), ec);
+    asio::detail::throw_error(ec, "cancel");
+    return s;
+  }
+
+#if !defined(ASIO_NO_DEPRECATED)
+  /// (Deprecated: Use non-error_code overload.) Cancel any asynchronous
+  /// operations that are waiting on the timer.
+  /**
+   * This function forces the completion of any pending asynchronous wait
+   * operations against the timer. The handler for each cancelled operation will
+   * be invoked with the asio::error::operation_aborted error code.
+   *
+   * Cancelling the timer does not change the expiry time.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @return The number of asynchronous operations that were cancelled.
+   *
+   * @note If the timer has already expired when cancel() is called, then the
+   * handlers for asynchronous wait operations will:
+   *
+   * @li have already been invoked; or
+   *
+   * @li have been queued for invocation in the near future.
+   *
+   * These handlers can no longer be cancelled, and therefore are passed an
+   * error code that indicates the successful completion of the wait operation.
+   */
+  std::size_t cancel(asio::error_code& ec)
+  {
+    return impl_.get_service().cancel(impl_.get_implementation(), ec);
+  }
+#endif // !defined(ASIO_NO_DEPRECATED)
+
+  /// Cancels one asynchronous operation that is waiting on the timer.
+  /**
+   * This function forces the completion of one pending asynchronous wait
+   * operation against the timer. Handlers are cancelled in FIFO order. The
+   * handler for the cancelled operation will be invoked with the
+   * asio::error::operation_aborted error code.
+   *
+   * Cancelling the timer does not change the expiry time.
+   *
+   * @return The number of asynchronous operations that were cancelled. That is,
+   * either 0 or 1.
+   *
+   * @throws asio::system_error Thrown on failure.
+   *
+   * @note If the timer has already expired when cancel_one() is called, then
+   * the handlers for asynchronous wait operations will:
+   *
+   * @li have already been invoked; or
+   *
+   * @li have been queued for invocation in the near future.
+   *
+   * These handlers can no longer be cancelled, and therefore are passed an
+   * error code that indicates the successful completion of the wait operation.
+   */
+  std::size_t cancel_one()
+  {
+    asio::error_code ec;
+    std::size_t s = impl_.get_service().cancel_one(
+        impl_.get_implementation(), ec);
+    asio::detail::throw_error(ec, "cancel_one");
+    return s;
+  }
+
+#if !defined(ASIO_NO_DEPRECATED)
+  /// (Deprecated: Use non-error_code overload.) Cancels one asynchronous
+  /// operation that is waiting on the timer.
+  /**
+   * This function forces the completion of one pending asynchronous wait
+   * operation against the timer. Handlers are cancelled in FIFO order. The
+   * handler for the cancelled operation will be invoked with the
+   * asio::error::operation_aborted error code.
+   *
+   * Cancelling the timer does not change the expiry time.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @return The number of asynchronous operations that were cancelled. That is,
+   * either 0 or 1.
+   *
+   * @note If the timer has already expired when cancel_one() is called, then
+   * the handlers for asynchronous wait operations will:
+   *
+   * @li have already been invoked; or
+   *
+   * @li have been queued for invocation in the near future.
+   *
+   * These handlers can no longer be cancelled, and therefore are passed an
+   * error code that indicates the successful completion of the wait operation.
+   */
+  std::size_t cancel_one(asio::error_code& ec)
+  {
+    return impl_.get_service().cancel_one(impl_.get_implementation(), ec);
+  }
+
+  /// (Deprecated: Use expiry().) Get the timer's expiry time as an absolute
+  /// time.
+  /**
+   * This function may be used to obtain the timer's current expiry time.
+   * Whether the timer has expired or not does not affect this value.
+   */
+  time_point expires_at() const
+  {
+    return impl_.get_service().expires_at(impl_.get_implementation());
+  }
+#endif // !defined(ASIO_NO_DEPRECATED)
+
+  /// Get the timer's expiry time as an absolute time.
+  /**
+   * This function may be used to obtain the timer's current expiry time.
+   * Whether the timer has expired or not does not affect this value.
+   */
+  time_point expiry() const
+  {
+    return impl_.get_service().expiry(impl_.get_implementation());
+  }
+
+  /// Set the timer's expiry time as an absolute time.
+  /**
+   * This function sets the expiry time. Any pending asynchronous wait
+   * operations will be cancelled. The handler for each cancelled operation will
+   * be invoked with the asio::error::operation_aborted error code.
+   *
+   * @param expiry_time The expiry time to be used for the timer.
+   *
+   * @return The number of asynchronous operations that were cancelled.
+   *
+   * @throws asio::system_error Thrown on failure.
+   *
+   * @note If the timer has already expired when expires_at() is called, then
+   * the handlers for asynchronous wait operations will:
+   *
+   * @li have already been invoked; or
+   *
+   * @li have been queued for invocation in the near future.
+   *
+   * These handlers can no longer be cancelled, and therefore are passed an
+   * error code that indicates the successful completion of the wait operation.
+   */
+  std::size_t expires_at(const time_point& expiry_time)
+  {
+    asio::error_code ec;
+    std::size_t s = impl_.get_service().expires_at(
+        impl_.get_implementation(), expiry_time, ec);
+    asio::detail::throw_error(ec, "expires_at");
+    return s;
+  }
+
+#if !defined(ASIO_NO_DEPRECATED)
+  /// (Deprecated: Use non-error_code overload.) Set the timer's expiry time as
+  /// an absolute time.
+  /**
+   * This function sets the expiry time. Any pending asynchronous wait
+   * operations will be cancelled. The handler for each cancelled operation will
+   * be invoked with the asio::error::operation_aborted error code.
+   *
+   * @param expiry_time The expiry time to be used for the timer.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @return The number of asynchronous operations that were cancelled.
+   *
+   * @note If the timer has already expired when expires_at() is called, then
+   * the handlers for asynchronous wait operations will:
+   *
+   * @li have already been invoked; or
+   *
+   * @li have been queued for invocation in the near future.
+   *
+   * These handlers can no longer be cancelled, and therefore are passed an
+   * error code that indicates the successful completion of the wait operation.
+   */
+  std::size_t expires_at(const time_point& expiry_time,
+      asio::error_code& ec)
+  {
+    return impl_.get_service().expires_at(
+        impl_.get_implementation(), expiry_time, ec);
+  }
+#endif // !defined(ASIO_NO_DEPRECATED)
+
+  /// Set the timer's expiry time relative to now.
+  /**
+   * This function sets the expiry time. Any pending asynchronous wait
+   * operations will be cancelled. The handler for each cancelled operation will
+   * be invoked with the asio::error::operation_aborted error code.
+   *
+   * @param expiry_time The expiry time to be used for the timer.
+   *
+   * @return The number of asynchronous operations that were cancelled.
+   *
+   * @throws asio::system_error Thrown on failure.
+   *
+   * @note If the timer has already expired when expires_after() is called,
+   * then the handlers for asynchronous wait operations will:
+   *
+   * @li have already been invoked; or
+   *
+   * @li have been queued for invocation in the near future.
+   *
+   * These handlers can no longer be cancelled, and therefore are passed an
+   * error code that indicates the successful completion of the wait operation.
+   */
+  std::size_t expires_after(const duration& expiry_time)
+  {
+    asio::error_code ec;
+    std::size_t s = impl_.get_service().expires_after(
+        impl_.get_implementation(), expiry_time, ec);
+    asio::detail::throw_error(ec, "expires_after");
+    return s;
+  }
+
+#if !defined(ASIO_NO_DEPRECATED)
+  /// (Deprecated: Use expiry().) Get the timer's expiry time relative to now.
+  /**
+   * This function may be used to obtain the timer's current expiry time.
+   * Whether the timer has expired or not does not affect this value.
+   */
+  duration expires_from_now() const
+  {
+    return impl_.get_service().expires_from_now(impl_.get_implementation());
+  }
+
+  /// (Deprecated: Use expires_after().) Set the timer's expiry time relative
+  /// to now.
+  /**
+   * This function sets the expiry time. Any pending asynchronous wait
+   * operations will be cancelled. The handler for each cancelled operation will
+   * be invoked with the asio::error::operation_aborted error code.
+   *
+   * @param expiry_time The expiry time to be used for the timer.
+   *
+   * @return The number of asynchronous operations that were cancelled.
+   *
+   * @throws asio::system_error Thrown on failure.
+   *
+   * @note If the timer has already expired when expires_from_now() is called,
+   * then the handlers for asynchronous wait operations will:
+   *
+   * @li have already been invoked; or
+   *
+   * @li have been queued for invocation in the near future.
+   *
+   * These handlers can no longer be cancelled, and therefore are passed an
+   * error code that indicates the successful completion of the wait operation.
+   */
+  std::size_t expires_from_now(const duration& expiry_time)
+  {
+    asio::error_code ec;
+    std::size_t s = impl_.get_service().expires_from_now(
+        impl_.get_implementation(), expiry_time, ec);
+    asio::detail::throw_error(ec, "expires_from_now");
+    return s;
+  }
+
+  /// (Deprecated: Use expires_after().) Set the timer's expiry time relative
+  /// to now.
+  /**
+   * This function sets the expiry time. Any pending asynchronous wait
+   * operations will be cancelled. The handler for each cancelled operation will
+   * be invoked with the asio::error::operation_aborted error code.
+   *
+   * @param expiry_time The expiry time to be used for the timer.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @return The number of asynchronous operations that were cancelled.
+   *
+   * @note If the timer has already expired when expires_from_now() is called,
+   * then the handlers for asynchronous wait operations will:
+   *
+   * @li have already been invoked; or
+   *
+   * @li have been queued for invocation in the near future.
+   *
+   * These handlers can no longer be cancelled, and therefore are passed an
+   * error code that indicates the successful completion of the wait operation.
+   */
+  std::size_t expires_from_now(const duration& expiry_time,
+      asio::error_code& ec)
+  {
+    return impl_.get_service().expires_from_now(
+        impl_.get_implementation(), expiry_time, ec);
+  }
+#endif // !defined(ASIO_NO_DEPRECATED)
+
+  /// Perform a blocking wait on the timer.
+  /**
+   * This function is used to wait for the timer to expire. This function
+   * blocks and does not return until the timer has expired.
+   *
+   * @throws asio::system_error Thrown on failure.
+   */
+  void wait()
+  {
+    asio::error_code ec;
+    impl_.get_service().wait(impl_.get_implementation(), ec);
+    asio::detail::throw_error(ec, "wait");
+  }
+
+  /// Perform a blocking wait on the timer.
+  /**
+   * This function is used to wait for the timer to expire. This function
+   * blocks and does not return until the timer has expired.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   */
+  void wait(asio::error_code& ec)
+  {
+    impl_.get_service().wait(impl_.get_implementation(), ec);
+  }
+
+  /// Start an asynchronous wait on the timer.
+  /**
+   * This function may be used to initiate an asynchronous wait against the
+   * timer. It is an initiating function for an @ref asynchronous_operation,
+   * and always returns immediately.
+   *
+   * For each call to async_wait(), the completion handler will be called
+   * exactly once. The completion handler will be called when:
+   *
+   * @li The timer has expired.
+   *
+   * @li The timer was cancelled, in which case the handler is passed the error
+   * code asio::error::operation_aborted.
+   *
+   * @param token The @ref completion_token that will be used to produce a
+   * completion handler, which will be called when the timer expires. Potential
+   * completion tokens include @ref use_future, @ref use_awaitable, @ref
+   * yield_context, or a function object with the correct completion signature.
+   * The function signature of the completion handler must be:
+   * @code void handler(
+   *   const asio::error_code& error // Result of operation.
+   * ); @endcode
+   * Regardless of whether the asynchronous operation completes immediately or
+   * not, the completion handler will not be invoked from within this function.
+   * On immediate completion, invocation of the handler will be performed in a
+   * manner equivalent to using asio::post().
+   *
+   * @par Completion Signature
+   * @code void(asio::error_code) @endcode
+   *
+   * @par Per-Operation Cancellation
+   * This asynchronous operation supports cancellation for the following
+   * asio::cancellation_type values:
+   *
+   * @li @c cancellation_type::terminal
+   *
+   * @li @c cancellation_type::partial
+   *
+   * @li @c cancellation_type::total
+   */
+  template <
+      ASIO_COMPLETION_TOKEN_FOR(void (asio::error_code))
+        WaitToken ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(executor_type)>
+  ASIO_INITFN_AUTO_RESULT_TYPE(WaitToken,
+      void (asio::error_code))
+  async_wait(
+      ASIO_MOVE_ARG(WaitToken) token
+        ASIO_DEFAULT_COMPLETION_TOKEN(executor_type))
+  {
+    return async_initiate<WaitToken, void (asio::error_code)>(
+        initiate_async_wait(this), token);
+  }
+
+private:
+  // Disallow copying and assignment.
+  basic_waitable_timer(const basic_waitable_timer&) ASIO_DELETED;
+  basic_waitable_timer& operator=(
+      const basic_waitable_timer&) ASIO_DELETED;
+
+  class initiate_async_wait
+  {
+  public:
+    typedef Executor executor_type;
+
+    explicit initiate_async_wait(basic_waitable_timer* self)
+      : self_(self)
+    {
+    }
+
+    executor_type get_executor() const ASIO_NOEXCEPT
+    {
+      return self_->get_executor();
+    }
+
+    template <typename WaitHandler>
+    void operator()(ASIO_MOVE_ARG(WaitHandler) handler) const
+    {
+      // If you get an error on the following line it means that your handler
+      // does not meet the documented type requirements for a WaitHandler.
+      ASIO_WAIT_HANDLER_CHECK(WaitHandler, handler) type_check;
+
+      detail::non_const_lvalue<WaitHandler> handler2(handler);
+      self_->impl_.get_service().async_wait(
+          self_->impl_.get_implementation(),
+          handler2.value, self_->impl_.get_executor());
+    }
+
+  private:
+    basic_waitable_timer* self_;
+  };
+
+  detail::io_object_impl<
+    detail::deadline_timer_service<
+      detail::chrono_time_traits<Clock, WaitTraits> >,
+    executor_type > impl_;
+};
+
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // ASIO_BASIC_WAITABLE_TIMER_HPP

lib/asio/include/asio/basic_writable_pipe.hpp

@@ -0,0 +1,525 @@
+//
+// basic_writable_pipe.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_BASIC_WRITABLE_PIPE_HPP
+#define ASIO_BASIC_WRITABLE_PIPE_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_HAS_PIPE) \
+  || defined(GENERATING_DOCUMENTATION)
+
+#include <string>
+#include "asio/any_io_executor.hpp"
+#include "asio/async_result.hpp"
+#include "asio/detail/handler_type_requirements.hpp"
+#include "asio/detail/io_object_impl.hpp"
+#include "asio/detail/non_const_lvalue.hpp"
+#include "asio/detail/throw_error.hpp"
+#include "asio/detail/type_traits.hpp"
+#include "asio/error.hpp"
+#include "asio/execution_context.hpp"
+#if defined(ASIO_HAS_IOCP)
+# include "asio/detail/win_iocp_handle_service.hpp"
+#elif defined(ASIO_HAS_IO_URING_AS_DEFAULT)
+# include "asio/detail/io_uring_descriptor_service.hpp"
+#else
+# include "asio/detail/reactive_descriptor_service.hpp"
+#endif
+
+#if defined(ASIO_HAS_MOVE)
+# include <utility>
+#endif // defined(ASIO_HAS_MOVE)
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+
+/// Provides pipe functionality.
+/**
+ * The basic_writable_pipe class provides a wrapper over pipe
+ * functionality.
+ *
+ * @par Thread Safety
+ * @e Distinct @e objects: Safe.@n
+ * @e Shared @e objects: Unsafe.
+ */
+template <typename Executor = any_io_executor>
+class basic_writable_pipe
+{
+public:
+  /// The type of the executor associated with the object.
+  typedef Executor executor_type;
+
+  /// Rebinds the pipe type to another executor.
+  template <typename Executor1>
+  struct rebind_executor
+  {
+    /// The pipe type when rebound to the specified executor.
+    typedef basic_writable_pipe<Executor1> other;
+  };
+
+  /// The native representation of a pipe.
+#if defined(GENERATING_DOCUMENTATION)
+  typedef implementation_defined native_handle_type;
+#elif defined(ASIO_HAS_IOCP)
+  typedef detail::win_iocp_handle_service::native_handle_type
+    native_handle_type;
+#elif defined(ASIO_HAS_IO_URING_AS_DEFAULT)
+  typedef detail::io_uring_descriptor_service::native_handle_type
+    native_handle_type;
+#else
+  typedef detail::reactive_descriptor_service::native_handle_type
+    native_handle_type;
+#endif
+
+  /// A basic_writable_pipe is always the lowest layer.
+  typedef basic_writable_pipe lowest_layer_type;
+
+  /// Construct a basic_writable_pipe without opening it.
+  /**
+   * This constructor creates a pipe without opening it.
+   *
+   * @param ex The I/O executor that the pipe will use, by default, to dispatch
+   * handlers for any asynchronous operations performed on the pipe.
+   */
+  explicit basic_writable_pipe(const executor_type& ex)
+    : impl_(0, ex)
+  {
+  }
+
+  /// Construct a basic_writable_pipe without opening it.
+  /**
+   * This constructor creates a pipe without opening it.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the pipe will use, by default, to dispatch handlers for any asynchronous
+   * operations performed on the pipe.
+   */
+  template <typename ExecutionContext>
+  explicit basic_writable_pipe(ExecutionContext& context,
+      typename constraint<
+        is_convertible<ExecutionContext&, execution_context&>::value,
+        defaulted_constraint
+      >::type = defaulted_constraint())
+    : impl_(0, 0, context)
+  {
+  }
+
+  /// Construct a basic_writable_pipe on an existing native pipe.
+  /**
+   * This constructor creates a pipe object to hold an existing native
+   * pipe.
+   *
+   * @param ex The I/O executor that the pipe will use, by default, to
+   * dispatch handlers for any asynchronous operations performed on the
+   * pipe.
+   *
+   * @param native_pipe A native pipe.
+   *
+   * @throws asio::system_error Thrown on failure.
+   */
+  basic_writable_pipe(const executor_type& ex,
+      const native_handle_type& native_pipe)
+    : impl_(0, ex)
+  {
+    asio::error_code ec;
+    impl_.get_service().assign(impl_.get_implementation(),
+        native_pipe, ec);
+    asio::detail::throw_error(ec, "assign");
+  }
+
+  /// Construct a basic_writable_pipe on an existing native pipe.
+  /**
+   * This constructor creates a pipe object to hold an existing native
+   * pipe.
+   *
+   * @param context An execution context which provides the I/O executor that
+   * the pipe will use, by default, to dispatch handlers for any
+   * asynchronous operations performed on the pipe.
+   *
+   * @param native_pipe A native pipe.
+   *
+   * @throws asio::system_error Thrown on failure.
+   */
+  template <typename ExecutionContext>
+  basic_writable_pipe(ExecutionContext& context,
+      const native_handle_type& native_pipe,
+      typename constraint<
+        is_convertible<ExecutionContext&, execution_context&>::value
+      >::type = 0)
+    : impl_(0, 0, context)
+  {
+    asio::error_code ec;
+    impl_.get_service().assign(impl_.get_implementation(),
+        native_pipe, ec);
+    asio::detail::throw_error(ec, "assign");
+  }
+
+#if defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+  /// Move-construct a basic_writable_pipe from another.
+  /**
+   * This constructor moves a pipe from one object to another.
+   *
+   * @param other The other basic_writable_pipe object from which the move will
+   * occur.
+   *
+   * @note Following the move, the moved-from object is in the same state as if
+   * constructed using the @c basic_writable_pipe(const executor_type&)
+   * constructor.
+   */
+  basic_writable_pipe(basic_writable_pipe&& other)
+    : impl_(std::move(other.impl_))
+  {
+  }
+
+  /// Move-assign a basic_writable_pipe from another.
+  /**
+   * This assignment operator moves a pipe from one object to another.
+   *
+   * @param other The other basic_writable_pipe object from which the move will
+   * occur.
+   *
+   * @note Following the move, the moved-from object is in the same state as if
+   * constructed using the @c basic_writable_pipe(const executor_type&)
+   * constructor.
+   */
+  basic_writable_pipe& operator=(basic_writable_pipe&& other)
+  {
+    impl_ = std::move(other.impl_);
+    return *this;
+  }
+#endif // defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+
+  /// Destroys the pipe.
+  /**
+   * This function destroys the pipe, cancelling any outstanding
+   * asynchronous wait operations associated with the pipe as if by
+   * calling @c cancel.
+   */
+  ~basic_writable_pipe()
+  {
+  }
+
+  /// Get the executor associated with the object.
+  executor_type get_executor() ASIO_NOEXCEPT
+  {
+    return impl_.get_executor();
+  }
+
+  /// Get a reference to the lowest layer.
+  /**
+   * This function returns a reference to the lowest layer in a stack of
+   * layers. Since a basic_writable_pipe cannot contain any further layers, it
+   * simply returns a reference to itself.
+   *
+   * @return A reference to the lowest layer in the stack of layers. Ownership
+   * is not transferred to the caller.
+   */
+  lowest_layer_type& lowest_layer()
+  {
+    return *this;
+  }
+
+  /// Get a const reference to the lowest layer.
+  /**
+   * This function returns a const reference to the lowest layer in a stack of
+   * layers. Since a basic_writable_pipe cannot contain any further layers, it
+   * simply returns a reference to itself.
+   *
+   * @return A const reference to the lowest layer in the stack of layers.
+   * Ownership is not transferred to the caller.
+   */
+  const lowest_layer_type& lowest_layer() const
+  {
+    return *this;
+  }
+
+  /// Assign an existing native pipe to the pipe.
+  /*
+   * This function opens the pipe to hold an existing native pipe.
+   *
+   * @param native_pipe A native pipe.
+   *
+   * @throws asio::system_error Thrown on failure.
+   */
+  void assign(const native_handle_type& native_pipe)
+  {
+    asio::error_code ec;
+    impl_.get_service().assign(impl_.get_implementation(), native_pipe, ec);
+    asio::detail::throw_error(ec, "assign");
+  }
+
+  /// Assign an existing native pipe to the pipe.
+  /*
+   * This function opens the pipe to hold an existing native pipe.
+   *
+   * @param native_pipe A native pipe.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   */
+  ASIO_SYNC_OP_VOID assign(const native_handle_type& native_pipe,
+      asio::error_code& ec)
+  {
+    impl_.get_service().assign(impl_.get_implementation(), native_pipe, ec);
+    ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Determine whether the pipe is open.
+  bool is_open() const
+  {
+    return impl_.get_service().is_open(impl_.get_implementation());
+  }
+
+  /// Close the pipe.
+  /**
+   * This function is used to close the pipe. Any asynchronous write operations
+   * will be cancelled immediately, and will complete with the
+   * asio::error::operation_aborted error.
+   *
+   * @throws asio::system_error Thrown on failure.
+   */
+  void close()
+  {
+    asio::error_code ec;
+    impl_.get_service().close(impl_.get_implementation(), ec);
+    asio::detail::throw_error(ec, "close");
+  }
+
+  /// Close the pipe.
+  /**
+   * This function is used to close the pipe. Any asynchronous write operations
+   * will be cancelled immediately, and will complete with the
+   * asio::error::operation_aborted error.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   */
+  ASIO_SYNC_OP_VOID close(asio::error_code& ec)
+  {
+    impl_.get_service().close(impl_.get_implementation(), ec);
+    ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Get the native pipe representation.
+  /**
+   * This function may be used to obtain the underlying representation of the
+   * pipe. This is intended to allow access to native pipe
+   * functionality that is not otherwise provided.
+   */
+  native_handle_type native_handle()
+  {
+    return impl_.get_service().native_handle(impl_.get_implementation());
+  }
+
+  /// Cancel all asynchronous operations associated with the pipe.
+  /**
+   * This function causes all outstanding asynchronous write operations to
+   * finish immediately, and the handlers for cancelled operations will be
+   * passed the asio::error::operation_aborted error.
+   *
+   * @throws asio::system_error Thrown on failure.
+   */
+  void cancel()
+  {
+    asio::error_code ec;
+    impl_.get_service().cancel(impl_.get_implementation(), ec);
+    asio::detail::throw_error(ec, "cancel");
+  }
+
+  /// Cancel all asynchronous operations associated with the pipe.
+  /**
+   * This function causes all outstanding asynchronous write operations to
+   * finish immediately, and the handlers for cancelled operations will be
+   * passed the asio::error::operation_aborted error.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   */
+  ASIO_SYNC_OP_VOID cancel(asio::error_code& ec)
+  {
+    impl_.get_service().cancel(impl_.get_implementation(), ec);
+    ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Write some data to the pipe.
+  /**
+   * This function is used to write data to the pipe. The function call will
+   * block until one or more bytes of the data has been written successfully,
+   * or until an error occurs.
+   *
+   * @param buffers One or more data buffers to be written to the pipe.
+   *
+   * @returns The number of bytes written.
+   *
+   * @throws asio::system_error Thrown on failure. An error code of
+   * asio::error::eof indicates that the connection was closed by the
+   * peer.
+   *
+   * @note The write_some operation may not transmit all of the data to the
+   * peer. Consider using the @ref write function if you need to ensure that
+   * all data is written before the blocking operation completes.
+   *
+   * @par Example
+   * To write a single data buffer use the @ref buffer function as follows:
+   * @code
+   * pipe.write_some(asio::buffer(data, size));
+   * @endcode
+   * See the @ref buffer documentation for information on writing multiple
+   * buffers in one go, and how to use it with arrays, boost::array or
+   * std::vector.
+   */
+  template <typename ConstBufferSequence>
+  std::size_t write_some(const ConstBufferSequence& buffers)
+  {
+    asio::error_code ec;
+    std::size_t s = impl_.get_service().write_some(
+        impl_.get_implementation(), buffers, ec);
+    asio::detail::throw_error(ec, "write_some");
+    return s;
+  }
+
+  /// Write some data to the pipe.
+  /**
+   * This function is used to write data to the pipe. The function call will
+   * block until one or more bytes of the data has been written successfully,
+   * or until an error occurs.
+   *
+   * @param buffers One or more data buffers to be written to the pipe.
+   *
+   * @param ec Set to indicate what error occurred, if any.
+   *
+   * @returns The number of bytes written. Returns 0 if an error occurred.
+   *
+   * @note The write_some operation may not transmit all of the data to the
+   * peer. Consider using the @ref write function if you need to ensure that
+   * all data is written before the blocking operation completes.
+   */
+  template <typename ConstBufferSequence>
+  std::size_t write_some(const ConstBufferSequence& buffers,
+      asio::error_code& ec)
+  {
+    return impl_.get_service().write_some(
+        impl_.get_implementation(), buffers, ec);
+  }
+
+  /// Start an asynchronous write.
+  /**
+   * This function is used to asynchronously write data to the pipe. It is an
+   * initiating function for an @ref asynchronous_operation, and always returns
+   * immediately.
+   *
+   * @param buffers One or more data buffers to be written to the pipe.
+   * Although the buffers object may be copied as necessary, ownership of the
+   * underlying memory blocks is retained by the caller, which must guarantee
+   * that they remain valid until the completion handler is called.
+   *
+   * @param token The @ref completion_token that will be used to produce a
+   * completion handler, which will be called when the write completes.
+   * Potential completion tokens include @ref use_future, @ref use_awaitable,
+   * @ref yield_context, or a function object with the correct completion
+   * signature. The function signature of the completion handler must be:
+   * @code void handler(
+   *   const asio::error_code& error, // Result of operation.
+   *   std::size_t bytes_transferred // Number of bytes written.
+   * ); @endcode
+   * Regardless of whether the asynchronous operation completes immediately or
+   * not, the completion handler will not be invoked from within this function.
+   * On immediate completion, invocation of the handler will be performed in a
+   * manner equivalent to using asio::post().
+   *
+   * @par Completion Signature
+   * @code void(asio::error_code, std::size_t) @endcode
+   *
+   * @note The write operation may not transmit all of the data to the peer.
+   * Consider using the @ref async_write function if you need to ensure that all
+   * data is written before the asynchronous operation completes.
+   *
+   * @par Example
+   * To write a single data buffer use the @ref buffer function as follows:
+   * @code
+   * pipe.async_write_some(asio::buffer(data, size), handler);
+   * @endcode
+   * See the @ref buffer documentation for information on writing multiple
+   * buffers in one go, and how to use it with arrays, boost::array or
+   * std::vector.
+   */
+  template <typename ConstBufferSequence,
+      ASIO_COMPLETION_TOKEN_FOR(void (asio::error_code,
+        std::size_t)) WriteToken
+          ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(executor_type)>
+  ASIO_INITFN_AUTO_RESULT_TYPE(WriteToken,
+      void (asio::error_code, std::size_t))
+  async_write_some(const ConstBufferSequence& buffers,
+      ASIO_MOVE_ARG(WriteToken) token
+        ASIO_DEFAULT_COMPLETION_TOKEN(executor_type))
+  {
+    return async_initiate<WriteToken,
+      void (asio::error_code, std::size_t)>(
+        initiate_async_write_some(this), token, buffers);
+  }
+
+private:
+  // Disallow copying and assignment.
+  basic_writable_pipe(const basic_writable_pipe&) ASIO_DELETED;
+  basic_writable_pipe& operator=(const basic_writable_pipe&) ASIO_DELETED;
+
+  class initiate_async_write_some
+  {
+  public:
+    typedef Executor executor_type;
+
+    explicit initiate_async_write_some(basic_writable_pipe* self)
+      : self_(self)
+    {
+    }
+
+    executor_type get_executor() const ASIO_NOEXCEPT
+    {
+      return self_->get_executor();
+    }
+
+    template <typename WriteHandler, typename ConstBufferSequence>
+    void operator()(ASIO_MOVE_ARG(WriteHandler) handler,
+        const ConstBufferSequence& buffers) const
+    {
+      // If you get an error on the following line it means that your handler
+      // does not meet the documented type requirements for a WriteHandler.
+      ASIO_WRITE_HANDLER_CHECK(WriteHandler, handler) type_check;
+
+      detail::non_const_lvalue<WriteHandler> handler2(handler);
+      self_->impl_.get_service().async_write_some(
+          self_->impl_.get_implementation(), buffers,
+          handler2.value, self_->impl_.get_executor());
+    }
+
+  private:
+    basic_writable_pipe* self_;
+  };
+
+#if defined(ASIO_HAS_IOCP)
+  detail::io_object_impl<detail::win_iocp_handle_service, Executor> impl_;
+#elif defined(ASIO_HAS_IO_URING_AS_DEFAULT)
+  detail::io_object_impl<detail::io_uring_descriptor_service, Executor> impl_;
+#else
+  detail::io_object_impl<detail::reactive_descriptor_service, Executor> impl_;
+#endif
+};
+
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // defined(ASIO_HAS_PIPE)
+       //   || defined(GENERATING_DOCUMENTATION)
+
+#endif // ASIO_BASIC_WRITABLE_PIPE_HPP

lib/asio/include/asio/bind_allocator.hpp

@@ -0,0 +1,722 @@
+//
+// bind_allocator.hpp
+// ~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_BIND_ALLOCATOR_HPP
+#define ASIO_BIND_ALLOCATOR_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+#include "asio/detail/type_traits.hpp"
+#include "asio/detail/variadic_templates.hpp"
+#include "asio/associated_allocator.hpp"
+#include "asio/associator.hpp"
+#include "asio/async_result.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+// Helper to automatically define nested typedef result_type.
+
+template <typename T, typename = void>
+struct allocator_binder_result_type
+{
+protected:
+  typedef void result_type_or_void;
+};
+
+template <typename T>
+struct allocator_binder_result_type<T,
+  typename void_type<typename T::result_type>::type>
+{
+  typedef typename T::result_type result_type;
+protected:
+  typedef result_type result_type_or_void;
+};
+
+template <typename R>
+struct allocator_binder_result_type<R(*)()>
+{
+  typedef R result_type;
+protected:
+  typedef result_type result_type_or_void;
+};
+
+template <typename R>
+struct allocator_binder_result_type<R(&)()>
+{
+  typedef R result_type;
+protected:
+  typedef result_type result_type_or_void;
+};
+
+template <typename R, typename A1>
+struct allocator_binder_result_type<R(*)(A1)>
+{
+  typedef R result_type;
+protected:
+  typedef result_type result_type_or_void;
+};
+
+template <typename R, typename A1>
+struct allocator_binder_result_type<R(&)(A1)>
+{
+  typedef R result_type;
+protected:
+  typedef result_type result_type_or_void;
+};
+
+template <typename R, typename A1, typename A2>
+struct allocator_binder_result_type<R(*)(A1, A2)>
+{
+  typedef R result_type;
+protected:
+  typedef result_type result_type_or_void;
+};
+
+template <typename R, typename A1, typename A2>
+struct allocator_binder_result_type<R(&)(A1, A2)>
+{
+  typedef R result_type;
+protected:
+  typedef result_type result_type_or_void;
+};
+
+// Helper to automatically define nested typedef argument_type.
+
+template <typename T, typename = void>
+struct allocator_binder_argument_type {};
+
+template <typename T>
+struct allocator_binder_argument_type<T,
+  typename void_type<typename T::argument_type>::type>
+{
+  typedef typename T::argument_type argument_type;
+};
+
+template <typename R, typename A1>
+struct allocator_binder_argument_type<R(*)(A1)>
+{
+  typedef A1 argument_type;
+};
+
+template <typename R, typename A1>
+struct allocator_binder_argument_type<R(&)(A1)>
+{
+  typedef A1 argument_type;
+};
+
+// Helper to automatically define nested typedefs first_argument_type and
+// second_argument_type.
+
+template <typename T, typename = void>
+struct allocator_binder_argument_types {};
+
+template <typename T>
+struct allocator_binder_argument_types<T,
+  typename void_type<typename T::first_argument_type>::type>
+{
+  typedef typename T::first_argument_type first_argument_type;
+  typedef typename T::second_argument_type second_argument_type;
+};
+
+template <typename R, typename A1, typename A2>
+struct allocator_binder_argument_type<R(*)(A1, A2)>
+{
+  typedef A1 first_argument_type;
+  typedef A2 second_argument_type;
+};
+
+template <typename R, typename A1, typename A2>
+struct allocator_binder_argument_type<R(&)(A1, A2)>
+{
+  typedef A1 first_argument_type;
+  typedef A2 second_argument_type;
+};
+
+// Helper to enable SFINAE on zero-argument operator() below.
+
+template <typename T, typename = void>
+struct allocator_binder_result_of0
+{
+  typedef void type;
+};
+
+template <typename T>
+struct allocator_binder_result_of0<T,
+  typename void_type<typename result_of<T()>::type>::type>
+{
+  typedef typename result_of<T()>::type type;
+};
+
+} // namespace detail
+
+/// A call wrapper type to bind an allocator of type @c Allocator
+/// to an object of type @c T.
+template <typename T, typename Allocator>
+class allocator_binder
+#if !defined(GENERATING_DOCUMENTATION)
+  : public detail::allocator_binder_result_type<T>,
+    public detail::allocator_binder_argument_type<T>,
+    public detail::allocator_binder_argument_types<T>
+#endif // !defined(GENERATING_DOCUMENTATION)
+{
+public:
+  /// The type of the target object.
+  typedef T target_type;
+
+  /// The type of the associated allocator.
+  typedef Allocator allocator_type;
+
+#if defined(GENERATING_DOCUMENTATION)
+  /// The return type if a function.
+  /**
+   * The type of @c result_type is based on the type @c T of the wrapper's
+   * target object:
+   *
+   * @li if @c T is a pointer to function type, @c result_type is a synonym for
+   * the return type of @c T;
+   *
+   * @li if @c T is a class type with a member type @c result_type, then @c
+   * result_type is a synonym for @c T::result_type;
+   *
+   * @li otherwise @c result_type is not defined.
+   */
+  typedef see_below result_type;
+
+  /// The type of the function's argument.
+  /**
+   * The type of @c argument_type is based on the type @c T of the wrapper's
+   * target object:
+   *
+   * @li if @c T is a pointer to a function type accepting a single argument,
+   * @c argument_type is a synonym for the return type of @c T;
+   *
+   * @li if @c T is a class type with a member type @c argument_type, then @c
+   * argument_type is a synonym for @c T::argument_type;
+   *
+   * @li otherwise @c argument_type is not defined.
+   */
+  typedef see_below argument_type;
+
+  /// The type of the function's first argument.
+  /**
+   * The type of @c first_argument_type is based on the type @c T of the
+   * wrapper's target object:
+   *
+   * @li if @c T is a pointer to a function type accepting two arguments, @c
+   * first_argument_type is a synonym for the return type of @c T;
+   *
+   * @li if @c T is a class type with a member type @c first_argument_type,
+   * then @c first_argument_type is a synonym for @c T::first_argument_type;
+   *
+   * @li otherwise @c first_argument_type is not defined.
+   */
+  typedef see_below first_argument_type;
+
+  /// The type of the function's second argument.
+  /**
+   * The type of @c second_argument_type is based on the type @c T of the
+   * wrapper's target object:
+   *
+   * @li if @c T is a pointer to a function type accepting two arguments, @c
+   * second_argument_type is a synonym for the return type of @c T;
+   *
+   * @li if @c T is a class type with a member type @c first_argument_type,
+   * then @c second_argument_type is a synonym for @c T::second_argument_type;
+   *
+   * @li otherwise @c second_argument_type is not defined.
+   */
+  typedef see_below second_argument_type;
+#endif // defined(GENERATING_DOCUMENTATION)
+
+  /// Construct an allocator wrapper for the specified object.
+  /**
+   * This constructor is only valid if the type @c T is constructible from type
+   * @c U.
+   */
+  template <typename U>
+  allocator_binder(const allocator_type& s,
+      ASIO_MOVE_ARG(U) u)
+    : allocator_(s),
+      target_(ASIO_MOVE_CAST(U)(u))
+  {
+  }
+
+  /// Copy constructor.
+  allocator_binder(const allocator_binder& other)
+    : allocator_(other.get_allocator()),
+      target_(other.get())
+  {
+  }
+
+  /// Construct a copy, but specify a different allocator.
+  allocator_binder(const allocator_type& s,
+      const allocator_binder& other)
+    : allocator_(s),
+      target_(other.get())
+  {
+  }
+
+  /// Construct a copy of a different allocator wrapper type.
+  /**
+   * This constructor is only valid if the @c Allocator type is
+   * constructible from type @c OtherAllocator, and the type @c T is
+   * constructible from type @c U.
+   */
+  template <typename U, typename OtherAllocator>
+  allocator_binder(
+      const allocator_binder<U, OtherAllocator>& other)
+    : allocator_(other.get_allocator()),
+      target_(other.get())
+  {
+  }
+
+  /// Construct a copy of a different allocator wrapper type, but
+  /// specify a different allocator.
+  /**
+   * This constructor is only valid if the type @c T is constructible from type
+   * @c U.
+   */
+  template <typename U, typename OtherAllocator>
+  allocator_binder(const allocator_type& s,
+      const allocator_binder<U, OtherAllocator>& other)
+    : allocator_(s),
+      target_(other.get())
+  {
+  }
+
+#if defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+
+  /// Move constructor.
+  allocator_binder(allocator_binder&& other)
+    : allocator_(ASIO_MOVE_CAST(allocator_type)(
+          other.get_allocator())),
+      target_(ASIO_MOVE_CAST(T)(other.get()))
+  {
+  }
+
+  /// Move construct the target object, but specify a different allocator.
+  allocator_binder(const allocator_type& s,
+      allocator_binder&& other)
+    : allocator_(s),
+      target_(ASIO_MOVE_CAST(T)(other.get()))
+  {
+  }
+
+  /// Move construct from a different allocator wrapper type.
+  template <typename U, typename OtherAllocator>
+  allocator_binder(
+      allocator_binder<U, OtherAllocator>&& other)
+    : allocator_(ASIO_MOVE_CAST(OtherAllocator)(
+          other.get_allocator())),
+      target_(ASIO_MOVE_CAST(U)(other.get()))
+  {
+  }
+
+  /// Move construct from a different allocator wrapper type, but
+  /// specify a different allocator.
+  template <typename U, typename OtherAllocator>
+  allocator_binder(const allocator_type& s,
+      allocator_binder<U, OtherAllocator>&& other)
+    : allocator_(s),
+      target_(ASIO_MOVE_CAST(U)(other.get()))
+  {
+  }
+
+#endif // defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+
+  /// Destructor.
+  ~allocator_binder()
+  {
+  }
+
+  /// Obtain a reference to the target object.
+  target_type& get() ASIO_NOEXCEPT
+  {
+    return target_;
+  }
+
+  /// Obtain a reference to the target object.
+  const target_type& get() const ASIO_NOEXCEPT
+  {
+    return target_;
+  }
+
+  /// Obtain the associated allocator.
+  allocator_type get_allocator() const ASIO_NOEXCEPT
+  {
+    return allocator_;
+  }
+
+#if defined(GENERATING_DOCUMENTATION)
+
+  template <typename... Args> auto operator()(Args&& ...);
+  template <typename... Args> auto operator()(Args&& ...) const;
+
+#elif defined(ASIO_HAS_VARIADIC_TEMPLATES)
+
+  /// Forwarding function call operator.
+  template <typename... Args>
+  typename result_of<T(Args...)>::type operator()(
+      ASIO_MOVE_ARG(Args)... args)
+  {
+    return target_(ASIO_MOVE_CAST(Args)(args)...);
+  }
+
+  /// Forwarding function call operator.
+  template <typename... Args>
+  typename result_of<T(Args...)>::type operator()(
+      ASIO_MOVE_ARG(Args)... args) const
+  {
+    return target_(ASIO_MOVE_CAST(Args)(args)...);
+  }
+
+#elif defined(ASIO_HAS_STD_TYPE_TRAITS) && !defined(_MSC_VER)
+
+  typename detail::allocator_binder_result_of0<T>::type operator()()
+  {
+    return target_();
+  }
+
+  typename detail::allocator_binder_result_of0<T>::type
+  operator()() const
+  {
+    return target_();
+  }
+
+#define ASIO_PRIVATE_BINDER_CALL_DEF(n) \
+  template <ASIO_VARIADIC_TPARAMS(n)> \
+  typename result_of<T(ASIO_VARIADIC_TARGS(n))>::type operator()( \
+      ASIO_VARIADIC_MOVE_PARAMS(n)) \
+  { \
+    return target_(ASIO_VARIADIC_MOVE_ARGS(n)); \
+  } \
+  \
+  template <ASIO_VARIADIC_TPARAMS(n)> \
+  typename result_of<T(ASIO_VARIADIC_TARGS(n))>::type operator()( \
+      ASIO_VARIADIC_MOVE_PARAMS(n)) const \
+  { \
+    return target_(ASIO_VARIADIC_MOVE_ARGS(n)); \
+  } \
+  /**/
+  ASIO_VARIADIC_GENERATE(ASIO_PRIVATE_BINDER_CALL_DEF)
+#undef ASIO_PRIVATE_BINDER_CALL_DEF
+
+#else // defined(ASIO_HAS_STD_TYPE_TRAITS) && !defined(_MSC_VER)
+
+  typedef typename detail::allocator_binder_result_type<
+    T>::result_type_or_void result_type_or_void;
+
+  result_type_or_void operator()()
+  {
+    return target_();
+  }
+
+  result_type_or_void operator()() const
+  {
+    return target_();
+  }
+
+#define ASIO_PRIVATE_BINDER_CALL_DEF(n) \
+  template <ASIO_VARIADIC_TPARAMS(n)> \
+  result_type_or_void operator()( \
+      ASIO_VARIADIC_MOVE_PARAMS(n)) \
+  { \
+    return target_(ASIO_VARIADIC_MOVE_ARGS(n)); \
+  } \
+  \
+  template <ASIO_VARIADIC_TPARAMS(n)> \
+  result_type_or_void operator()( \
+      ASIO_VARIADIC_MOVE_PARAMS(n)) const \
+  { \
+    return target_(ASIO_VARIADIC_MOVE_ARGS(n)); \
+  } \
+  /**/
+  ASIO_VARIADIC_GENERATE(ASIO_PRIVATE_BINDER_CALL_DEF)
+#undef ASIO_PRIVATE_BINDER_CALL_DEF
+
+#endif // defined(ASIO_HAS_STD_TYPE_TRAITS) && !defined(_MSC_VER)
+
+private:
+  Allocator allocator_;
+  T target_;
+};
+
+/// Associate an object of type @c T with an allocator of type
+/// @c Allocator.
+template <typename Allocator, typename T>
+ASIO_NODISCARD inline allocator_binder<typename decay<T>::type, Allocator>
+bind_allocator(const Allocator& s, ASIO_MOVE_ARG(T) t)
+{
+  return allocator_binder<
+    typename decay<T>::type, Allocator>(
+      s, ASIO_MOVE_CAST(T)(t));
+}
+
+#if !defined(GENERATING_DOCUMENTATION)
+
+namespace detail {
+
+template <typename TargetAsyncResult,
+  typename Allocator, typename = void>
+struct allocator_binder_async_result_completion_handler_type
+{
+};
+
+template <typename TargetAsyncResult, typename Allocator>
+struct allocator_binder_async_result_completion_handler_type<
+  TargetAsyncResult, Allocator,
+  typename void_type<
+    typename TargetAsyncResult::completion_handler_type
+  >::type>
+{
+  typedef allocator_binder<
+    typename TargetAsyncResult::completion_handler_type, Allocator>
+      completion_handler_type;
+};
+
+template <typename TargetAsyncResult, typename = void>
+struct allocator_binder_async_result_return_type
+{
+};
+
+template <typename TargetAsyncResult>
+struct allocator_binder_async_result_return_type<
+  TargetAsyncResult,
+  typename void_type<
+    typename TargetAsyncResult::return_type
+  >::type>
+{
+  typedef typename TargetAsyncResult::return_type return_type;
+};
+
+} // namespace detail
+
+template <typename T, typename Allocator, typename Signature>
+class async_result<allocator_binder<T, Allocator>, Signature> :
+  public detail::allocator_binder_async_result_completion_handler_type<
+    async_result<T, Signature>, Allocator>,
+  public detail::allocator_binder_async_result_return_type<
+    async_result<T, Signature> >
+{
+public:
+  explicit async_result(allocator_binder<T, Allocator>& b)
+    : target_(b.get())
+  {
+  }
+
+  typename async_result<T, Signature>::return_type get()
+  {
+    return target_.get();
+  }
+
+  template <typename Initiation>
+  struct init_wrapper
+  {
+    template <typename Init>
+    init_wrapper(const Allocator& allocator, ASIO_MOVE_ARG(Init) init)
+      : allocator_(allocator),
+        initiation_(ASIO_MOVE_CAST(Init)(init))
+    {
+    }
+
+#if defined(ASIO_HAS_VARIADIC_TEMPLATES)
+
+    template <typename Handler, typename... Args>
+    void operator()(
+        ASIO_MOVE_ARG(Handler) handler,
+        ASIO_MOVE_ARG(Args)... args)
+    {
+      ASIO_MOVE_CAST(Initiation)(initiation_)(
+          allocator_binder<
+            typename decay<Handler>::type, Allocator>(
+              allocator_, ASIO_MOVE_CAST(Handler)(handler)),
+          ASIO_MOVE_CAST(Args)(args)...);
+    }
+
+    template <typename Handler, typename... Args>
+    void operator()(
+        ASIO_MOVE_ARG(Handler) handler,
+        ASIO_MOVE_ARG(Args)... args) const
+    {
+      initiation_(
+          allocator_binder<
+            typename decay<Handler>::type, Allocator>(
+              allocator_, ASIO_MOVE_CAST(Handler)(handler)),
+          ASIO_MOVE_CAST(Args)(args)...);
+    }
+
+#else // defined(ASIO_HAS_VARIADIC_TEMPLATES)
+
+    template <typename Handler>
+    void operator()(
+        ASIO_MOVE_ARG(Handler) handler)
+    {
+      ASIO_MOVE_CAST(Initiation)(initiation_)(
+          allocator_binder<
+            typename decay<Handler>::type, Allocator>(
+              allocator_, ASIO_MOVE_CAST(Handler)(handler)));
+    }
+
+    template <typename Handler>
+    void operator()(
+        ASIO_MOVE_ARG(Handler) handler) const
+    {
+      initiation_(
+          allocator_binder<
+            typename decay<Handler>::type, Allocator>(
+              allocator_, ASIO_MOVE_CAST(Handler)(handler)));
+    }
+
+#define ASIO_PRIVATE_INIT_WRAPPER_DEF(n) \
+    template <typename Handler, ASIO_VARIADIC_TPARAMS(n)> \
+    void operator()( \
+        ASIO_MOVE_ARG(Handler) handler, \
+        ASIO_VARIADIC_MOVE_PARAMS(n)) \
+    { \
+      ASIO_MOVE_CAST(Initiation)(initiation_)( \
+          allocator_binder< \
+            typename decay<Handler>::type, Allocator>( \
+              allocator_, ASIO_MOVE_CAST(Handler)(handler)), \
+          ASIO_VARIADIC_MOVE_ARGS(n)); \
+    } \
+    \
+    template <typename Handler, ASIO_VARIADIC_TPARAMS(n)> \
+    void operator()( \
+        ASIO_MOVE_ARG(Handler) handler, \
+        ASIO_VARIADIC_MOVE_PARAMS(n)) const \
+    { \
+      initiation_( \
+          allocator_binder< \
+            typename decay<Handler>::type, Allocator>( \
+              allocator_, ASIO_MOVE_CAST(Handler)(handler)), \
+          ASIO_VARIADIC_MOVE_ARGS(n)); \
+    } \
+    /**/
+    ASIO_VARIADIC_GENERATE(ASIO_PRIVATE_INIT_WRAPPER_DEF)
+#undef ASIO_PRIVATE_INIT_WRAPPER_DEF
+
+#endif // defined(ASIO_HAS_VARIADIC_TEMPLATES)
+
+    Allocator allocator_;
+    Initiation initiation_;
+  };
+
+#if defined(ASIO_HAS_VARIADIC_TEMPLATES)
+
+  template <typename Initiation, typename RawCompletionToken, typename... Args>
+  static ASIO_INITFN_DEDUCED_RESULT_TYPE(T, Signature,
+    (async_initiate<T, Signature>(
+        declval<init_wrapper<typename decay<Initiation>::type> >(),
+        declval<RawCompletionToken>().get(),
+        declval<ASIO_MOVE_ARG(Args)>()...)))
+  initiate(
+      ASIO_MOVE_ARG(Initiation) initiation,
+      ASIO_MOVE_ARG(RawCompletionToken) token,
+      ASIO_MOVE_ARG(Args)... args)
+  {
+    return async_initiate<T, Signature>(
+        init_wrapper<typename decay<Initiation>::type>(
+          token.get_allocator(),
+          ASIO_MOVE_CAST(Initiation)(initiation)),
+        token.get(), ASIO_MOVE_CAST(Args)(args)...);
+  }
+
+#else // defined(ASIO_HAS_VARIADIC_TEMPLATES)
+
+  template <typename Initiation, typename RawCompletionToken>
+  static ASIO_INITFN_DEDUCED_RESULT_TYPE(T, Signature,
+    (async_initiate<T, Signature>(
+        declval<init_wrapper<typename decay<Initiation>::type> >(),
+        declval<RawCompletionToken>().get())))
+  initiate(
+      ASIO_MOVE_ARG(Initiation) initiation,
+      ASIO_MOVE_ARG(RawCompletionToken) token)
+  {
+    return async_initiate<T, Signature>(
+        init_wrapper<typename decay<Initiation>::type>(
+          token.get_allocator(),
+          ASIO_MOVE_CAST(Initiation)(initiation)),
+        token.get());
+  }
+
+#define ASIO_PRIVATE_INITIATE_DEF(n) \
+  template <typename Initiation, typename RawCompletionToken, \
+      ASIO_VARIADIC_TPARAMS(n)> \
+  static ASIO_INITFN_DEDUCED_RESULT_TYPE(T, Signature, \
+    (async_initiate<T, Signature>( \
+        declval<init_wrapper<typename decay<Initiation>::type> >(), \
+        declval<RawCompletionToken>().get(), \
+        ASIO_VARIADIC_MOVE_DECLVAL(n)))) \
+  initiate( \
+      ASIO_MOVE_ARG(Initiation) initiation, \
+      ASIO_MOVE_ARG(RawCompletionToken) token, \
+      ASIO_VARIADIC_MOVE_PARAMS(n)) \
+  { \
+    return async_initiate<T, Signature>( \
+        init_wrapper<typename decay<Initiation>::type>( \
+          token.get_allocator(), \
+          ASIO_MOVE_CAST(Initiation)(initiation)), \
+        token.get(), ASIO_VARIADIC_MOVE_ARGS(n)); \
+  } \
+  /**/
+  ASIO_VARIADIC_GENERATE(ASIO_PRIVATE_INITIATE_DEF)
+#undef ASIO_PRIVATE_INITIATE_DEF
+
+#endif // defined(ASIO_HAS_VARIADIC_TEMPLATES)
+
+private:
+  async_result(const async_result&) ASIO_DELETED;
+  async_result& operator=(const async_result&) ASIO_DELETED;
+
+  async_result<T, Signature> target_;
+};
+
+template <template <typename, typename> class Associator,
+    typename T, typename Allocator, typename DefaultCandidate>
+struct associator<Associator,
+    allocator_binder<T, Allocator>,
+    DefaultCandidate>
+{
+  typedef typename Associator<T, DefaultCandidate>::type type;
+
+  static type get(const allocator_binder<T, Allocator>& b,
+      const DefaultCandidate& c = DefaultCandidate()) ASIO_NOEXCEPT
+  {
+    return Associator<T, DefaultCandidate>::get(b.get(), c);
+  }
+};
+
+template <typename T, typename Allocator, typename Allocator1>
+struct associated_allocator<
+    allocator_binder<T, Allocator>,
+    Allocator1>
+{
+  typedef Allocator type;
+
+  static type get(const allocator_binder<T, Allocator>& b,
+      const Allocator1& = Allocator1()) ASIO_NOEXCEPT
+  {
+    return b.get_allocator();
+  }
+};
+
+#endif // !defined(GENERATING_DOCUMENTATION)
+
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // ASIO_BIND_ALLOCATOR_HPP

lib/asio/include/asio/bind_cancellation_slot.hpp

@@ -0,0 +1,724 @@
+//
+// bind_cancellation_slot.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_BIND_CANCELLATION_SLOT_HPP
+#define ASIO_BIND_CANCELLATION_SLOT_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+#include "asio/detail/type_traits.hpp"
+#include "asio/detail/variadic_templates.hpp"
+#include "asio/associated_cancellation_slot.hpp"
+#include "asio/associator.hpp"
+#include "asio/async_result.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+// Helper to automatically define nested typedef result_type.
+
+template <typename T, typename = void>
+struct cancellation_slot_binder_result_type
+{
+protected:
+  typedef void result_type_or_void;
+};
+
+template <typename T>
+struct cancellation_slot_binder_result_type<T,
+  typename void_type<typename T::result_type>::type>
+{
+  typedef typename T::result_type result_type;
+protected:
+  typedef result_type result_type_or_void;
+};
+
+template <typename R>
+struct cancellation_slot_binder_result_type<R(*)()>
+{
+  typedef R result_type;
+protected:
+  typedef result_type result_type_or_void;
+};
+
+template <typename R>
+struct cancellation_slot_binder_result_type<R(&)()>
+{
+  typedef R result_type;
+protected:
+  typedef result_type result_type_or_void;
+};
+
+template <typename R, typename A1>
+struct cancellation_slot_binder_result_type<R(*)(A1)>
+{
+  typedef R result_type;
+protected:
+  typedef result_type result_type_or_void;
+};
+
+template <typename R, typename A1>
+struct cancellation_slot_binder_result_type<R(&)(A1)>
+{
+  typedef R result_type;
+protected:
+  typedef result_type result_type_or_void;
+};
+
+template <typename R, typename A1, typename A2>
+struct cancellation_slot_binder_result_type<R(*)(A1, A2)>
+{
+  typedef R result_type;
+protected:
+  typedef result_type result_type_or_void;
+};
+
+template <typename R, typename A1, typename A2>
+struct cancellation_slot_binder_result_type<R(&)(A1, A2)>
+{
+  typedef R result_type;
+protected:
+  typedef result_type result_type_or_void;
+};
+
+// Helper to automatically define nested typedef argument_type.
+
+template <typename T, typename = void>
+struct cancellation_slot_binder_argument_type {};
+
+template <typename T>
+struct cancellation_slot_binder_argument_type<T,
+  typename void_type<typename T::argument_type>::type>
+{
+  typedef typename T::argument_type argument_type;
+};
+
+template <typename R, typename A1>
+struct cancellation_slot_binder_argument_type<R(*)(A1)>
+{
+  typedef A1 argument_type;
+};
+
+template <typename R, typename A1>
+struct cancellation_slot_binder_argument_type<R(&)(A1)>
+{
+  typedef A1 argument_type;
+};
+
+// Helper to automatically define nested typedefs first_argument_type and
+// second_argument_type.
+
+template <typename T, typename = void>
+struct cancellation_slot_binder_argument_types {};
+
+template <typename T>
+struct cancellation_slot_binder_argument_types<T,
+  typename void_type<typename T::first_argument_type>::type>
+{
+  typedef typename T::first_argument_type first_argument_type;
+  typedef typename T::second_argument_type second_argument_type;
+};
+
+template <typename R, typename A1, typename A2>
+struct cancellation_slot_binder_argument_type<R(*)(A1, A2)>
+{
+  typedef A1 first_argument_type;
+  typedef A2 second_argument_type;
+};
+
+template <typename R, typename A1, typename A2>
+struct cancellation_slot_binder_argument_type<R(&)(A1, A2)>
+{
+  typedef A1 first_argument_type;
+  typedef A2 second_argument_type;
+};
+
+// Helper to enable SFINAE on zero-argument operator() below.
+
+template <typename T, typename = void>
+struct cancellation_slot_binder_result_of0
+{
+  typedef void type;
+};
+
+template <typename T>
+struct cancellation_slot_binder_result_of0<T,
+  typename void_type<typename result_of<T()>::type>::type>
+{
+  typedef typename result_of<T()>::type type;
+};
+
+} // namespace detail
+
+/// A call wrapper type to bind a cancellation slot of type @c CancellationSlot
+/// to an object of type @c T.
+template <typename T, typename CancellationSlot>
+class cancellation_slot_binder
+#if !defined(GENERATING_DOCUMENTATION)
+  : public detail::cancellation_slot_binder_result_type<T>,
+    public detail::cancellation_slot_binder_argument_type<T>,
+    public detail::cancellation_slot_binder_argument_types<T>
+#endif // !defined(GENERATING_DOCUMENTATION)
+{
+public:
+  /// The type of the target object.
+  typedef T target_type;
+
+  /// The type of the associated cancellation slot.
+  typedef CancellationSlot cancellation_slot_type;
+
+#if defined(GENERATING_DOCUMENTATION)
+  /// The return type if a function.
+  /**
+   * The type of @c result_type is based on the type @c T of the wrapper's
+   * target object:
+   *
+   * @li if @c T is a pointer to function type, @c result_type is a synonym for
+   * the return type of @c T;
+   *
+   * @li if @c T is a class type with a member type @c result_type, then @c
+   * result_type is a synonym for @c T::result_type;
+   *
+   * @li otherwise @c result_type is not defined.
+   */
+  typedef see_below result_type;
+
+  /// The type of the function's argument.
+  /**
+   * The type of @c argument_type is based on the type @c T of the wrapper's
+   * target object:
+   *
+   * @li if @c T is a pointer to a function type accepting a single argument,
+   * @c argument_type is a synonym for the return type of @c T;
+   *
+   * @li if @c T is a class type with a member type @c argument_type, then @c
+   * argument_type is a synonym for @c T::argument_type;
+   *
+   * @li otherwise @c argument_type is not defined.
+   */
+  typedef see_below argument_type;
+
+  /// The type of the function's first argument.
+  /**
+   * The type of @c first_argument_type is based on the type @c T of the
+   * wrapper's target object:
+   *
+   * @li if @c T is a pointer to a function type accepting two arguments, @c
+   * first_argument_type is a synonym for the return type of @c T;
+   *
+   * @li if @c T is a class type with a member type @c first_argument_type,
+   * then @c first_argument_type is a synonym for @c T::first_argument_type;
+   *
+   * @li otherwise @c first_argument_type is not defined.
+   */
+  typedef see_below first_argument_type;
+
+  /// The type of the function's second argument.
+  /**
+   * The type of @c second_argument_type is based on the type @c T of the
+   * wrapper's target object:
+   *
+   * @li if @c T is a pointer to a function type accepting two arguments, @c
+   * second_argument_type is a synonym for the return type of @c T;
+   *
+   * @li if @c T is a class type with a member type @c first_argument_type,
+   * then @c second_argument_type is a synonym for @c T::second_argument_type;
+   *
+   * @li otherwise @c second_argument_type is not defined.
+   */
+  typedef see_below second_argument_type;
+#endif // defined(GENERATING_DOCUMENTATION)
+
+  /// Construct a cancellation slot wrapper for the specified object.
+  /**
+   * This constructor is only valid if the type @c T is constructible from type
+   * @c U.
+   */
+  template <typename U>
+  cancellation_slot_binder(const cancellation_slot_type& s,
+      ASIO_MOVE_ARG(U) u)
+    : slot_(s),
+      target_(ASIO_MOVE_CAST(U)(u))
+  {
+  }
+
+  /// Copy constructor.
+  cancellation_slot_binder(const cancellation_slot_binder& other)
+    : slot_(other.get_cancellation_slot()),
+      target_(other.get())
+  {
+  }
+
+  /// Construct a copy, but specify a different cancellation slot.
+  cancellation_slot_binder(const cancellation_slot_type& s,
+      const cancellation_slot_binder& other)
+    : slot_(s),
+      target_(other.get())
+  {
+  }
+
+  /// Construct a copy of a different cancellation slot wrapper type.
+  /**
+   * This constructor is only valid if the @c CancellationSlot type is
+   * constructible from type @c OtherCancellationSlot, and the type @c T is
+   * constructible from type @c U.
+   */
+  template <typename U, typename OtherCancellationSlot>
+  cancellation_slot_binder(
+      const cancellation_slot_binder<U, OtherCancellationSlot>& other)
+    : slot_(other.get_cancellation_slot()),
+      target_(other.get())
+  {
+  }
+
+  /// Construct a copy of a different cancellation slot wrapper type, but
+  /// specify a different cancellation slot.
+  /**
+   * This constructor is only valid if the type @c T is constructible from type
+   * @c U.
+   */
+  template <typename U, typename OtherCancellationSlot>
+  cancellation_slot_binder(const cancellation_slot_type& s,
+      const cancellation_slot_binder<U, OtherCancellationSlot>& other)
+    : slot_(s),
+      target_(other.get())
+  {
+  }
+
+#if defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+
+  /// Move constructor.
+  cancellation_slot_binder(cancellation_slot_binder&& other)
+    : slot_(ASIO_MOVE_CAST(cancellation_slot_type)(
+          other.get_cancellation_slot())),
+      target_(ASIO_MOVE_CAST(T)(other.get()))
+  {
+  }
+
+  /// Move construct the target object, but specify a different cancellation
+  /// slot.
+  cancellation_slot_binder(const cancellation_slot_type& s,
+      cancellation_slot_binder&& other)
+    : slot_(s),
+      target_(ASIO_MOVE_CAST(T)(other.get()))
+  {
+  }
+
+  /// Move construct from a different cancellation slot wrapper type.
+  template <typename U, typename OtherCancellationSlot>
+  cancellation_slot_binder(
+      cancellation_slot_binder<U, OtherCancellationSlot>&& other)
+    : slot_(ASIO_MOVE_CAST(OtherCancellationSlot)(
+          other.get_cancellation_slot())),
+      target_(ASIO_MOVE_CAST(U)(other.get()))
+  {
+  }
+
+  /// Move construct from a different cancellation slot wrapper type, but
+  /// specify a different cancellation slot.
+  template <typename U, typename OtherCancellationSlot>
+  cancellation_slot_binder(const cancellation_slot_type& s,
+      cancellation_slot_binder<U, OtherCancellationSlot>&& other)
+    : slot_(s),
+      target_(ASIO_MOVE_CAST(U)(other.get()))
+  {
+  }
+
+#endif // defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+
+  /// Destructor.
+  ~cancellation_slot_binder()
+  {
+  }
+
+  /// Obtain a reference to the target object.
+  target_type& get() ASIO_NOEXCEPT
+  {
+    return target_;
+  }
+
+  /// Obtain a reference to the target object.
+  const target_type& get() const ASIO_NOEXCEPT
+  {
+    return target_;
+  }
+
+  /// Obtain the associated cancellation slot.
+  cancellation_slot_type get_cancellation_slot() const ASIO_NOEXCEPT
+  {
+    return slot_;
+  }
+
+#if defined(GENERATING_DOCUMENTATION)
+
+  template <typename... Args> auto operator()(Args&& ...);
+  template <typename... Args> auto operator()(Args&& ...) const;
+
+#elif defined(ASIO_HAS_VARIADIC_TEMPLATES)
+
+  /// Forwarding function call operator.
+  template <typename... Args>
+  typename result_of<T(Args...)>::type operator()(
+      ASIO_MOVE_ARG(Args)... args)
+  {
+    return target_(ASIO_MOVE_CAST(Args)(args)...);
+  }
+
+  /// Forwarding function call operator.
+  template <typename... Args>
+  typename result_of<T(Args...)>::type operator()(
+      ASIO_MOVE_ARG(Args)... args) const
+  {
+    return target_(ASIO_MOVE_CAST(Args)(args)...);
+  }
+
+#elif defined(ASIO_HAS_STD_TYPE_TRAITS) && !defined(_MSC_VER)
+
+  typename detail::cancellation_slot_binder_result_of0<T>::type operator()()
+  {
+    return target_();
+  }
+
+  typename detail::cancellation_slot_binder_result_of0<T>::type
+  operator()() const
+  {
+    return target_();
+  }
+
+#define ASIO_PRIVATE_BINDER_CALL_DEF(n) \
+  template <ASIO_VARIADIC_TPARAMS(n)> \
+  typename result_of<T(ASIO_VARIADIC_TARGS(n))>::type operator()( \
+      ASIO_VARIADIC_MOVE_PARAMS(n)) \
+  { \
+    return target_(ASIO_VARIADIC_MOVE_ARGS(n)); \
+  } \
+  \
+  template <ASIO_VARIADIC_TPARAMS(n)> \
+  typename result_of<T(ASIO_VARIADIC_TARGS(n))>::type operator()( \
+      ASIO_VARIADIC_MOVE_PARAMS(n)) const \
+  { \
+    return target_(ASIO_VARIADIC_MOVE_ARGS(n)); \
+  } \
+  /**/
+  ASIO_VARIADIC_GENERATE(ASIO_PRIVATE_BINDER_CALL_DEF)
+#undef ASIO_PRIVATE_BINDER_CALL_DEF
+
+#else // defined(ASIO_HAS_STD_TYPE_TRAITS) && !defined(_MSC_VER)
+
+  typedef typename detail::cancellation_slot_binder_result_type<
+    T>::result_type_or_void result_type_or_void;
+
+  result_type_or_void operator()()
+  {
+    return target_();
+  }
+
+  result_type_or_void operator()() const
+  {
+    return target_();
+  }
+
+#define ASIO_PRIVATE_BINDER_CALL_DEF(n) \
+  template <ASIO_VARIADIC_TPARAMS(n)> \
+  result_type_or_void operator()( \
+      ASIO_VARIADIC_MOVE_PARAMS(n)) \
+  { \
+    return target_(ASIO_VARIADIC_MOVE_ARGS(n)); \
+  } \
+  \
+  template <ASIO_VARIADIC_TPARAMS(n)> \
+  result_type_or_void operator()( \
+      ASIO_VARIADIC_MOVE_PARAMS(n)) const \
+  { \
+    return target_(ASIO_VARIADIC_MOVE_ARGS(n)); \
+  } \
+  /**/
+  ASIO_VARIADIC_GENERATE(ASIO_PRIVATE_BINDER_CALL_DEF)
+#undef ASIO_PRIVATE_BINDER_CALL_DEF
+
+#endif // defined(ASIO_HAS_STD_TYPE_TRAITS) && !defined(_MSC_VER)
+
+private:
+  CancellationSlot slot_;
+  T target_;
+};
+
+/// Associate an object of type @c T with a cancellation slot of type
+/// @c CancellationSlot.
+template <typename CancellationSlot, typename T>
+ASIO_NODISCARD inline
+cancellation_slot_binder<typename decay<T>::type, CancellationSlot>
+bind_cancellation_slot(const CancellationSlot& s, ASIO_MOVE_ARG(T) t)
+{
+  return cancellation_slot_binder<
+    typename decay<T>::type, CancellationSlot>(
+      s, ASIO_MOVE_CAST(T)(t));
+}
+
+#if !defined(GENERATING_DOCUMENTATION)
+
+namespace detail {
+
+template <typename TargetAsyncResult,
+  typename CancellationSlot, typename = void>
+struct cancellation_slot_binder_async_result_completion_handler_type
+{
+};
+
+template <typename TargetAsyncResult, typename CancellationSlot>
+struct cancellation_slot_binder_async_result_completion_handler_type<
+  TargetAsyncResult, CancellationSlot,
+  typename void_type<
+    typename TargetAsyncResult::completion_handler_type
+  >::type>
+{
+  typedef cancellation_slot_binder<
+    typename TargetAsyncResult::completion_handler_type, CancellationSlot>
+      completion_handler_type;
+};
+
+template <typename TargetAsyncResult, typename = void>
+struct cancellation_slot_binder_async_result_return_type
+{
+};
+
+template <typename TargetAsyncResult>
+struct cancellation_slot_binder_async_result_return_type<
+  TargetAsyncResult,
+  typename void_type<
+    typename TargetAsyncResult::return_type
+  >::type>
+{
+  typedef typename TargetAsyncResult::return_type return_type;
+};
+
+} // namespace detail
+
+template <typename T, typename CancellationSlot, typename Signature>
+class async_result<cancellation_slot_binder<T, CancellationSlot>, Signature> :
+  public detail::cancellation_slot_binder_async_result_completion_handler_type<
+    async_result<T, Signature>, CancellationSlot>,
+  public detail::cancellation_slot_binder_async_result_return_type<
+    async_result<T, Signature> >
+{
+public:
+  explicit async_result(cancellation_slot_binder<T, CancellationSlot>& b)
+    : target_(b.get())
+  {
+  }
+
+  typename async_result<T, Signature>::return_type get()
+  {
+    return target_.get();
+  }
+
+  template <typename Initiation>
+  struct init_wrapper
+  {
+    template <typename Init>
+    init_wrapper(const CancellationSlot& slot, ASIO_MOVE_ARG(Init) init)
+      : slot_(slot),
+        initiation_(ASIO_MOVE_CAST(Init)(init))
+    {
+    }
+
+#if defined(ASIO_HAS_VARIADIC_TEMPLATES)
+
+    template <typename Handler, typename... Args>
+    void operator()(
+        ASIO_MOVE_ARG(Handler) handler,
+        ASIO_MOVE_ARG(Args)... args)
+    {
+      ASIO_MOVE_CAST(Initiation)(initiation_)(
+          cancellation_slot_binder<
+            typename decay<Handler>::type, CancellationSlot>(
+              slot_, ASIO_MOVE_CAST(Handler)(handler)),
+          ASIO_MOVE_CAST(Args)(args)...);
+    }
+
+    template <typename Handler, typename... Args>
+    void operator()(
+        ASIO_MOVE_ARG(Handler) handler,
+        ASIO_MOVE_ARG(Args)... args) const
+    {
+      initiation_(
+          cancellation_slot_binder<
+            typename decay<Handler>::type, CancellationSlot>(
+              slot_, ASIO_MOVE_CAST(Handler)(handler)),
+          ASIO_MOVE_CAST(Args)(args)...);
+    }
+
+#else // defined(ASIO_HAS_VARIADIC_TEMPLATES)
+
+    template <typename Handler>
+    void operator()(
+        ASIO_MOVE_ARG(Handler) handler)
+    {
+      ASIO_MOVE_CAST(Initiation)(initiation_)(
+          cancellation_slot_binder<
+            typename decay<Handler>::type, CancellationSlot>(
+              slot_, ASIO_MOVE_CAST(Handler)(handler)));
+    }
+
+    template <typename Handler>
+    void operator()(
+        ASIO_MOVE_ARG(Handler) handler) const
+    {
+      initiation_(
+          cancellation_slot_binder<
+            typename decay<Handler>::type, CancellationSlot>(
+              slot_, ASIO_MOVE_CAST(Handler)(handler)));
+    }
+
+#define ASIO_PRIVATE_INIT_WRAPPER_DEF(n) \
+    template <typename Handler, ASIO_VARIADIC_TPARAMS(n)> \
+    void operator()( \
+        ASIO_MOVE_ARG(Handler) handler, \
+        ASIO_VARIADIC_MOVE_PARAMS(n)) \
+    { \
+      ASIO_MOVE_CAST(Initiation)(initiation_)( \
+          cancellation_slot_binder< \
+            typename decay<Handler>::type, CancellationSlot>( \
+              slot_, ASIO_MOVE_CAST(Handler)(handler)), \
+          ASIO_VARIADIC_MOVE_ARGS(n)); \
+    } \
+    \
+    template <typename Handler, ASIO_VARIADIC_TPARAMS(n)> \
+    void operator()( \
+        ASIO_MOVE_ARG(Handler) handler, \
+        ASIO_VARIADIC_MOVE_PARAMS(n)) const \
+    { \
+      initiation_( \
+          cancellation_slot_binder< \
+            typename decay<Handler>::type, CancellationSlot>( \
+              slot_, ASIO_MOVE_CAST(Handler)(handler)), \
+          ASIO_VARIADIC_MOVE_ARGS(n)); \
+    } \
+    /**/
+    ASIO_VARIADIC_GENERATE(ASIO_PRIVATE_INIT_WRAPPER_DEF)
+#undef ASIO_PRIVATE_INIT_WRAPPER_DEF
+
+#endif // defined(ASIO_HAS_VARIADIC_TEMPLATES)
+
+    CancellationSlot slot_;
+    Initiation initiation_;
+  };
+
+#if defined(ASIO_HAS_VARIADIC_TEMPLATES)
+
+  template <typename Initiation, typename RawCompletionToken, typename... Args>
+  static ASIO_INITFN_DEDUCED_RESULT_TYPE(T, Signature,
+    (async_initiate<T, Signature>(
+        declval<init_wrapper<typename decay<Initiation>::type> >(),
+        declval<RawCompletionToken>().get(),
+        declval<ASIO_MOVE_ARG(Args)>()...)))
+  initiate(
+      ASIO_MOVE_ARG(Initiation) initiation,
+      ASIO_MOVE_ARG(RawCompletionToken) token,
+      ASIO_MOVE_ARG(Args)... args)
+  {
+    return async_initiate<T, Signature>(
+        init_wrapper<typename decay<Initiation>::type>(
+          token.get_cancellation_slot(),
+          ASIO_MOVE_CAST(Initiation)(initiation)),
+        token.get(), ASIO_MOVE_CAST(Args)(args)...);
+  }
+
+#else // defined(ASIO_HAS_VARIADIC_TEMPLATES)
+
+  template <typename Initiation, typename RawCompletionToken>
+  static ASIO_INITFN_DEDUCED_RESULT_TYPE(T, Signature,
+    (async_initiate<T, Signature>(
+        declval<init_wrapper<typename decay<Initiation>::type> >(),
+        declval<RawCompletionToken>().get())))
+  initiate(
+      ASIO_MOVE_ARG(Initiation) initiation,
+      ASIO_MOVE_ARG(RawCompletionToken) token)
+  {
+    return async_initiate<T, Signature>(
+        init_wrapper<typename decay<Initiation>::type>(
+          token.get_cancellation_slot(),
+          ASIO_MOVE_CAST(Initiation)(initiation)),
+        token.get());
+  }
+
+#define ASIO_PRIVATE_INITIATE_DEF(n) \
+  template <typename Initiation, typename RawCompletionToken, \
+      ASIO_VARIADIC_TPARAMS(n)> \
+  static ASIO_INITFN_DEDUCED_RESULT_TYPE(T, Signature, \
+    (async_initiate<T, Signature>( \
+        declval<init_wrapper<typename decay<Initiation>::type> >(), \
+        declval<RawCompletionToken>().get(), \
+        ASIO_VARIADIC_MOVE_DECLVAL(n)))) \
+  initiate( \
+      ASIO_MOVE_ARG(Initiation) initiation, \
+      ASIO_MOVE_ARG(RawCompletionToken) token, \
+      ASIO_VARIADIC_MOVE_PARAMS(n)) \
+  { \
+    return async_initiate<T, Signature>( \
+        init_wrapper<typename decay<Initiation>::type>( \
+          token.get_cancellation_slot(), \
+          ASIO_MOVE_CAST(Initiation)(initiation)), \
+        token.get(), ASIO_VARIADIC_MOVE_ARGS(n)); \
+  } \
+  /**/
+  ASIO_VARIADIC_GENERATE(ASIO_PRIVATE_INITIATE_DEF)
+#undef ASIO_PRIVATE_INITIATE_DEF
+
+#endif // defined(ASIO_HAS_VARIADIC_TEMPLATES)
+
+private:
+  async_result(const async_result&) ASIO_DELETED;
+  async_result& operator=(const async_result&) ASIO_DELETED;
+
+  async_result<T, Signature> target_;
+};
+
+template <template <typename, typename> class Associator,
+    typename T, typename CancellationSlot, typename DefaultCandidate>
+struct associator<Associator,
+    cancellation_slot_binder<T, CancellationSlot>,
+    DefaultCandidate>
+{
+  typedef typename Associator<T, DefaultCandidate>::type type;
+
+  static type get(const cancellation_slot_binder<T, CancellationSlot>& b,
+      const DefaultCandidate& c = DefaultCandidate()) ASIO_NOEXCEPT
+  {
+    return Associator<T, DefaultCandidate>::get(b.get(), c);
+  }
+};
+
+template <typename T, typename CancellationSlot, typename CancellationSlot1>
+struct associated_cancellation_slot<
+    cancellation_slot_binder<T, CancellationSlot>,
+    CancellationSlot1>
+{
+  typedef CancellationSlot type;
+
+  static type get(const cancellation_slot_binder<T, CancellationSlot>& b,
+      const CancellationSlot1& = CancellationSlot1()) ASIO_NOEXCEPT
+  {
+    return b.get_cancellation_slot();
+  }
+};
+
+#endif // !defined(GENERATING_DOCUMENTATION)
+
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // ASIO_BIND_CANCELLATION_SLOT_HPP

lib/asio/include/asio/bind_executor.hpp

@@ -0,0 +1,770 @@
+//
+// bind_executor.hpp
+// ~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_BIND_EXECUTOR_HPP
+#define ASIO_BIND_EXECUTOR_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+#include "asio/detail/type_traits.hpp"
+#include "asio/detail/variadic_templates.hpp"
+#include "asio/associated_executor.hpp"
+#include "asio/associator.hpp"
+#include "asio/async_result.hpp"
+#include "asio/execution/executor.hpp"
+#include "asio/execution_context.hpp"
+#include "asio/is_executor.hpp"
+#include "asio/uses_executor.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+// Helper to automatically define nested typedef result_type.
+
+template <typename T, typename = void>
+struct executor_binder_result_type
+{
+protected:
+  typedef void result_type_or_void;
+};
+
+template <typename T>
+struct executor_binder_result_type<T,
+  typename void_type<typename T::result_type>::type>
+{
+  typedef typename T::result_type result_type;
+protected:
+  typedef result_type result_type_or_void;
+};
+
+template <typename R>
+struct executor_binder_result_type<R(*)()>
+{
+  typedef R result_type;
+protected:
+  typedef result_type result_type_or_void;
+};
+
+template <typename R>
+struct executor_binder_result_type<R(&)()>
+{
+  typedef R result_type;
+protected:
+  typedef result_type result_type_or_void;
+};
+
+template <typename R, typename A1>
+struct executor_binder_result_type<R(*)(A1)>
+{
+  typedef R result_type;
+protected:
+  typedef result_type result_type_or_void;
+};
+
+template <typename R, typename A1>
+struct executor_binder_result_type<R(&)(A1)>
+{
+  typedef R result_type;
+protected:
+  typedef result_type result_type_or_void;
+};
+
+template <typename R, typename A1, typename A2>
+struct executor_binder_result_type<R(*)(A1, A2)>
+{
+  typedef R result_type;
+protected:
+  typedef result_type result_type_or_void;
+};
+
+template <typename R, typename A1, typename A2>
+struct executor_binder_result_type<R(&)(A1, A2)>
+{
+  typedef R result_type;
+protected:
+  typedef result_type result_type_or_void;
+};
+
+// Helper to automatically define nested typedef argument_type.
+
+template <typename T, typename = void>
+struct executor_binder_argument_type {};
+
+template <typename T>
+struct executor_binder_argument_type<T,
+  typename void_type<typename T::argument_type>::type>
+{
+  typedef typename T::argument_type argument_type;
+};
+
+template <typename R, typename A1>
+struct executor_binder_argument_type<R(*)(A1)>
+{
+  typedef A1 argument_type;
+};
+
+template <typename R, typename A1>
+struct executor_binder_argument_type<R(&)(A1)>
+{
+  typedef A1 argument_type;
+};
+
+// Helper to automatically define nested typedefs first_argument_type and
+// second_argument_type.
+
+template <typename T, typename = void>
+struct executor_binder_argument_types {};
+
+template <typename T>
+struct executor_binder_argument_types<T,
+  typename void_type<typename T::first_argument_type>::type>
+{
+  typedef typename T::first_argument_type first_argument_type;
+  typedef typename T::second_argument_type second_argument_type;
+};
+
+template <typename R, typename A1, typename A2>
+struct executor_binder_argument_type<R(*)(A1, A2)>
+{
+  typedef A1 first_argument_type;
+  typedef A2 second_argument_type;
+};
+
+template <typename R, typename A1, typename A2>
+struct executor_binder_argument_type<R(&)(A1, A2)>
+{
+  typedef A1 first_argument_type;
+  typedef A2 second_argument_type;
+};
+
+// Helper to perform uses_executor construction of the target type, if
+// required.
+
+template <typename T, typename Executor, bool UsesExecutor>
+class executor_binder_base;
+
+template <typename T, typename Executor>
+class executor_binder_base<T, Executor, true>
+{
+protected:
+  template <typename E, typename U>
+  executor_binder_base(ASIO_MOVE_ARG(E) e, ASIO_MOVE_ARG(U) u)
+    : executor_(ASIO_MOVE_CAST(E)(e)),
+      target_(executor_arg_t(), executor_, ASIO_MOVE_CAST(U)(u))
+  {
+  }
+
+  Executor executor_;
+  T target_;
+};
+
+template <typename T, typename Executor>
+class executor_binder_base<T, Executor, false>
+{
+protected:
+  template <typename E, typename U>
+  executor_binder_base(ASIO_MOVE_ARG(E) e, ASIO_MOVE_ARG(U) u)
+    : executor_(ASIO_MOVE_CAST(E)(e)),
+      target_(ASIO_MOVE_CAST(U)(u))
+  {
+  }
+
+  Executor executor_;
+  T target_;
+};
+
+// Helper to enable SFINAE on zero-argument operator() below.
+
+template <typename T, typename = void>
+struct executor_binder_result_of0
+{
+  typedef void type;
+};
+
+template <typename T>
+struct executor_binder_result_of0<T,
+  typename void_type<typename result_of<T()>::type>::type>
+{
+  typedef typename result_of<T()>::type type;
+};
+
+} // namespace detail
+
+/// A call wrapper type to bind an executor of type @c Executor to an object of
+/// type @c T.
+template <typename T, typename Executor>
+class executor_binder
+#if !defined(GENERATING_DOCUMENTATION)
+  : public detail::executor_binder_result_type<T>,
+    public detail::executor_binder_argument_type<T>,
+    public detail::executor_binder_argument_types<T>,
+    private detail::executor_binder_base<
+      T, Executor, uses_executor<T, Executor>::value>
+#endif // !defined(GENERATING_DOCUMENTATION)
+{
+public:
+  /// The type of the target object.
+  typedef T target_type;
+
+  /// The type of the associated executor.
+  typedef Executor executor_type;
+
+#if defined(GENERATING_DOCUMENTATION)
+  /// The return type if a function.
+  /**
+   * The type of @c result_type is based on the type @c T of the wrapper's
+   * target object:
+   *
+   * @li if @c T is a pointer to function type, @c result_type is a synonym for
+   * the return type of @c T;
+   *
+   * @li if @c T is a class type with a member type @c result_type, then @c
+   * result_type is a synonym for @c T::result_type;
+   *
+   * @li otherwise @c result_type is not defined.
+   */
+  typedef see_below result_type;
+
+  /// The type of the function's argument.
+  /**
+   * The type of @c argument_type is based on the type @c T of the wrapper's
+   * target object:
+   *
+   * @li if @c T is a pointer to a function type accepting a single argument,
+   * @c argument_type is a synonym for the return type of @c T;
+   *
+   * @li if @c T is a class type with a member type @c argument_type, then @c
+   * argument_type is a synonym for @c T::argument_type;
+   *
+   * @li otherwise @c argument_type is not defined.
+   */
+  typedef see_below argument_type;
+
+  /// The type of the function's first argument.
+  /**
+   * The type of @c first_argument_type is based on the type @c T of the
+   * wrapper's target object:
+   *
+   * @li if @c T is a pointer to a function type accepting two arguments, @c
+   * first_argument_type is a synonym for the return type of @c T;
+   *
+   * @li if @c T is a class type with a member type @c first_argument_type,
+   * then @c first_argument_type is a synonym for @c T::first_argument_type;
+   *
+   * @li otherwise @c first_argument_type is not defined.
+   */
+  typedef see_below first_argument_type;
+
+  /// The type of the function's second argument.
+  /**
+   * The type of @c second_argument_type is based on the type @c T of the
+   * wrapper's target object:
+   *
+   * @li if @c T is a pointer to a function type accepting two arguments, @c
+   * second_argument_type is a synonym for the return type of @c T;
+   *
+   * @li if @c T is a class type with a member type @c first_argument_type,
+   * then @c second_argument_type is a synonym for @c T::second_argument_type;
+   *
+   * @li otherwise @c second_argument_type is not defined.
+   */
+  typedef see_below second_argument_type;
+#endif // defined(GENERATING_DOCUMENTATION)
+
+  /// Construct an executor wrapper for the specified object.
+  /**
+   * This constructor is only valid if the type @c T is constructible from type
+   * @c U.
+   */
+  template <typename U>
+  executor_binder(executor_arg_t, const executor_type& e,
+      ASIO_MOVE_ARG(U) u)
+    : base_type(e, ASIO_MOVE_CAST(U)(u))
+  {
+  }
+
+  /// Copy constructor.
+  executor_binder(const executor_binder& other)
+    : base_type(other.get_executor(), other.get())
+  {
+  }
+
+  /// Construct a copy, but specify a different executor.
+  executor_binder(executor_arg_t, const executor_type& e,
+      const executor_binder& other)
+    : base_type(e, other.get())
+  {
+  }
+
+  /// Construct a copy of a different executor wrapper type.
+  /**
+   * This constructor is only valid if the @c Executor type is constructible
+   * from type @c OtherExecutor, and the type @c T is constructible from type
+   * @c U.
+   */
+  template <typename U, typename OtherExecutor>
+  executor_binder(const executor_binder<U, OtherExecutor>& other)
+    : base_type(other.get_executor(), other.get())
+  {
+  }
+
+  /// Construct a copy of a different executor wrapper type, but specify a
+  /// different executor.
+  /**
+   * This constructor is only valid if the type @c T is constructible from type
+   * @c U.
+   */
+  template <typename U, typename OtherExecutor>
+  executor_binder(executor_arg_t, const executor_type& e,
+      const executor_binder<U, OtherExecutor>& other)
+    : base_type(e, other.get())
+  {
+  }
+
+#if defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+
+  /// Move constructor.
+  executor_binder(executor_binder&& other)
+    : base_type(ASIO_MOVE_CAST(executor_type)(other.get_executor()),
+        ASIO_MOVE_CAST(T)(other.get()))
+  {
+  }
+
+  /// Move construct the target object, but specify a different executor.
+  executor_binder(executor_arg_t, const executor_type& e,
+      executor_binder&& other)
+    : base_type(e, ASIO_MOVE_CAST(T)(other.get()))
+  {
+  }
+
+  /// Move construct from a different executor wrapper type.
+  template <typename U, typename OtherExecutor>
+  executor_binder(executor_binder<U, OtherExecutor>&& other)
+    : base_type(ASIO_MOVE_CAST(OtherExecutor)(other.get_executor()),
+        ASIO_MOVE_CAST(U)(other.get()))
+  {
+  }
+
+  /// Move construct from a different executor wrapper type, but specify a
+  /// different executor.
+  template <typename U, typename OtherExecutor>
+  executor_binder(executor_arg_t, const executor_type& e,
+      executor_binder<U, OtherExecutor>&& other)
+    : base_type(e, ASIO_MOVE_CAST(U)(other.get()))
+  {
+  }
+
+#endif // defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+
+  /// Destructor.
+  ~executor_binder()
+  {
+  }
+
+  /// Obtain a reference to the target object.
+  target_type& get() ASIO_NOEXCEPT
+  {
+    return this->target_;
+  }
+
+  /// Obtain a reference to the target object.
+  const target_type& get() const ASIO_NOEXCEPT
+  {
+    return this->target_;
+  }
+
+  /// Obtain the associated executor.
+  executor_type get_executor() const ASIO_NOEXCEPT
+  {
+    return this->executor_;
+  }
+
+#if defined(GENERATING_DOCUMENTATION)
+
+  template <typename... Args> auto operator()(Args&& ...);
+  template <typename... Args> auto operator()(Args&& ...) const;
+
+#elif defined(ASIO_HAS_VARIADIC_TEMPLATES)
+
+  /// Forwarding function call operator.
+  template <typename... Args>
+  typename result_of<T(Args...)>::type operator()(
+      ASIO_MOVE_ARG(Args)... args)
+  {
+    return this->target_(ASIO_MOVE_CAST(Args)(args)...);
+  }
+
+  /// Forwarding function call operator.
+  template <typename... Args>
+  typename result_of<T(Args...)>::type operator()(
+      ASIO_MOVE_ARG(Args)... args) const
+  {
+    return this->target_(ASIO_MOVE_CAST(Args)(args)...);
+  }
+
+#elif defined(ASIO_HAS_STD_TYPE_TRAITS) && !defined(_MSC_VER)
+
+  typename detail::executor_binder_result_of0<T>::type operator()()
+  {
+    return this->target_();
+  }
+
+  typename detail::executor_binder_result_of0<T>::type operator()() const
+  {
+    return this->target_();
+  }
+
+#define ASIO_PRIVATE_BIND_EXECUTOR_CALL_DEF(n) \
+  template <ASIO_VARIADIC_TPARAMS(n)> \
+  typename result_of<T(ASIO_VARIADIC_TARGS(n))>::type operator()( \
+      ASIO_VARIADIC_MOVE_PARAMS(n)) \
+  { \
+    return this->target_(ASIO_VARIADIC_MOVE_ARGS(n)); \
+  } \
+  \
+  template <ASIO_VARIADIC_TPARAMS(n)> \
+  typename result_of<T(ASIO_VARIADIC_TARGS(n))>::type operator()( \
+      ASIO_VARIADIC_MOVE_PARAMS(n)) const \
+  { \
+    return this->target_(ASIO_VARIADIC_MOVE_ARGS(n)); \
+  } \
+  /**/
+  ASIO_VARIADIC_GENERATE(ASIO_PRIVATE_BIND_EXECUTOR_CALL_DEF)
+#undef ASIO_PRIVATE_BIND_EXECUTOR_CALL_DEF
+
+#else // defined(ASIO_HAS_STD_TYPE_TRAITS) && !defined(_MSC_VER)
+
+  typedef typename detail::executor_binder_result_type<T>::result_type_or_void
+    result_type_or_void;
+
+  result_type_or_void operator()()
+  {
+    return this->target_();
+  }
+
+  result_type_or_void operator()() const
+  {
+    return this->target_();
+  }
+
+#define ASIO_PRIVATE_BIND_EXECUTOR_CALL_DEF(n) \
+  template <ASIO_VARIADIC_TPARAMS(n)> \
+  result_type_or_void operator()( \
+      ASIO_VARIADIC_MOVE_PARAMS(n)) \
+  { \
+    return this->target_(ASIO_VARIADIC_MOVE_ARGS(n)); \
+  } \
+  \
+  template <ASIO_VARIADIC_TPARAMS(n)> \
+  result_type_or_void operator()( \
+      ASIO_VARIADIC_MOVE_PARAMS(n)) const \
+  { \
+    return this->target_(ASIO_VARIADIC_MOVE_ARGS(n)); \
+  } \
+  /**/
+  ASIO_VARIADIC_GENERATE(ASIO_PRIVATE_BIND_EXECUTOR_CALL_DEF)
+#undef ASIO_PRIVATE_BIND_EXECUTOR_CALL_DEF
+
+#endif // defined(ASIO_HAS_STD_TYPE_TRAITS) && !defined(_MSC_VER)
+
+private:
+  typedef detail::executor_binder_base<T, Executor,
+    uses_executor<T, Executor>::value> base_type;
+};
+
+/// Associate an object of type @c T with an executor of type @c Executor.
+template <typename Executor, typename T>
+ASIO_NODISCARD inline executor_binder<typename decay<T>::type, Executor>
+bind_executor(const Executor& ex, ASIO_MOVE_ARG(T) t,
+    typename constraint<
+      is_executor<Executor>::value || execution::is_executor<Executor>::value
+    >::type = 0)
+{
+  return executor_binder<typename decay<T>::type, Executor>(
+      executor_arg_t(), ex, ASIO_MOVE_CAST(T)(t));
+}
+
+/// Associate an object of type @c T with an execution context's executor.
+template <typename ExecutionContext, typename T>
+ASIO_NODISCARD inline executor_binder<typename decay<T>::type,
+  typename ExecutionContext::executor_type>
+bind_executor(ExecutionContext& ctx, ASIO_MOVE_ARG(T) t,
+    typename constraint<is_convertible<
+      ExecutionContext&, execution_context&>::value>::type = 0)
+{
+  return executor_binder<typename decay<T>::type,
+    typename ExecutionContext::executor_type>(
+      executor_arg_t(), ctx.get_executor(), ASIO_MOVE_CAST(T)(t));
+}
+
+#if !defined(GENERATING_DOCUMENTATION)
+
+template <typename T, typename Executor>
+struct uses_executor<executor_binder<T, Executor>, Executor>
+  : true_type {};
+
+namespace detail {
+
+template <typename TargetAsyncResult, typename Executor, typename = void>
+class executor_binder_completion_handler_async_result
+{
+public:
+  template <typename T>
+  explicit executor_binder_completion_handler_async_result(T&)
+  {
+  }
+};
+
+template <typename TargetAsyncResult, typename Executor>
+class executor_binder_completion_handler_async_result<
+  TargetAsyncResult, Executor,
+  typename void_type<
+    typename TargetAsyncResult::completion_handler_type
+  >::type>
+{
+public:
+  typedef executor_binder<
+    typename TargetAsyncResult::completion_handler_type, Executor>
+      completion_handler_type;
+
+  explicit executor_binder_completion_handler_async_result(
+      typename TargetAsyncResult::completion_handler_type& handler)
+    : target_(handler)
+  {
+  }
+
+  typename TargetAsyncResult::return_type get()
+  {
+    return target_.get();
+  }
+
+private:
+  TargetAsyncResult target_;
+};
+
+template <typename TargetAsyncResult, typename = void>
+struct executor_binder_async_result_return_type
+{
+};
+
+template <typename TargetAsyncResult>
+struct executor_binder_async_result_return_type<
+  TargetAsyncResult,
+  typename void_type<
+    typename TargetAsyncResult::return_type
+  >::type>
+{
+  typedef typename TargetAsyncResult::return_type return_type;
+};
+
+} // namespace detail
+
+template <typename T, typename Executor, typename Signature>
+class async_result<executor_binder<T, Executor>, Signature> :
+  public detail::executor_binder_completion_handler_async_result<
+    async_result<T, Signature>, Executor>,
+  public detail::executor_binder_async_result_return_type<
+    async_result<T, Signature> >
+{
+public:
+  explicit async_result(executor_binder<T, Executor>& b)
+    : detail::executor_binder_completion_handler_async_result<
+        async_result<T, Signature>, Executor>(b.get())
+  {
+  }
+
+  template <typename Initiation>
+  struct init_wrapper
+  {
+    template <typename Init>
+    init_wrapper(const Executor& ex, ASIO_MOVE_ARG(Init) init)
+      : ex_(ex),
+        initiation_(ASIO_MOVE_CAST(Init)(init))
+    {
+    }
+
+#if defined(ASIO_HAS_VARIADIC_TEMPLATES)
+
+    template <typename Handler, typename... Args>
+    void operator()(
+        ASIO_MOVE_ARG(Handler) handler,
+        ASIO_MOVE_ARG(Args)... args)
+    {
+      ASIO_MOVE_CAST(Initiation)(initiation_)(
+          executor_binder<typename decay<Handler>::type, Executor>(
+            executor_arg_t(), ex_, ASIO_MOVE_CAST(Handler)(handler)),
+          ASIO_MOVE_CAST(Args)(args)...);
+    }
+
+    template <typename Handler, typename... Args>
+    void operator()(
+        ASIO_MOVE_ARG(Handler) handler,
+        ASIO_MOVE_ARG(Args)... args) const
+    {
+      initiation_(
+          executor_binder<typename decay<Handler>::type, Executor>(
+            executor_arg_t(), ex_, ASIO_MOVE_CAST(Handler)(handler)),
+          ASIO_MOVE_CAST(Args)(args)...);
+    }
+
+#else // defined(ASIO_HAS_VARIADIC_TEMPLATES)
+
+    template <typename Handler>
+    void operator()(
+        ASIO_MOVE_ARG(Handler) handler)
+    {
+      ASIO_MOVE_CAST(Initiation)(initiation_)(
+          executor_binder<typename decay<Handler>::type, Executor>(
+            executor_arg_t(), ex_, ASIO_MOVE_CAST(Handler)(handler)));
+    }
+
+    template <typename Handler>
+    void operator()(
+        ASIO_MOVE_ARG(Handler) handler) const
+    {
+      initiation_(
+          executor_binder<typename decay<Handler>::type, Executor>(
+            executor_arg_t(), ex_, ASIO_MOVE_CAST(Handler)(handler)));
+    }
+
+#define ASIO_PRIVATE_INIT_WRAPPER_DEF(n) \
+    template <typename Handler, ASIO_VARIADIC_TPARAMS(n)> \
+    void operator()( \
+        ASIO_MOVE_ARG(Handler) handler, \
+        ASIO_VARIADIC_MOVE_PARAMS(n)) \
+    { \
+      ASIO_MOVE_CAST(Initiation)(initiation_)( \
+          executor_binder<typename decay<Handler>::type, Executor>( \
+            executor_arg_t(), ex_, ASIO_MOVE_CAST(Handler)(handler)), \
+          ASIO_VARIADIC_MOVE_ARGS(n)); \
+    } \
+    \
+    template <typename Handler, ASIO_VARIADIC_TPARAMS(n)> \
+    void operator()( \
+        ASIO_MOVE_ARG(Handler) handler, \
+        ASIO_VARIADIC_MOVE_PARAMS(n)) const \
+    { \
+      initiation_( \
+          executor_binder<typename decay<Handler>::type, Executor>( \
+            executor_arg_t(), ex_, ASIO_MOVE_CAST(Handler)(handler)), \
+          ASIO_VARIADIC_MOVE_ARGS(n)); \
+    } \
+    /**/
+    ASIO_VARIADIC_GENERATE(ASIO_PRIVATE_INIT_WRAPPER_DEF)
+#undef ASIO_PRIVATE_INIT_WRAPPER_DEF
+
+#endif // defined(ASIO_HAS_VARIADIC_TEMPLATES)
+
+    Executor ex_;
+    Initiation initiation_;
+  };
+
+#if defined(ASIO_HAS_VARIADIC_TEMPLATES)
+
+  template <typename Initiation, typename RawCompletionToken, typename... Args>
+  static ASIO_INITFN_DEDUCED_RESULT_TYPE(T, Signature,
+    (async_initiate<T, Signature>(
+        declval<init_wrapper<typename decay<Initiation>::type> >(),
+        declval<RawCompletionToken>().get(),
+        declval<ASIO_MOVE_ARG(Args)>()...)))
+  initiate(
+      ASIO_MOVE_ARG(Initiation) initiation,
+      ASIO_MOVE_ARG(RawCompletionToken) token,
+      ASIO_MOVE_ARG(Args)... args)
+  {
+    return async_initiate<T, Signature>(
+        init_wrapper<typename decay<Initiation>::type>(
+          token.get_executor(), ASIO_MOVE_CAST(Initiation)(initiation)),
+        token.get(), ASIO_MOVE_CAST(Args)(args)...);
+  }
+
+#else // defined(ASIO_HAS_VARIADIC_TEMPLATES)
+
+  template <typename Initiation, typename RawCompletionToken>
+  static ASIO_INITFN_DEDUCED_RESULT_TYPE(T, Signature,
+    (async_initiate<T, Signature>(
+        declval<init_wrapper<typename decay<Initiation>::type> >(),
+        declval<RawCompletionToken>().get())))
+  initiate(
+      ASIO_MOVE_ARG(Initiation) initiation,
+      ASIO_MOVE_ARG(RawCompletionToken) token)
+  {
+    return async_initiate<T, Signature>(
+        init_wrapper<typename decay<Initiation>::type>(
+          token.get_executor(), ASIO_MOVE_CAST(Initiation)(initiation)),
+        token.get());
+  }
+
+#define ASIO_PRIVATE_INITIATE_DEF(n) \
+  template <typename Initiation, typename RawCompletionToken, \
+      ASIO_VARIADIC_TPARAMS(n)> \
+  static ASIO_INITFN_DEDUCED_RESULT_TYPE(T, Signature, \
+    (async_initiate<T, Signature>( \
+        declval<init_wrapper<typename decay<Initiation>::type> >(), \
+        declval<RawCompletionToken>().get(), \
+        ASIO_VARIADIC_MOVE_DECLVAL(n)))) \
+  initiate( \
+      ASIO_MOVE_ARG(Initiation) initiation, \
+      ASIO_MOVE_ARG(RawCompletionToken) token, \
+      ASIO_VARIADIC_MOVE_PARAMS(n)) \
+  { \
+    return async_initiate<T, Signature>( \
+        init_wrapper<typename decay<Initiation>::type>( \
+          token.get_executor(), ASIO_MOVE_CAST(Initiation)(initiation)), \
+        token.get(), ASIO_VARIADIC_MOVE_ARGS(n)); \
+  } \
+  /**/
+  ASIO_VARIADIC_GENERATE(ASIO_PRIVATE_INITIATE_DEF)
+#undef ASIO_PRIVATE_INITIATE_DEF
+
+#endif // defined(ASIO_HAS_VARIADIC_TEMPLATES)
+
+private:
+  async_result(const async_result&) ASIO_DELETED;
+  async_result& operator=(const async_result&) ASIO_DELETED;
+};
+
+template <template <typename, typename> class Associator,
+    typename T, typename Executor, typename DefaultCandidate>
+struct associator<Associator, executor_binder<T, Executor>, DefaultCandidate>
+{
+  typedef typename Associator<T, DefaultCandidate>::type type;
+
+  static type get(const executor_binder<T, Executor>& b,
+      const DefaultCandidate& c = DefaultCandidate()) ASIO_NOEXCEPT
+  {
+    return Associator<T, DefaultCandidate>::get(b.get(), c);
+  }
+};
+
+template <typename T, typename Executor, typename Executor1>
+struct associated_executor<executor_binder<T, Executor>, Executor1>
+{
+  typedef Executor type;
+
+  static type get(const executor_binder<T, Executor>& b,
+      const Executor1& = Executor1()) ASIO_NOEXCEPT
+  {
+    return b.get_executor();
+  }
+};
+
+#endif // !defined(GENERATING_DOCUMENTATION)
+
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // ASIO_BIND_EXECUTOR_HPP

lib/asio/include/asio/buffer_registration.hpp

@@ -0,0 +1,328 @@
+//
+// buffer_registration.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_BUFFER_REGISTRATION_HPP
+#define ASIO_BUFFER_REGISTRATION_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+#include <iterator>
+#include <vector>
+#include "asio/detail/memory.hpp"
+#include "asio/execution/context.hpp"
+#include "asio/execution/executor.hpp"
+#include "asio/execution_context.hpp"
+#include "asio/is_executor.hpp"
+#include "asio/query.hpp"
+#include "asio/registered_buffer.hpp"
+
+#if defined(ASIO_HAS_IO_URING)
+# include "asio/detail/scheduler.hpp"
+# include "asio/detail/io_uring_service.hpp"
+#endif // defined(ASIO_HAS_IO_URING)
+
+#if defined(ASIO_HAS_MOVE)
+# include <utility>
+#endif // defined(ASIO_HAS_MOVE)
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+class buffer_registration_base
+{
+protected:
+  static mutable_registered_buffer make_buffer(const mutable_buffer& b,
+      const void* scope, int index) ASIO_NOEXCEPT
+  {
+    return mutable_registered_buffer(b, registered_buffer_id(scope, index));
+  }
+};
+
+} // namespace detail
+
+/// Automatically registers and unregistered buffers with an execution context.
+/**
+ * For portability, applications should assume that only one registration is
+ * permitted per execution context.
+ */
+template <typename MutableBufferSequence,
+    typename Allocator = std::allocator<void> >
+class buffer_registration
+  : detail::buffer_registration_base
+{
+public:
+  /// The allocator type used for allocating storage for the buffers container.
+  typedef Allocator allocator_type;
+
+#if defined(GENERATING_DOCUMENTATION)
+  /// The type of an iterator over the registered buffers.
+  typedef unspecified iterator;
+
+  /// The type of a const iterator over the registered buffers.
+  typedef unspecified const_iterator;
+#else // defined(GENERATING_DOCUMENTATION)
+  typedef std::vector<mutable_registered_buffer>::const_iterator iterator;
+  typedef std::vector<mutable_registered_buffer>::const_iterator const_iterator;
+#endif // defined(GENERATING_DOCUMENTATION)
+
+  /// Register buffers with an executor's execution context.
+  template <typename Executor>
+  buffer_registration(const Executor& ex,
+      const MutableBufferSequence& buffer_sequence,
+      const allocator_type& alloc = allocator_type(),
+      typename constraint<
+        is_executor<Executor>::value || execution::is_executor<Executor>::value
+      >::type = 0)
+    : buffer_sequence_(buffer_sequence),
+      buffers_(
+          ASIO_REBIND_ALLOC(allocator_type,
+            mutable_registered_buffer)(alloc))
+  {
+    init_buffers(buffer_registration::get_context(ex),
+        asio::buffer_sequence_begin(buffer_sequence_),
+        asio::buffer_sequence_end(buffer_sequence_));
+  }
+
+  /// Register buffers with an execution context.
+  template <typename ExecutionContext>
+  buffer_registration(ExecutionContext& ctx,
+      const MutableBufferSequence& buffer_sequence,
+      const allocator_type& alloc = allocator_type(),
+      typename constraint<
+        is_convertible<ExecutionContext&, execution_context&>::value
+      >::type = 0)
+    : buffer_sequence_(buffer_sequence),
+      buffers_(
+          ASIO_REBIND_ALLOC(allocator_type,
+            mutable_registered_buffer)(alloc))
+  {
+    init_buffers(ctx,
+        asio::buffer_sequence_begin(buffer_sequence_),
+        asio::buffer_sequence_end(buffer_sequence_));
+  }
+
+#if defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+  /// Move constructor.
+  buffer_registration(buffer_registration&& other) ASIO_NOEXCEPT
+    : buffer_sequence_(std::move(other.buffer_sequence_)),
+      buffers_(std::move(other.buffers_))
+  {
+#if defined(ASIO_HAS_IO_URING)
+    service_ = other.service_;
+    other.service_ = 0;
+#endif // defined(ASIO_HAS_IO_URING)
+  }
+#endif // defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+
+  /// Unregisters the buffers.
+  ~buffer_registration()
+  {
+#if defined(ASIO_HAS_IO_URING)
+    if (service_)
+      service_->unregister_buffers();
+#endif // defined(ASIO_HAS_IO_URING)
+  }
+  
+#if defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+  /// Move assignment.
+  buffer_registration& operator=(
+      buffer_registration&& other) ASIO_NOEXCEPT
+  {
+    if (this != &other)
+    {
+      buffer_sequence_ = std::move(other.buffer_sequence_);
+      buffers_ = std::move(other.buffers_);
+#if defined(ASIO_HAS_IO_URING)
+      if (service_)
+        service_->unregister_buffers();
+      service_ = other.service_;
+      other.service_ = 0;
+#endif // defined(ASIO_HAS_IO_URING)
+    }
+    return *this;
+  }
+#endif // defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+
+  /// Get the number of registered buffers.
+  std::size_t size() const ASIO_NOEXCEPT
+  {
+    return buffers_.size();
+  }
+
+  /// Get the begin iterator for the sequence of registered buffers.
+  const_iterator begin() const ASIO_NOEXCEPT
+  {
+    return buffers_.begin();
+  }
+
+  /// Get the begin iterator for the sequence of registered buffers.
+  const_iterator cbegin() const ASIO_NOEXCEPT
+  {
+    return buffers_.cbegin();
+  }
+
+  /// Get the end iterator for the sequence of registered buffers.
+  const_iterator end() const ASIO_NOEXCEPT
+  {
+    return buffers_.end();
+  }
+
+  /// Get the end iterator for the sequence of registered buffers.
+  const_iterator cend() const ASIO_NOEXCEPT
+  {
+    return buffers_.cend();
+  }
+
+  /// Get the buffer at the specified index.
+  const mutable_registered_buffer& operator[](std::size_t i) ASIO_NOEXCEPT
+  {
+    return buffers_[i];
+  }
+
+  /// Get the buffer at the specified index.
+  const mutable_registered_buffer& at(std::size_t i) ASIO_NOEXCEPT
+  {
+    return buffers_.at(i);
+  }
+
+private:
+  // Disallow copying and assignment.
+  buffer_registration(const buffer_registration&) ASIO_DELETED;
+  buffer_registration& operator=(const buffer_registration&) ASIO_DELETED;
+
+  // Helper function to get an executor's context.
+  template <typename T>
+  static execution_context& get_context(const T& t,
+      typename enable_if<execution::is_executor<T>::value>::type* = 0)
+  {
+    return asio::query(t, execution::context);
+  }
+
+  // Helper function to get an executor's context.
+  template <typename T>
+  static execution_context& get_context(const T& t,
+      typename enable_if<!execution::is_executor<T>::value>::type* = 0)
+  {
+    return t.context();
+  }
+
+  // Helper function to initialise the container of buffers.
+  template <typename Iterator>
+  void init_buffers(execution_context& ctx, Iterator begin, Iterator end)
+  {
+    std::size_t n = std::distance(begin, end);
+    buffers_.resize(n);
+
+#if defined(ASIO_HAS_IO_URING)
+    service_ = &use_service<detail::io_uring_service>(ctx);
+    std::vector<iovec,
+      ASIO_REBIND_ALLOC(allocator_type, iovec)> iovecs(n,
+          ASIO_REBIND_ALLOC(allocator_type, iovec)(
+            buffers_.get_allocator()));
+#endif // defined(ASIO_HAS_IO_URING)
+
+    Iterator iter = begin;
+    for (int index = 0; iter != end; ++index, ++iter)
+    {
+      mutable_buffer b(*iter);
+      std::size_t i = static_cast<std::size_t>(index);
+      buffers_[i] = this->make_buffer(b, &ctx, index);
+
+#if defined(ASIO_HAS_IO_URING)
+      iovecs[i].iov_base = buffers_[i].data();
+      iovecs[i].iov_len = buffers_[i].size();
+#endif // defined(ASIO_HAS_IO_URING)
+    }
+
+#if defined(ASIO_HAS_IO_URING)
+    if (n > 0)
+    {
+      service_->register_buffers(&iovecs[0],
+          static_cast<unsigned>(iovecs.size()));
+    }
+#endif // defined(ASIO_HAS_IO_URING)
+  }
+
+  MutableBufferSequence buffer_sequence_;
+  std::vector<mutable_registered_buffer,
+    ASIO_REBIND_ALLOC(allocator_type,
+      mutable_registered_buffer)> buffers_;
+#if defined(ASIO_HAS_IO_URING)
+  detail::io_uring_service* service_;
+#endif // defined(ASIO_HAS_IO_URING)
+};
+
+#if defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+/// Register buffers with an execution context.
+template <typename Executor, typename MutableBufferSequence>
+ASIO_NODISCARD inline
+buffer_registration<MutableBufferSequence>
+register_buffers(const Executor& ex,
+    const MutableBufferSequence& buffer_sequence,
+    typename constraint<
+      is_executor<Executor>::value || execution::is_executor<Executor>::value
+    >::type = 0)
+{
+  return buffer_registration<MutableBufferSequence>(ex, buffer_sequence);
+}
+
+/// Register buffers with an execution context.
+template <typename Executor, typename MutableBufferSequence, typename Allocator>
+ASIO_NODISCARD inline
+buffer_registration<MutableBufferSequence, Allocator>
+register_buffers(const Executor& ex,
+    const MutableBufferSequence& buffer_sequence, const Allocator& alloc,
+    typename constraint<
+      is_executor<Executor>::value || execution::is_executor<Executor>::value
+    >::type = 0)
+{
+  return buffer_registration<MutableBufferSequence, Allocator>(
+      ex, buffer_sequence, alloc);
+}
+
+/// Register buffers with an execution context.
+template <typename ExecutionContext, typename MutableBufferSequence>
+ASIO_NODISCARD inline
+buffer_registration<MutableBufferSequence>
+register_buffers(ExecutionContext& ctx,
+    const MutableBufferSequence& buffer_sequence,
+    typename constraint<
+      is_convertible<ExecutionContext&, execution_context&>::value
+    >::type = 0)
+{
+  return buffer_registration<MutableBufferSequence>(ctx, buffer_sequence);
+}
+
+/// Register buffers with an execution context.
+template <typename ExecutionContext,
+    typename MutableBufferSequence, typename Allocator>
+ASIO_NODISCARD inline
+buffer_registration<MutableBufferSequence, Allocator>
+register_buffers(ExecutionContext& ctx,
+    const MutableBufferSequence& buffer_sequence, const Allocator& alloc,
+    typename constraint<
+      is_convertible<ExecutionContext&, execution_context&>::value
+    >::type = 0)
+{
+  return buffer_registration<MutableBufferSequence, Allocator>(
+      ctx, buffer_sequence, alloc);
+}
+#endif // defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // ASIO_BUFFER_REGISTRATION_HPP

lib/asio/include/asio/buffered_read_stream.hpp

@@ -0,0 +1,265 @@
+//
+// buffered_read_stream.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_BUFFERED_READ_STREAM_HPP
+#define ASIO_BUFFERED_READ_STREAM_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+#include <cstddef>
+#include "asio/async_result.hpp"
+#include "asio/buffered_read_stream_fwd.hpp"
+#include "asio/buffer.hpp"
+#include "asio/detail/bind_handler.hpp"
+#include "asio/detail/buffer_resize_guard.hpp"
+#include "asio/detail/buffered_stream_storage.hpp"
+#include "asio/detail/noncopyable.hpp"
+#include "asio/detail/type_traits.hpp"
+#include "asio/error.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+
+/// Adds buffering to the read-related operations of a stream.
+/**
+ * The buffered_read_stream class template can be used to add buffering to the
+ * synchronous and asynchronous read operations of a stream.
+ *
+ * @par Thread Safety
+ * @e Distinct @e objects: Safe.@n
+ * @e Shared @e objects: Unsafe.
+ *
+ * @par Concepts:
+ * AsyncReadStream, AsyncWriteStream, Stream, SyncReadStream, SyncWriteStream.
+ */
+template <typename Stream>
+class buffered_read_stream
+  : private noncopyable
+{
+public:
+  /// The type of the next layer.
+  typedef typename remove_reference<Stream>::type next_layer_type;
+
+  /// The type of the lowest layer.
+  typedef typename next_layer_type::lowest_layer_type lowest_layer_type;
+
+  /// The type of the executor associated with the object.
+  typedef typename lowest_layer_type::executor_type executor_type;
+
+#if defined(GENERATING_DOCUMENTATION)
+  /// The default buffer size.
+  static const std::size_t default_buffer_size = implementation_defined;
+#else
+  ASIO_STATIC_CONSTANT(std::size_t, default_buffer_size = 1024);
+#endif
+
+  /// Construct, passing the specified argument to initialise the next layer.
+  template <typename Arg>
+  explicit buffered_read_stream(Arg& a)
+    : next_layer_(a),
+      storage_(default_buffer_size)
+  {
+  }
+
+  /// Construct, passing the specified argument to initialise the next layer.
+  template <typename Arg>
+  buffered_read_stream(Arg& a, std::size_t buffer_size)
+    : next_layer_(a),
+      storage_(buffer_size)
+  {
+  }
+
+  /// Get a reference to the next layer.
+  next_layer_type& next_layer()
+  {
+    return next_layer_;
+  }
+
+  /// Get a reference to the lowest layer.
+  lowest_layer_type& lowest_layer()
+  {
+    return next_layer_.lowest_layer();
+  }
+
+  /// Get a const reference to the lowest layer.
+  const lowest_layer_type& lowest_layer() const
+  {
+    return next_layer_.lowest_layer();
+  }
+
+  /// Get the executor associated with the object.
+  executor_type get_executor() ASIO_NOEXCEPT
+  {
+    return next_layer_.lowest_layer().get_executor();
+  }
+
+  /// Close the stream.
+  void close()
+  {
+    next_layer_.close();
+  }
+
+  /// Close the stream.
+  ASIO_SYNC_OP_VOID close(asio::error_code& ec)
+  {
+    next_layer_.close(ec);
+    ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Write the given data to the stream. Returns the number of bytes written.
+  /// Throws an exception on failure.
+  template <typename ConstBufferSequence>
+  std::size_t write_some(const ConstBufferSequence& buffers)
+  {
+    return next_layer_.write_some(buffers);
+  }
+
+  /// Write the given data to the stream. Returns the number of bytes written,
+  /// or 0 if an error occurred.
+  template <typename ConstBufferSequence>
+  std::size_t write_some(const ConstBufferSequence& buffers,
+      asio::error_code& ec)
+  {
+    return next_layer_.write_some(buffers, ec);
+  }
+
+  /// Start an asynchronous write. The data being written must be valid for the
+  /// lifetime of the asynchronous operation.
+  /**
+   * @par Completion Signature
+   * @code void(asio::error_code, std::size_t) @endcode
+   */
+  template <typename ConstBufferSequence,
+      ASIO_COMPLETION_TOKEN_FOR(void (asio::error_code,
+        std::size_t)) WriteHandler
+          ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(executor_type)>
+  ASIO_INITFN_AUTO_RESULT_TYPE(WriteHandler,
+      void (asio::error_code, std::size_t))
+  async_write_some(const ConstBufferSequence& buffers,
+      ASIO_MOVE_ARG(WriteHandler) handler
+        ASIO_DEFAULT_COMPLETION_TOKEN(executor_type))
+  {
+    return next_layer_.async_write_some(buffers,
+        ASIO_MOVE_CAST(WriteHandler)(handler));
+  }
+
+  /// Fill the buffer with some data. Returns the number of bytes placed in the
+  /// buffer as a result of the operation. Throws an exception on failure.
+  std::size_t fill();
+
+  /// Fill the buffer with some data. Returns the number of bytes placed in the
+  /// buffer as a result of the operation, or 0 if an error occurred.
+  std::size_t fill(asio::error_code& ec);
+
+  /// Start an asynchronous fill.
+  /**
+   * @par Completion Signature
+   * @code void(asio::error_code, std::size_t) @endcode
+   */
+  template <
+      ASIO_COMPLETION_TOKEN_FOR(void (asio::error_code,
+        std::size_t)) ReadHandler
+          ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(executor_type)>
+  ASIO_INITFN_AUTO_RESULT_TYPE(ReadHandler,
+      void (asio::error_code, std::size_t))
+  async_fill(
+      ASIO_MOVE_ARG(ReadHandler) handler
+        ASIO_DEFAULT_COMPLETION_TOKEN(executor_type));
+
+  /// Read some data from the stream. Returns the number of bytes read. Throws
+  /// an exception on failure.
+  template <typename MutableBufferSequence>
+  std::size_t read_some(const MutableBufferSequence& buffers);
+
+  /// Read some data from the stream. Returns the number of bytes read or 0 if
+  /// an error occurred.
+  template <typename MutableBufferSequence>
+  std::size_t read_some(const MutableBufferSequence& buffers,
+      asio::error_code& ec);
+
+  /// Start an asynchronous read. The buffer into which the data will be read
+  /// must be valid for the lifetime of the asynchronous operation.
+  /**
+   * @par Completion Signature
+   * @code void(asio::error_code, std::size_t) @endcode
+   */
+  template <typename MutableBufferSequence,
+      ASIO_COMPLETION_TOKEN_FOR(void (asio::error_code,
+        std::size_t)) ReadHandler
+          ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(executor_type)>
+  ASIO_INITFN_AUTO_RESULT_TYPE(ReadHandler,
+      void (asio::error_code, std::size_t))
+  async_read_some(const MutableBufferSequence& buffers,
+      ASIO_MOVE_ARG(ReadHandler) handler
+        ASIO_DEFAULT_COMPLETION_TOKEN(executor_type));
+
+  /// Peek at the incoming data on the stream. Returns the number of bytes read.
+  /// Throws an exception on failure.
+  template <typename MutableBufferSequence>
+  std::size_t peek(const MutableBufferSequence& buffers);
+
+  /// Peek at the incoming data on the stream. Returns the number of bytes read,
+  /// or 0 if an error occurred.
+  template <typename MutableBufferSequence>
+  std::size_t peek(const MutableBufferSequence& buffers,
+      asio::error_code& ec);
+
+  /// Determine the amount of data that may be read without blocking.
+  std::size_t in_avail()
+  {
+    return storage_.size();
+  }
+
+  /// Determine the amount of data that may be read without blocking.
+  std::size_t in_avail(asio::error_code& ec)
+  {
+    ec = asio::error_code();
+    return storage_.size();
+  }
+
+private:
+  /// Copy data out of the internal buffer to the specified target buffer.
+  /// Returns the number of bytes copied.
+  template <typename MutableBufferSequence>
+  std::size_t copy(const MutableBufferSequence& buffers)
+  {
+    std::size_t bytes_copied = asio::buffer_copy(
+        buffers, storage_.data(), storage_.size());
+    storage_.consume(bytes_copied);
+    return bytes_copied;
+  }
+
+  /// Copy data from the internal buffer to the specified target buffer, without
+  /// removing the data from the internal buffer. Returns the number of bytes
+  /// copied.
+  template <typename MutableBufferSequence>
+  std::size_t peek_copy(const MutableBufferSequence& buffers)
+  {
+    return asio::buffer_copy(buffers, storage_.data(), storage_.size());
+  }
+
+  /// The next layer.
+  Stream next_layer_;
+
+  // The data in the buffer.
+  detail::buffered_stream_storage storage_;
+};
+
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#include "asio/impl/buffered_read_stream.hpp"
+
+#endif // ASIO_BUFFERED_READ_STREAM_HPP

lib/asio/include/asio/buffered_read_stream_fwd.hpp

@@ -0,0 +1,25 @@
+//
+// buffered_read_stream_fwd.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_BUFFERED_READ_STREAM_FWD_HPP
+#define ASIO_BUFFERED_READ_STREAM_FWD_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+namespace asio {
+
+template <typename Stream>
+class buffered_read_stream;
+
+} // namespace asio
+
+#endif // ASIO_BUFFERED_READ_STREAM_FWD_HPP

lib/asio/include/asio/buffered_stream.hpp

@@ -0,0 +1,295 @@
+//
+// buffered_stream.hpp
+// ~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_BUFFERED_STREAM_HPP
+#define ASIO_BUFFERED_STREAM_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+#include <cstddef>
+#include "asio/async_result.hpp"
+#include "asio/buffered_read_stream.hpp"
+#include "asio/buffered_write_stream.hpp"
+#include "asio/buffered_stream_fwd.hpp"
+#include "asio/detail/noncopyable.hpp"
+#include "asio/error.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+
+/// Adds buffering to the read- and write-related operations of a stream.
+/**
+ * The buffered_stream class template can be used to add buffering to the
+ * synchronous and asynchronous read and write operations of a stream.
+ *
+ * @par Thread Safety
+ * @e Distinct @e objects: Safe.@n
+ * @e Shared @e objects: Unsafe.
+ *
+ * @par Concepts:
+ * AsyncReadStream, AsyncWriteStream, Stream, SyncReadStream, SyncWriteStream.
+ */
+template <typename Stream>
+class buffered_stream
+  : private noncopyable
+{
+public:
+  /// The type of the next layer.
+  typedef typename remove_reference<Stream>::type next_layer_type;
+
+  /// The type of the lowest layer.
+  typedef typename next_layer_type::lowest_layer_type lowest_layer_type;
+
+  /// The type of the executor associated with the object.
+  typedef typename lowest_layer_type::executor_type executor_type;
+
+  /// Construct, passing the specified argument to initialise the next layer.
+  template <typename Arg>
+  explicit buffered_stream(Arg& a)
+    : inner_stream_impl_(a),
+      stream_impl_(inner_stream_impl_)
+  {
+  }
+
+  /// Construct, passing the specified argument to initialise the next layer.
+  template <typename Arg>
+  explicit buffered_stream(Arg& a, std::size_t read_buffer_size,
+      std::size_t write_buffer_size)
+    : inner_stream_impl_(a, write_buffer_size),
+      stream_impl_(inner_stream_impl_, read_buffer_size)
+  {
+  }
+
+  /// Get a reference to the next layer.
+  next_layer_type& next_layer()
+  {
+    return stream_impl_.next_layer().next_layer();
+  }
+
+  /// Get a reference to the lowest layer.
+  lowest_layer_type& lowest_layer()
+  {
+    return stream_impl_.lowest_layer();
+  }
+
+  /// Get a const reference to the lowest layer.
+  const lowest_layer_type& lowest_layer() const
+  {
+    return stream_impl_.lowest_layer();
+  }
+
+  /// Get the executor associated with the object.
+  executor_type get_executor() ASIO_NOEXCEPT
+  {
+    return stream_impl_.lowest_layer().get_executor();
+  }
+
+  /// Close the stream.
+  void close()
+  {
+    stream_impl_.close();
+  }
+
+  /// Close the stream.
+  ASIO_SYNC_OP_VOID close(asio::error_code& ec)
+  {
+    stream_impl_.close(ec);
+    ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Flush all data from the buffer to the next layer. Returns the number of
+  /// bytes written to the next layer on the last write operation. Throws an
+  /// exception on failure.
+  std::size_t flush()
+  {
+    return stream_impl_.next_layer().flush();
+  }
+
+  /// Flush all data from the buffer to the next layer. Returns the number of
+  /// bytes written to the next layer on the last write operation, or 0 if an
+  /// error occurred.
+  std::size_t flush(asio::error_code& ec)
+  {
+    return stream_impl_.next_layer().flush(ec);
+  }
+
+  /// Start an asynchronous flush.
+  /**
+   * @par Completion Signature
+   * @code void(asio::error_code, std::size_t) @endcode
+   */
+  template <
+      ASIO_COMPLETION_TOKEN_FOR(void (asio::error_code,
+        std::size_t)) WriteHandler
+          ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(executor_type)>
+  ASIO_INITFN_AUTO_RESULT_TYPE(WriteHandler,
+      void (asio::error_code, std::size_t))
+  async_flush(
+      ASIO_MOVE_ARG(WriteHandler) handler
+        ASIO_DEFAULT_COMPLETION_TOKEN(executor_type))
+  {
+    return stream_impl_.next_layer().async_flush(
+        ASIO_MOVE_CAST(WriteHandler)(handler));
+  }
+
+  /// Write the given data to the stream. Returns the number of bytes written.
+  /// Throws an exception on failure.
+  template <typename ConstBufferSequence>
+  std::size_t write_some(const ConstBufferSequence& buffers)
+  {
+    return stream_impl_.write_some(buffers);
+  }
+
+  /// Write the given data to the stream. Returns the number of bytes written,
+  /// or 0 if an error occurred.
+  template <typename ConstBufferSequence>
+  std::size_t write_some(const ConstBufferSequence& buffers,
+      asio::error_code& ec)
+  {
+    return stream_impl_.write_some(buffers, ec);
+  }
+
+  /// Start an asynchronous write. The data being written must be valid for the
+  /// lifetime of the asynchronous operation.
+  /**
+   * @par Completion Signature
+   * @code void(asio::error_code, std::size_t) @endcode
+   */
+  template <typename ConstBufferSequence,
+      ASIO_COMPLETION_TOKEN_FOR(void (asio::error_code,
+        std::size_t)) WriteHandler
+          ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(executor_type)>
+  ASIO_INITFN_AUTO_RESULT_TYPE(WriteHandler,
+      void (asio::error_code, std::size_t))
+  async_write_some(const ConstBufferSequence& buffers,
+      ASIO_MOVE_ARG(WriteHandler) handler
+        ASIO_DEFAULT_COMPLETION_TOKEN(executor_type))
+  {
+    return stream_impl_.async_write_some(buffers,
+        ASIO_MOVE_CAST(WriteHandler)(handler));
+  }
+
+  /// Fill the buffer with some data. Returns the number of bytes placed in the
+  /// buffer as a result of the operation. Throws an exception on failure.
+  std::size_t fill()
+  {
+    return stream_impl_.fill();
+  }
+
+  /// Fill the buffer with some data. Returns the number of bytes placed in the
+  /// buffer as a result of the operation, or 0 if an error occurred.
+  std::size_t fill(asio::error_code& ec)
+  {
+    return stream_impl_.fill(ec);
+  }
+
+  /// Start an asynchronous fill.
+  /**
+   * @par Completion Signature
+   * @code void(asio::error_code, std::size_t) @endcode
+   */
+  template <
+      ASIO_COMPLETION_TOKEN_FOR(void (asio::error_code,
+        std::size_t)) ReadHandler
+          ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(executor_type)>
+  ASIO_INITFN_AUTO_RESULT_TYPE(ReadHandler,
+      void (asio::error_code, std::size_t))
+  async_fill(
+      ASIO_MOVE_ARG(ReadHandler) handler
+        ASIO_DEFAULT_COMPLETION_TOKEN(executor_type))
+  {
+    return stream_impl_.async_fill(ASIO_MOVE_CAST(ReadHandler)(handler));
+  }
+
+  /// Read some data from the stream. Returns the number of bytes read. Throws
+  /// an exception on failure.
+  template <typename MutableBufferSequence>
+  std::size_t read_some(const MutableBufferSequence& buffers)
+  {
+    return stream_impl_.read_some(buffers);
+  }
+
+  /// Read some data from the stream. Returns the number of bytes read or 0 if
+  /// an error occurred.
+  template <typename MutableBufferSequence>
+  std::size_t read_some(const MutableBufferSequence& buffers,
+      asio::error_code& ec)
+  {
+    return stream_impl_.read_some(buffers, ec);
+  }
+
+  /// Start an asynchronous read. The buffer into which the data will be read
+  /// must be valid for the lifetime of the asynchronous operation.
+  /**
+   * @par Completion Signature
+   * @code void(asio::error_code, std::size_t) @endcode
+   */
+  template <typename MutableBufferSequence,
+      ASIO_COMPLETION_TOKEN_FOR(void (asio::error_code,
+        std::size_t)) ReadHandler
+          ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(executor_type)>
+  ASIO_INITFN_AUTO_RESULT_TYPE(ReadHandler,
+      void (asio::error_code, std::size_t))
+  async_read_some(const MutableBufferSequence& buffers,
+      ASIO_MOVE_ARG(ReadHandler) handler
+        ASIO_DEFAULT_COMPLETION_TOKEN(executor_type))
+  {
+    return stream_impl_.async_read_some(buffers,
+        ASIO_MOVE_CAST(ReadHandler)(handler));
+  }
+
+  /// Peek at the incoming data on the stream. Returns the number of bytes read.
+  /// Throws an exception on failure.
+  template <typename MutableBufferSequence>
+  std::size_t peek(const MutableBufferSequence& buffers)
+  {
+    return stream_impl_.peek(buffers);
+  }
+
+  /// Peek at the incoming data on the stream. Returns the number of bytes read,
+  /// or 0 if an error occurred.
+  template <typename MutableBufferSequence>
+  std::size_t peek(const MutableBufferSequence& buffers,
+      asio::error_code& ec)
+  {
+    return stream_impl_.peek(buffers, ec);
+  }
+
+  /// Determine the amount of data that may be read without blocking.
+  std::size_t in_avail()
+  {
+    return stream_impl_.in_avail();
+  }
+
+  /// Determine the amount of data that may be read without blocking.
+  std::size_t in_avail(asio::error_code& ec)
+  {
+    return stream_impl_.in_avail(ec);
+  }
+
+private:
+  // The buffered write stream.
+  typedef buffered_write_stream<Stream> write_stream_type;
+  write_stream_type inner_stream_impl_;
+
+  // The buffered read stream.
+  typedef buffered_read_stream<write_stream_type&> read_stream_type;
+  read_stream_type stream_impl_;
+};
+
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // ASIO_BUFFERED_STREAM_HPP

lib/asio/include/asio/buffered_stream_fwd.hpp

@@ -0,0 +1,25 @@
+//
+// buffered_stream_fwd.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_BUFFERED_STREAM_FWD_HPP
+#define ASIO_BUFFERED_STREAM_FWD_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+namespace asio {
+
+template <typename Stream>
+class buffered_stream;
+
+} // namespace asio
+
+#endif // ASIO_BUFFERED_STREAM_FWD_HPP

lib/asio/include/asio/buffered_write_stream.hpp

@@ -0,0 +1,257 @@
+//
+// buffered_write_stream.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_BUFFERED_WRITE_STREAM_HPP
+#define ASIO_BUFFERED_WRITE_STREAM_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+#include <cstddef>
+#include "asio/buffered_write_stream_fwd.hpp"
+#include "asio/buffer.hpp"
+#include "asio/completion_condition.hpp"
+#include "asio/detail/bind_handler.hpp"
+#include "asio/detail/buffered_stream_storage.hpp"
+#include "asio/detail/noncopyable.hpp"
+#include "asio/detail/type_traits.hpp"
+#include "asio/error.hpp"
+#include "asio/write.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+
+/// Adds buffering to the write-related operations of a stream.
+/**
+ * The buffered_write_stream class template can be used to add buffering to the
+ * synchronous and asynchronous write operations of a stream.
+ *
+ * @par Thread Safety
+ * @e Distinct @e objects: Safe.@n
+ * @e Shared @e objects: Unsafe.
+ *
+ * @par Concepts:
+ * AsyncReadStream, AsyncWriteStream, Stream, SyncReadStream, SyncWriteStream.
+ */
+template <typename Stream>
+class buffered_write_stream
+  : private noncopyable
+{
+public:
+  /// The type of the next layer.
+  typedef typename remove_reference<Stream>::type next_layer_type;
+
+  /// The type of the lowest layer.
+  typedef typename next_layer_type::lowest_layer_type lowest_layer_type;
+
+  /// The type of the executor associated with the object.
+  typedef typename lowest_layer_type::executor_type executor_type;
+
+#if defined(GENERATING_DOCUMENTATION)
+  /// The default buffer size.
+  static const std::size_t default_buffer_size = implementation_defined;
+#else
+  ASIO_STATIC_CONSTANT(std::size_t, default_buffer_size = 1024);
+#endif
+
+  /// Construct, passing the specified argument to initialise the next layer.
+  template <typename Arg>
+  explicit buffered_write_stream(Arg& a)
+    : next_layer_(a),
+      storage_(default_buffer_size)
+  {
+  }
+
+  /// Construct, passing the specified argument to initialise the next layer.
+  template <typename Arg>
+  buffered_write_stream(Arg& a, std::size_t buffer_size)
+    : next_layer_(a),
+      storage_(buffer_size)
+  {
+  }
+
+  /// Get a reference to the next layer.
+  next_layer_type& next_layer()
+  {
+    return next_layer_;
+  }
+
+  /// Get a reference to the lowest layer.
+  lowest_layer_type& lowest_layer()
+  {
+    return next_layer_.lowest_layer();
+  }
+
+  /// Get a const reference to the lowest layer.
+  const lowest_layer_type& lowest_layer() const
+  {
+    return next_layer_.lowest_layer();
+  }
+
+  /// Get the executor associated with the object.
+  executor_type get_executor() ASIO_NOEXCEPT
+  {
+    return next_layer_.lowest_layer().get_executor();
+  }
+
+  /// Close the stream.
+  void close()
+  {
+    next_layer_.close();
+  }
+
+  /// Close the stream.
+  ASIO_SYNC_OP_VOID close(asio::error_code& ec)
+  {
+    next_layer_.close(ec);
+    ASIO_SYNC_OP_VOID_RETURN(ec);
+  }
+
+  /// Flush all data from the buffer to the next layer. Returns the number of
+  /// bytes written to the next layer on the last write operation. Throws an
+  /// exception on failure.
+  std::size_t flush();
+
+  /// Flush all data from the buffer to the next layer. Returns the number of
+  /// bytes written to the next layer on the last write operation, or 0 if an
+  /// error occurred.
+  std::size_t flush(asio::error_code& ec);
+
+  /// Start an asynchronous flush.
+  /**
+   * @par Completion Signature
+   * @code void(asio::error_code, std::size_t) @endcode
+   */
+  template <
+      ASIO_COMPLETION_TOKEN_FOR(void (asio::error_code,
+        std::size_t)) WriteHandler
+          ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(executor_type)>
+  ASIO_INITFN_AUTO_RESULT_TYPE(WriteHandler,
+      void (asio::error_code, std::size_t))
+  async_flush(
+      ASIO_MOVE_ARG(WriteHandler) handler
+        ASIO_DEFAULT_COMPLETION_TOKEN(executor_type));
+
+  /// Write the given data to the stream. Returns the number of bytes written.
+  /// Throws an exception on failure.
+  template <typename ConstBufferSequence>
+  std::size_t write_some(const ConstBufferSequence& buffers);
+
+  /// Write the given data to the stream. Returns the number of bytes written,
+  /// or 0 if an error occurred and the error handler did not throw.
+  template <typename ConstBufferSequence>
+  std::size_t write_some(const ConstBufferSequence& buffers,
+      asio::error_code& ec);
+
+  /// Start an asynchronous write. The data being written must be valid for the
+  /// lifetime of the asynchronous operation.
+  /**
+   * @par Completion Signature
+   * @code void(asio::error_code, std::size_t) @endcode
+   */
+  template <typename ConstBufferSequence,
+      ASIO_COMPLETION_TOKEN_FOR(void (asio::error_code,
+        std::size_t)) WriteHandler
+          ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(executor_type)>
+  ASIO_INITFN_AUTO_RESULT_TYPE(WriteHandler,
+      void (asio::error_code, std::size_t))
+  async_write_some(const ConstBufferSequence& buffers,
+      ASIO_MOVE_ARG(WriteHandler) handler
+        ASIO_DEFAULT_COMPLETION_TOKEN(executor_type));
+
+  /// Read some data from the stream. Returns the number of bytes read. Throws
+  /// an exception on failure.
+  template <typename MutableBufferSequence>
+  std::size_t read_some(const MutableBufferSequence& buffers)
+  {
+    return next_layer_.read_some(buffers);
+  }
+
+  /// Read some data from the stream. Returns the number of bytes read or 0 if
+  /// an error occurred.
+  template <typename MutableBufferSequence>
+  std::size_t read_some(const MutableBufferSequence& buffers,
+      asio::error_code& ec)
+  {
+    return next_layer_.read_some(buffers, ec);
+  }
+
+  /// Start an asynchronous read. The buffer into which the data will be read
+  /// must be valid for the lifetime of the asynchronous operation.
+  /**
+   * @par Completion Signature
+   * @code void(asio::error_code, std::size_t) @endcode
+   */
+  template <typename MutableBufferSequence,
+      ASIO_COMPLETION_TOKEN_FOR(void (asio::error_code,
+        std::size_t)) ReadHandler
+          ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(executor_type)>
+  ASIO_INITFN_AUTO_RESULT_TYPE(ReadHandler,
+      void (asio::error_code, std::size_t))
+  async_read_some(const MutableBufferSequence& buffers,
+      ASIO_MOVE_ARG(ReadHandler) handler
+        ASIO_DEFAULT_COMPLETION_TOKEN(executor_type))
+  {
+    return next_layer_.async_read_some(buffers,
+        ASIO_MOVE_CAST(ReadHandler)(handler));
+  }
+
+  /// Peek at the incoming data on the stream. Returns the number of bytes read.
+  /// Throws an exception on failure.
+  template <typename MutableBufferSequence>
+  std::size_t peek(const MutableBufferSequence& buffers)
+  {
+    return next_layer_.peek(buffers);
+  }
+
+  /// Peek at the incoming data on the stream. Returns the number of bytes read,
+  /// or 0 if an error occurred.
+  template <typename MutableBufferSequence>
+  std::size_t peek(const MutableBufferSequence& buffers,
+      asio::error_code& ec)
+  {
+    return next_layer_.peek(buffers, ec);
+  }
+
+  /// Determine the amount of data that may be read without blocking.
+  std::size_t in_avail()
+  {
+    return next_layer_.in_avail();
+  }
+
+  /// Determine the amount of data that may be read without blocking.
+  std::size_t in_avail(asio::error_code& ec)
+  {
+    return next_layer_.in_avail(ec);
+  }
+
+private:
+  /// Copy data into the internal buffer from the specified source buffer.
+  /// Returns the number of bytes copied.
+  template <typename ConstBufferSequence>
+  std::size_t copy(const ConstBufferSequence& buffers);
+
+  /// The next layer.
+  Stream next_layer_;
+
+  // The data in the buffer.
+  detail::buffered_stream_storage storage_;
+};
+
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#include "asio/impl/buffered_write_stream.hpp"
+
+#endif // ASIO_BUFFERED_WRITE_STREAM_HPP

lib/asio/include/asio/buffered_write_stream_fwd.hpp

@@ -0,0 +1,25 @@
+//
+// buffered_write_stream_fwd.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_BUFFERED_WRITE_STREAM_FWD_HPP
+#define ASIO_BUFFERED_WRITE_STREAM_FWD_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+namespace asio {
+
+template <typename Stream>
+class buffered_write_stream;
+
+} // namespace asio
+
+#endif // ASIO_BUFFERED_WRITE_STREAM_FWD_HPP

lib/asio/include/asio/buffers_iterator.hpp

@@ -0,0 +1,521 @@
+//
+// buffers_iterator.hpp
+// ~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_BUFFERS_ITERATOR_HPP
+#define ASIO_BUFFERS_ITERATOR_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+#include <cstddef>
+#include <iterator>
+#include "asio/buffer.hpp"
+#include "asio/detail/assert.hpp"
+#include "asio/detail/type_traits.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+
+namespace detail
+{
+  template <bool IsMutable>
+  struct buffers_iterator_types_helper;
+
+  template <>
+  struct buffers_iterator_types_helper<false>
+  {
+    typedef const_buffer buffer_type;
+    template <typename ByteType>
+    struct byte_type
+    {
+      typedef typename add_const<ByteType>::type type;
+    };
+  };
+
+  template <>
+  struct buffers_iterator_types_helper<true>
+  {
+    typedef mutable_buffer buffer_type;
+    template <typename ByteType>
+    struct byte_type
+    {
+      typedef ByteType type;
+    };
+  };
+
+  template <typename BufferSequence, typename ByteType>
+  struct buffers_iterator_types
+  {
+    enum
+    {
+      is_mutable = is_convertible<
+          typename BufferSequence::value_type,
+          mutable_buffer>::value
+    };
+    typedef buffers_iterator_types_helper<is_mutable> helper;
+    typedef typename helper::buffer_type buffer_type;
+    typedef typename helper::template byte_type<ByteType>::type byte_type;
+    typedef typename BufferSequence::const_iterator const_iterator;
+  };
+
+  template <typename ByteType>
+  struct buffers_iterator_types<mutable_buffer, ByteType>
+  {
+    typedef mutable_buffer buffer_type;
+    typedef ByteType byte_type;
+    typedef const mutable_buffer* const_iterator;
+  };
+
+  template <typename ByteType>
+  struct buffers_iterator_types<const_buffer, ByteType>
+  {
+    typedef const_buffer buffer_type;
+    typedef typename add_const<ByteType>::type byte_type;
+    typedef const const_buffer* const_iterator;
+  };
+
+#if !defined(ASIO_NO_DEPRECATED)
+
+  template <typename ByteType>
+  struct buffers_iterator_types<mutable_buffers_1, ByteType>
+  {
+    typedef mutable_buffer buffer_type;
+    typedef ByteType byte_type;
+    typedef const mutable_buffer* const_iterator;
+  };
+
+  template <typename ByteType>
+  struct buffers_iterator_types<const_buffers_1, ByteType>
+  {
+    typedef const_buffer buffer_type;
+    typedef typename add_const<ByteType>::type byte_type;
+    typedef const const_buffer* const_iterator;
+  };
+
+#endif // !defined(ASIO_NO_DEPRECATED)
+}
+
+/// A random access iterator over the bytes in a buffer sequence.
+template <typename BufferSequence, typename ByteType = char>
+class buffers_iterator
+{
+private:
+  typedef typename detail::buffers_iterator_types<
+      BufferSequence, ByteType>::buffer_type buffer_type;
+
+  typedef typename detail::buffers_iterator_types<BufferSequence,
+          ByteType>::const_iterator buffer_sequence_iterator_type;
+
+public:
+  /// The type used for the distance between two iterators.
+  typedef std::ptrdiff_t difference_type;
+
+  /// The type of the value pointed to by the iterator.
+  typedef ByteType value_type;
+
+#if defined(GENERATING_DOCUMENTATION)
+  /// The type of the result of applying operator->() to the iterator.
+  /**
+   * If the buffer sequence stores buffer objects that are convertible to
+   * mutable_buffer, this is a pointer to a non-const ByteType. Otherwise, a
+   * pointer to a const ByteType.
+   */
+  typedef const_or_non_const_ByteType* pointer;
+#else // defined(GENERATING_DOCUMENTATION)
+  typedef typename detail::buffers_iterator_types<
+      BufferSequence, ByteType>::byte_type* pointer;
+#endif // defined(GENERATING_DOCUMENTATION)
+
+#if defined(GENERATING_DOCUMENTATION)
+  /// The type of the result of applying operator*() to the iterator.
+  /**
+   * If the buffer sequence stores buffer objects that are convertible to
+   * mutable_buffer, this is a reference to a non-const ByteType. Otherwise, a
+   * reference to a const ByteType.
+   */
+  typedef const_or_non_const_ByteType& reference;
+#else // defined(GENERATING_DOCUMENTATION)
+  typedef typename detail::buffers_iterator_types<
+      BufferSequence, ByteType>::byte_type& reference;
+#endif // defined(GENERATING_DOCUMENTATION)
+
+  /// The iterator category.
+  typedef std::random_access_iterator_tag iterator_category;
+
+  /// Default constructor. Creates an iterator in an undefined state.
+  buffers_iterator()
+    : current_buffer_(),
+      current_buffer_position_(0),
+      begin_(),
+      current_(),
+      end_(),
+      position_(0)
+  {
+  }
+
+  /// Construct an iterator representing the beginning of the buffers' data.
+  static buffers_iterator begin(const BufferSequence& buffers)
+#if defined(__GNUC__) && (__GNUC__ == 4) && (__GNUC_MINOR__ == 3)
+    __attribute__ ((__noinline__))
+#endif // defined(__GNUC__) && (__GNUC__ == 4) && (__GNUC_MINOR__ == 3)
+  {
+    buffers_iterator new_iter;
+    new_iter.begin_ = asio::buffer_sequence_begin(buffers);
+    new_iter.current_ = asio::buffer_sequence_begin(buffers);
+    new_iter.end_ = asio::buffer_sequence_end(buffers);
+    while (new_iter.current_ != new_iter.end_)
+    {
+      new_iter.current_buffer_ = *new_iter.current_;
+      if (new_iter.current_buffer_.size() > 0)
+        break;
+      ++new_iter.current_;
+    }
+    return new_iter;
+  }
+
+  /// Construct an iterator representing the end of the buffers' data.
+  static buffers_iterator end(const BufferSequence& buffers)
+#if defined(__GNUC__) && (__GNUC__ == 4) && (__GNUC_MINOR__ == 3)
+    __attribute__ ((__noinline__))
+#endif // defined(__GNUC__) && (__GNUC__ == 4) && (__GNUC_MINOR__ == 3)
+  {
+    buffers_iterator new_iter;
+    new_iter.begin_ = asio::buffer_sequence_begin(buffers);
+    new_iter.current_ = asio::buffer_sequence_begin(buffers);
+    new_iter.end_ = asio::buffer_sequence_end(buffers);
+    while (new_iter.current_ != new_iter.end_)
+    {
+      buffer_type buffer = *new_iter.current_;
+      new_iter.position_ += buffer.size();
+      ++new_iter.current_;
+    }
+    return new_iter;
+  }
+
+  /// Dereference an iterator.
+  reference operator*() const
+  {
+    return dereference();
+  }
+
+  /// Dereference an iterator.
+  pointer operator->() const
+  {
+    return &dereference();
+  }
+
+  /// Access an individual element.
+  reference operator[](std::ptrdiff_t difference) const
+  {
+    buffers_iterator tmp(*this);
+    tmp.advance(difference);
+    return *tmp;
+  }
+
+  /// Increment operator (prefix).
+  buffers_iterator& operator++()
+  {
+    increment();
+    return *this;
+  }
+
+  /// Increment operator (postfix).
+  buffers_iterator operator++(int)
+  {
+    buffers_iterator tmp(*this);
+    ++*this;
+    return tmp;
+  }
+
+  /// Decrement operator (prefix).
+  buffers_iterator& operator--()
+  {
+    decrement();
+    return *this;
+  }
+
+  /// Decrement operator (postfix).
+  buffers_iterator operator--(int)
+  {
+    buffers_iterator tmp(*this);
+    --*this;
+    return tmp;
+  }
+
+  /// Addition operator.
+  buffers_iterator& operator+=(std::ptrdiff_t difference)
+  {
+    advance(difference);
+    return *this;
+  }
+
+  /// Subtraction operator.
+  buffers_iterator& operator-=(std::ptrdiff_t difference)
+  {
+    advance(-difference);
+    return *this;
+  }
+
+  /// Addition operator.
+  friend buffers_iterator operator+(const buffers_iterator& iter,
+      std::ptrdiff_t difference)
+  {
+    buffers_iterator tmp(iter);
+    tmp.advance(difference);
+    return tmp;
+  }
+
+  /// Addition operator.
+  friend buffers_iterator operator+(std::ptrdiff_t difference,
+      const buffers_iterator& iter)
+  {
+    buffers_iterator tmp(iter);
+    tmp.advance(difference);
+    return tmp;
+  }
+
+  /// Subtraction operator.
+  friend buffers_iterator operator-(const buffers_iterator& iter,
+      std::ptrdiff_t difference)
+  {
+    buffers_iterator tmp(iter);
+    tmp.advance(-difference);
+    return tmp;
+  }
+
+  /// Subtraction operator.
+  friend std::ptrdiff_t operator-(const buffers_iterator& a,
+      const buffers_iterator& b)
+  {
+    return b.distance_to(a);
+  }
+
+  /// Test two iterators for equality.
+  friend bool operator==(const buffers_iterator& a, const buffers_iterator& b)
+  {
+    return a.equal(b);
+  }
+
+  /// Test two iterators for inequality.
+  friend bool operator!=(const buffers_iterator& a, const buffers_iterator& b)
+  {
+    return !a.equal(b);
+  }
+
+  /// Compare two iterators.
+  friend bool operator<(const buffers_iterator& a, const buffers_iterator& b)
+  {
+    return a.distance_to(b) > 0;
+  }
+
+  /// Compare two iterators.
+  friend bool operator<=(const buffers_iterator& a, const buffers_iterator& b)
+  {
+    return !(b < a);
+  }
+
+  /// Compare two iterators.
+  friend bool operator>(const buffers_iterator& a, const buffers_iterator& b)
+  {
+    return b < a;
+  }
+
+  /// Compare two iterators.
+  friend bool operator>=(const buffers_iterator& a, const buffers_iterator& b)
+  {
+    return !(a < b);
+  }
+
+private:
+  // Dereference the iterator.
+  reference dereference() const
+  {
+    return static_cast<pointer>(
+        current_buffer_.data())[current_buffer_position_];
+  }
+
+  // Compare two iterators for equality.
+  bool equal(const buffers_iterator& other) const
+  {
+    return position_ == other.position_;
+  }
+
+  // Increment the iterator.
+  void increment()
+  {
+    ASIO_ASSERT(current_ != end_ && "iterator out of bounds");
+    ++position_;
+
+    // Check if the increment can be satisfied by the current buffer.
+    ++current_buffer_position_;
+    if (current_buffer_position_ != current_buffer_.size())
+      return;
+
+    // Find the next non-empty buffer.
+    ++current_;
+    current_buffer_position_ = 0;
+    while (current_ != end_)
+    {
+      current_buffer_ = *current_;
+      if (current_buffer_.size() > 0)
+        return;
+      ++current_;
+    }
+  }
+
+  // Decrement the iterator.
+  void decrement()
+  {
+    ASIO_ASSERT(position_ > 0 && "iterator out of bounds");
+    --position_;
+
+    // Check if the decrement can be satisfied by the current buffer.
+    if (current_buffer_position_ != 0)
+    {
+      --current_buffer_position_;
+      return;
+    }
+
+    // Find the previous non-empty buffer.
+    buffer_sequence_iterator_type iter = current_;
+    while (iter != begin_)
+    {
+      --iter;
+      buffer_type buffer = *iter;
+      std::size_t buffer_size = buffer.size();
+      if (buffer_size > 0)
+      {
+        current_ = iter;
+        current_buffer_ = buffer;
+        current_buffer_position_ = buffer_size - 1;
+        return;
+      }
+    }
+  }
+
+  // Advance the iterator by the specified distance.
+  void advance(std::ptrdiff_t n)
+  {
+    if (n > 0)
+    {
+      ASIO_ASSERT(current_ != end_ && "iterator out of bounds");
+      for (;;)
+      {
+        std::ptrdiff_t current_buffer_balance
+          = current_buffer_.size() - current_buffer_position_;
+
+        // Check if the advance can be satisfied by the current buffer.
+        if (current_buffer_balance > n)
+        {
+          position_ += n;
+          current_buffer_position_ += n;
+          return;
+        }
+
+        // Update position.
+        n -= current_buffer_balance;
+        position_ += current_buffer_balance;
+
+        // Move to next buffer. If it is empty then it will be skipped on the
+        // next iteration of this loop.
+        if (++current_ == end_)
+        {
+          ASIO_ASSERT(n == 0 && "iterator out of bounds");
+          current_buffer_ = buffer_type();
+          current_buffer_position_ = 0;
+          return;
+        }
+        current_buffer_ = *current_;
+        current_buffer_position_ = 0;
+      }
+    }
+    else if (n < 0)
+    {
+      std::size_t abs_n = -n;
+      ASIO_ASSERT(position_ >= abs_n && "iterator out of bounds");
+      for (;;)
+      {
+        // Check if the advance can be satisfied by the current buffer.
+        if (current_buffer_position_ >= abs_n)
+        {
+          position_ -= abs_n;
+          current_buffer_position_ -= abs_n;
+          return;
+        }
+
+        // Update position.
+        abs_n -= current_buffer_position_;
+        position_ -= current_buffer_position_;
+
+        // Check if we've reached the beginning of the buffers.
+        if (current_ == begin_)
+        {
+          ASIO_ASSERT(abs_n == 0 && "iterator out of bounds");
+          current_buffer_position_ = 0;
+          return;
+        }
+
+        // Find the previous non-empty buffer.
+        buffer_sequence_iterator_type iter = current_;
+        while (iter != begin_)
+        {
+          --iter;
+          buffer_type buffer = *iter;
+          std::size_t buffer_size = buffer.size();
+          if (buffer_size > 0)
+          {
+            current_ = iter;
+            current_buffer_ = buffer;
+            current_buffer_position_ = buffer_size;
+            break;
+          }
+        }
+      }
+    }
+  }
+
+  // Determine the distance between two iterators.
+  std::ptrdiff_t distance_to(const buffers_iterator& other) const
+  {
+    return other.position_ - position_;
+  }
+
+  buffer_type current_buffer_;
+  std::size_t current_buffer_position_;
+  buffer_sequence_iterator_type begin_;
+  buffer_sequence_iterator_type current_;
+  buffer_sequence_iterator_type end_;
+  std::size_t position_;
+};
+
+/// Construct an iterator representing the beginning of the buffers' data.
+template <typename BufferSequence>
+inline buffers_iterator<BufferSequence> buffers_begin(
+    const BufferSequence& buffers)
+{
+  return buffers_iterator<BufferSequence>::begin(buffers);
+}
+
+/// Construct an iterator representing the end of the buffers' data.
+template <typename BufferSequence>
+inline buffers_iterator<BufferSequence> buffers_end(
+    const BufferSequence& buffers)
+{
+  return buffers_iterator<BufferSequence>::end(buffers);
+}
+
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // ASIO_BUFFERS_ITERATOR_HPP

lib/asio/include/asio/cancellation_signal.hpp

@@ -0,0 +1,305 @@
+//
+// cancellation_signal.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_CANCELLATION_SIGNAL_HPP
+#define ASIO_CANCELLATION_SIGNAL_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+#include <cassert>
+#include <new>
+#include <utility>
+#include "asio/cancellation_type.hpp"
+#include "asio/detail/cstddef.hpp"
+#include "asio/detail/type_traits.hpp"
+#include "asio/detail/variadic_templates.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+class cancellation_handler_base
+{
+public:
+  virtual void call(cancellation_type_t) = 0;
+  virtual std::pair<void*, std::size_t> destroy() ASIO_NOEXCEPT = 0;
+
+protected:
+  ~cancellation_handler_base() {}
+};
+
+template <typename Handler>
+class cancellation_handler
+  : public cancellation_handler_base
+{
+public:
+#if defined(ASIO_HAS_VARIADIC_TEMPLATES)
+  template <typename... Args>
+  cancellation_handler(std::size_t size, ASIO_MOVE_ARG(Args)... args)
+    : handler_(ASIO_MOVE_CAST(Args)(args)...),
+      size_(size)
+  {
+  }
+#else // defined(ASIO_HAS_VARIADIC_TEMPLATES)
+  cancellation_handler(std::size_t size)
+    : handler_(),
+      size_(size)
+  {
+  }
+
+#define ASIO_PRIVATE_HANDLER_CTOR_DEF(n) \
+  template <ASIO_VARIADIC_TPARAMS(n)> \
+  cancellation_handler(std::size_t size, ASIO_VARIADIC_MOVE_PARAMS(n)) \
+    : handler_(ASIO_VARIADIC_MOVE_ARGS(n)), \
+      size_(size) \
+  { \
+  } \
+  /**/
+  ASIO_VARIADIC_GENERATE(ASIO_PRIVATE_HANDLER_CTOR_DEF)
+#undef ASIO_PRIVATE_HANDLER_CTOR_DEF
+#endif // defined(ASIO_HAS_VARIADIC_TEMPLATES)
+
+  void call(cancellation_type_t type)
+  {
+    handler_(type);
+  }
+
+  std::pair<void*, std::size_t> destroy() ASIO_NOEXCEPT
+  {
+    std::pair<void*, std::size_t> mem(this, size_);
+    this->cancellation_handler::~cancellation_handler();
+    return mem;
+  }
+
+  Handler& handler() ASIO_NOEXCEPT
+  {
+    return handler_;
+  }
+
+private:
+  ~cancellation_handler()
+  {
+  }
+
+  Handler handler_;
+  std::size_t size_;
+};
+
+} // namespace detail
+
+class cancellation_slot;
+
+/// A cancellation signal with a single slot.
+class cancellation_signal
+{
+public:
+  ASIO_CONSTEXPR cancellation_signal()
+    : handler_(0)
+  {
+  }
+
+  ASIO_DECL ~cancellation_signal();
+
+  /// Emits the signal and causes invocation of the slot's handler, if any.
+  void emit(cancellation_type_t type)
+  {
+    if (handler_)
+      handler_->call(type);
+  }
+
+  /// Returns the single slot associated with the signal.
+  /**
+   * The signal object must remain valid for as long the slot may be used.
+   * Destruction of the signal invalidates the slot.
+   */
+  cancellation_slot slot() ASIO_NOEXCEPT;
+
+private:
+  cancellation_signal(const cancellation_signal&) ASIO_DELETED;
+  cancellation_signal& operator=(const cancellation_signal&) ASIO_DELETED;
+
+  detail::cancellation_handler_base* handler_;
+};
+
+/// A slot associated with a cancellation signal.
+class cancellation_slot
+{
+public:
+  /// Creates a slot that is not connected to any cancellation signal.
+  ASIO_CONSTEXPR cancellation_slot()
+    : handler_(0)
+  {
+  }
+
+#if defined(ASIO_HAS_VARIADIC_TEMPLATES) \
+  || defined(GENERATING_DOCUMENTATION)
+  /// Installs a handler into the slot, constructing the new object directly.
+  /**
+   * Destroys any existing handler in the slot, then installs the new handler,
+   * constructing it with the supplied @c args.
+   *
+   * The handler is a function object to be called when the signal is emitted.
+   * The signature of the handler must be
+   * @code void handler(asio::cancellation_type_t); @endcode
+   *
+   * @param args Arguments to be passed to the @c CancellationHandler object's
+   * constructor.
+   *
+   * @returns A reference to the newly installed handler.
+   *
+   * @note Handlers installed into the slot via @c emplace are not required to
+   * be copy constructible or move constructible.
+   */
+  template <typename CancellationHandler, typename... Args>
+  CancellationHandler& emplace(ASIO_MOVE_ARG(Args)... args)
+  {
+    typedef detail::cancellation_handler<CancellationHandler>
+      cancellation_handler_type;
+    auto_delete_helper del = { prepare_memory(
+        sizeof(cancellation_handler_type),
+        ASIO_ALIGNOF(CancellationHandler)) };
+    cancellation_handler_type* handler_obj =
+      new (del.mem.first) cancellation_handler_type(
+        del.mem.second, ASIO_MOVE_CAST(Args)(args)...);
+    del.mem.first = 0;
+    *handler_ = handler_obj;
+    return handler_obj->handler();
+  }
+#else // defined(ASIO_HAS_VARIADIC_TEMPLATES)
+      //   || defined(GENERATING_DOCUMENTATION)
+  template <typename CancellationHandler>
+  CancellationHandler& emplace()
+  {
+    typedef detail::cancellation_handler<CancellationHandler>
+      cancellation_handler_type;
+    auto_delete_helper del = { prepare_memory(
+        sizeof(cancellation_handler_type),
+        ASIO_ALIGNOF(CancellationHandler)) };
+    cancellation_handler_type* handler_obj =
+      new (del.mem.first) cancellation_handler_type(del.mem.second);
+    del.mem.first = 0;
+    *handler_ = handler_obj;
+    return handler_obj->handler();
+  }
+
+#define ASIO_PRIVATE_HANDLER_EMPLACE_DEF(n) \
+  template <typename CancellationHandler, ASIO_VARIADIC_TPARAMS(n)> \
+  CancellationHandler& emplace(ASIO_VARIADIC_MOVE_PARAMS(n)) \
+  { \
+    typedef detail::cancellation_handler<CancellationHandler> \
+      cancellation_handler_type; \
+    auto_delete_helper del = { prepare_memory( \
+        sizeof(cancellation_handler_type), \
+        ASIO_ALIGNOF(CancellationHandler)) }; \
+    cancellation_handler_type* handler_obj = \
+      new (del.mem.first) cancellation_handler_type( \
+        del.mem.second, ASIO_VARIADIC_MOVE_ARGS(n)); \
+    del.mem.first = 0; \
+    *handler_ = handler_obj; \
+    return handler_obj->handler(); \
+  } \
+  /**/
+  ASIO_VARIADIC_GENERATE(ASIO_PRIVATE_HANDLER_EMPLACE_DEF)
+#undef ASIO_PRIVATE_HANDLER_EMPLACE_DEF
+#endif // defined(ASIO_HAS_VARIADIC_TEMPLATES)
+
+  /// Installs a handler into the slot.
+  /**
+   * Destroys any existing handler in the slot, then installs the new handler,
+   * constructing it as a decay-copy of the supplied handler.
+   *
+   * The handler is a function object to be called when the signal is emitted.
+   * The signature of the handler must be
+   * @code void handler(asio::cancellation_type_t); @endcode
+   *
+   * @param handler The handler to be installed.
+   *
+   * @returns A reference to the newly installed handler.
+   */
+  template <typename CancellationHandler>
+  typename decay<CancellationHandler>::type& assign(
+      ASIO_MOVE_ARG(CancellationHandler) handler)
+  {
+    return this->emplace<typename decay<CancellationHandler>::type>(
+        ASIO_MOVE_CAST(CancellationHandler)(handler));
+  }
+
+  /// Clears the slot.
+  /**
+   * Destroys any existing handler in the slot.
+   */
+  ASIO_DECL void clear();
+
+  /// Returns whether the slot is connected to a signal.
+  ASIO_CONSTEXPR bool is_connected() const ASIO_NOEXCEPT
+  {
+    return handler_ != 0;
+  }
+
+  /// Returns whether the slot is connected and has an installed handler.
+  ASIO_CONSTEXPR bool has_handler() const ASIO_NOEXCEPT
+  {
+    return handler_ != 0 && *handler_ != 0;
+  }
+
+  /// Compare two slots for equality.
+  friend ASIO_CONSTEXPR bool operator==(const cancellation_slot& lhs,
+      const cancellation_slot& rhs) ASIO_NOEXCEPT
+  {
+    return lhs.handler_ == rhs.handler_;
+  }
+
+  /// Compare two slots for inequality.
+  friend ASIO_CONSTEXPR bool operator!=(const cancellation_slot& lhs,
+      const cancellation_slot& rhs) ASIO_NOEXCEPT
+  {
+    return lhs.handler_ != rhs.handler_;
+  }
+
+private:
+  friend class cancellation_signal;
+
+  ASIO_CONSTEXPR cancellation_slot(int,
+      detail::cancellation_handler_base** handler)
+    : handler_(handler)
+  {
+  }
+
+  ASIO_DECL std::pair<void*, std::size_t> prepare_memory(
+      std::size_t size, std::size_t align);
+
+  struct auto_delete_helper
+  {
+    std::pair<void*, std::size_t> mem;
+
+    ASIO_DECL ~auto_delete_helper();
+  };
+
+  detail::cancellation_handler_base** handler_;
+};
+
+inline cancellation_slot cancellation_signal::slot() ASIO_NOEXCEPT
+{
+  return cancellation_slot(0, &handler_);
+}
+
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#if defined(ASIO_HEADER_ONLY)
+# include "asio/impl/cancellation_signal.ipp"
+#endif // defined(ASIO_HEADER_ONLY)
+
+#endif // ASIO_CANCELLATION_SIGNAL_HPP

lib/asio/include/asio/cancellation_state.hpp

@@ -0,0 +1,235 @@
+//
+// cancellation_state.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_CANCELLATION_STATE_HPP
+#define ASIO_CANCELLATION_STATE_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+#include <cassert>
+#include <new>
+#include <utility>
+#include "asio/cancellation_signal.hpp"
+#include "asio/detail/cstddef.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+
+/// A simple cancellation signal propagation filter.
+template <cancellation_type_t Mask>
+struct cancellation_filter
+{
+  /// Returns <tt>type & Mask</tt>.
+  cancellation_type_t operator()(
+      cancellation_type_t type) const ASIO_NOEXCEPT
+  {
+    return type & Mask;
+  }
+};
+
+/// A cancellation filter that disables cancellation.
+typedef cancellation_filter<cancellation_type::none>
+  disable_cancellation;
+
+/// A cancellation filter that enables terminal cancellation only.
+typedef cancellation_filter<cancellation_type::terminal>
+  enable_terminal_cancellation;
+
+#if defined(GENERATING_DOCUMENTATION)
+
+/// A cancellation filter that enables terminal and partial cancellation.
+typedef cancellation_filter<
+    cancellation_type::terminal | cancellation_type::partial>
+  enable_partial_cancellation;
+
+/// A cancellation filter that enables terminal, partial and total cancellation.
+typedef cancellation_filter<cancellation_type::terminal
+    | cancellation_type::partial | cancellation_type::total>
+  enable_total_cancellation;
+
+#else // defined(GENERATING_DOCUMENTATION)
+
+typedef cancellation_filter<
+    static_cast<cancellation_type_t>(
+      static_cast<unsigned int>(cancellation_type::terminal)
+        | static_cast<unsigned int>(cancellation_type::partial))>
+  enable_partial_cancellation;
+
+typedef cancellation_filter<
+    static_cast<cancellation_type_t>(
+      static_cast<unsigned int>(cancellation_type::terminal)
+        | static_cast<unsigned int>(cancellation_type::partial)
+        | static_cast<unsigned int>(cancellation_type::total))>
+  enable_total_cancellation;
+
+#endif // defined(GENERATING_DOCUMENTATION)
+
+/// A cancellation state is used for chaining signals and slots in compositions.
+class cancellation_state
+{
+public:
+  /// Construct a disconnected cancellation state.
+  ASIO_CONSTEXPR cancellation_state() ASIO_NOEXCEPT
+    : impl_(0)
+  {
+  }
+
+  /// Construct and attach to a parent slot to create a new child slot.
+  /**
+   * Initialises the cancellation state so that it allows terminal cancellation
+   * only. Equivalent to <tt>cancellation_state(slot,
+   * enable_terminal_cancellation())</tt>.
+   *
+   * @param slot The parent cancellation slot to which the state will be
+   * attached.
+   */
+  template <typename CancellationSlot>
+  ASIO_CONSTEXPR explicit cancellation_state(CancellationSlot slot)
+    : impl_(slot.is_connected() ? &slot.template emplace<impl<> >() : 0)
+  {
+  }
+
+  /// Construct and attach to a parent slot to create a new child slot.
+  /**
+   * @param slot The parent cancellation slot to which the state will be
+   * attached.
+   *
+   * @param filter A function object that is used to transform incoming
+   * cancellation signals as they are received from the parent slot. This
+   * function object must have the signature:
+   * @code asio::cancellation_type_t filter(
+   *     asio::cancellation_type_t); @endcode
+   *
+   * The library provides the following pre-defined cancellation filters:
+   *
+   * @li asio::disable_cancellation
+   * @li asio::enable_terminal_cancellation
+   * @li asio::enable_partial_cancellation
+   * @li asio::enable_total_cancellation
+   */
+  template <typename CancellationSlot, typename Filter>
+  ASIO_CONSTEXPR cancellation_state(CancellationSlot slot, Filter filter)
+    : impl_(slot.is_connected()
+        ? &slot.template emplace<impl<Filter, Filter> >(filter, filter)
+        : 0)
+  {
+  }
+
+  /// Construct and attach to a parent slot to create a new child slot.
+  /**
+   * @param slot The parent cancellation slot to which the state will be
+   * attached.
+   *
+   * @param in_filter A function object that is used to transform incoming
+   * cancellation signals as they are received from the parent slot. This
+   * function object must have the signature:
+   * @code asio::cancellation_type_t in_filter(
+   *     asio::cancellation_type_t); @endcode
+   *
+   * @param out_filter A function object that is used to transform outcoming
+   * cancellation signals as they are relayed to the child slot. This function
+   * object must have the signature:
+   * @code asio::cancellation_type_t out_filter(
+   *     asio::cancellation_type_t); @endcode
+   *
+   * The library provides the following pre-defined cancellation filters:
+   *
+   * @li asio::disable_cancellation
+   * @li asio::enable_terminal_cancellation
+   * @li asio::enable_partial_cancellation
+   * @li asio::enable_total_cancellation
+   */
+  template <typename CancellationSlot, typename InFilter, typename OutFilter>
+  ASIO_CONSTEXPR cancellation_state(CancellationSlot slot,
+      InFilter in_filter, OutFilter out_filter)
+    : impl_(slot.is_connected()
+        ? &slot.template emplace<impl<InFilter, OutFilter> >(
+            ASIO_MOVE_CAST(InFilter)(in_filter),
+            ASIO_MOVE_CAST(OutFilter)(out_filter))
+        : 0)
+  {
+  }
+
+  /// Returns the single child slot associated with the state.
+  /**
+   * This sub-slot is used with the operations that are being composed.
+   */
+  ASIO_CONSTEXPR cancellation_slot slot() const ASIO_NOEXCEPT
+  {
+    return impl_ ? impl_->signal_.slot() : cancellation_slot();
+  }
+
+  /// Returns the cancellation types that have been triggered.
+  cancellation_type_t cancelled() const ASIO_NOEXCEPT
+  {
+    return impl_ ? impl_->cancelled_ : cancellation_type_t();
+  }
+
+  /// Clears the specified cancellation types, if they have been triggered.
+  void clear(cancellation_type_t mask = cancellation_type::all)
+    ASIO_NOEXCEPT
+  {
+    if (impl_)
+      impl_->cancelled_ &= ~mask;
+  }
+
+private:
+  struct impl_base
+  {
+    impl_base()
+      : cancelled_()
+    {
+    }
+
+    cancellation_signal signal_;
+    cancellation_type_t cancelled_;
+  };
+
+  template <
+      typename InFilter = enable_terminal_cancellation,
+      typename OutFilter = InFilter>
+  struct impl : impl_base
+  {
+    impl()
+      : in_filter_(),
+        out_filter_()
+    {
+    }
+
+    impl(InFilter in_filter, OutFilter out_filter)
+      : in_filter_(ASIO_MOVE_CAST(InFilter)(in_filter)),
+        out_filter_(ASIO_MOVE_CAST(OutFilter)(out_filter))
+    {
+    }
+
+    void operator()(cancellation_type_t in)
+    {
+      this->cancelled_ = in_filter_(in);
+      cancellation_type_t out = out_filter_(this->cancelled_);
+      if (out != cancellation_type::none)
+        this->signal_.emit(out);
+    }
+
+    InFilter in_filter_;
+    OutFilter out_filter_;
+  };
+
+  impl_base* impl_;
+};
+
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // ASIO_CANCELLATION_STATE_HPP

lib/asio/include/asio/cancellation_type.hpp

@@ -0,0 +1,174 @@
+//
+// cancellation_type.hpp
+// ~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_CANCELLATION_TYPE_HPP
+#define ASIO_CANCELLATION_TYPE_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+
+# if defined(GENERATING_DOCUMENTATION)
+
+/// Enumeration representing the different types of cancellation that may
+/// be requested from or implemented by an asynchronous operation.
+enum cancellation_type
+{
+  /// Bitmask representing no types of cancellation.
+  none = 0,
+
+  /// Requests cancellation where, following a successful cancellation, the only
+  /// safe operations on the I/O object are closure or destruction.
+  terminal = 1,
+
+  /// Requests cancellation where a successful cancellation may result in
+  /// partial side effects or no side effects. Following cancellation, the I/O
+  /// object is in a well-known state, and may be used for further operations.
+  partial = 2,
+
+  /// Requests cancellation where a successful cancellation results in no
+  /// apparent side effects. Following cancellation, the I/O object is in the
+  /// same observable state as it was prior to the operation.
+  total = 4,
+
+  /// Bitmask representing all types of cancellation.
+  all = 0xFFFFFFFF
+};
+
+/// Portability typedef.
+typedef cancellation_type cancellation_type_t;
+
+#elif defined(ASIO_HAS_ENUM_CLASS)
+
+enum class cancellation_type : unsigned int
+{
+  none = 0,
+  terminal = 1,
+  partial = 2,
+  total = 4,
+  all = 0xFFFFFFFF
+};
+
+typedef cancellation_type cancellation_type_t;
+
+#else // defined(ASIO_HAS_ENUM_CLASS)
+
+namespace cancellation_type {
+
+enum cancellation_type_t
+{
+  none = 0,
+  terminal = 1,
+  partial = 2,
+  total = 4,
+  all = 0xFFFFFFFF
+};
+
+} // namespace cancellation_type
+
+typedef cancellation_type::cancellation_type_t cancellation_type_t;
+
+#endif // defined(ASIO_HAS_ENUM_CLASS)
+
+/// Negation operator.
+/**
+ * @relates cancellation_type
+ */
+inline ASIO_CONSTEXPR bool operator!(cancellation_type_t x)
+{
+  return static_cast<unsigned int>(x) == 0;
+}
+
+/// Bitwise and operator.
+/**
+ * @relates cancellation_type
+ */
+inline ASIO_CONSTEXPR cancellation_type_t operator&(
+    cancellation_type_t x, cancellation_type_t y)
+{
+  return static_cast<cancellation_type_t>(
+      static_cast<unsigned int>(x) & static_cast<unsigned int>(y));
+}
+
+/// Bitwise or operator.
+/**
+ * @relates cancellation_type
+ */
+inline ASIO_CONSTEXPR cancellation_type_t operator|(
+    cancellation_type_t x, cancellation_type_t y)
+{
+  return static_cast<cancellation_type_t>(
+      static_cast<unsigned int>(x) | static_cast<unsigned int>(y));
+}
+
+/// Bitwise xor operator.
+/**
+ * @relates cancellation_type
+ */
+inline ASIO_CONSTEXPR cancellation_type_t operator^(
+    cancellation_type_t x, cancellation_type_t y)
+{
+  return static_cast<cancellation_type_t>(
+      static_cast<unsigned int>(x) ^ static_cast<unsigned int>(y));
+}
+
+/// Bitwise negation operator.
+/**
+ * @relates cancellation_type
+ */
+inline ASIO_CONSTEXPR cancellation_type_t operator~(cancellation_type_t x)
+{
+  return static_cast<cancellation_type_t>(~static_cast<unsigned int>(x));
+}
+
+/// Bitwise and-assignment operator.
+/**
+ * @relates cancellation_type
+ */
+inline cancellation_type_t& operator&=(
+    cancellation_type_t& x, cancellation_type_t y)
+{
+  x = x & y;
+  return x;
+}
+
+/// Bitwise or-assignment operator.
+/**
+ * @relates cancellation_type
+ */
+inline cancellation_type_t& operator|=(
+    cancellation_type_t& x, cancellation_type_t y)
+{
+  x = x | y;
+  return x;
+}
+
+/// Bitwise xor-assignment operator.
+/**
+ * @relates cancellation_type
+ */
+inline cancellation_type_t& operator^=(
+    cancellation_type_t& x, cancellation_type_t y)
+{
+  x = x ^ y;
+  return x;
+}
+
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // ASIO_CANCELLATION_TYPE_HPP

lib/asio/include/asio/co_spawn.hpp

@@ -0,0 +1,523 @@
+//
+// co_spawn.hpp
+// ~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_CO_SPAWN_HPP
+#define ASIO_CO_SPAWN_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_HAS_CO_AWAIT) || defined(GENERATING_DOCUMENTATION)
+
+#include "asio/awaitable.hpp"
+#include "asio/execution/executor.hpp"
+#include "asio/execution_context.hpp"
+#include "asio/is_executor.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+template <typename T>
+struct awaitable_signature;
+
+template <typename T, typename Executor>
+struct awaitable_signature<awaitable<T, Executor>>
+{
+  typedef void type(std::exception_ptr, T);
+};
+
+template <typename Executor>
+struct awaitable_signature<awaitable<void, Executor>>
+{
+  typedef void type(std::exception_ptr);
+};
+
+} // namespace detail
+
+/// Spawn a new coroutined-based thread of execution.
+/**
+ * @param ex The executor that will be used to schedule the new thread of
+ * execution.
+ *
+ * @param a The asio::awaitable object that is the result of calling the
+ * coroutine's entry point function.
+ *
+ * @param token The @ref completion_token that will handle the notification that
+ * the thread of execution has completed. The function signature of the
+ * completion handler must be:
+ * @code void handler(std::exception_ptr, T); @endcode
+ *
+ * @par Completion Signature
+ * @code void(std::exception_ptr, T) @endcode
+ *
+ * @par Example
+ * @code
+ * asio::awaitable<std::size_t> echo(tcp::socket socket)
+ * {
+ *   std::size_t bytes_transferred = 0;
+ *
+ *   try
+ *   {
+ *     char data[1024];
+ *     for (;;)
+ *     {
+ *       std::size_t n = co_await socket.async_read_some(
+ *           asio::buffer(data), asio::use_awaitable);
+ *
+ *       co_await asio::async_write(socket,
+ *           asio::buffer(data, n), asio::use_awaitable);
+ *
+ *       bytes_transferred += n;
+ *     }
+ *   }
+ *   catch (const std::exception&)
+ *   {
+ *   }
+ *
+ *   co_return bytes_transferred;
+ * }
+ *
+ * // ...
+ *
+ * asio::co_spawn(my_executor,
+ *   echo(std::move(my_tcp_socket)),
+ *   [](std::exception_ptr e, std::size_t n)
+ *   {
+ *     std::cout << "transferred " << n << "\n";
+ *   });
+ * @endcode
+ *
+ * @par Per-Operation Cancellation
+ * The new thread of execution is created with a cancellation state that
+ * supports @c cancellation_type::terminal values only. To change the
+ * cancellation state, call asio::this_coro::reset_cancellation_state.
+ */
+template <typename Executor, typename T, typename AwaitableExecutor,
+    ASIO_COMPLETION_TOKEN_FOR(
+      void(std::exception_ptr, T)) CompletionToken
+        ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(Executor)>
+inline ASIO_INITFN_AUTO_RESULT_TYPE(
+    CompletionToken, void(std::exception_ptr, T))
+co_spawn(const Executor& ex, awaitable<T, AwaitableExecutor> a,
+    CompletionToken&& token
+      ASIO_DEFAULT_COMPLETION_TOKEN(Executor),
+    typename constraint<
+      (is_executor<Executor>::value || execution::is_executor<Executor>::value)
+        && is_convertible<Executor, AwaitableExecutor>::value
+    >::type = 0);
+
+/// Spawn a new coroutined-based thread of execution.
+/**
+ * @param ex The executor that will be used to schedule the new thread of
+ * execution.
+ *
+ * @param a The asio::awaitable object that is the result of calling the
+ * coroutine's entry point function.
+ *
+ * @param token The @ref completion_token that will handle the notification that
+ * the thread of execution has completed. The function signature of the
+ * completion handler must be:
+ * @code void handler(std::exception_ptr); @endcode
+ *
+ * @par Completion Signature
+ * @code void(std::exception_ptr) @endcode
+ *
+ * @par Example
+ * @code
+ * asio::awaitable<void> echo(tcp::socket socket)
+ * {
+ *   try
+ *   {
+ *     char data[1024];
+ *     for (;;)
+ *     {
+ *       std::size_t n = co_await socket.async_read_some(
+ *           asio::buffer(data), asio::use_awaitable);
+ *
+ *       co_await asio::async_write(socket,
+ *           asio::buffer(data, n), asio::use_awaitable);
+ *     }
+ *   }
+ *   catch (const std::exception& e)
+ *   {
+ *     std::cerr << "Exception: " << e.what() << "\n";
+ *   }
+ * }
+ *
+ * // ...
+ *
+ * asio::co_spawn(my_executor,
+ *   echo(std::move(my_tcp_socket)),
+ *   asio::detached);
+ * @endcode
+ *
+ * @par Per-Operation Cancellation
+ * The new thread of execution is created with a cancellation state that
+ * supports @c cancellation_type::terminal values only. To change the
+ * cancellation state, call asio::this_coro::reset_cancellation_state.
+ */
+template <typename Executor, typename AwaitableExecutor,
+    ASIO_COMPLETION_TOKEN_FOR(
+      void(std::exception_ptr)) CompletionToken
+        ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(Executor)>
+inline ASIO_INITFN_AUTO_RESULT_TYPE(
+    CompletionToken, void(std::exception_ptr))
+co_spawn(const Executor& ex, awaitable<void, AwaitableExecutor> a,
+    CompletionToken&& token
+      ASIO_DEFAULT_COMPLETION_TOKEN(Executor),
+    typename constraint<
+      (is_executor<Executor>::value || execution::is_executor<Executor>::value)
+        && is_convertible<Executor, AwaitableExecutor>::value
+    >::type = 0);
+
+/// Spawn a new coroutined-based thread of execution.
+/**
+ * @param ctx An execution context that will provide the executor to be used to
+ * schedule the new thread of execution.
+ *
+ * @param a The asio::awaitable object that is the result of calling the
+ * coroutine's entry point function.
+ *
+ * @param token The @ref completion_token that will handle the notification that
+ * the thread of execution has completed. The function signature of the
+ * completion handler must be:
+ * @code void handler(std::exception_ptr); @endcode
+ *
+ * @par Completion Signature
+ * @code void(std::exception_ptr, T) @endcode
+ *
+ * @par Example
+ * @code
+ * asio::awaitable<std::size_t> echo(tcp::socket socket)
+ * {
+ *   std::size_t bytes_transferred = 0;
+ *
+ *   try
+ *   {
+ *     char data[1024];
+ *     for (;;)
+ *     {
+ *       std::size_t n = co_await socket.async_read_some(
+ *           asio::buffer(data), asio::use_awaitable);
+ *
+ *       co_await asio::async_write(socket,
+ *           asio::buffer(data, n), asio::use_awaitable);
+ *
+ *       bytes_transferred += n;
+ *     }
+ *   }
+ *   catch (const std::exception&)
+ *   {
+ *   }
+ *
+ *   co_return bytes_transferred;
+ * }
+ *
+ * // ...
+ *
+ * asio::co_spawn(my_io_context,
+ *   echo(std::move(my_tcp_socket)),
+ *   [](std::exception_ptr e, std::size_t n)
+ *   {
+ *     std::cout << "transferred " << n << "\n";
+ *   });
+ * @endcode
+ *
+ * @par Per-Operation Cancellation
+ * The new thread of execution is created with a cancellation state that
+ * supports @c cancellation_type::terminal values only. To change the
+ * cancellation state, call asio::this_coro::reset_cancellation_state.
+ */
+template <typename ExecutionContext, typename T, typename AwaitableExecutor,
+    ASIO_COMPLETION_TOKEN_FOR(
+      void(std::exception_ptr, T)) CompletionToken
+        ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(
+          typename ExecutionContext::executor_type)>
+inline ASIO_INITFN_AUTO_RESULT_TYPE(
+    CompletionToken, void(std::exception_ptr, T))
+co_spawn(ExecutionContext& ctx, awaitable<T, AwaitableExecutor> a,
+    CompletionToken&& token
+      ASIO_DEFAULT_COMPLETION_TOKEN(
+        typename ExecutionContext::executor_type),
+    typename constraint<
+      is_convertible<ExecutionContext&, execution_context&>::value
+        && is_convertible<typename ExecutionContext::executor_type,
+          AwaitableExecutor>::value
+    >::type = 0);
+
+/// Spawn a new coroutined-based thread of execution.
+/**
+ * @param ctx An execution context that will provide the executor to be used to
+ * schedule the new thread of execution.
+ *
+ * @param a The asio::awaitable object that is the result of calling the
+ * coroutine's entry point function.
+ *
+ * @param token The @ref completion_token that will handle the notification that
+ * the thread of execution has completed. The function signature of the
+ * completion handler must be:
+ * @code void handler(std::exception_ptr); @endcode
+ *
+ * @par Completion Signature
+ * @code void(std::exception_ptr) @endcode
+ *
+ * @par Example
+ * @code
+ * asio::awaitable<void> echo(tcp::socket socket)
+ * {
+ *   try
+ *   {
+ *     char data[1024];
+ *     for (;;)
+ *     {
+ *       std::size_t n = co_await socket.async_read_some(
+ *           asio::buffer(data), asio::use_awaitable);
+ *
+ *       co_await asio::async_write(socket,
+ *           asio::buffer(data, n), asio::use_awaitable);
+ *     }
+ *   }
+ *   catch (const std::exception& e)
+ *   {
+ *     std::cerr << "Exception: " << e.what() << "\n";
+ *   }
+ * }
+ *
+ * // ...
+ *
+ * asio::co_spawn(my_io_context,
+ *   echo(std::move(my_tcp_socket)),
+ *   asio::detached);
+ * @endcode
+ *
+ * @par Per-Operation Cancellation
+ * The new thread of execution is created with a cancellation state that
+ * supports @c cancellation_type::terminal values only. To change the
+ * cancellation state, call asio::this_coro::reset_cancellation_state.
+ */
+template <typename ExecutionContext, typename AwaitableExecutor,
+    ASIO_COMPLETION_TOKEN_FOR(
+      void(std::exception_ptr)) CompletionToken
+        ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(
+          typename ExecutionContext::executor_type)>
+inline ASIO_INITFN_AUTO_RESULT_TYPE(
+    CompletionToken, void(std::exception_ptr))
+co_spawn(ExecutionContext& ctx, awaitable<void, AwaitableExecutor> a,
+    CompletionToken&& token
+      ASIO_DEFAULT_COMPLETION_TOKEN(
+        typename ExecutionContext::executor_type),
+    typename constraint<
+      is_convertible<ExecutionContext&, execution_context&>::value
+        && is_convertible<typename ExecutionContext::executor_type,
+          AwaitableExecutor>::value
+    >::type = 0);
+
+/// Spawn a new coroutined-based thread of execution.
+/**
+ * @param ex The executor that will be used to schedule the new thread of
+ * execution.
+ *
+ * @param f A nullary function object with a return type of the form
+ * @c asio::awaitable<R,E> that will be used as the coroutine's entry
+ * point.
+ *
+ * @param token The @ref completion_token that will handle the notification
+ * that the thread of execution has completed. If @c R is @c void, the function
+ * signature of the completion handler must be:
+ *
+ * @code void handler(std::exception_ptr); @endcode
+ * Otherwise, the function signature of the completion handler must be:
+ * @code void handler(std::exception_ptr, R); @endcode
+ *
+ * @par Completion Signature
+ * @code void(std::exception_ptr, R) @endcode
+ * where @c R is the first template argument to the @c awaitable returned by the
+ * supplied function object @c F:
+ * @code asio::awaitable<R, AwaitableExecutor> F() @endcode
+ *
+ * @par Example
+ * @code
+ * asio::awaitable<std::size_t> echo(tcp::socket socket)
+ * {
+ *   std::size_t bytes_transferred = 0;
+ *
+ *   try
+ *   {
+ *     char data[1024];
+ *     for (;;)
+ *     {
+ *       std::size_t n = co_await socket.async_read_some(
+ *           asio::buffer(data), asio::use_awaitable);
+ *
+ *       co_await asio::async_write(socket,
+ *           asio::buffer(data, n), asio::use_awaitable);
+ *
+ *       bytes_transferred += n;
+ *     }
+ *   }
+ *   catch (const std::exception&)
+ *   {
+ *   }
+ *
+ *   co_return bytes_transferred;
+ * }
+ *
+ * // ...
+ *
+ * asio::co_spawn(my_executor,
+ *   [socket = std::move(my_tcp_socket)]() mutable
+ *     -> asio::awaitable<void>
+ *   {
+ *     try
+ *     {
+ *       char data[1024];
+ *       for (;;)
+ *       {
+ *         std::size_t n = co_await socket.async_read_some(
+ *             asio::buffer(data), asio::use_awaitable);
+ *
+ *         co_await asio::async_write(socket,
+ *             asio::buffer(data, n), asio::use_awaitable);
+ *       }
+ *     }
+ *     catch (const std::exception& e)
+ *     {
+ *       std::cerr << "Exception: " << e.what() << "\n";
+ *     }
+ *   }, asio::detached);
+ * @endcode
+ *
+ * @par Per-Operation Cancellation
+ * The new thread of execution is created with a cancellation state that
+ * supports @c cancellation_type::terminal values only. To change the
+ * cancellation state, call asio::this_coro::reset_cancellation_state.
+ */
+template <typename Executor, typename F,
+    ASIO_COMPLETION_TOKEN_FOR(typename detail::awaitable_signature<
+      typename result_of<F()>::type>::type) CompletionToken
+        ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(Executor)>
+ASIO_INITFN_AUTO_RESULT_TYPE(CompletionToken,
+    typename detail::awaitable_signature<typename result_of<F()>::type>::type)
+co_spawn(const Executor& ex, F&& f,
+    CompletionToken&& token
+      ASIO_DEFAULT_COMPLETION_TOKEN(Executor),
+    typename constraint<
+      is_executor<Executor>::value || execution::is_executor<Executor>::value
+    >::type = 0);
+
+/// Spawn a new coroutined-based thread of execution.
+/**
+ * @param ctx An execution context that will provide the executor to be used to
+ * schedule the new thread of execution.
+ *
+ * @param f A nullary function object with a return type of the form
+ * @c asio::awaitable<R,E> that will be used as the coroutine's entry
+ * point.
+ *
+ * @param token The @ref completion_token that will handle the notification
+ * that the thread of execution has completed. If @c R is @c void, the function
+ * signature of the completion handler must be:
+ *
+ * @code void handler(std::exception_ptr); @endcode
+ * Otherwise, the function signature of the completion handler must be:
+ * @code void handler(std::exception_ptr, R); @endcode
+ *
+ * @par Completion Signature
+ * @code void(std::exception_ptr, R) @endcode
+ * where @c R is the first template argument to the @c awaitable returned by the
+ * supplied function object @c F:
+ * @code asio::awaitable<R, AwaitableExecutor> F() @endcode
+ *
+ * @par Example
+ * @code
+ * asio::awaitable<std::size_t> echo(tcp::socket socket)
+ * {
+ *   std::size_t bytes_transferred = 0;
+ *
+ *   try
+ *   {
+ *     char data[1024];
+ *     for (;;)
+ *     {
+ *       std::size_t n = co_await socket.async_read_some(
+ *           asio::buffer(data), asio::use_awaitable);
+ *
+ *       co_await asio::async_write(socket,
+ *           asio::buffer(data, n), asio::use_awaitable);
+ *
+ *       bytes_transferred += n;
+ *     }
+ *   }
+ *   catch (const std::exception&)
+ *   {
+ *   }
+ *
+ *   co_return bytes_transferred;
+ * }
+ *
+ * // ...
+ *
+ * asio::co_spawn(my_io_context,
+ *   [socket = std::move(my_tcp_socket)]() mutable
+ *     -> asio::awaitable<void>
+ *   {
+ *     try
+ *     {
+ *       char data[1024];
+ *       for (;;)
+ *       {
+ *         std::size_t n = co_await socket.async_read_some(
+ *             asio::buffer(data), asio::use_awaitable);
+ *
+ *         co_await asio::async_write(socket,
+ *             asio::buffer(data, n), asio::use_awaitable);
+ *       }
+ *     }
+ *     catch (const std::exception& e)
+ *     {
+ *       std::cerr << "Exception: " << e.what() << "\n";
+ *     }
+ *   }, asio::detached);
+ * @endcode
+ *
+ * @par Per-Operation Cancellation
+ * The new thread of execution is created with a cancellation state that
+ * supports @c cancellation_type::terminal values only. To change the
+ * cancellation state, call asio::this_coro::reset_cancellation_state.
+ */
+template <typename ExecutionContext, typename F,
+    ASIO_COMPLETION_TOKEN_FOR(typename detail::awaitable_signature<
+      typename result_of<F()>::type>::type) CompletionToken
+        ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(
+          typename ExecutionContext::executor_type)>
+ASIO_INITFN_AUTO_RESULT_TYPE(CompletionToken,
+    typename detail::awaitable_signature<typename result_of<F()>::type>::type)
+co_spawn(ExecutionContext& ctx, F&& f,
+    CompletionToken&& token
+      ASIO_DEFAULT_COMPLETION_TOKEN(
+        typename ExecutionContext::executor_type),
+    typename constraint<
+      is_convertible<ExecutionContext&, execution_context&>::value
+    >::type = 0);
+
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#include "asio/impl/co_spawn.hpp"
+
+#endif // defined(ASIO_HAS_CO_AWAIT) || defined(GENERATING_DOCUMENTATION)
+
+#endif // ASIO_CO_SPAWN_HPP

lib/asio/include/asio/completion_condition.hpp

@@ -0,0 +1,218 @@
+//
+// completion_condition.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_COMPLETION_CONDITION_HPP
+#define ASIO_COMPLETION_CONDITION_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+#include <cstddef>
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+
+namespace detail {
+
+// The default maximum number of bytes to transfer in a single operation.
+enum default_max_transfer_size_t { default_max_transfer_size = 65536 };
+
+// Adapt result of old-style completion conditions (which had a bool result
+// where true indicated that the operation was complete).
+inline std::size_t adapt_completion_condition_result(bool result)
+{
+  return result ? 0 : default_max_transfer_size;
+}
+
+// Adapt result of current completion conditions (which have a size_t result
+// where 0 means the operation is complete, and otherwise the result is the
+// maximum number of bytes to transfer on the next underlying operation).
+inline std::size_t adapt_completion_condition_result(std::size_t result)
+{
+  return result;
+}
+
+class transfer_all_t
+{
+public:
+  typedef std::size_t result_type;
+
+  template <typename Error>
+  std::size_t operator()(const Error& err, std::size_t)
+  {
+    return !!err ? 0 : default_max_transfer_size;
+  }
+};
+
+class transfer_at_least_t
+{
+public:
+  typedef std::size_t result_type;
+
+  explicit transfer_at_least_t(std::size_t minimum)
+    : minimum_(minimum)
+  {
+  }
+
+  template <typename Error>
+  std::size_t operator()(const Error& err, std::size_t bytes_transferred)
+  {
+    return (!!err || bytes_transferred >= minimum_)
+      ? 0 : default_max_transfer_size;
+  }
+
+private:
+  std::size_t minimum_;
+};
+
+class transfer_exactly_t
+{
+public:
+  typedef std::size_t result_type;
+
+  explicit transfer_exactly_t(std::size_t size)
+    : size_(size)
+  {
+  }
+
+  template <typename Error>
+  std::size_t operator()(const Error& err, std::size_t bytes_transferred)
+  {
+    return (!!err || bytes_transferred >= size_) ? 0 :
+      (size_ - bytes_transferred < default_max_transfer_size
+        ? size_ - bytes_transferred : std::size_t(default_max_transfer_size));
+  }
+
+private:
+  std::size_t size_;
+};
+
+} // namespace detail
+
+/**
+ * @defgroup completion_condition Completion Condition Function Objects
+ *
+ * Function objects used for determining when a read or write operation should
+ * complete.
+ */
+/*@{*/
+
+/// Return a completion condition function object that indicates that a read or
+/// write operation should continue until all of the data has been transferred,
+/// or until an error occurs.
+/**
+ * This function is used to create an object, of unspecified type, that meets
+ * CompletionCondition requirements.
+ *
+ * @par Example
+ * Reading until a buffer is full:
+ * @code
+ * boost::array<char, 128> buf;
+ * asio::error_code ec;
+ * std::size_t n = asio::read(
+ *     sock, asio::buffer(buf),
+ *     asio::transfer_all(), ec);
+ * if (ec)
+ * {
+ *   // An error occurred.
+ * }
+ * else
+ * {
+ *   // n == 128
+ * }
+ * @endcode
+ */
+#if defined(GENERATING_DOCUMENTATION)
+unspecified transfer_all();
+#else
+inline detail::transfer_all_t transfer_all()
+{
+  return detail::transfer_all_t();
+}
+#endif
+
+/// Return a completion condition function object that indicates that a read or
+/// write operation should continue until a minimum number of bytes has been
+/// transferred, or until an error occurs.
+/**
+ * This function is used to create an object, of unspecified type, that meets
+ * CompletionCondition requirements.
+ *
+ * @par Example
+ * Reading until a buffer is full or contains at least 64 bytes:
+ * @code
+ * boost::array<char, 128> buf;
+ * asio::error_code ec;
+ * std::size_t n = asio::read(
+ *     sock, asio::buffer(buf),
+ *     asio::transfer_at_least(64), ec);
+ * if (ec)
+ * {
+ *   // An error occurred.
+ * }
+ * else
+ * {
+ *   // n >= 64 && n <= 128
+ * }
+ * @endcode
+ */
+#if defined(GENERATING_DOCUMENTATION)
+unspecified transfer_at_least(std::size_t minimum);
+#else
+inline detail::transfer_at_least_t transfer_at_least(std::size_t minimum)
+{
+  return detail::transfer_at_least_t(minimum);
+}
+#endif
+
+/// Return a completion condition function object that indicates that a read or
+/// write operation should continue until an exact number of bytes has been
+/// transferred, or until an error occurs.
+/**
+ * This function is used to create an object, of unspecified type, that meets
+ * CompletionCondition requirements.
+ *
+ * @par Example
+ * Reading until a buffer is full or contains exactly 64 bytes:
+ * @code
+ * boost::array<char, 128> buf;
+ * asio::error_code ec;
+ * std::size_t n = asio::read(
+ *     sock, asio::buffer(buf),
+ *     asio::transfer_exactly(64), ec);
+ * if (ec)
+ * {
+ *   // An error occurred.
+ * }
+ * else
+ * {
+ *   // n == 64
+ * }
+ * @endcode
+ */
+#if defined(GENERATING_DOCUMENTATION)
+unspecified transfer_exactly(std::size_t size);
+#else
+inline detail::transfer_exactly_t transfer_exactly(std::size_t size)
+{
+  return detail::transfer_exactly_t(size);
+}
+#endif
+
+/*@}*/
+
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // ASIO_COMPLETION_CONDITION_HPP

lib/asio/include/asio/compose.hpp

@@ -0,0 +1,136 @@
+//
+// compose.hpp
+// ~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_COMPOSE_HPP
+#define ASIO_COMPOSE_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+#include "asio/async_result.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+
+#if defined(ASIO_HAS_VARIADIC_TEMPLATES) \
+  || defined(GENERATING_DOCUMENTATION)
+
+/// Launch an asynchronous operation with a stateful implementation.
+/**
+ * The async_compose function simplifies the implementation of composed
+ * asynchronous operations automatically wrapping a stateful function object
+ * with a conforming intermediate completion handler.
+ *
+ * @param implementation A function object that contains the implementation of
+ * the composed asynchronous operation. The first argument to the function
+ * object is a non-const reference to the enclosing intermediate completion
+ * handler. The remaining arguments are any arguments that originate from the
+ * completion handlers of any asynchronous operations performed by the
+ * implementation.
+
+ * @param token The completion token.
+ *
+ * @param io_objects_or_executors Zero or more I/O objects or I/O executors for
+ * which outstanding work must be maintained.
+ *
+ * @par Example:
+ *
+ * @code struct async_echo_implementation
+ * {
+ *   tcp::socket& socket_;
+ *   asio::mutable_buffer buffer_;
+ *   enum { starting, reading, writing } state_;
+ *
+ *   template <typename Self>
+ *   void operator()(Self& self,
+ *       asio::error_code error = {},
+ *       std::size_t n = 0)
+ *   {
+ *     switch (state_)
+ *     {
+ *     case starting:
+ *       state_ = reading;
+ *       socket_.async_read_some(
+ *           buffer_, std::move(self));
+ *       break;
+ *     case reading:
+ *       if (error)
+ *       {
+ *         self.complete(error, 0);
+ *       }
+ *       else
+ *       {
+ *         state_ = writing;
+ *         asio::async_write(socket_, buffer_,
+ *             asio::transfer_exactly(n),
+ *             std::move(self));
+ *       }
+ *       break;
+ *     case writing:
+ *       self.complete(error, n);
+ *       break;
+ *     }
+ *   }
+ * };
+ *
+ * template <typename CompletionToken>
+ * auto async_echo(tcp::socket& socket,
+ *     asio::mutable_buffer buffer,
+ *     CompletionToken&& token) ->
+ *   typename asio::async_result<
+ *     typename std::decay<CompletionToken>::type,
+ *       void(asio::error_code, std::size_t)>::return_type
+ * {
+ *   return asio::async_compose<CompletionToken,
+ *     void(asio::error_code, std::size_t)>(
+ *       async_echo_implementation{socket, buffer,
+ *         async_echo_implementation::starting},
+ *       token, socket);
+ * } @endcode
+ */
+template <typename CompletionToken, typename Signature,
+    typename Implementation, typename... IoObjectsOrExecutors>
+ASIO_INITFN_AUTO_RESULT_TYPE(CompletionToken, Signature)
+async_compose(ASIO_MOVE_ARG(Implementation) implementation,
+    ASIO_NONDEDUCED_MOVE_ARG(CompletionToken) token,
+    ASIO_MOVE_ARG(IoObjectsOrExecutors)... io_objects_or_executors);
+
+#else // defined(ASIO_HAS_VARIADIC_TEMPLATES)
+      //   || defined(GENERATING_DOCUMENTATION)
+
+template <typename CompletionToken, typename Signature, typename Implementation>
+ASIO_INITFN_AUTO_RESULT_TYPE(CompletionToken, Signature)
+async_compose(ASIO_MOVE_ARG(Implementation) implementation,
+    ASIO_NONDEDUCED_MOVE_ARG(CompletionToken) token);
+
+#define ASIO_PRIVATE_ASYNC_COMPOSE_DEF(n) \
+  template <typename CompletionToken, typename Signature, \
+      typename Implementation, ASIO_VARIADIC_TPARAMS(n)> \
+  ASIO_INITFN_AUTO_RESULT_TYPE(CompletionToken, Signature) \
+  async_compose(ASIO_MOVE_ARG(Implementation) implementation, \
+      ASIO_NONDEDUCED_MOVE_ARG(CompletionToken) token, \
+      ASIO_VARIADIC_MOVE_PARAMS(n));
+  /**/
+  ASIO_VARIADIC_GENERATE(ASIO_PRIVATE_ASYNC_COMPOSE_DEF)
+#undef ASIO_PRIVATE_ASYNC_COMPOSE_DEF
+
+#endif // defined(ASIO_HAS_VARIADIC_TEMPLATES)
+       //   || defined(GENERATING_DOCUMENTATION)
+
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#include "asio/impl/compose.hpp"
+
+#endif // ASIO_COMPOSE_HPP

lib/asio/include/asio/connect_pipe.hpp

@@ -0,0 +1,83 @@
+//
+// connect_pipe.hpp
+// ~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_CONNECT_PIPE_HPP
+#define ASIO_CONNECT_PIPE_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_HAS_PIPE) \
+  || defined(GENERATING_DOCUMENTATION)
+
+#include "asio/basic_readable_pipe.hpp"
+#include "asio/basic_writable_pipe.hpp"
+#include "asio/error.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+#if defined(ASIO_HAS_IOCP)
+typedef HANDLE native_pipe_handle;
+#else // defined(ASIO_HAS_IOCP)
+typedef int native_pipe_handle;
+#endif // defined(ASIO_HAS_IOCP)
+
+ASIO_DECL void create_pipe(native_pipe_handle p[2],
+    asio::error_code& ec);
+
+ASIO_DECL void close_pipe(native_pipe_handle p);
+
+} // namespace detail
+
+/// Connect two pipe ends using an anonymous pipe.
+/**
+ * @param read_end The read end of the pipe.
+ *
+ * @param write_end The write end of the pipe.
+ *
+ * @throws asio::system_error Thrown on failure.
+ */
+template <typename Executor1, typename Executor2>
+void connect_pipe(basic_readable_pipe<Executor1>& read_end,
+    basic_writable_pipe<Executor2>& write_end);
+
+/// Connect two pipe ends using an anonymous pipe.
+/**
+ * @param read_end The read end of the pipe.
+ *
+ * @param write_end The write end of the pipe.
+ *
+ * @throws asio::system_error Thrown on failure.
+ *
+ * @param ec Set to indicate what error occurred, if any.
+ */
+template <typename Executor1, typename Executor2>
+ASIO_SYNC_OP_VOID connect_pipe(basic_readable_pipe<Executor1>& read_end,
+    basic_writable_pipe<Executor2>& write_end, asio::error_code& ec);
+
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#include "asio/impl/connect_pipe.hpp"
+#if defined(ASIO_HEADER_ONLY)
+# include "asio/impl/connect_pipe.ipp"
+#endif // defined(ASIO_HEADER_ONLY)
+
+#endif // defined(ASIO_HAS_PIPE)
+       //   || defined(GENERATING_DOCUMENTATION)
+
+#endif // ASIO_CONNECT_PIPE_HPP

lib/asio/include/asio/coroutine.hpp

@@ -0,0 +1,328 @@
+//
+// coroutine.hpp
+// ~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_COROUTINE_HPP
+#define ASIO_COROUTINE_HPP
+
+namespace asio {
+namespace detail {
+
+class coroutine_ref;
+
+} // namespace detail
+
+/// Provides support for implementing stackless coroutines.
+/**
+ * The @c coroutine class may be used to implement stackless coroutines. The
+ * class itself is used to store the current state of the coroutine.
+ *
+ * Coroutines are copy-constructible and assignable, and the space overhead is
+ * a single int. They can be used as a base class:
+ *
+ * @code class session : coroutine
+ * {
+ *   ...
+ * }; @endcode
+ *
+ * or as a data member:
+ *
+ * @code class session
+ * {
+ *   ...
+ *   coroutine coro_;
+ * }; @endcode
+ *
+ * or even bound in as a function argument using lambdas or @c bind(). The
+ * important thing is that as the application maintains a copy of the object
+ * for as long as the coroutine must be kept alive.
+ *
+ * @par Pseudo-keywords
+ *
+ * A coroutine is used in conjunction with certain "pseudo-keywords", which
+ * are implemented as macros. These macros are defined by a header file:
+ *
+ * @code #include <asio/yield.hpp>@endcode
+ *
+ * and may conversely be undefined as follows:
+ *
+ * @code #include <asio/unyield.hpp>@endcode
+ *
+ * <b>reenter</b>
+ *
+ * The @c reenter macro is used to define the body of a coroutine. It takes a
+ * single argument: a pointer or reference to a coroutine object. For example,
+ * if the base class is a coroutine object you may write:
+ *
+ * @code reenter (this)
+ * {
+ *   ... coroutine body ...
+ * } @endcode
+ *
+ * and if a data member or other variable you can write:
+ *
+ * @code reenter (coro_)
+ * {
+ *   ... coroutine body ...
+ * } @endcode
+ *
+ * When @c reenter is executed at runtime, control jumps to the location of the
+ * last @c yield or @c fork.
+ *
+ * The coroutine body may also be a single statement, such as:
+ *
+ * @code reenter (this) for (;;)
+ * {
+ *   ...
+ * } @endcode
+ *
+ * @b Limitation: The @c reenter macro is implemented using a switch. This
+ * means that you must take care when using local variables within the
+ * coroutine body. The local variable is not allowed in a position where
+ * reentering the coroutine could bypass the variable definition.
+ *
+ * <b>yield <em>statement</em></b>
+ *
+ * This form of the @c yield keyword is often used with asynchronous operations:
+ *
+ * @code yield socket_->async_read_some(buffer(*buffer_), *this); @endcode
+ *
+ * This divides into four logical steps:
+ *
+ * @li @c yield saves the current state of the coroutine.
+ * @li The statement initiates the asynchronous operation.
+ * @li The resume point is defined immediately following the statement.
+ * @li Control is transferred to the end of the coroutine body.
+ *
+ * When the asynchronous operation completes, the function object is invoked
+ * and @c reenter causes control to transfer to the resume point. It is
+ * important to remember to carry the coroutine state forward with the
+ * asynchronous operation. In the above snippet, the current class is a
+ * function object object with a coroutine object as base class or data member.
+ *
+ * The statement may also be a compound statement, and this permits us to
+ * define local variables with limited scope:
+ *
+ * @code yield
+ * {
+ *   mutable_buffers_1 b = buffer(*buffer_);
+ *   socket_->async_read_some(b, *this);
+ * } @endcode
+ *
+ * <b>yield return <em>expression</em> ;</b>
+ *
+ * This form of @c yield is often used in generators or coroutine-based parsers.
+ * For example, the function object:
+ *
+ * @code struct interleave : coroutine
+ * {
+ *   istream& is1;
+ *   istream& is2;
+ *   char operator()(char c)
+ *   {
+ *     reenter (this) for (;;)
+ *     {
+ *       yield return is1.get();
+ *       yield return is2.get();
+ *     }
+ *   }
+ * }; @endcode
+ *
+ * defines a trivial coroutine that interleaves the characters from two input
+ * streams.
+ *
+ * This type of @c yield divides into three logical steps:
+ *
+ * @li @c yield saves the current state of the coroutine.
+ * @li The resume point is defined immediately following the semicolon.
+ * @li The value of the expression is returned from the function.
+ *
+ * <b>yield ;</b>
+ *
+ * This form of @c yield is equivalent to the following steps:
+ *
+ * @li @c yield saves the current state of the coroutine.
+ * @li The resume point is defined immediately following the semicolon.
+ * @li Control is transferred to the end of the coroutine body.
+ *
+ * This form might be applied when coroutines are used for cooperative
+ * threading and scheduling is explicitly managed. For example:
+ *
+ * @code struct task : coroutine
+ * {
+ *   ...
+ *   void operator()()
+ *   {
+ *     reenter (this)
+ *     {
+ *       while (... not finished ...)
+ *       {
+ *         ... do something ...
+ *         yield;
+ *         ... do some more ...
+ *         yield;
+ *       }
+ *     }
+ *   }
+ *   ...
+ * };
+ * ...
+ * task t1, t2;
+ * for (;;)
+ * {
+ *   t1();
+ *   t2();
+ * } @endcode
+ *
+ * <b>yield break ;</b>
+ *
+ * The final form of @c yield is used to explicitly terminate the coroutine.
+ * This form is comprised of two steps:
+ *
+ * @li @c yield sets the coroutine state to indicate termination.
+ * @li Control is transferred to the end of the coroutine body.
+ *
+ * Once terminated, calls to is_complete() return true and the coroutine cannot
+ * be reentered.
+ *
+ * Note that a coroutine may also be implicitly terminated if the coroutine
+ * body is exited without a yield, e.g. by return, throw or by running to the
+ * end of the body.
+ *
+ * <b>fork <em>statement</em></b>
+ *
+ * The @c fork pseudo-keyword is used when "forking" a coroutine, i.e. splitting
+ * it into two (or more) copies. One use of @c fork is in a server, where a new
+ * coroutine is created to handle each client connection:
+ * 
+ * @code reenter (this)
+ * {
+ *   do
+ *   {
+ *     socket_.reset(new tcp::socket(my_context_));
+ *     yield acceptor->async_accept(*socket_, *this);
+ *     fork server(*this)();
+ *   } while (is_parent());
+ *   ... client-specific handling follows ...
+ * } @endcode
+ * 
+ * The logical steps involved in a @c fork are:
+ * 
+ * @li @c fork saves the current state of the coroutine.
+ * @li The statement creates a copy of the coroutine and either executes it
+ *     immediately or schedules it for later execution.
+ * @li The resume point is defined immediately following the semicolon.
+ * @li For the "parent", control immediately continues from the next line.
+ *
+ * The functions is_parent() and is_child() can be used to differentiate
+ * between parent and child. You would use these functions to alter subsequent
+ * control flow.
+ *
+ * Note that @c fork doesn't do the actual forking by itself. It is the
+ * application's responsibility to create a clone of the coroutine and call it.
+ * The clone can be called immediately, as above, or scheduled for delayed
+ * execution using something like asio::post().
+ *
+ * @par Alternate macro names
+ *
+ * If preferred, an application can use macro names that follow a more typical
+ * naming convention, rather than the pseudo-keywords. These are:
+ *
+ * @li @c ASIO_CORO_REENTER instead of @c reenter
+ * @li @c ASIO_CORO_YIELD instead of @c yield
+ * @li @c ASIO_CORO_FORK instead of @c fork
+ */
+class coroutine
+{
+public:
+  /// Constructs a coroutine in its initial state.
+  coroutine() : value_(0) {}
+
+  /// Returns true if the coroutine is the child of a fork.
+  bool is_child() const { return value_ < 0; }
+
+  /// Returns true if the coroutine is the parent of a fork.
+  bool is_parent() const { return !is_child(); }
+
+  /// Returns true if the coroutine has reached its terminal state.
+  bool is_complete() const { return value_ == -1; }
+
+private:
+  friend class detail::coroutine_ref;
+  int value_;
+};
+
+
+namespace detail {
+
+class coroutine_ref
+{
+public:
+  coroutine_ref(coroutine& c) : value_(c.value_), modified_(false) {}
+  coroutine_ref(coroutine* c) : value_(c->value_), modified_(false) {}
+  ~coroutine_ref() { if (!modified_) value_ = -1; }
+  operator int() const { return value_; }
+  int& operator=(int v) { modified_ = true; return value_ = v; }
+private:
+  void operator=(const coroutine_ref&);
+  int& value_;
+  bool modified_;
+};
+
+} // namespace detail
+} // namespace asio
+
+#define ASIO_CORO_REENTER(c) \
+  switch (::asio::detail::coroutine_ref _coro_value = c) \
+    case -1: if (_coro_value) \
+    { \
+      goto terminate_coroutine; \
+      terminate_coroutine: \
+      _coro_value = -1; \
+      goto bail_out_of_coroutine; \
+      bail_out_of_coroutine: \
+      break; \
+    } \
+    else /* fall-through */ case 0:
+
+#define ASIO_CORO_YIELD_IMPL(n) \
+  for (_coro_value = (n);;) \
+    if (_coro_value == 0) \
+    { \
+      case (n): ; \
+      break; \
+    } \
+    else \
+      switch (_coro_value ? 0 : 1) \
+        for (;;) \
+          /* fall-through */ case -1: if (_coro_value) \
+            goto terminate_coroutine; \
+          else for (;;) \
+            /* fall-through */ case 1: if (_coro_value) \
+              goto bail_out_of_coroutine; \
+            else /* fall-through */ case 0:
+
+#define ASIO_CORO_FORK_IMPL(n) \
+  for (_coro_value = -(n);; _coro_value = (n)) \
+    if (_coro_value == (n)) \
+    { \
+      case -(n): ; \
+      break; \
+    } \
+    else
+
+#if defined(_MSC_VER)
+# define ASIO_CORO_YIELD ASIO_CORO_YIELD_IMPL(__COUNTER__ + 1)
+# define ASIO_CORO_FORK ASIO_CORO_FORK_IMPL(__COUNTER__ + 1)
+#else // defined(_MSC_VER)
+# define ASIO_CORO_YIELD ASIO_CORO_YIELD_IMPL(__LINE__)
+# define ASIO_CORO_FORK ASIO_CORO_FORK_IMPL(__LINE__)
+#endif // defined(_MSC_VER)
+
+#endif // ASIO_COROUTINE_HPP

lib/asio/include/asio/deadline_timer.hpp

@@ -0,0 +1,38 @@
+//
+// deadline_timer.hpp
+// ~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DEADLINE_TIMER_HPP
+#define ASIO_DEADLINE_TIMER_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_HAS_BOOST_DATE_TIME) \
+  || defined(GENERATING_DOCUMENTATION)
+
+#include "asio/detail/socket_types.hpp" // Must come before posix_time.
+#include "asio/basic_deadline_timer.hpp"
+
+#include <boost/date_time/posix_time/posix_time_types.hpp>
+
+namespace asio {
+
+/// Typedef for the typical usage of timer. Uses a UTC clock.
+typedef basic_deadline_timer<boost::posix_time::ptime> deadline_timer;
+
+} // namespace asio
+
+#endif // defined(ASIO_HAS_BOOST_DATE_TIME)
+       // || defined(GENERATING_DOCUMENTATION)
+
+#endif // ASIO_DEADLINE_TIMER_HPP

lib/asio/include/asio/defer.hpp

@@ -0,0 +1,200 @@
+//
+// defer.hpp
+// ~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DEFER_HPP
+#define ASIO_DEFER_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+#include "asio/async_result.hpp"
+#include "asio/detail/type_traits.hpp"
+#include "asio/execution_context.hpp"
+#include "asio/execution/executor.hpp"
+#include "asio/is_executor.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+
+/// Submits a completion token or function object for execution.
+/**
+ * This function submits an object for execution using the object's associated
+ * executor. The function object is queued for execution, and is never called
+ * from the current thread prior to returning from <tt>defer()</tt>.
+ *
+ * The use of @c defer(), rather than @ref post(), indicates the caller's
+ * preference that the executor defer the queueing of the function object. This
+ * may allow the executor to optimise queueing for cases when the function
+ * object represents a continuation of the current call context.
+ *
+ * @param token The @ref completion_token that will be used to produce a
+ * completion handler. The function signature of the completion handler must be:
+ * @code void handler(); @endcode
+ *
+ * @returns This function returns <tt>async_initiate<NullaryToken,
+ * void()>(Init{}, token)</tt>, where @c Init is a function object type defined
+ * as:
+ *
+ * @code class Init
+ * {
+ * public:
+ *   template <typename CompletionHandler>
+ *     void operator()(CompletionHandler&& completion_handler) const;
+ * }; @endcode
+ *
+ * The function call operator of @c Init:
+ *
+ * @li Obtains the handler's associated executor object @c ex of type @c Ex by
+ * performing @code auto ex = get_associated_executor(handler); @endcode
+ *
+ * @li Obtains the handler's associated allocator object @c alloc by performing
+ * @code auto alloc = get_associated_allocator(handler); @endcode
+ *
+ * @li If <tt>execution::is_executor<Ex>::value</tt> is true, performs
+ * @code execution::execute(
+ *     prefer(
+ *       require(ex, execution::blocking.never),
+ *       execution::relationship.continuation,
+ *       execution::allocator(alloc)),
+ *     std::forward<CompletionHandler>(completion_handler)); @endcode
+ *
+ * @li If <tt>execution::is_executor<Ex>::value</tt> is false, performs
+ * @code ex.defer(
+ *     std::forward<CompletionHandler>(completion_handler),
+ *     alloc); @endcode
+ *
+ * @par Completion Signature
+ * @code void() @endcode
+ */
+template <ASIO_COMPLETION_TOKEN_FOR(void()) NullaryToken>
+ASIO_INITFN_AUTO_RESULT_TYPE(NullaryToken, void()) defer(
+    ASIO_MOVE_ARG(NullaryToken) token);
+
+/// Submits a completion token or function object for execution.
+/**
+ * This function submits an object for execution using the specified executor.
+ * The function object is queued for execution, and is never called from the
+ * current thread prior to returning from <tt>defer()</tt>.
+ *
+ * The use of @c defer(), rather than @ref post(), indicates the caller's
+ * preference that the executor defer the queueing of the function object. This
+ * may allow the executor to optimise queueing for cases when the function
+ * object represents a continuation of the current call context.
+ *
+ * @param ex The target executor.
+ *
+ * @param token The @ref completion_token that will be used to produce a
+ * completion handler. The function signature of the completion handler must be:
+ * @code void handler(); @endcode
+ *
+ * @returns This function returns <tt>async_initiate<NullaryToken,
+ * void()>(Init{ex}, token)</tt>, where @c Init is a function object type
+ * defined as:
+ *
+ * @code class Init
+ * {
+ * public:
+ *   using executor_type = Executor;
+ *   explicit Init(const Executor& ex) : ex_(ex) {}
+ *   executor_type get_executor() const noexcept { return ex_; }
+ *   template <typename CompletionHandler>
+ *     void operator()(CompletionHandler&& completion_handler) const;
+ * private:
+ *   Executor ex_; // exposition only
+ * }; @endcode
+ *
+ * The function call operator of @c Init:
+ *
+ * @li Obtains the handler's associated executor object @c ex1 of type @c Ex1 by
+ * performing @code auto ex1 = get_associated_executor(handler, ex); @endcode
+ *
+ * @li Obtains the handler's associated allocator object @c alloc by performing
+ * @code auto alloc = get_associated_allocator(handler); @endcode
+ *
+ * @li If <tt>execution::is_executor<Ex1>::value</tt> is true, constructs a
+ * function object @c f with a member @c executor_ that is initialised with
+ * <tt>prefer(ex1, execution::outstanding_work.tracked)</tt>, a member @c
+ * handler_ that is a decay-copy of @c completion_handler, and a function call
+ * operator that performs:
+ * @code auto a = get_associated_allocator(handler_);
+ * execution::execute(
+ *     prefer(executor_,
+ *       execution::blocking.possibly,
+ *       execution::allocator(a)),
+ *     std::move(handler_)); @endcode
+ *
+ * @li If <tt>execution::is_executor<Ex1>::value</tt> is false, constructs a
+ * function object @c f with a member @c work_ that is initialised with
+ * <tt>make_work_guard(ex1)</tt>, a member @c handler_ that is a decay-copy of
+ * @c completion_handler, and a function call operator that performs:
+ * @code auto a = get_associated_allocator(handler_);
+ * work_.get_executor().dispatch(std::move(handler_), a);
+ * work_.reset(); @endcode
+ *
+ * @li If <tt>execution::is_executor<Ex>::value</tt> is true, performs
+ * @code execution::execute(
+ *     prefer(
+ *       require(ex, execution::blocking.never),
+ *       execution::relationship.continuation,
+ *       execution::allocator(alloc)),
+ *     std::move(f)); @endcode
+ *
+ * @li If <tt>execution::is_executor<Ex>::value</tt> is false, performs
+ * @code ex.defer(std::move(f), alloc); @endcode
+ *
+ * @par Completion Signature
+ * @code void() @endcode
+ */
+template <typename Executor,
+    ASIO_COMPLETION_TOKEN_FOR(void()) NullaryToken
+      ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(Executor)>
+ASIO_INITFN_AUTO_RESULT_TYPE(NullaryToken, void()) defer(
+    const Executor& ex,
+    ASIO_MOVE_ARG(NullaryToken) token
+      ASIO_DEFAULT_COMPLETION_TOKEN(Executor),
+    typename constraint<
+      execution::is_executor<Executor>::value || is_executor<Executor>::value
+    >::type = 0);
+
+/// Submits a completion token or function object for execution.
+/**
+ * @param ctx An execution context, from which the target executor is obtained.
+ *
+ * @param token The @ref completion_token that will be used to produce a
+ * completion handler. The function signature of the completion handler must be:
+ * @code void handler(); @endcode
+ *
+ * @returns <tt>defer(ctx.get_executor(), forward<NullaryToken>(token))</tt>.
+ *
+ * @par Completion Signature
+ * @code void() @endcode
+ */
+template <typename ExecutionContext,
+    ASIO_COMPLETION_TOKEN_FOR(void()) NullaryToken
+      ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(
+        typename ExecutionContext::executor_type)>
+ASIO_INITFN_AUTO_RESULT_TYPE(NullaryToken, void()) defer(
+    ExecutionContext& ctx,
+    ASIO_MOVE_ARG(NullaryToken) token
+      ASIO_DEFAULT_COMPLETION_TOKEN(
+        typename ExecutionContext::executor_type),
+    typename constraint<is_convertible<
+      ExecutionContext&, execution_context&>::value>::type = 0);
+
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#include "asio/impl/defer.hpp"
+
+#endif // ASIO_DEFER_HPP

lib/asio/include/asio/detached.hpp

@@ -0,0 +1,112 @@
+//
+// detached.hpp
+// ~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETACHED_HPP
+#define ASIO_DETACHED_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+#include <memory>
+#include "asio/detail/type_traits.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+
+/// Class used to specify that an asynchronous operation is detached.
+/**
+
+ * The detached_t class is used to indicate that an asynchronous operation is
+ * detached. That is, there is no completion handler waiting for the
+ * operation's result. A detached_t object may be passed as a handler to an
+ * asynchronous operation, typically using the special value
+ * @c asio::detached. For example:
+
+ * @code my_socket.async_send(my_buffer, asio::detached);
+ * @endcode
+ */
+class detached_t
+{
+public:
+  /// Constructor. 
+  ASIO_CONSTEXPR detached_t()
+  {
+  }
+
+  /// Adapts an executor to add the @c detached_t completion token as the
+  /// default.
+  template <typename InnerExecutor>
+  struct executor_with_default : InnerExecutor
+  {
+    /// Specify @c detached_t as the default completion token type.
+    typedef detached_t default_completion_token_type;
+
+    /// Construct the adapted executor from the inner executor type.
+    executor_with_default(const InnerExecutor& ex) ASIO_NOEXCEPT
+      : InnerExecutor(ex)
+    {
+    }
+
+    /// Convert the specified executor to the inner executor type, then use
+    /// that to construct the adapted executor.
+    template <typename OtherExecutor>
+    executor_with_default(const OtherExecutor& ex,
+        typename constraint<
+          is_convertible<OtherExecutor, InnerExecutor>::value
+        >::type = 0) ASIO_NOEXCEPT
+      : InnerExecutor(ex)
+    {
+    }
+  };
+
+  /// Type alias to adapt an I/O object to use @c detached_t as its
+  /// default completion token type.
+#if defined(ASIO_HAS_ALIAS_TEMPLATES) \
+  || defined(GENERATING_DOCUMENTATION)
+  template <typename T>
+  using as_default_on_t = typename T::template rebind_executor<
+      executor_with_default<typename T::executor_type> >::other;
+#endif // defined(ASIO_HAS_ALIAS_TEMPLATES)
+       //   || defined(GENERATING_DOCUMENTATION)
+
+  /// Function helper to adapt an I/O object to use @c detached_t as its
+  /// default completion token type.
+  template <typename T>
+  static typename decay<T>::type::template rebind_executor<
+      executor_with_default<typename decay<T>::type::executor_type>
+    >::other
+  as_default_on(ASIO_MOVE_ARG(T) object)
+  {
+    return typename decay<T>::type::template rebind_executor<
+        executor_with_default<typename decay<T>::type::executor_type>
+      >::other(ASIO_MOVE_CAST(T)(object));
+  }
+};
+
+/// A special value, similar to std::nothrow.
+/**
+ * See the documentation for asio::detached_t for a usage example.
+ */
+#if defined(ASIO_HAS_CONSTEXPR) || defined(GENERATING_DOCUMENTATION)
+constexpr detached_t detached;
+#elif defined(ASIO_MSVC)
+__declspec(selectany) detached_t detached;
+#endif
+
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#include "asio/impl/detached.hpp"
+
+#endif // ASIO_DETACHED_HPP

lib/asio/include/asio/detail/array.hpp

@@ -0,0 +1,38 @@
+//
+// detail/array.hpp
+// ~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_ARRAY_HPP
+#define ASIO_DETAIL_ARRAY_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_HAS_STD_ARRAY)
+# include <array>
+#else // defined(ASIO_HAS_STD_ARRAY)
+# include <boost/array.hpp>
+#endif // defined(ASIO_HAS_STD_ARRAY)
+
+namespace asio {
+namespace detail {
+
+#if defined(ASIO_HAS_STD_ARRAY)
+using std::array;
+#else // defined(ASIO_HAS_STD_ARRAY)
+using boost::array;
+#endif // defined(ASIO_HAS_STD_ARRAY)
+
+} // namespace detail
+} // namespace asio
+
+#endif // ASIO_DETAIL_ARRAY_HPP

lib/asio/include/asio/detail/array_fwd.hpp

@@ -0,0 +1,34 @@
+//
+// detail/array_fwd.hpp
+// ~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_ARRAY_FWD_HPP
+#define ASIO_DETAIL_ARRAY_FWD_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+namespace boost {
+
+template<class T, std::size_t N>
+class array;
+
+} // namespace boost
+
+// Standard library components can't be forward declared, so we'll have to
+// include the array header. Fortunately, it's fairly lightweight and doesn't
+// add significantly to the compile time.
+#if defined(ASIO_HAS_STD_ARRAY)
+# include <array>
+#endif // defined(ASIO_HAS_STD_ARRAY)
+
+#endif // ASIO_DETAIL_ARRAY_FWD_HPP

lib/asio/include/asio/detail/assert.hpp

@@ -0,0 +1,32 @@
+//
+// detail/assert.hpp
+// ~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_ASSERT_HPP
+#define ASIO_DETAIL_ASSERT_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_HAS_BOOST_ASSERT)
+# include <boost/assert.hpp>
+#else // defined(ASIO_HAS_BOOST_ASSERT)
+# include <cassert>
+#endif // defined(ASIO_HAS_BOOST_ASSERT)
+
+#if defined(ASIO_HAS_BOOST_ASSERT)
+# define ASIO_ASSERT(expr) BOOST_ASSERT(expr)
+#else // defined(ASIO_HAS_BOOST_ASSERT)
+# define ASIO_ASSERT(expr) assert(expr)
+#endif // defined(ASIO_HAS_BOOST_ASSERT)
+
+#endif // ASIO_DETAIL_ASSERT_HPP

lib/asio/include/asio/detail/atomic_count.hpp

@@ -0,0 +1,67 @@
+//
+// detail/atomic_count.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_ATOMIC_COUNT_HPP
+#define ASIO_DETAIL_ATOMIC_COUNT_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if !defined(ASIO_HAS_THREADS)
+// Nothing to include.
+#elif defined(ASIO_HAS_STD_ATOMIC)
+# include <atomic>
+#else // defined(ASIO_HAS_STD_ATOMIC)
+# include <boost/detail/atomic_count.hpp>
+#endif // defined(ASIO_HAS_STD_ATOMIC)
+
+namespace asio {
+namespace detail {
+
+#if !defined(ASIO_HAS_THREADS)
+typedef long atomic_count;
+inline void increment(atomic_count& a, long b) { a += b; }
+inline void decrement(atomic_count& a, long b) { a -= b; }
+inline void ref_count_up(atomic_count& a) { ++a; }
+inline bool ref_count_down(atomic_count& a) { return --a == 0; }
+#elif defined(ASIO_HAS_STD_ATOMIC)
+typedef std::atomic<long> atomic_count;
+inline void increment(atomic_count& a, long b) { a += b; }
+inline void decrement(atomic_count& a, long b) { a -= b; }
+
+inline void ref_count_up(atomic_count& a)
+{
+  a.fetch_add(1, std::memory_order_relaxed);
+}
+
+inline bool ref_count_down(atomic_count& a)
+{
+  if (a.fetch_sub(1, std::memory_order_release) == 1)
+  {
+    std::atomic_thread_fence(std::memory_order_acquire);
+    return true;
+  }
+  return false;
+}
+#else // defined(ASIO_HAS_STD_ATOMIC)
+typedef boost::detail::atomic_count atomic_count;
+inline void increment(atomic_count& a, long b) { while (b > 0) ++a, --b; }
+inline void decrement(atomic_count& a, long b) { while (b > 0) --a, --b; }
+inline void ref_count_up(atomic_count& a) { ++a; }
+inline bool ref_count_down(atomic_count& a) { return --a == 0; }
+#endif // defined(ASIO_HAS_STD_ATOMIC)
+
+} // namespace detail
+} // namespace asio
+
+#endif // ASIO_DETAIL_ATOMIC_COUNT_HPP

lib/asio/include/asio/detail/base_from_cancellation_state.hpp

@@ -0,0 +1,163 @@
+//
+// detail/base_from_cancellation_state.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_BASE_FROM_CANCELLATION_STATE_HPP
+#define ASIO_DETAIL_BASE_FROM_CANCELLATION_STATE_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+#include "asio/associated_cancellation_slot.hpp"
+#include "asio/cancellation_state.hpp"
+#include "asio/detail/type_traits.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+template <typename Handler, typename = void>
+class base_from_cancellation_state
+{
+public:
+  typedef cancellation_slot cancellation_slot_type;
+
+  cancellation_slot_type get_cancellation_slot() const ASIO_NOEXCEPT
+  {
+    return cancellation_state_.slot();
+  }
+
+  cancellation_state get_cancellation_state() const ASIO_NOEXCEPT
+  {
+    return cancellation_state_;
+  }
+
+protected:
+  explicit base_from_cancellation_state(const Handler& handler)
+    : cancellation_state_(
+        asio::get_associated_cancellation_slot(handler))
+  {
+  }
+
+  template <typename Filter>
+  base_from_cancellation_state(const Handler& handler, Filter filter)
+    : cancellation_state_(
+        asio::get_associated_cancellation_slot(handler), filter, filter)
+  {
+  }
+
+  template <typename InFilter, typename OutFilter>
+  base_from_cancellation_state(const Handler& handler,
+      ASIO_MOVE_ARG(InFilter) in_filter,
+      ASIO_MOVE_ARG(OutFilter) out_filter)
+    : cancellation_state_(
+        asio::get_associated_cancellation_slot(handler),
+        ASIO_MOVE_CAST(InFilter)(in_filter),
+        ASIO_MOVE_CAST(OutFilter)(out_filter))
+  {
+  }
+
+  void reset_cancellation_state(const Handler& handler)
+  {
+    cancellation_state_ = cancellation_state(
+        asio::get_associated_cancellation_slot(handler));
+  }
+
+  template <typename Filter>
+  void reset_cancellation_state(const Handler& handler, Filter filter)
+  {
+    cancellation_state_ = cancellation_state(
+        asio::get_associated_cancellation_slot(handler), filter, filter);
+  }
+
+  template <typename InFilter, typename OutFilter>
+  void reset_cancellation_state(const Handler& handler,
+      ASIO_MOVE_ARG(InFilter) in_filter,
+      ASIO_MOVE_ARG(OutFilter) out_filter)
+  {
+    cancellation_state_ = cancellation_state(
+        asio::get_associated_cancellation_slot(handler),
+        ASIO_MOVE_CAST(InFilter)(in_filter),
+        ASIO_MOVE_CAST(OutFilter)(out_filter));
+  }
+
+  cancellation_type_t cancelled() const ASIO_NOEXCEPT
+  {
+    return cancellation_state_.cancelled();
+  }
+
+private:
+  cancellation_state cancellation_state_;
+};
+
+template <typename Handler>
+class base_from_cancellation_state<Handler,
+    typename enable_if<
+      is_same<
+        typename associated_cancellation_slot<
+          Handler, cancellation_slot
+        >::asio_associated_cancellation_slot_is_unspecialised,
+        void
+      >::value
+    >::type>
+{
+public:
+  cancellation_state get_cancellation_state() const ASIO_NOEXCEPT
+  {
+    return cancellation_state();
+  }
+
+protected:
+  explicit base_from_cancellation_state(const Handler&)
+  {
+  }
+
+  template <typename Filter>
+  base_from_cancellation_state(const Handler&, Filter)
+  {
+  }
+
+  template <typename InFilter, typename OutFilter>
+  base_from_cancellation_state(const Handler&,
+      ASIO_MOVE_ARG(InFilter),
+      ASIO_MOVE_ARG(OutFilter))
+  {
+  }
+
+  void reset_cancellation_state(const Handler&)
+  {
+  }
+
+  template <typename Filter>
+  void reset_cancellation_state(const Handler&, Filter)
+  {
+  }
+
+  template <typename InFilter, typename OutFilter>
+  void reset_cancellation_state(const Handler&,
+      ASIO_MOVE_ARG(InFilter),
+      ASIO_MOVE_ARG(OutFilter))
+  {
+  }
+
+  ASIO_CONSTEXPR cancellation_type_t cancelled() const ASIO_NOEXCEPT
+  {
+    return cancellation_type::none;
+  }
+};
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // ASIO_DETAIL_BASE_FROM_CANCELLATION_STATE_HPP

lib/asio/include/asio/detail/base_from_completion_cond.hpp

@@ -0,0 +1,69 @@
+//
+// detail/base_from_completion_cond.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_BASE_FROM_COMPLETION_COND_HPP
+#define ASIO_DETAIL_BASE_FROM_COMPLETION_COND_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+#include "asio/completion_condition.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+template <typename CompletionCondition>
+class base_from_completion_cond
+{
+protected:
+  explicit base_from_completion_cond(CompletionCondition& completion_condition)
+    : completion_condition_(
+        ASIO_MOVE_CAST(CompletionCondition)(completion_condition))
+  {
+  }
+
+  std::size_t check_for_completion(
+      const asio::error_code& ec,
+      std::size_t total_transferred)
+  {
+    return detail::adapt_completion_condition_result(
+        completion_condition_(ec, total_transferred));
+  }
+
+private:
+  CompletionCondition completion_condition_;
+};
+
+template <>
+class base_from_completion_cond<transfer_all_t>
+{
+protected:
+  explicit base_from_completion_cond(transfer_all_t)
+  {
+  }
+
+  static std::size_t check_for_completion(
+      const asio::error_code& ec,
+      std::size_t total_transferred)
+  {
+    return transfer_all_t()(ec, total_transferred);
+  }
+};
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // ASIO_DETAIL_BASE_FROM_COMPLETION_COND_HPP

lib/asio/include/asio/detail/blocking_executor_op.hpp

@@ -0,0 +1,107 @@
+//
+// detail/blocking_executor_op.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_BLOCKING_EXECUTOR_OP_HPP
+#define ASIO_DETAIL_BLOCKING_EXECUTOR_OP_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+#include "asio/detail/event.hpp"
+#include "asio/detail/fenced_block.hpp"
+#include "asio/detail/handler_invoke_helpers.hpp"
+#include "asio/detail/mutex.hpp"
+#include "asio/detail/scheduler_operation.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+template <typename Operation = scheduler_operation>
+class blocking_executor_op_base : public Operation
+{
+public:
+  blocking_executor_op_base(typename Operation::func_type complete_func)
+    : Operation(complete_func),
+      is_complete_(false)
+  {
+  }
+
+  void wait()
+  {
+    asio::detail::mutex::scoped_lock lock(mutex_);
+    while (!is_complete_)
+      event_.wait(lock);
+  }
+
+protected:
+  struct do_complete_cleanup
+  {
+    ~do_complete_cleanup()
+    {
+      asio::detail::mutex::scoped_lock lock(op_->mutex_);
+      op_->is_complete_ = true;
+      op_->event_.unlock_and_signal_one_for_destruction(lock);
+    }
+
+    blocking_executor_op_base* op_;
+  };
+
+private:
+  asio::detail::mutex mutex_;
+  asio::detail::event event_;
+  bool is_complete_;
+};
+
+template <typename Handler, typename Operation = scheduler_operation>
+class blocking_executor_op : public blocking_executor_op_base<Operation>
+{
+public:
+  blocking_executor_op(Handler& h)
+    : blocking_executor_op_base<Operation>(&blocking_executor_op::do_complete),
+      handler_(h)
+  {
+  }
+
+  static void do_complete(void* owner, Operation* base,
+      const asio::error_code& /*ec*/,
+      std::size_t /*bytes_transferred*/)
+  {
+    blocking_executor_op* o(static_cast<blocking_executor_op*>(base));
+
+    typename blocking_executor_op_base<Operation>::do_complete_cleanup
+      on_exit = { o };
+    (void)on_exit;
+
+    ASIO_HANDLER_COMPLETION((*o));
+
+    // Make the upcall if required.
+    if (owner)
+    {
+      fenced_block b(fenced_block::half);
+      ASIO_HANDLER_INVOCATION_BEGIN(());
+      asio_handler_invoke_helpers::invoke(o->handler_, o->handler_);
+      ASIO_HANDLER_INVOCATION_END;
+    }
+  }
+
+private:
+  Handler& handler_;
+};
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // ASIO_DETAIL_BLOCKING_EXECUTOR_OP_HPP

lib/asio/include/asio/detail/buffer_resize_guard.hpp

@@ -0,0 +1,66 @@
+//
+// detail/buffer_resize_guard.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_BUFFER_RESIZE_GUARD_HPP
+#define ASIO_DETAIL_BUFFER_RESIZE_GUARD_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+#include "asio/detail/limits.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+// Helper class to manage buffer resizing in an exception safe way.
+template <typename Buffer>
+class buffer_resize_guard
+{
+public:
+  // Constructor.
+  buffer_resize_guard(Buffer& buffer)
+    : buffer_(buffer),
+      old_size_(buffer.size())
+  {
+  }
+
+  // Destructor rolls back the buffer resize unless commit was called.
+  ~buffer_resize_guard()
+  {
+    if (old_size_ != (std::numeric_limits<size_t>::max)())
+    {
+      buffer_.resize(old_size_);
+    }
+  }
+
+  // Commit the resize transaction.
+  void commit()
+  {
+    old_size_ = (std::numeric_limits<size_t>::max)();
+  }
+
+private:
+  // The buffer being managed.
+  Buffer& buffer_;
+
+  // The size of the buffer at the time the guard was constructed.
+  size_t old_size_;
+};
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // ASIO_DETAIL_BUFFER_RESIZE_GUARD_HPP

lib/asio/include/asio/detail/buffer_sequence_adapter.hpp

@@ -0,0 +1,841 @@
+//
+// detail/buffer_sequence_adapter.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_BUFFER_SEQUENCE_ADAPTER_HPP
+#define ASIO_DETAIL_BUFFER_SEQUENCE_ADAPTER_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+#include "asio/buffer.hpp"
+#include "asio/detail/array_fwd.hpp"
+#include "asio/detail/socket_types.hpp"
+#include "asio/registered_buffer.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+class buffer_sequence_adapter_base
+{
+#if defined(ASIO_WINDOWS_RUNTIME)
+public:
+  // The maximum number of buffers to support in a single operation.
+  enum { max_buffers = 1 };
+
+protected:
+  typedef Windows::Storage::Streams::IBuffer^ native_buffer_type;
+
+  ASIO_DECL static void init_native_buffer(
+      native_buffer_type& buf,
+      const asio::mutable_buffer& buffer);
+
+  ASIO_DECL static void init_native_buffer(
+      native_buffer_type& buf,
+      const asio::const_buffer& buffer);
+#elif defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+public:
+  // The maximum number of buffers to support in a single operation.
+  enum { max_buffers = 64 < max_iov_len ? 64 : max_iov_len };
+
+protected:
+  typedef WSABUF native_buffer_type;
+
+  static void init_native_buffer(WSABUF& buf,
+      const asio::mutable_buffer& buffer)
+  {
+    buf.buf = static_cast<char*>(buffer.data());
+    buf.len = static_cast<ULONG>(buffer.size());
+  }
+
+  static void init_native_buffer(WSABUF& buf,
+      const asio::const_buffer& buffer)
+  {
+    buf.buf = const_cast<char*>(static_cast<const char*>(buffer.data()));
+    buf.len = static_cast<ULONG>(buffer.size());
+  }
+#else // defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+public:
+  // The maximum number of buffers to support in a single operation.
+  enum { max_buffers = 64 < max_iov_len ? 64 : max_iov_len };
+
+protected:
+  typedef iovec native_buffer_type;
+
+  static void init_iov_base(void*& base, void* addr)
+  {
+    base = addr;
+  }
+
+  template <typename T>
+  static void init_iov_base(T& base, void* addr)
+  {
+    base = static_cast<T>(addr);
+  }
+
+  static void init_native_buffer(iovec& iov,
+      const asio::mutable_buffer& buffer)
+  {
+    init_iov_base(iov.iov_base, buffer.data());
+    iov.iov_len = buffer.size();
+  }
+
+  static void init_native_buffer(iovec& iov,
+      const asio::const_buffer& buffer)
+  {
+    init_iov_base(iov.iov_base, const_cast<void*>(buffer.data()));
+    iov.iov_len = buffer.size();
+  }
+#endif // defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+};
+
+// Helper class to translate buffers into the native buffer representation.
+template <typename Buffer, typename Buffers>
+class buffer_sequence_adapter
+  : buffer_sequence_adapter_base
+{
+public:
+  enum { is_single_buffer = false };
+  enum { is_registered_buffer = false };
+
+  explicit buffer_sequence_adapter(const Buffers& buffer_sequence)
+    : count_(0), total_buffer_size_(0)
+  {
+    buffer_sequence_adapter::init(
+        asio::buffer_sequence_begin(buffer_sequence),
+        asio::buffer_sequence_end(buffer_sequence));
+  }
+
+  native_buffer_type* buffers()
+  {
+    return buffers_;
+  }
+
+  std::size_t count() const
+  {
+    return count_;
+  }
+
+  std::size_t total_size() const
+  {
+    return total_buffer_size_;
+  }
+
+  registered_buffer_id registered_id() const
+  {
+    return registered_buffer_id();
+  }
+
+  bool all_empty() const
+  {
+    return total_buffer_size_ == 0;
+  }
+
+  static bool all_empty(const Buffers& buffer_sequence)
+  {
+    return buffer_sequence_adapter::all_empty(
+        asio::buffer_sequence_begin(buffer_sequence),
+        asio::buffer_sequence_end(buffer_sequence));
+  }
+
+  static void validate(const Buffers& buffer_sequence)
+  {
+    buffer_sequence_adapter::validate(
+        asio::buffer_sequence_begin(buffer_sequence),
+        asio::buffer_sequence_end(buffer_sequence));
+  }
+
+  static Buffer first(const Buffers& buffer_sequence)
+  {
+    return buffer_sequence_adapter::first(
+        asio::buffer_sequence_begin(buffer_sequence),
+        asio::buffer_sequence_end(buffer_sequence));
+  }
+
+  enum { linearisation_storage_size = 8192 };
+
+  static Buffer linearise(const Buffers& buffer_sequence,
+      const asio::mutable_buffer& storage)
+  {
+    return buffer_sequence_adapter::linearise(
+        asio::buffer_sequence_begin(buffer_sequence),
+        asio::buffer_sequence_end(buffer_sequence), storage);
+  }
+
+private:
+  template <typename Iterator>
+  void init(Iterator begin, Iterator end)
+  {
+    Iterator iter = begin;
+    for (; iter != end && count_ < max_buffers; ++iter, ++count_)
+    {
+      Buffer buffer(*iter);
+      init_native_buffer(buffers_[count_], buffer);
+      total_buffer_size_ += buffer.size();
+    }
+  }
+
+  template <typename Iterator>
+  static bool all_empty(Iterator begin, Iterator end)
+  {
+    Iterator iter = begin;
+    std::size_t i = 0;
+    for (; iter != end && i < max_buffers; ++iter, ++i)
+      if (Buffer(*iter).size() > 0)
+        return false;
+    return true;
+  }
+
+  template <typename Iterator>
+  static void validate(Iterator begin, Iterator end)
+  {
+    Iterator iter = begin;
+    for (; iter != end; ++iter)
+    {
+      Buffer buffer(*iter);
+      buffer.data();
+    }
+  }
+
+  template <typename Iterator>
+  static Buffer first(Iterator begin, Iterator end)
+  {
+    Iterator iter = begin;
+    for (; iter != end; ++iter)
+    {
+      Buffer buffer(*iter);
+      if (buffer.size() != 0)
+        return buffer;
+    }
+    return Buffer();
+  }
+
+  template <typename Iterator>
+  static Buffer linearise(Iterator begin, Iterator end,
+      const asio::mutable_buffer& storage)
+  {
+    asio::mutable_buffer unused_storage = storage;
+    Iterator iter = begin;
+    while (iter != end && unused_storage.size() != 0)
+    {
+      Buffer buffer(*iter);
+      ++iter;
+      if (buffer.size() == 0)
+        continue;
+      if (unused_storage.size() == storage.size())
+      {
+        if (iter == end)
+          return buffer;
+        if (buffer.size() >= unused_storage.size())
+          return buffer;
+      }
+      unused_storage += asio::buffer_copy(unused_storage, buffer);
+    }
+    return Buffer(storage.data(), storage.size() - unused_storage.size());
+  }
+
+  native_buffer_type buffers_[max_buffers];
+  std::size_t count_;
+  std::size_t total_buffer_size_;
+};
+
+template <typename Buffer>
+class buffer_sequence_adapter<Buffer, asio::mutable_buffer>
+  : buffer_sequence_adapter_base
+{
+public:
+  enum { is_single_buffer = true };
+  enum { is_registered_buffer = false };
+
+  explicit buffer_sequence_adapter(
+      const asio::mutable_buffer& buffer_sequence)
+  {
+    init_native_buffer(buffer_, Buffer(buffer_sequence));
+    total_buffer_size_ = buffer_sequence.size();
+  }
+
+  native_buffer_type* buffers()
+  {
+    return &buffer_;
+  }
+
+  std::size_t count() const
+  {
+    return 1;
+  }
+
+  std::size_t total_size() const
+  {
+    return total_buffer_size_;
+  }
+
+  registered_buffer_id registered_id() const
+  {
+    return registered_buffer_id();
+  }
+
+  bool all_empty() const
+  {
+    return total_buffer_size_ == 0;
+  }
+
+  static bool all_empty(const asio::mutable_buffer& buffer_sequence)
+  {
+    return buffer_sequence.size() == 0;
+  }
+
+  static void validate(const asio::mutable_buffer& buffer_sequence)
+  {
+    buffer_sequence.data();
+  }
+
+  static Buffer first(const asio::mutable_buffer& buffer_sequence)
+  {
+    return Buffer(buffer_sequence);
+  }
+
+  enum { linearisation_storage_size = 1 };
+
+  static Buffer linearise(const asio::mutable_buffer& buffer_sequence,
+      const Buffer&)
+  {
+    return Buffer(buffer_sequence);
+  }
+
+private:
+  native_buffer_type buffer_;
+  std::size_t total_buffer_size_;
+};
+
+template <typename Buffer>
+class buffer_sequence_adapter<Buffer, asio::const_buffer>
+  : buffer_sequence_adapter_base
+{
+public:
+  enum { is_single_buffer = true };
+  enum { is_registered_buffer = false };
+
+  explicit buffer_sequence_adapter(
+      const asio::const_buffer& buffer_sequence)
+  {
+    init_native_buffer(buffer_, Buffer(buffer_sequence));
+    total_buffer_size_ = buffer_sequence.size();
+  }
+
+  native_buffer_type* buffers()
+  {
+    return &buffer_;
+  }
+
+  std::size_t count() const
+  {
+    return 1;
+  }
+
+  std::size_t total_size() const
+  {
+    return total_buffer_size_;
+  }
+
+  registered_buffer_id registered_id() const
+  {
+    return registered_buffer_id();
+  }
+
+  bool all_empty() const
+  {
+    return total_buffer_size_ == 0;
+  }
+
+  static bool all_empty(const asio::const_buffer& buffer_sequence)
+  {
+    return buffer_sequence.size() == 0;
+  }
+
+  static void validate(const asio::const_buffer& buffer_sequence)
+  {
+    buffer_sequence.data();
+  }
+
+  static Buffer first(const asio::const_buffer& buffer_sequence)
+  {
+    return Buffer(buffer_sequence);
+  }
+
+  enum { linearisation_storage_size = 1 };
+
+  static Buffer linearise(const asio::const_buffer& buffer_sequence,
+      const Buffer&)
+  {
+    return Buffer(buffer_sequence);
+  }
+
+private:
+  native_buffer_type buffer_;
+  std::size_t total_buffer_size_;
+};
+
+#if !defined(ASIO_NO_DEPRECATED)
+
+template <typename Buffer>
+class buffer_sequence_adapter<Buffer, asio::mutable_buffers_1>
+  : buffer_sequence_adapter_base
+{
+public:
+  enum { is_single_buffer = true };
+  enum { is_registered_buffer = false };
+
+  explicit buffer_sequence_adapter(
+      const asio::mutable_buffers_1& buffer_sequence)
+  {
+    init_native_buffer(buffer_, Buffer(buffer_sequence));
+    total_buffer_size_ = buffer_sequence.size();
+  }
+
+  native_buffer_type* buffers()
+  {
+    return &buffer_;
+  }
+
+  std::size_t count() const
+  {
+    return 1;
+  }
+
+  std::size_t total_size() const
+  {
+    return total_buffer_size_;
+  }
+
+  registered_buffer_id registered_id() const
+  {
+    return registered_buffer_id();
+  }
+
+  bool all_empty() const
+  {
+    return total_buffer_size_ == 0;
+  }
+
+  static bool all_empty(const asio::mutable_buffers_1& buffer_sequence)
+  {
+    return buffer_sequence.size() == 0;
+  }
+
+  static void validate(const asio::mutable_buffers_1& buffer_sequence)
+  {
+    buffer_sequence.data();
+  }
+
+  static Buffer first(const asio::mutable_buffers_1& buffer_sequence)
+  {
+    return Buffer(buffer_sequence);
+  }
+
+  enum { linearisation_storage_size = 1 };
+
+  static Buffer linearise(const asio::mutable_buffers_1& buffer_sequence,
+      const Buffer&)
+  {
+    return Buffer(buffer_sequence);
+  }
+
+private:
+  native_buffer_type buffer_;
+  std::size_t total_buffer_size_;
+};
+
+template <typename Buffer>
+class buffer_sequence_adapter<Buffer, asio::const_buffers_1>
+  : buffer_sequence_adapter_base
+{
+public:
+  enum { is_single_buffer = true };
+  enum { is_registered_buffer = false };
+
+  explicit buffer_sequence_adapter(
+      const asio::const_buffers_1& buffer_sequence)
+  {
+    init_native_buffer(buffer_, Buffer(buffer_sequence));
+    total_buffer_size_ = buffer_sequence.size();
+  }
+
+  native_buffer_type* buffers()
+  {
+    return &buffer_;
+  }
+
+  std::size_t count() const
+  {
+    return 1;
+  }
+
+  std::size_t total_size() const
+  {
+    return total_buffer_size_;
+  }
+
+  registered_buffer_id registered_id() const
+  {
+    return registered_buffer_id();
+  }
+
+  bool all_empty() const
+  {
+    return total_buffer_size_ == 0;
+  }
+
+  static bool all_empty(const asio::const_buffers_1& buffer_sequence)
+  {
+    return buffer_sequence.size() == 0;
+  }
+
+  static void validate(const asio::const_buffers_1& buffer_sequence)
+  {
+    buffer_sequence.data();
+  }
+
+  static Buffer first(const asio::const_buffers_1& buffer_sequence)
+  {
+    return Buffer(buffer_sequence);
+  }
+
+  enum { linearisation_storage_size = 1 };
+
+  static Buffer linearise(const asio::const_buffers_1& buffer_sequence,
+      const Buffer&)
+  {
+    return Buffer(buffer_sequence);
+  }
+
+private:
+  native_buffer_type buffer_;
+  std::size_t total_buffer_size_;
+};
+
+#endif // !defined(ASIO_NO_DEPRECATED)
+
+template <typename Buffer>
+class buffer_sequence_adapter<Buffer, asio::mutable_registered_buffer>
+  : buffer_sequence_adapter_base
+{
+public:
+  enum { is_single_buffer = true };
+  enum { is_registered_buffer = true };
+
+  explicit buffer_sequence_adapter(
+      const asio::mutable_registered_buffer& buffer_sequence)
+  {
+    init_native_buffer(buffer_, buffer_sequence.buffer());
+    total_buffer_size_ = buffer_sequence.size();
+    registered_id_ = buffer_sequence.id();
+  }
+
+  native_buffer_type* buffers()
+  {
+    return &buffer_;
+  }
+
+  std::size_t count() const
+  {
+    return 1;
+  }
+
+  std::size_t total_size() const
+  {
+    return total_buffer_size_;
+  }
+
+  registered_buffer_id registered_id() const
+  {
+    return registered_id_;
+  }
+
+  bool all_empty() const
+  {
+    return total_buffer_size_ == 0;
+  }
+
+  static bool all_empty(
+      const asio::mutable_registered_buffer& buffer_sequence)
+  {
+    return buffer_sequence.size() == 0;
+  }
+
+  static void validate(
+      const asio::mutable_registered_buffer& buffer_sequence)
+  {
+    buffer_sequence.data();
+  }
+
+  static Buffer first(
+      const asio::mutable_registered_buffer& buffer_sequence)
+  {
+    return Buffer(buffer_sequence.buffer());
+  }
+
+  enum { linearisation_storage_size = 1 };
+
+  static Buffer linearise(
+      const asio::mutable_registered_buffer& buffer_sequence,
+      const Buffer&)
+  {
+    return Buffer(buffer_sequence.buffer());
+  }
+
+private:
+  native_buffer_type buffer_;
+  std::size_t total_buffer_size_;
+  registered_buffer_id registered_id_;
+};
+
+template <typename Buffer>
+class buffer_sequence_adapter<Buffer, asio::const_registered_buffer>
+  : buffer_sequence_adapter_base
+{
+public:
+  enum { is_single_buffer = true };
+  enum { is_registered_buffer = true };
+
+  explicit buffer_sequence_adapter(
+      const asio::const_registered_buffer& buffer_sequence)
+  {
+    init_native_buffer(buffer_, buffer_sequence.buffer());
+    total_buffer_size_ = buffer_sequence.size();
+    registered_id_ = buffer_sequence.id();
+  }
+
+  native_buffer_type* buffers()
+  {
+    return &buffer_;
+  }
+
+  std::size_t count() const
+  {
+    return 1;
+  }
+
+  std::size_t total_size() const
+  {
+    return total_buffer_size_;
+  }
+
+  registered_buffer_id registered_id() const
+  {
+    return registered_id_;
+  }
+
+  bool all_empty() const
+  {
+    return total_buffer_size_ == 0;
+  }
+
+  static bool all_empty(
+      const asio::const_registered_buffer& buffer_sequence)
+  {
+    return buffer_sequence.size() == 0;
+  }
+
+  static void validate(
+      const asio::const_registered_buffer& buffer_sequence)
+  {
+    buffer_sequence.data();
+  }
+
+  static Buffer first(
+      const asio::const_registered_buffer& buffer_sequence)
+  {
+    return Buffer(buffer_sequence.buffer());
+  }
+
+  enum { linearisation_storage_size = 1 };
+
+  static Buffer linearise(
+      const asio::const_registered_buffer& buffer_sequence,
+      const Buffer&)
+  {
+    return Buffer(buffer_sequence.buffer());
+  }
+
+private:
+  native_buffer_type buffer_;
+  std::size_t total_buffer_size_;
+  registered_buffer_id registered_id_;
+};
+
+template <typename Buffer, typename Elem>
+class buffer_sequence_adapter<Buffer, boost::array<Elem, 2> >
+  : buffer_sequence_adapter_base
+{
+public:
+  enum { is_single_buffer = false };
+  enum { is_registered_buffer = false };
+
+  explicit buffer_sequence_adapter(
+      const boost::array<Elem, 2>& buffer_sequence)
+  {
+    init_native_buffer(buffers_[0], Buffer(buffer_sequence[0]));
+    init_native_buffer(buffers_[1], Buffer(buffer_sequence[1]));
+    total_buffer_size_ = buffer_sequence[0].size() + buffer_sequence[1].size();
+  }
+
+  native_buffer_type* buffers()
+  {
+    return buffers_;
+  }
+
+  std::size_t count() const
+  {
+    return 2;
+  }
+
+  std::size_t total_size() const
+  {
+    return total_buffer_size_;
+  }
+
+  registered_buffer_id registered_id() const
+  {
+    return registered_buffer_id();
+  }
+
+  bool all_empty() const
+  {
+    return total_buffer_size_ == 0;
+  }
+
+  static bool all_empty(const boost::array<Elem, 2>& buffer_sequence)
+  {
+    return buffer_sequence[0].size() == 0 && buffer_sequence[1].size() == 0;
+  }
+
+  static void validate(const boost::array<Elem, 2>& buffer_sequence)
+  {
+    buffer_sequence[0].data();
+    buffer_sequence[1].data();
+  }
+
+  static Buffer first(const boost::array<Elem, 2>& buffer_sequence)
+  {
+    return Buffer(buffer_sequence[0].size() != 0
+        ? buffer_sequence[0] : buffer_sequence[1]);
+  }
+
+  enum { linearisation_storage_size = 8192 };
+
+  static Buffer linearise(const boost::array<Elem, 2>& buffer_sequence,
+      const asio::mutable_buffer& storage)
+  {
+    if (buffer_sequence[0].size() == 0)
+      return Buffer(buffer_sequence[1]);
+    if (buffer_sequence[1].size() == 0)
+      return Buffer(buffer_sequence[0]);
+    return Buffer(storage.data(),
+        asio::buffer_copy(storage, buffer_sequence));
+  }
+
+private:
+  native_buffer_type buffers_[2];
+  std::size_t total_buffer_size_;
+};
+
+#if defined(ASIO_HAS_STD_ARRAY)
+
+template <typename Buffer, typename Elem>
+class buffer_sequence_adapter<Buffer, std::array<Elem, 2> >
+  : buffer_sequence_adapter_base
+{
+public:
+  enum { is_single_buffer = false };
+  enum { is_registered_buffer = false };
+
+  explicit buffer_sequence_adapter(
+      const std::array<Elem, 2>& buffer_sequence)
+  {
+    init_native_buffer(buffers_[0], Buffer(buffer_sequence[0]));
+    init_native_buffer(buffers_[1], Buffer(buffer_sequence[1]));
+    total_buffer_size_ = buffer_sequence[0].size() + buffer_sequence[1].size();
+  }
+
+  native_buffer_type* buffers()
+  {
+    return buffers_;
+  }
+
+  std::size_t count() const
+  {
+    return 2;
+  }
+
+  std::size_t total_size() const
+  {
+    return total_buffer_size_;
+  }
+
+  registered_buffer_id registered_id() const
+  {
+    return registered_buffer_id();
+  }
+
+  bool all_empty() const
+  {
+    return total_buffer_size_ == 0;
+  }
+
+  static bool all_empty(const std::array<Elem, 2>& buffer_sequence)
+  {
+    return buffer_sequence[0].size() == 0 && buffer_sequence[1].size() == 0;
+  }
+
+  static void validate(const std::array<Elem, 2>& buffer_sequence)
+  {
+    buffer_sequence[0].data();
+    buffer_sequence[1].data();
+  }
+
+  static Buffer first(const std::array<Elem, 2>& buffer_sequence)
+  {
+    return Buffer(buffer_sequence[0].size() != 0
+        ? buffer_sequence[0] : buffer_sequence[1]);
+  }
+
+  enum { linearisation_storage_size = 8192 };
+
+  static Buffer linearise(const std::array<Elem, 2>& buffer_sequence,
+      const asio::mutable_buffer& storage)
+  {
+    if (buffer_sequence[0].size() == 0)
+      return Buffer(buffer_sequence[1]);
+    if (buffer_sequence[1].size() == 0)
+      return Buffer(buffer_sequence[0]);
+    return Buffer(storage.data(),
+        asio::buffer_copy(storage, buffer_sequence));
+  }
+
+private:
+  native_buffer_type buffers_[2];
+  std::size_t total_buffer_size_;
+};
+
+#endif // defined(ASIO_HAS_STD_ARRAY)
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#if defined(ASIO_HEADER_ONLY)
+# include "asio/detail/impl/buffer_sequence_adapter.ipp"
+#endif // defined(ASIO_HEADER_ONLY)
+
+#endif // ASIO_DETAIL_BUFFER_SEQUENCE_ADAPTER_HPP

lib/asio/include/asio/detail/buffered_stream_storage.hpp

@@ -0,0 +1,126 @@
+//
+// detail/buffered_stream_storage.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_BUFFERED_STREAM_STORAGE_HPP
+#define ASIO_DETAIL_BUFFERED_STREAM_STORAGE_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+#include "asio/buffer.hpp"
+#include "asio/detail/assert.hpp"
+#include <cstddef>
+#include <cstring>
+#include <vector>
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+class buffered_stream_storage
+{
+public:
+  // The type of the bytes stored in the buffer.
+  typedef unsigned char byte_type;
+
+  // The type used for offsets into the buffer.
+  typedef std::size_t size_type;
+
+  // Constructor.
+  explicit buffered_stream_storage(std::size_t buffer_capacity)
+    : begin_offset_(0),
+      end_offset_(0),
+      buffer_(buffer_capacity)
+  {
+  }
+
+  /// Clear the buffer.
+  void clear()
+  {
+    begin_offset_ = 0;
+    end_offset_ = 0;
+  }
+
+  // Return a pointer to the beginning of the unread data.
+  mutable_buffer data()
+  {
+    return asio::buffer(buffer_) + begin_offset_;
+  }
+
+  // Return a pointer to the beginning of the unread data.
+  const_buffer data() const
+  {
+    return asio::buffer(buffer_) + begin_offset_;
+  }
+
+  // Is there no unread data in the buffer.
+  bool empty() const
+  {
+    return begin_offset_ == end_offset_;
+  }
+
+  // Return the amount of unread data the is in the buffer.
+  size_type size() const
+  {
+    return end_offset_ - begin_offset_;
+  }
+
+  // Resize the buffer to the specified length.
+  void resize(size_type length)
+  {
+    ASIO_ASSERT(length <= capacity());
+    if (begin_offset_ + length <= capacity())
+    {
+      end_offset_ = begin_offset_ + length;
+    }
+    else
+    {
+      using namespace std; // For memmove.
+      memmove(&buffer_[0], &buffer_[0] + begin_offset_, size());
+      end_offset_ = length;
+      begin_offset_ = 0;
+    }
+  }
+
+  // Return the maximum size for data in the buffer.
+  size_type capacity() const
+  {
+    return buffer_.size();
+  }
+
+  // Consume multiple bytes from the beginning of the buffer.
+  void consume(size_type count)
+  {
+    ASIO_ASSERT(begin_offset_ + count <= end_offset_);
+    begin_offset_ += count;
+    if (empty())
+      clear();
+  }
+
+private:
+  // The offset to the beginning of the unread data.
+  size_type begin_offset_;
+
+  // The offset to the end of the unread data.
+  size_type end_offset_;
+  
+  // The data in the buffer.
+  std::vector<byte_type> buffer_;
+};
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // ASIO_DETAIL_BUFFERED_STREAM_STORAGE_HPP

lib/asio/include/asio/detail/bulk_executor_op.hpp

@@ -0,0 +1,88 @@
+//
+// detail/bulk_executor_op.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_BULK_EXECUTOR_OP_HPP
+#define ASIO_DETAIL_BULK_EXECUTOR_OP_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+#include "asio/detail/bind_handler.hpp"
+#include "asio/detail/fenced_block.hpp"
+#include "asio/detail/handler_alloc_helpers.hpp"
+#include "asio/detail/handler_invoke_helpers.hpp"
+#include "asio/detail/scheduler_operation.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+template <typename Handler, typename Alloc,
+    typename Operation = scheduler_operation>
+class bulk_executor_op : public Operation
+{
+public:
+  ASIO_DEFINE_HANDLER_ALLOCATOR_PTR(bulk_executor_op);
+
+  template <typename H>
+  bulk_executor_op(ASIO_MOVE_ARG(H) h,
+      const Alloc& allocator, std::size_t i)
+    : Operation(&bulk_executor_op::do_complete),
+      handler_(ASIO_MOVE_CAST(H)(h)),
+      allocator_(allocator),
+      index_(i)
+  {
+  }
+
+  static void do_complete(void* owner, Operation* base,
+      const asio::error_code& /*ec*/,
+      std::size_t /*bytes_transferred*/)
+  {
+    // Take ownership of the handler object.
+    bulk_executor_op* o(static_cast<bulk_executor_op*>(base));
+    Alloc allocator(o->allocator_);
+    ptr p = { detail::addressof(allocator), o, o };
+
+    ASIO_HANDLER_COMPLETION((*o));
+
+    // Make a copy of the handler so that the memory can be deallocated before
+    // the upcall is made. Even if we're not about to make an upcall, a
+    // sub-object of the handler may be the true owner of the memory associated
+    // with the handler. Consequently, a local copy of the handler is required
+    // to ensure that any owning sub-object remains valid until after we have
+    // deallocated the memory here.
+    detail::binder1<Handler, std::size_t> handler(o->handler_, o->index_);
+    p.reset();
+
+    // Make the upcall if required.
+    if (owner)
+    {
+      fenced_block b(fenced_block::half);
+      ASIO_HANDLER_INVOCATION_BEGIN(());
+      asio_handler_invoke_helpers::invoke(handler, handler.handler_);
+      ASIO_HANDLER_INVOCATION_END;
+    }
+  }
+
+private:
+  Handler handler_;
+  Alloc allocator_;
+  std::size_t index_;
+};
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // ASIO_DETAIL_BULK_EXECUTOR_OP_HPP

lib/asio/include/asio/detail/call_stack.hpp

@@ -0,0 +1,125 @@
+//
+// detail/call_stack.hpp
+// ~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_CALL_STACK_HPP
+#define ASIO_DETAIL_CALL_STACK_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+#include "asio/detail/noncopyable.hpp"
+#include "asio/detail/tss_ptr.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+// Helper class to determine whether or not the current thread is inside an
+// invocation of io_context::run() for a specified io_context object.
+template <typename Key, typename Value = unsigned char>
+class call_stack
+{
+public:
+  // Context class automatically pushes the key/value pair on to the stack.
+  class context
+    : private noncopyable
+  {
+  public:
+    // Push the key on to the stack.
+    explicit context(Key* k)
+      : key_(k),
+        next_(call_stack<Key, Value>::top_)
+    {
+      value_ = reinterpret_cast<unsigned char*>(this);
+      call_stack<Key, Value>::top_ = this;
+    }
+
+    // Push the key/value pair on to the stack.
+    context(Key* k, Value& v)
+      : key_(k),
+        value_(&v),
+        next_(call_stack<Key, Value>::top_)
+    {
+      call_stack<Key, Value>::top_ = this;
+    }
+
+    // Pop the key/value pair from the stack.
+    ~context()
+    {
+      call_stack<Key, Value>::top_ = next_;
+    }
+
+    // Find the next context with the same key.
+    Value* next_by_key() const
+    {
+      context* elem = next_;
+      while (elem)
+      {
+        if (elem->key_ == key_)
+          return elem->value_;
+        elem = elem->next_;
+      }
+      return 0;
+    }
+
+  private:
+    friend class call_stack<Key, Value>;
+
+    // The key associated with the context.
+    Key* key_;
+
+    // The value associated with the context.
+    Value* value_;
+
+    // The next element in the stack.
+    context* next_;
+  };
+
+  friend class context;
+
+  // Determine whether the specified owner is on the stack. Returns address of
+  // key if present, 0 otherwise.
+  static Value* contains(Key* k)
+  {
+    context* elem = top_;
+    while (elem)
+    {
+      if (elem->key_ == k)
+        return elem->value_;
+      elem = elem->next_;
+    }
+    return 0;
+  }
+
+  // Obtain the value at the top of the stack.
+  static Value* top()
+  {
+    context* elem = top_;
+    return elem ? elem->value_ : 0;
+  }
+
+private:
+  // The top of the stack of calls for the current thread.
+  static tss_ptr<context> top_;
+};
+
+template <typename Key, typename Value>
+tss_ptr<typename call_stack<Key, Value>::context>
+call_stack<Key, Value>::top_;
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // ASIO_DETAIL_CALL_STACK_HPP

lib/asio/include/asio/detail/chrono.hpp

@@ -0,0 +1,66 @@
+//
+// detail/chrono.hpp
+// ~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_CHRONO_HPP
+#define ASIO_DETAIL_CHRONO_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_HAS_STD_CHRONO)
+# include <chrono>
+#elif defined(ASIO_HAS_BOOST_CHRONO)
+# include <boost/chrono/system_clocks.hpp>
+#endif // defined(ASIO_HAS_BOOST_CHRONO)
+
+namespace asio {
+namespace chrono {
+
+#if defined(ASIO_HAS_STD_CHRONO)
+using std::chrono::duration;
+using std::chrono::time_point;
+using std::chrono::duration_cast;
+using std::chrono::nanoseconds;
+using std::chrono::microseconds;
+using std::chrono::milliseconds;
+using std::chrono::seconds;
+using std::chrono::minutes;
+using std::chrono::hours;
+using std::chrono::time_point_cast;
+#if defined(ASIO_HAS_STD_CHRONO_MONOTONIC_CLOCK)
+typedef std::chrono::monotonic_clock steady_clock;
+#else // defined(ASIO_HAS_STD_CHRONO_MONOTONIC_CLOCK)
+using std::chrono::steady_clock;
+#endif // defined(ASIO_HAS_STD_CHRONO_MONOTONIC_CLOCK)
+using std::chrono::system_clock;
+using std::chrono::high_resolution_clock;
+#elif defined(ASIO_HAS_BOOST_CHRONO)
+using boost::chrono::duration;
+using boost::chrono::time_point;
+using boost::chrono::duration_cast;
+using boost::chrono::nanoseconds;
+using boost::chrono::microseconds;
+using boost::chrono::milliseconds;
+using boost::chrono::seconds;
+using boost::chrono::minutes;
+using boost::chrono::hours;
+using boost::chrono::time_point_cast;
+using boost::chrono::system_clock;
+using boost::chrono::steady_clock;
+using boost::chrono::high_resolution_clock;
+#endif // defined(ASIO_HAS_BOOST_CHRONO)
+
+} // namespace chrono
+} // namespace asio
+
+#endif // ASIO_DETAIL_CHRONO_HPP

lib/asio/include/asio/detail/chrono_time_traits.hpp

@@ -0,0 +1,190 @@
+//
+// detail/chrono_time_traits.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_CHRONO_TIME_TRAITS_HPP
+#define ASIO_DETAIL_CHRONO_TIME_TRAITS_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/cstdint.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+// Helper template to compute the greatest common divisor.
+template <int64_t v1, int64_t v2>
+struct gcd { enum { value = gcd<v2, v1 % v2>::value }; };
+
+template <int64_t v1>
+struct gcd<v1, 0> { enum { value = v1 }; };
+
+// Adapts std::chrono clocks for use with a deadline timer.
+template <typename Clock, typename WaitTraits>
+struct chrono_time_traits
+{
+  // The clock type.
+  typedef Clock clock_type;
+
+  // The duration type of the clock.
+  typedef typename clock_type::duration duration_type;
+
+  // The time point type of the clock.
+  typedef typename clock_type::time_point time_type;
+
+  // The period of the clock.
+  typedef typename duration_type::period period_type;
+
+  // Get the current time.
+  static time_type now()
+  {
+    return clock_type::now();
+  }
+
+  // Add a duration to a time.
+  static time_type add(const time_type& t, const duration_type& d)
+  {
+    const time_type epoch;
+    if (t >= epoch)
+    {
+      if ((time_type::max)() - t < d)
+        return (time_type::max)();
+    }
+    else // t < epoch
+    {
+      if (-(t - (time_type::min)()) > d)
+        return (time_type::min)();
+    }
+
+    return t + d;
+  }
+
+  // Subtract one time from another.
+  static duration_type subtract(const time_type& t1, const time_type& t2)
+  {
+    const time_type epoch;
+    if (t1 >= epoch)
+    {
+      if (t2 >= epoch)
+      {
+        return t1 - t2;
+      }
+      else if (t2 == (time_type::min)())
+      {
+        return (duration_type::max)();
+      }
+      else if ((time_type::max)() - t1 < epoch - t2)
+      {
+        return (duration_type::max)();
+      }
+      else
+      {
+        return t1 - t2;
+      }
+    }
+    else // t1 < epoch
+    {
+      if (t2 < epoch)
+      {
+        return t1 - t2;
+      }
+      else if (t1 == (time_type::min)())
+      {
+        return (duration_type::min)();
+      }
+      else if ((time_type::max)() - t2 < epoch - t1)
+      {
+        return (duration_type::min)();
+      }
+      else
+      {
+        return -(t2 - t1);
+      }
+    }
+  }
+
+  // Test whether one time is less than another.
+  static bool less_than(const time_type& t1, const time_type& t2)
+  {
+    return t1 < t2;
+  }
+
+  // Implement just enough of the posix_time::time_duration interface to supply
+  // what the timer_queue requires.
+  class posix_time_duration
+  {
+  public:
+    explicit posix_time_duration(const duration_type& d)
+      : d_(d)
+    {
+    }
+
+    int64_t ticks() const
+    {
+      return d_.count();
+    }
+
+    int64_t total_seconds() const
+    {
+      return duration_cast<1, 1>();
+    }
+
+    int64_t total_milliseconds() const
+    {
+      return duration_cast<1, 1000>();
+    }
+
+    int64_t total_microseconds() const
+    {
+      return duration_cast<1, 1000000>();
+    }
+
+  private:
+    template <int64_t Num, int64_t Den>
+    int64_t duration_cast() const
+    {
+      const int64_t num1 = period_type::num / gcd<period_type::num, Num>::value;
+      const int64_t num2 = Num / gcd<period_type::num, Num>::value;
+
+      const int64_t den1 = period_type::den / gcd<period_type::den, Den>::value;
+      const int64_t den2 = Den / gcd<period_type::den, Den>::value;
+
+      const int64_t num = num1 * den2;
+      const int64_t den = num2 * den1;
+
+      if (num == 1 && den == 1)
+        return ticks();
+      else if (num != 1 && den == 1)
+        return ticks() * num;
+      else if (num == 1 && period_type::den != 1)
+        return ticks() / den;
+      else
+        return ticks() * num / den;
+    }
+
+    duration_type d_;
+  };
+
+  // Convert to POSIX duration type.
+  static posix_time_duration to_posix_duration(const duration_type& d)
+  {
+    return posix_time_duration(WaitTraits::to_wait_duration(d));
+  }
+};
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // ASIO_DETAIL_CHRONO_TIME_TRAITS_HPP

lib/asio/include/asio/detail/completion_handler.hpp

@@ -0,0 +1,88 @@
+//
+// detail/completion_handler.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_COMPLETION_HANDLER_HPP
+#define ASIO_DETAIL_COMPLETION_HANDLER_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+#include "asio/detail/fenced_block.hpp"
+#include "asio/detail/handler_alloc_helpers.hpp"
+#include "asio/detail/handler_work.hpp"
+#include "asio/detail/memory.hpp"
+#include "asio/detail/operation.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+template <typename Handler, typename IoExecutor>
+class completion_handler : public operation
+{
+public:
+  ASIO_DEFINE_HANDLER_PTR(completion_handler);
+
+  completion_handler(Handler& h, const IoExecutor& io_ex)
+    : operation(&completion_handler::do_complete),
+      handler_(ASIO_MOVE_CAST(Handler)(h)),
+      work_(handler_, io_ex)
+  {
+  }
+
+  static void do_complete(void* owner, operation* base,
+      const asio::error_code& /*ec*/,
+      std::size_t /*bytes_transferred*/)
+  {
+    // Take ownership of the handler object.
+    completion_handler* h(static_cast<completion_handler*>(base));
+    ptr p = { asio::detail::addressof(h->handler_), h, h };
+
+    ASIO_HANDLER_COMPLETION((*h));
+
+    // Take ownership of the operation's outstanding work.
+    handler_work<Handler, IoExecutor> w(
+        ASIO_MOVE_CAST2(handler_work<Handler, IoExecutor>)(
+          h->work_));
+
+    // Make a copy of the handler so that the memory can be deallocated before
+    // the upcall is made. Even if we're not about to make an upcall, a
+    // sub-object of the handler may be the true owner of the memory associated
+    // with the handler. Consequently, a local copy of the handler is required
+    // to ensure that any owning sub-object remains valid until after we have
+    // deallocated the memory here.
+    Handler handler(ASIO_MOVE_CAST(Handler)(h->handler_));
+    p.h = asio::detail::addressof(handler);
+    p.reset();
+
+    // Make the upcall if required.
+    if (owner)
+    {
+      fenced_block b(fenced_block::half);
+      ASIO_HANDLER_INVOCATION_BEGIN(());
+      w.complete(handler, handler);
+      ASIO_HANDLER_INVOCATION_END;
+    }
+  }
+
+private:
+  Handler handler_;
+  handler_work<Handler, IoExecutor> work_;
+};
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // ASIO_DETAIL_COMPLETION_HANDLER_HPP

lib/asio/include/asio/detail/concurrency_hint.hpp

@@ -0,0 +1,94 @@
+//
+// detail/concurrency_hint.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_CONCURRENCY_HINT_HPP
+#define ASIO_DETAIL_CONCURRENCY_HINT_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+#include "asio/detail/noncopyable.hpp"
+
+// The concurrency hint ID and mask are used to identify when a "well-known"
+// concurrency hint value has been passed to the io_context.
+#define ASIO_CONCURRENCY_HINT_ID 0xA5100000u
+#define ASIO_CONCURRENCY_HINT_ID_MASK 0xFFFF0000u
+
+// If set, this bit indicates that the scheduler should perform locking.
+#define ASIO_CONCURRENCY_HINT_LOCKING_SCHEDULER 0x1u
+
+// If set, this bit indicates that the reactor should perform locking when
+// managing descriptor registrations.
+#define ASIO_CONCURRENCY_HINT_LOCKING_REACTOR_REGISTRATION 0x2u
+
+// If set, this bit indicates that the reactor should perform locking for I/O.
+#define ASIO_CONCURRENCY_HINT_LOCKING_REACTOR_IO 0x4u
+
+// Helper macro to determine if we have a special concurrency hint.
+#define ASIO_CONCURRENCY_HINT_IS_SPECIAL(hint) \
+  ((static_cast<unsigned>(hint) \
+    & ASIO_CONCURRENCY_HINT_ID_MASK) \
+      == ASIO_CONCURRENCY_HINT_ID)
+
+// Helper macro to determine if locking is enabled for a given facility.
+#define ASIO_CONCURRENCY_HINT_IS_LOCKING(facility, hint) \
+  (((static_cast<unsigned>(hint) \
+    & (ASIO_CONCURRENCY_HINT_ID_MASK \
+      | ASIO_CONCURRENCY_HINT_LOCKING_ ## facility)) \
+        ^ ASIO_CONCURRENCY_HINT_ID) != 0)
+
+// This special concurrency hint disables locking in both the scheduler and
+// reactor I/O. This hint has the following restrictions:
+//
+// - Care must be taken to ensure that all operations on the io_context and any
+//   of its associated I/O objects (such as sockets and timers) occur in only
+//   one thread at a time.
+//
+// - Asynchronous resolve operations fail with operation_not_supported.
+//
+// - If a signal_set is used with the io_context, signal_set objects cannot be
+//   used with any other io_context in the program.
+#define ASIO_CONCURRENCY_HINT_UNSAFE \
+  static_cast<int>(ASIO_CONCURRENCY_HINT_ID)
+
+// This special concurrency hint disables locking in the reactor I/O. This hint
+// has the following restrictions:
+//
+// - Care must be taken to ensure that run functions on the io_context, and all
+//   operations on the io_context's associated I/O objects (such as sockets and
+//   timers), occur in only one thread at a time.
+#define ASIO_CONCURRENCY_HINT_UNSAFE_IO \
+  static_cast<int>(ASIO_CONCURRENCY_HINT_ID \
+      | ASIO_CONCURRENCY_HINT_LOCKING_SCHEDULER \
+      | ASIO_CONCURRENCY_HINT_LOCKING_REACTOR_REGISTRATION)
+
+// The special concurrency hint provides full thread safety.
+#define ASIO_CONCURRENCY_HINT_SAFE \
+  static_cast<int>(ASIO_CONCURRENCY_HINT_ID \
+      | ASIO_CONCURRENCY_HINT_LOCKING_SCHEDULER \
+      | ASIO_CONCURRENCY_HINT_LOCKING_REACTOR_REGISTRATION \
+      | ASIO_CONCURRENCY_HINT_LOCKING_REACTOR_IO)
+
+// This #define may be overridden at compile time to specify a program-wide
+// default concurrency hint, used by the zero-argument io_context constructor.
+#if !defined(ASIO_CONCURRENCY_HINT_DEFAULT)
+# define ASIO_CONCURRENCY_HINT_DEFAULT -1
+#endif // !defined(ASIO_CONCURRENCY_HINT_DEFAULT)
+
+// This #define may be overridden at compile time to specify a program-wide
+// concurrency hint, used by the one-argument io_context constructor when
+// passed a value of 1.
+#if !defined(ASIO_CONCURRENCY_HINT_1)
+# define ASIO_CONCURRENCY_HINT_1 1
+#endif // !defined(ASIO_CONCURRENCY_HINT_DEFAULT)
+
+#endif // ASIO_DETAIL_CONCURRENCY_HINT_HPP

lib/asio/include/asio/detail/conditionally_enabled_event.hpp

@@ -0,0 +1,120 @@
+//
+// detail/conditionally_enabled_event.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_CONDITIONALLY_ENABLED_EVENT_HPP
+#define ASIO_DETAIL_CONDITIONALLY_ENABLED_EVENT_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+#include "asio/detail/conditionally_enabled_mutex.hpp"
+#include "asio/detail/event.hpp"
+#include "asio/detail/noncopyable.hpp"
+#include "asio/detail/null_event.hpp"
+#include "asio/detail/scoped_lock.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+// Mutex adapter used to conditionally enable or disable locking.
+class conditionally_enabled_event
+  : private noncopyable
+{
+public:
+  // Constructor.
+  conditionally_enabled_event()
+  {
+  }
+
+  // Destructor.
+  ~conditionally_enabled_event()
+  {
+  }
+
+  // Signal the event. (Retained for backward compatibility.)
+  void signal(conditionally_enabled_mutex::scoped_lock& lock)
+  {
+    if (lock.mutex_.enabled_)
+      event_.signal(lock);
+  }
+
+  // Signal all waiters.
+  void signal_all(conditionally_enabled_mutex::scoped_lock& lock)
+  {
+    if (lock.mutex_.enabled_)
+      event_.signal_all(lock);
+  }
+
+  // Unlock the mutex and signal one waiter.
+  void unlock_and_signal_one(
+      conditionally_enabled_mutex::scoped_lock& lock)
+  {
+    if (lock.mutex_.enabled_)
+      event_.unlock_and_signal_one(lock);
+  }
+
+  // Unlock the mutex and signal one waiter who may destroy us.
+  void unlock_and_signal_one_for_destruction(
+      conditionally_enabled_mutex::scoped_lock& lock)
+  {
+    if (lock.mutex_.enabled_)
+      event_.unlock_and_signal_one(lock);
+  }
+
+  // If there's a waiter, unlock the mutex and signal it.
+  bool maybe_unlock_and_signal_one(
+      conditionally_enabled_mutex::scoped_lock& lock)
+  {
+    if (lock.mutex_.enabled_)
+      return event_.maybe_unlock_and_signal_one(lock);
+    else
+      return false;
+  }
+
+  // Reset the event.
+  void clear(conditionally_enabled_mutex::scoped_lock& lock)
+  {
+    if (lock.mutex_.enabled_)
+      event_.clear(lock);
+  }
+
+  // Wait for the event to become signalled.
+  void wait(conditionally_enabled_mutex::scoped_lock& lock)
+  {
+    if (lock.mutex_.enabled_)
+      event_.wait(lock);
+    else
+      null_event().wait(lock);
+  }
+
+  // Timed wait for the event to become signalled.
+  bool wait_for_usec(
+      conditionally_enabled_mutex::scoped_lock& lock, long usec)
+  {
+    if (lock.mutex_.enabled_)
+      return event_.wait_for_usec(lock, usec);
+    else
+      return null_event().wait_for_usec(lock, usec);
+  }
+
+private:
+  asio::detail::event event_;
+};
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // ASIO_DETAIL_CONDITIONALLY_ENABLED_EVENT_HPP

lib/asio/include/asio/detail/conditionally_enabled_mutex.hpp

@@ -0,0 +1,149 @@
+//
+// detail/conditionally_enabled_mutex.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_CONDITIONALLY_ENABLED_MUTEX_HPP
+#define ASIO_DETAIL_CONDITIONALLY_ENABLED_MUTEX_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+#include "asio/detail/mutex.hpp"
+#include "asio/detail/noncopyable.hpp"
+#include "asio/detail/scoped_lock.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+// Mutex adapter used to conditionally enable or disable locking.
+class conditionally_enabled_mutex
+  : private noncopyable
+{
+public:
+  // Helper class to lock and unlock a mutex automatically.
+  class scoped_lock
+    : private noncopyable
+  {
+  public:
+    // Tag type used to distinguish constructors.
+    enum adopt_lock_t { adopt_lock };
+
+    // Constructor adopts a lock that is already held.
+    scoped_lock(conditionally_enabled_mutex& m, adopt_lock_t)
+      : mutex_(m),
+        locked_(m.enabled_)
+    {
+    }
+
+    // Constructor acquires the lock.
+    explicit scoped_lock(conditionally_enabled_mutex& m)
+      : mutex_(m)
+    {
+      if (m.enabled_)
+      {
+        mutex_.mutex_.lock();
+        locked_ = true;
+      }
+      else
+        locked_ = false;
+    }
+
+    // Destructor releases the lock.
+    ~scoped_lock()
+    {
+      if (locked_)
+        mutex_.mutex_.unlock();
+    }
+
+    // Explicitly acquire the lock.
+    void lock()
+    {
+      if (mutex_.enabled_ && !locked_)
+      {
+        mutex_.mutex_.lock();
+        locked_ = true;
+      }
+    }
+
+    // Explicitly release the lock.
+    void unlock()
+    {
+      if (locked_)
+      {
+        mutex_.unlock();
+        locked_ = false;
+      }
+    }
+
+    // Test whether the lock is held.
+    bool locked() const
+    {
+      return locked_;
+    }
+
+    // Get the underlying mutex.
+    asio::detail::mutex& mutex()
+    {
+      return mutex_.mutex_;
+    }
+
+  private:
+    friend class conditionally_enabled_event;
+    conditionally_enabled_mutex& mutex_;
+    bool locked_;
+  };
+
+  // Constructor.
+  explicit conditionally_enabled_mutex(bool enabled)
+    : enabled_(enabled)
+  {
+  }
+
+  // Destructor.
+  ~conditionally_enabled_mutex()
+  {
+  }
+
+  // Determine whether locking is enabled.
+  bool enabled() const
+  {
+    return enabled_;
+  }
+
+  // Lock the mutex.
+  void lock()
+  {
+    if (enabled_)
+      mutex_.lock();
+  }
+
+  // Unlock the mutex.
+  void unlock()
+  {
+    if (enabled_)
+      mutex_.unlock();
+  }
+
+private:
+  friend class scoped_lock;
+  friend class conditionally_enabled_event;
+  asio::detail::mutex mutex_;
+  const bool enabled_;
+};
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // ASIO_DETAIL_CONDITIONALLY_ENABLED_MUTEX_HPP

lib/asio/include/asio/detail/consuming_buffers.hpp

@@ -0,0 +1,451 @@
+//
+// detail/consuming_buffers.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_CONSUMING_BUFFERS_HPP
+#define ASIO_DETAIL_CONSUMING_BUFFERS_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+#include <cstddef>
+#include "asio/buffer.hpp"
+#include "asio/detail/buffer_sequence_adapter.hpp"
+#include "asio/detail/limits.hpp"
+#include "asio/registered_buffer.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+// Helper template to determine the maximum number of prepared buffers.
+template <typename Buffers>
+struct prepared_buffers_max
+{
+  enum { value = buffer_sequence_adapter_base::max_buffers };
+};
+
+template <typename Elem, std::size_t N>
+struct prepared_buffers_max<boost::array<Elem, N> >
+{
+  enum { value = N };
+};
+
+#if defined(ASIO_HAS_STD_ARRAY)
+
+template <typename Elem, std::size_t N>
+struct prepared_buffers_max<std::array<Elem, N> >
+{
+  enum { value = N };
+};
+
+#endif // defined(ASIO_HAS_STD_ARRAY)
+
+// A buffer sequence used to represent a subsequence of the buffers.
+template <typename Buffer, std::size_t MaxBuffers>
+struct prepared_buffers
+{
+  typedef Buffer value_type;
+  typedef const Buffer* const_iterator;
+
+  enum { max_buffers = MaxBuffers < 16 ? MaxBuffers : 16 };
+
+  prepared_buffers() : count(0) {}
+  const_iterator begin() const { return elems; }
+  const_iterator end() const { return elems + count; }
+
+  Buffer elems[max_buffers];
+  std::size_t count;
+};
+
+// A proxy for a sub-range in a list of buffers.
+template <typename Buffer, typename Buffers, typename Buffer_Iterator>
+class consuming_buffers
+{
+public:
+  typedef prepared_buffers<Buffer, prepared_buffers_max<Buffers>::value>
+    prepared_buffers_type;
+
+  // Construct to represent the entire list of buffers.
+  explicit consuming_buffers(const Buffers& buffers)
+    : buffers_(buffers),
+      total_consumed_(0),
+      next_elem_(0),
+      next_elem_offset_(0)
+  {
+    using asio::buffer_size;
+    total_size_ = buffer_size(buffers);
+  }
+
+  // Determine if we are at the end of the buffers.
+  bool empty() const
+  {
+    return total_consumed_ >= total_size_;
+  }
+
+  // Get the buffer for a single transfer, with a size.
+  prepared_buffers_type prepare(std::size_t max_size)
+  {
+    prepared_buffers_type result;
+
+    Buffer_Iterator next = asio::buffer_sequence_begin(buffers_);
+    Buffer_Iterator end = asio::buffer_sequence_end(buffers_);
+
+    std::advance(next, next_elem_);
+    std::size_t elem_offset = next_elem_offset_;
+    while (next != end && max_size > 0 && (result.count) < result.max_buffers)
+    {
+      Buffer next_buf = Buffer(*next) + elem_offset;
+      result.elems[result.count] = asio::buffer(next_buf, max_size);
+      max_size -= result.elems[result.count].size();
+      elem_offset = 0;
+      if (result.elems[result.count].size() > 0)
+        ++result.count;
+      ++next;
+    }
+
+    return result;
+  }
+
+  // Consume the specified number of bytes from the buffers.
+  void consume(std::size_t size)
+  {
+    total_consumed_ += size;
+
+    Buffer_Iterator next = asio::buffer_sequence_begin(buffers_);
+    Buffer_Iterator end = asio::buffer_sequence_end(buffers_);
+
+    std::advance(next, next_elem_);
+    while (next != end && size > 0)
+    {
+      Buffer next_buf = Buffer(*next) + next_elem_offset_;
+      if (size < next_buf.size())
+      {
+        next_elem_offset_ += size;
+        size = 0;
+      }
+      else
+      {
+        size -= next_buf.size();
+        next_elem_offset_ = 0;
+        ++next_elem_;
+        ++next;
+      }
+    }
+  }
+
+  // Get the total number of bytes consumed from the buffers.
+  std::size_t total_consumed() const
+  {
+    return total_consumed_;
+  }
+
+private:
+  Buffers buffers_;
+  std::size_t total_size_;
+  std::size_t total_consumed_;
+  std::size_t next_elem_;
+  std::size_t next_elem_offset_;
+};
+
+// Base class of all consuming_buffers specialisations for single buffers.
+template <typename Buffer>
+class consuming_single_buffer
+{
+public:
+  // Construct to represent the entire list of buffers.
+  template <typename Buffer1>
+  explicit consuming_single_buffer(const Buffer1& buffer)
+    : buffer_(buffer),
+      total_consumed_(0)
+  {
+  }
+
+  // Determine if we are at the end of the buffers.
+  bool empty() const
+  {
+    return total_consumed_ >= buffer_.size();
+  }
+
+  // Get the buffer for a single transfer, with a size.
+  Buffer prepare(std::size_t max_size)
+  {
+    return asio::buffer(buffer_ + total_consumed_, max_size);
+  }
+
+  // Consume the specified number of bytes from the buffers.
+  void consume(std::size_t size)
+  {
+    total_consumed_ += size;
+  }
+
+  // Get the total number of bytes consumed from the buffers.
+  std::size_t total_consumed() const
+  {
+    return total_consumed_;
+  }
+
+private:
+  Buffer buffer_;
+  std::size_t total_consumed_;
+};
+
+template <>
+class consuming_buffers<mutable_buffer, mutable_buffer, const mutable_buffer*>
+  : public consuming_single_buffer<ASIO_MUTABLE_BUFFER>
+{
+public:
+  explicit consuming_buffers(const mutable_buffer& buffer)
+    : consuming_single_buffer<ASIO_MUTABLE_BUFFER>(buffer)
+  {
+  }
+};
+
+template <>
+class consuming_buffers<const_buffer, mutable_buffer, const mutable_buffer*>
+  : public consuming_single_buffer<ASIO_CONST_BUFFER>
+{
+public:
+  explicit consuming_buffers(const mutable_buffer& buffer)
+    : consuming_single_buffer<ASIO_CONST_BUFFER>(buffer)
+  {
+  }
+};
+
+template <>
+class consuming_buffers<const_buffer, const_buffer, const const_buffer*>
+  : public consuming_single_buffer<ASIO_CONST_BUFFER>
+{
+public:
+  explicit consuming_buffers(const const_buffer& buffer)
+    : consuming_single_buffer<ASIO_CONST_BUFFER>(buffer)
+  {
+  }
+};
+
+#if !defined(ASIO_NO_DEPRECATED)
+
+template <>
+class consuming_buffers<mutable_buffer,
+    mutable_buffers_1, const mutable_buffer*>
+  : public consuming_single_buffer<ASIO_MUTABLE_BUFFER>
+{
+public:
+  explicit consuming_buffers(const mutable_buffers_1& buffer)
+    : consuming_single_buffer<ASIO_MUTABLE_BUFFER>(buffer)
+  {
+  }
+};
+
+template <>
+class consuming_buffers<const_buffer, mutable_buffers_1, const mutable_buffer*>
+  : public consuming_single_buffer<ASIO_CONST_BUFFER>
+{
+public:
+  explicit consuming_buffers(const mutable_buffers_1& buffer)
+    : consuming_single_buffer<ASIO_CONST_BUFFER>(buffer)
+  {
+  }
+};
+
+template <>
+class consuming_buffers<const_buffer, const_buffers_1, const const_buffer*>
+  : public consuming_single_buffer<ASIO_CONST_BUFFER>
+{
+public:
+  explicit consuming_buffers(const const_buffers_1& buffer)
+    : consuming_single_buffer<ASIO_CONST_BUFFER>(buffer)
+  {
+  }
+};
+
+#endif // !defined(ASIO_NO_DEPRECATED)
+
+template <>
+class consuming_buffers<mutable_buffer,
+    mutable_registered_buffer, const mutable_buffer*>
+  : public consuming_single_buffer<mutable_registered_buffer>
+{
+public:
+  explicit consuming_buffers(const mutable_registered_buffer& buffer)
+    : consuming_single_buffer<mutable_registered_buffer>(buffer)
+  {
+  }
+};
+
+template <>
+class consuming_buffers<const_buffer,
+    mutable_registered_buffer, const mutable_buffer*>
+  : public consuming_single_buffer<mutable_registered_buffer>
+{
+public:
+  explicit consuming_buffers(const mutable_registered_buffer& buffer)
+    : consuming_single_buffer<mutable_registered_buffer>(buffer)
+  {
+  }
+};
+
+template <>
+class consuming_buffers<const_buffer,
+    const_registered_buffer, const const_buffer*>
+  : public consuming_single_buffer<const_registered_buffer>
+{
+public:
+  explicit consuming_buffers(const const_registered_buffer& buffer)
+    : consuming_single_buffer<const_registered_buffer>(buffer)
+  {
+  }
+};
+
+template <typename Buffer, typename Elem>
+class consuming_buffers<Buffer, boost::array<Elem, 2>,
+    typename boost::array<Elem, 2>::const_iterator>
+{
+public:
+  // Construct to represent the entire list of buffers.
+  explicit consuming_buffers(const boost::array<Elem, 2>& buffers)
+    : buffers_(buffers),
+      total_consumed_(0)
+  {
+  }
+
+  // Determine if we are at the end of the buffers.
+  bool empty() const
+  {
+    return total_consumed_ >=
+      Buffer(buffers_[0]).size() + Buffer(buffers_[1]).size();
+  }
+
+  // Get the buffer for a single transfer, with a size.
+  boost::array<Buffer, 2> prepare(std::size_t max_size)
+  {
+    boost::array<Buffer, 2> result = {{
+      Buffer(buffers_[0]), Buffer(buffers_[1]) }};
+    std::size_t buffer0_size = result[0].size();
+    result[0] = asio::buffer(result[0] + total_consumed_, max_size);
+    result[1] = asio::buffer(
+        result[1] + (total_consumed_ < buffer0_size
+          ? 0 : total_consumed_ - buffer0_size),
+        max_size - result[0].size());
+    return result;
+  }
+
+  // Consume the specified number of bytes from the buffers.
+  void consume(std::size_t size)
+  {
+    total_consumed_ += size;
+  }
+
+  // Get the total number of bytes consumed from the buffers.
+  std::size_t total_consumed() const
+  {
+    return total_consumed_;
+  }
+
+private:
+  boost::array<Elem, 2> buffers_;
+  std::size_t total_consumed_;
+};
+
+#if defined(ASIO_HAS_STD_ARRAY)
+
+template <typename Buffer, typename Elem>
+class consuming_buffers<Buffer, std::array<Elem, 2>,
+    typename std::array<Elem, 2>::const_iterator>
+{
+public:
+  // Construct to represent the entire list of buffers.
+  explicit consuming_buffers(const std::array<Elem, 2>& buffers)
+    : buffers_(buffers),
+      total_consumed_(0)
+  {
+  }
+
+  // Determine if we are at the end of the buffers.
+  bool empty() const
+  {
+    return total_consumed_ >=
+      Buffer(buffers_[0]).size() + Buffer(buffers_[1]).size();
+  }
+
+  // Get the buffer for a single transfer, with a size.
+  std::array<Buffer, 2> prepare(std::size_t max_size)
+  {
+    std::array<Buffer, 2> result = {{
+      Buffer(buffers_[0]), Buffer(buffers_[1]) }};
+    std::size_t buffer0_size = result[0].size();
+    result[0] = asio::buffer(result[0] + total_consumed_, max_size);
+    result[1] = asio::buffer(
+        result[1] + (total_consumed_ < buffer0_size
+          ? 0 : total_consumed_ - buffer0_size),
+        max_size - result[0].size());
+    return result;
+  }
+
+  // Consume the specified number of bytes from the buffers.
+  void consume(std::size_t size)
+  {
+    total_consumed_ += size;
+  }
+
+  // Get the total number of bytes consumed from the buffers.
+  std::size_t total_consumed() const
+  {
+    return total_consumed_;
+  }
+
+private:
+  std::array<Elem, 2> buffers_;
+  std::size_t total_consumed_;
+};
+
+#endif // defined(ASIO_HAS_STD_ARRAY)
+
+// Specialisation for null_buffers to ensure that the null_buffers type is
+// always passed through to the underlying read or write operation.
+template <typename Buffer>
+class consuming_buffers<Buffer, null_buffers, const mutable_buffer*>
+  : public asio::null_buffers
+{
+public:
+  consuming_buffers(const null_buffers&)
+  {
+    // No-op.
+  }
+
+  bool empty()
+  {
+    return false;
+  }
+
+  null_buffers prepare(std::size_t)
+  {
+    return null_buffers();
+  }
+
+  void consume(std::size_t)
+  {
+    // No-op.
+  }
+
+  std::size_t total_consumed() const
+  {
+    return 0;
+  }
+};
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // ASIO_DETAIL_CONSUMING_BUFFERS_HPP

lib/asio/include/asio/detail/cstddef.hpp

@@ -0,0 +1,31 @@
+//
+// detail/cstddef.hpp
+// ~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_CSTDDEF_HPP
+#define ASIO_DETAIL_CSTDDEF_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+#include <cstddef>
+
+namespace asio {
+
+#if defined(ASIO_HAS_NULLPTR)
+using std::nullptr_t;
+#else // defined(ASIO_HAS_NULLPTR)
+struct nullptr_t {};
+#endif // defined(ASIO_HAS_NULLPTR)
+
+} // namespace asio
+
+#endif // ASIO_DETAIL_CSTDDEF_HPP

lib/asio/include/asio/detail/cstdint.hpp

@@ -0,0 +1,62 @@
+//
+// detail/cstdint.hpp
+// ~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_CSTDINT_HPP
+#define ASIO_DETAIL_CSTDINT_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_HAS_CSTDINT)
+# include <cstdint>
+#else // defined(ASIO_HAS_CSTDINT)
+# include <boost/cstdint.hpp>
+#endif // defined(ASIO_HAS_CSTDINT)
+
+namespace asio {
+
+#if defined(ASIO_HAS_CSTDINT)
+using std::int16_t;
+using std::int_least16_t;
+using std::uint16_t;
+using std::uint_least16_t;
+using std::int32_t;
+using std::int_least32_t;
+using std::uint32_t;
+using std::uint_least32_t;
+using std::int64_t;
+using std::int_least64_t;
+using std::uint64_t;
+using std::uint_least64_t;
+using std::uintptr_t;
+using std::uintmax_t;
+#else // defined(ASIO_HAS_CSTDINT)
+using boost::int16_t;
+using boost::int_least16_t;
+using boost::uint16_t;
+using boost::uint_least16_t;
+using boost::int32_t;
+using boost::int_least32_t;
+using boost::uint32_t;
+using boost::uint_least32_t;
+using boost::int64_t;
+using boost::int_least64_t;
+using boost::uint64_t;
+using boost::uint_least64_t;
+using boost::uintptr_t;
+using boost::uintmax_t;
+#endif // defined(ASIO_HAS_CSTDINT)
+
+} // namespace asio
+
+#endif // ASIO_DETAIL_CSTDINT_HPP

lib/asio/include/asio/detail/date_time_fwd.hpp

@@ -0,0 +1,34 @@
+//
+// detail/date_time_fwd.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_DATE_TIME_FWD_HPP
+#define ASIO_DETAIL_DATE_TIME_FWD_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+namespace boost {
+namespace date_time {
+
+template<class T, class TimeSystem>
+class base_time;
+
+} // namespace date_time
+namespace posix_time {
+
+class ptime;
+
+} // namespace posix_time
+} // namespace boost
+
+#endif // ASIO_DETAIL_DATE_TIME_FWD_HPP

lib/asio/include/asio/detail/deadline_timer_service.hpp

@@ -0,0 +1,335 @@
+//
+// detail/deadline_timer_service.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_DEADLINE_TIMER_SERVICE_HPP
+#define ASIO_DETAIL_DEADLINE_TIMER_SERVICE_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+#include <cstddef>
+#include "asio/associated_cancellation_slot.hpp"
+#include "asio/cancellation_type.hpp"
+#include "asio/error.hpp"
+#include "asio/execution_context.hpp"
+#include "asio/detail/bind_handler.hpp"
+#include "asio/detail/fenced_block.hpp"
+#include "asio/detail/memory.hpp"
+#include "asio/detail/noncopyable.hpp"
+#include "asio/detail/socket_ops.hpp"
+#include "asio/detail/socket_types.hpp"
+#include "asio/detail/timer_queue.hpp"
+#include "asio/detail/timer_queue_ptime.hpp"
+#include "asio/detail/timer_scheduler.hpp"
+#include "asio/detail/wait_handler.hpp"
+#include "asio/detail/wait_op.hpp"
+
+#if defined(ASIO_WINDOWS_RUNTIME)
+# include <chrono>
+# include <thread>
+#endif // defined(ASIO_WINDOWS_RUNTIME)
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+template <typename Time_Traits>
+class deadline_timer_service
+  : public execution_context_service_base<deadline_timer_service<Time_Traits> >
+{
+public:
+  // The time type.
+  typedef typename Time_Traits::time_type time_type;
+
+  // The duration type.
+  typedef typename Time_Traits::duration_type duration_type;
+
+  // The implementation type of the timer. This type is dependent on the
+  // underlying implementation of the timer service.
+  struct implementation_type
+    : private asio::detail::noncopyable
+  {
+    time_type expiry;
+    bool might_have_pending_waits;
+    typename timer_queue<Time_Traits>::per_timer_data timer_data;
+  };
+
+  // Constructor.
+  deadline_timer_service(execution_context& context)
+    : execution_context_service_base<
+        deadline_timer_service<Time_Traits> >(context),
+      scheduler_(asio::use_service<timer_scheduler>(context))
+  {
+    scheduler_.init_task();
+    scheduler_.add_timer_queue(timer_queue_);
+  }
+
+  // Destructor.
+  ~deadline_timer_service()
+  {
+    scheduler_.remove_timer_queue(timer_queue_);
+  }
+
+  // Destroy all user-defined handler objects owned by the service.
+  void shutdown()
+  {
+  }
+
+  // Construct a new timer implementation.
+  void construct(implementation_type& impl)
+  {
+    impl.expiry = time_type();
+    impl.might_have_pending_waits = false;
+  }
+
+  // Destroy a timer implementation.
+  void destroy(implementation_type& impl)
+  {
+    asio::error_code ec;
+    cancel(impl, ec);
+  }
+
+  // Move-construct a new timer implementation.
+  void move_construct(implementation_type& impl,
+      implementation_type& other_impl)
+  {
+    scheduler_.move_timer(timer_queue_, impl.timer_data, other_impl.timer_data);
+
+    impl.expiry = other_impl.expiry;
+    other_impl.expiry = time_type();
+
+    impl.might_have_pending_waits = other_impl.might_have_pending_waits;
+    other_impl.might_have_pending_waits = false;
+  }
+
+  // Move-assign from another timer implementation.
+  void move_assign(implementation_type& impl,
+      deadline_timer_service& other_service,
+      implementation_type& other_impl)
+  {
+    if (this != &other_service)
+      if (impl.might_have_pending_waits)
+        scheduler_.cancel_timer(timer_queue_, impl.timer_data);
+
+    other_service.scheduler_.move_timer(other_service.timer_queue_,
+        impl.timer_data, other_impl.timer_data);
+
+    impl.expiry = other_impl.expiry;
+    other_impl.expiry = time_type();
+
+    impl.might_have_pending_waits = other_impl.might_have_pending_waits;
+    other_impl.might_have_pending_waits = false;
+  }
+
+  // Move-construct a new timer implementation.
+  void converting_move_construct(implementation_type& impl,
+      deadline_timer_service&, implementation_type& other_impl)
+  {
+    move_construct(impl, other_impl);
+  }
+
+  // Move-assign from another timer implementation.
+  void converting_move_assign(implementation_type& impl,
+      deadline_timer_service& other_service,
+      implementation_type& other_impl)
+  {
+    move_assign(impl, other_service, other_impl);
+  }
+
+  // Cancel any asynchronous wait operations associated with the timer.
+  std::size_t cancel(implementation_type& impl, asio::error_code& ec)
+  {
+    if (!impl.might_have_pending_waits)
+    {
+      ec = asio::error_code();
+      return 0;
+    }
+
+    ASIO_HANDLER_OPERATION((scheduler_.context(),
+          "deadline_timer", &impl, 0, "cancel"));
+
+    std::size_t count = scheduler_.cancel_timer(timer_queue_, impl.timer_data);
+    impl.might_have_pending_waits = false;
+    ec = asio::error_code();
+    return count;
+  }
+
+  // Cancels one asynchronous wait operation associated with the timer.
+  std::size_t cancel_one(implementation_type& impl,
+      asio::error_code& ec)
+  {
+    if (!impl.might_have_pending_waits)
+    {
+      ec = asio::error_code();
+      return 0;
+    }
+
+    ASIO_HANDLER_OPERATION((scheduler_.context(),
+          "deadline_timer", &impl, 0, "cancel_one"));
+
+    std::size_t count = scheduler_.cancel_timer(
+        timer_queue_, impl.timer_data, 1);
+    if (count == 0)
+      impl.might_have_pending_waits = false;
+    ec = asio::error_code();
+    return count;
+  }
+
+  // Get the expiry time for the timer as an absolute time.
+  time_type expiry(const implementation_type& impl) const
+  {
+    return impl.expiry;
+  }
+
+  // Get the expiry time for the timer as an absolute time.
+  time_type expires_at(const implementation_type& impl) const
+  {
+    return impl.expiry;
+  }
+
+  // Get the expiry time for the timer relative to now.
+  duration_type expires_from_now(const implementation_type& impl) const
+  {
+    return Time_Traits::subtract(this->expiry(impl), Time_Traits::now());
+  }
+
+  // Set the expiry time for the timer as an absolute time.
+  std::size_t expires_at(implementation_type& impl,
+      const time_type& expiry_time, asio::error_code& ec)
+  {
+    std::size_t count = cancel(impl, ec);
+    impl.expiry = expiry_time;
+    ec = asio::error_code();
+    return count;
+  }
+
+  // Set the expiry time for the timer relative to now.
+  std::size_t expires_after(implementation_type& impl,
+      const duration_type& expiry_time, asio::error_code& ec)
+  {
+    return expires_at(impl,
+        Time_Traits::add(Time_Traits::now(), expiry_time), ec);
+  }
+
+  // Set the expiry time for the timer relative to now.
+  std::size_t expires_from_now(implementation_type& impl,
+      const duration_type& expiry_time, asio::error_code& ec)
+  {
+    return expires_at(impl,
+        Time_Traits::add(Time_Traits::now(), expiry_time), ec);
+  }
+
+  // Perform a blocking wait on the timer.
+  void wait(implementation_type& impl, asio::error_code& ec)
+  {
+    time_type now = Time_Traits::now();
+    ec = asio::error_code();
+    while (Time_Traits::less_than(now, impl.expiry) && !ec)
+    {
+      this->do_wait(Time_Traits::to_posix_duration(
+            Time_Traits::subtract(impl.expiry, now)), ec);
+      now = Time_Traits::now();
+    }
+  }
+
+  // Start an asynchronous wait on the timer.
+  template <typename Handler, typename IoExecutor>
+  void async_wait(implementation_type& impl,
+      Handler& handler, const IoExecutor& io_ex)
+  {
+    typename associated_cancellation_slot<Handler>::type slot
+      = asio::get_associated_cancellation_slot(handler);
+
+    // Allocate and construct an operation to wrap the handler.
+    typedef wait_handler<Handler, IoExecutor> op;
+    typename op::ptr p = { asio::detail::addressof(handler),
+      op::ptr::allocate(handler), 0 };
+    p.p = new (p.v) op(handler, io_ex);
+
+    // Optionally register for per-operation cancellation.
+    if (slot.is_connected())
+    {
+      p.p->cancellation_key_ =
+        &slot.template emplace<op_cancellation>(this, &impl.timer_data);
+    }
+
+    impl.might_have_pending_waits = true;
+
+    ASIO_HANDLER_CREATION((scheduler_.context(),
+          *p.p, "deadline_timer", &impl, 0, "async_wait"));
+
+    scheduler_.schedule_timer(timer_queue_, impl.expiry, impl.timer_data, p.p);
+    p.v = p.p = 0;
+  }
+
+private:
+  // Helper function to wait given a duration type. The duration type should
+  // either be of type boost::posix_time::time_duration, or implement the
+  // required subset of its interface.
+  template <typename Duration>
+  void do_wait(const Duration& timeout, asio::error_code& ec)
+  {
+#if defined(ASIO_WINDOWS_RUNTIME)
+    std::this_thread::sleep_for(
+        std::chrono::seconds(timeout.total_seconds())
+        + std::chrono::microseconds(timeout.total_microseconds()));
+    ec = asio::error_code();
+#else // defined(ASIO_WINDOWS_RUNTIME)
+    ::timeval tv;
+    tv.tv_sec = timeout.total_seconds();
+    tv.tv_usec = timeout.total_microseconds() % 1000000;
+    socket_ops::select(0, 0, 0, 0, &tv, ec);
+#endif // defined(ASIO_WINDOWS_RUNTIME)
+  }
+
+  // Helper class used to implement per-operation cancellation.
+  class op_cancellation
+  {
+  public:
+    op_cancellation(deadline_timer_service* s,
+        typename timer_queue<Time_Traits>::per_timer_data* p)
+      : service_(s),
+        timer_data_(p)
+    {
+    }
+
+    void operator()(cancellation_type_t type)
+    {
+      if (!!(type &
+            (cancellation_type::terminal
+              | cancellation_type::partial
+              | cancellation_type::total)))
+      {
+        service_->scheduler_.cancel_timer_by_key(
+            service_->timer_queue_, timer_data_, this);
+      }
+    }
+
+  private:
+    deadline_timer_service* service_;
+    typename timer_queue<Time_Traits>::per_timer_data* timer_data_;
+  };
+
+  // The queue of timers.
+  timer_queue<Time_Traits> timer_queue_;
+
+  // The object that schedules and executes timers. Usually a reactor.
+  timer_scheduler& scheduler_;
+};
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // ASIO_DETAIL_DEADLINE_TIMER_SERVICE_HPP

lib/asio/include/asio/detail/dependent_type.hpp

@@ -0,0 +1,36 @@
+//
+// detail/dependent_type.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_DEPENDENT_TYPE_HPP
+#define ASIO_DETAIL_DEPENDENT_TYPE_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+template <typename DependsOn, typename T>
+struct dependent_type
+{
+  typedef T type;
+};
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // ASIO_DETAIL_DEPENDENT_TYPE_HPP

lib/asio/include/asio/detail/descriptor_ops.hpp

@@ -0,0 +1,179 @@
+//
+// detail/descriptor_ops.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_DESCRIPTOR_OPS_HPP
+#define ASIO_DETAIL_DESCRIPTOR_OPS_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if !defined(ASIO_WINDOWS) \
+  && !defined(ASIO_WINDOWS_RUNTIME) \
+  && !defined(__CYGWIN__)
+
+#include <cstddef>
+#include "asio/error.hpp"
+#include "asio/error_code.hpp"
+#include "asio/detail/cstdint.hpp"
+#include "asio/detail/socket_types.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+namespace descriptor_ops {
+
+// Descriptor state bits.
+enum
+{
+  // The user wants a non-blocking descriptor.
+  user_set_non_blocking = 1,
+
+  // The descriptor has been set non-blocking.
+  internal_non_blocking = 2,
+
+  // Helper "state" used to determine whether the descriptor is non-blocking.
+  non_blocking = user_set_non_blocking | internal_non_blocking,
+
+  // The descriptor may have been dup()-ed.
+  possible_dup = 4
+};
+
+typedef unsigned char state_type;
+
+inline void get_last_error(
+    asio::error_code& ec, bool is_error_condition)
+{
+  if (!is_error_condition)
+  {
+    ec.assign(0, ec.category());
+  }
+  else
+  {
+    ec = asio::error_code(errno,
+        asio::error::get_system_category());
+  }
+}
+
+ASIO_DECL int open(const char* path, int flags,
+    asio::error_code& ec);
+
+ASIO_DECL int open(const char* path, int flags, unsigned mode,
+    asio::error_code& ec);
+
+ASIO_DECL int close(int d, state_type& state,
+    asio::error_code& ec);
+
+ASIO_DECL bool set_user_non_blocking(int d,
+    state_type& state, bool value, asio::error_code& ec);
+
+ASIO_DECL bool set_internal_non_blocking(int d,
+    state_type& state, bool value, asio::error_code& ec);
+
+typedef iovec buf;
+
+ASIO_DECL std::size_t sync_read(int d, state_type state, buf* bufs,
+    std::size_t count, bool all_empty, asio::error_code& ec);
+
+ASIO_DECL std::size_t sync_read1(int d, state_type state, void* data,
+    std::size_t size, asio::error_code& ec);
+
+ASIO_DECL bool non_blocking_read(int d, buf* bufs, std::size_t count,
+    asio::error_code& ec, std::size_t& bytes_transferred);
+
+ASIO_DECL bool non_blocking_read1(int d, void* data, std::size_t size,
+    asio::error_code& ec, std::size_t& bytes_transferred);
+
+ASIO_DECL std::size_t sync_write(int d, state_type state,
+    const buf* bufs, std::size_t count, bool all_empty,
+    asio::error_code& ec);
+
+ASIO_DECL std::size_t sync_write1(int d, state_type state,
+    const void* data, std::size_t size, asio::error_code& ec);
+
+ASIO_DECL bool non_blocking_write(int d,
+    const buf* bufs, std::size_t count,
+    asio::error_code& ec, std::size_t& bytes_transferred);
+
+ASIO_DECL bool non_blocking_write1(int d,
+    const void* data, std::size_t size,
+    asio::error_code& ec, std::size_t& bytes_transferred);
+
+#if defined(ASIO_HAS_FILE)
+
+ASIO_DECL std::size_t sync_read_at(int d, state_type state,
+    uint64_t offset, buf* bufs, std::size_t count, bool all_empty,
+    asio::error_code& ec);
+
+ASIO_DECL std::size_t sync_read_at1(int d, state_type state,
+    uint64_t offset, void* data, std::size_t size,
+    asio::error_code& ec);
+
+ASIO_DECL bool non_blocking_read_at(int d, uint64_t offset,
+    buf* bufs, std::size_t count, asio::error_code& ec,
+    std::size_t& bytes_transferred);
+
+ASIO_DECL bool non_blocking_read_at1(int d, uint64_t offset,
+    void* data, std::size_t size, asio::error_code& ec,
+    std::size_t& bytes_transferred);
+
+ASIO_DECL std::size_t sync_write_at(int d, state_type state,
+    uint64_t offset, const buf* bufs, std::size_t count, bool all_empty,
+    asio::error_code& ec);
+
+ASIO_DECL std::size_t sync_write_at1(int d, state_type state,
+    uint64_t offset, const void* data, std::size_t size,
+    asio::error_code& ec);
+
+ASIO_DECL bool non_blocking_write_at(int d,
+    uint64_t offset, const buf* bufs, std::size_t count,
+    asio::error_code& ec, std::size_t& bytes_transferred);
+
+ASIO_DECL bool non_blocking_write_at1(int d,
+    uint64_t offset, const void* data, std::size_t size,
+    asio::error_code& ec, std::size_t& bytes_transferred);
+
+#endif // defined(ASIO_HAS_FILE)
+
+ASIO_DECL int ioctl(int d, state_type& state, long cmd,
+    ioctl_arg_type* arg, asio::error_code& ec);
+
+ASIO_DECL int fcntl(int d, int cmd, asio::error_code& ec);
+
+ASIO_DECL int fcntl(int d, int cmd,
+    long arg, asio::error_code& ec);
+
+ASIO_DECL int poll_read(int d,
+    state_type state, asio::error_code& ec);
+
+ASIO_DECL int poll_write(int d,
+    state_type state, asio::error_code& ec);
+
+ASIO_DECL int poll_error(int d,
+    state_type state, asio::error_code& ec);
+
+} // namespace descriptor_ops
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#if defined(ASIO_HEADER_ONLY)
+# include "asio/detail/impl/descriptor_ops.ipp"
+#endif // defined(ASIO_HEADER_ONLY)
+
+#endif // !defined(ASIO_WINDOWS)
+       //   && !defined(ASIO_WINDOWS_RUNTIME)
+       //   && !defined(__CYGWIN__)
+
+#endif // ASIO_DETAIL_DESCRIPTOR_OPS_HPP

lib/asio/include/asio/detail/descriptor_read_op.hpp

@@ -0,0 +1,148 @@
+//
+// detail/descriptor_read_op.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_DESCRIPTOR_READ_OP_HPP
+#define ASIO_DETAIL_DESCRIPTOR_READ_OP_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if !defined(ASIO_WINDOWS) && !defined(__CYGWIN__)
+
+#include "asio/detail/bind_handler.hpp"
+#include "asio/detail/buffer_sequence_adapter.hpp"
+#include "asio/detail/descriptor_ops.hpp"
+#include "asio/detail/fenced_block.hpp"
+#include "asio/detail/handler_work.hpp"
+#include "asio/detail/memory.hpp"
+#include "asio/detail/reactor_op.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+template <typename MutableBufferSequence>
+class descriptor_read_op_base : public reactor_op
+{
+public:
+  descriptor_read_op_base(const asio::error_code& success_ec,
+      int descriptor, const MutableBufferSequence& buffers,
+      func_type complete_func)
+    : reactor_op(success_ec,
+        &descriptor_read_op_base::do_perform, complete_func),
+      descriptor_(descriptor),
+      buffers_(buffers)
+  {
+  }
+
+  static status do_perform(reactor_op* base)
+  {
+    descriptor_read_op_base* o(static_cast<descriptor_read_op_base*>(base));
+
+    typedef buffer_sequence_adapter<asio::mutable_buffer,
+        MutableBufferSequence> bufs_type;
+
+    status result;
+    if (bufs_type::is_single_buffer)
+    {
+      result = descriptor_ops::non_blocking_read1(o->descriptor_,
+          bufs_type::first(o->buffers_).data(),
+          bufs_type::first(o->buffers_).size(),
+          o->ec_, o->bytes_transferred_) ? done : not_done;
+    }
+    else
+    {
+      bufs_type bufs(o->buffers_);
+      result = descriptor_ops::non_blocking_read(o->descriptor_,
+          bufs.buffers(), bufs.count(), o->ec_, o->bytes_transferred_)
+        ? done : not_done;
+    }
+
+    ASIO_HANDLER_REACTOR_OPERATION((*o, "non_blocking_read",
+          o->ec_, o->bytes_transferred_));
+
+    return result;
+  }
+
+private:
+  int descriptor_;
+  MutableBufferSequence buffers_;
+};
+
+template <typename MutableBufferSequence, typename Handler, typename IoExecutor>
+class descriptor_read_op
+  : public descriptor_read_op_base<MutableBufferSequence>
+{
+public:
+  ASIO_DEFINE_HANDLER_PTR(descriptor_read_op);
+
+  descriptor_read_op(const asio::error_code& success_ec,
+      int descriptor, const MutableBufferSequence& buffers,
+      Handler& handler, const IoExecutor& io_ex)
+    : descriptor_read_op_base<MutableBufferSequence>(success_ec,
+        descriptor, buffers, &descriptor_read_op::do_complete),
+      handler_(ASIO_MOVE_CAST(Handler)(handler)),
+      work_(handler_, io_ex)
+  {
+  }
+
+  static void do_complete(void* owner, operation* base,
+      const asio::error_code& /*ec*/,
+      std::size_t /*bytes_transferred*/)
+  {
+    // Take ownership of the handler object.
+    descriptor_read_op* o(static_cast<descriptor_read_op*>(base));
+    ptr p = { asio::detail::addressof(o->handler_), o, o };
+
+    ASIO_HANDLER_COMPLETION((*o));
+
+    // Take ownership of the operation's outstanding work.
+    handler_work<Handler, IoExecutor> w(
+        ASIO_MOVE_CAST2(handler_work<Handler, IoExecutor>)(
+          o->work_));
+
+    // Make a copy of the handler so that the memory can be deallocated before
+    // the upcall is made. Even if we're not about to make an upcall, a
+    // sub-object of the handler may be the true owner of the memory associated
+    // with the handler. Consequently, a local copy of the handler is required
+    // to ensure that any owning sub-object remains valid until after we have
+    // deallocated the memory here.
+    detail::binder2<Handler, asio::error_code, std::size_t>
+      handler(o->handler_, o->ec_, o->bytes_transferred_);
+    p.h = asio::detail::addressof(handler.handler_);
+    p.reset();
+
+    // Make the upcall if required.
+    if (owner)
+    {
+      fenced_block b(fenced_block::half);
+      ASIO_HANDLER_INVOCATION_BEGIN((handler.arg1_, handler.arg2_));
+      w.complete(handler, handler.handler_);
+      ASIO_HANDLER_INVOCATION_END;
+    }
+  }
+
+private:
+  Handler handler_;
+  handler_work<Handler, IoExecutor> work_;
+};
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // !defined(ASIO_WINDOWS) && !defined(__CYGWIN__)
+
+#endif // ASIO_DETAIL_DESCRIPTOR_READ_OP_HPP

lib/asio/include/asio/detail/descriptor_write_op.hpp

@@ -0,0 +1,148 @@
+//
+// detail/descriptor_write_op.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_DESCRIPTOR_WRITE_OP_HPP
+#define ASIO_DETAIL_DESCRIPTOR_WRITE_OP_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if !defined(ASIO_WINDOWS) && !defined(__CYGWIN__)
+
+#include "asio/detail/bind_handler.hpp"
+#include "asio/detail/buffer_sequence_adapter.hpp"
+#include "asio/detail/descriptor_ops.hpp"
+#include "asio/detail/fenced_block.hpp"
+#include "asio/detail/handler_work.hpp"
+#include "asio/detail/memory.hpp"
+#include "asio/detail/reactor_op.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+template <typename ConstBufferSequence>
+class descriptor_write_op_base : public reactor_op
+{
+public:
+  descriptor_write_op_base(const asio::error_code& success_ec,
+      int descriptor, const ConstBufferSequence& buffers,
+      func_type complete_func)
+    : reactor_op(success_ec,
+        &descriptor_write_op_base::do_perform, complete_func),
+      descriptor_(descriptor),
+      buffers_(buffers)
+  {
+  }
+
+  static status do_perform(reactor_op* base)
+  {
+    descriptor_write_op_base* o(static_cast<descriptor_write_op_base*>(base));
+
+    typedef buffer_sequence_adapter<asio::const_buffer,
+        ConstBufferSequence> bufs_type;
+
+    status result;
+    if (bufs_type::is_single_buffer)
+    {
+      result = descriptor_ops::non_blocking_write1(o->descriptor_,
+          bufs_type::first(o->buffers_).data(),
+          bufs_type::first(o->buffers_).size(),
+          o->ec_, o->bytes_transferred_) ? done : not_done;
+    }
+    else
+    {
+      bufs_type bufs(o->buffers_);
+      result = descriptor_ops::non_blocking_write(o->descriptor_,
+          bufs.buffers(), bufs.count(), o->ec_, o->bytes_transferred_)
+        ? done : not_done;
+    }
+
+    ASIO_HANDLER_REACTOR_OPERATION((*o, "non_blocking_write",
+          o->ec_, o->bytes_transferred_));
+
+    return result;
+  }
+
+private:
+  int descriptor_;
+  ConstBufferSequence buffers_;
+};
+
+template <typename ConstBufferSequence, typename Handler, typename IoExecutor>
+class descriptor_write_op
+  : public descriptor_write_op_base<ConstBufferSequence>
+{
+public:
+  ASIO_DEFINE_HANDLER_PTR(descriptor_write_op);
+
+  descriptor_write_op(const asio::error_code& success_ec,
+      int descriptor, const ConstBufferSequence& buffers,
+      Handler& handler, const IoExecutor& io_ex)
+    : descriptor_write_op_base<ConstBufferSequence>(success_ec,
+        descriptor, buffers, &descriptor_write_op::do_complete),
+      handler_(ASIO_MOVE_CAST(Handler)(handler)),
+      work_(handler_, io_ex)
+  {
+  }
+
+  static void do_complete(void* owner, operation* base,
+      const asio::error_code& /*ec*/,
+      std::size_t /*bytes_transferred*/)
+  {
+    // Take ownership of the handler object.
+    descriptor_write_op* o(static_cast<descriptor_write_op*>(base));
+    ptr p = { asio::detail::addressof(o->handler_), o, o };
+
+    ASIO_HANDLER_COMPLETION((*o));
+
+    // Take ownership of the operation's outstanding work.
+    handler_work<Handler, IoExecutor> w(
+        ASIO_MOVE_CAST2(handler_work<Handler, IoExecutor>)(
+          o->work_));
+
+    // Make a copy of the handler so that the memory can be deallocated before
+    // the upcall is made. Even if we're not about to make an upcall, a
+    // sub-object of the handler may be the true owner of the memory associated
+    // with the handler. Consequently, a local copy of the handler is required
+    // to ensure that any owning sub-object remains valid until after we have
+    // deallocated the memory here.
+    detail::binder2<Handler, asio::error_code, std::size_t>
+      handler(o->handler_, o->ec_, o->bytes_transferred_);
+    p.h = asio::detail::addressof(handler.handler_);
+    p.reset();
+
+    // Make the upcall if required.
+    if (owner)
+    {
+      fenced_block b(fenced_block::half);
+      ASIO_HANDLER_INVOCATION_BEGIN((handler.arg1_, handler.arg2_));
+      w.complete(handler, handler.handler_);
+      ASIO_HANDLER_INVOCATION_END;
+    }
+  }
+
+private:
+  Handler handler_;
+  handler_work<Handler, IoExecutor> work_;
+};
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // !defined(ASIO_WINDOWS) && !defined(__CYGWIN__)
+
+#endif // ASIO_DETAIL_DESCRIPTOR_WRITE_OP_HPP

lib/asio/include/asio/detail/dev_poll_reactor.hpp

@@ -0,0 +1,230 @@
+//
+// detail/dev_poll_reactor.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_DEV_POLL_REACTOR_HPP
+#define ASIO_DETAIL_DEV_POLL_REACTOR_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_HAS_DEV_POLL)
+
+#include <cstddef>
+#include <vector>
+#include <sys/devpoll.h>
+#include "asio/detail/hash_map.hpp"
+#include "asio/detail/limits.hpp"
+#include "asio/detail/mutex.hpp"
+#include "asio/detail/op_queue.hpp"
+#include "asio/detail/reactor_op.hpp"
+#include "asio/detail/reactor_op_queue.hpp"
+#include "asio/detail/scheduler_task.hpp"
+#include "asio/detail/select_interrupter.hpp"
+#include "asio/detail/socket_types.hpp"
+#include "asio/detail/timer_queue_base.hpp"
+#include "asio/detail/timer_queue_set.hpp"
+#include "asio/detail/wait_op.hpp"
+#include "asio/execution_context.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+class dev_poll_reactor
+  : public execution_context_service_base<dev_poll_reactor>,
+    public scheduler_task
+{
+public:
+  enum op_types { read_op = 0, write_op = 1,
+    connect_op = 1, except_op = 2, max_ops = 3 };
+
+  // Per-descriptor data.
+  struct per_descriptor_data
+  {
+  };
+
+  // Constructor.
+  ASIO_DECL dev_poll_reactor(asio::execution_context& ctx);
+
+  // Destructor.
+  ASIO_DECL ~dev_poll_reactor();
+
+  // Destroy all user-defined handler objects owned by the service.
+  ASIO_DECL void shutdown();
+
+  // Recreate internal descriptors following a fork.
+  ASIO_DECL void notify_fork(
+      asio::execution_context::fork_event fork_ev);
+
+  // Initialise the task.
+  ASIO_DECL void init_task();
+
+  // Register a socket with the reactor. Returns 0 on success, system error
+  // code on failure.
+  ASIO_DECL int register_descriptor(socket_type, per_descriptor_data&);
+
+  // Register a descriptor with an associated single operation. Returns 0 on
+  // success, system error code on failure.
+  ASIO_DECL int register_internal_descriptor(
+      int op_type, socket_type descriptor,
+      per_descriptor_data& descriptor_data, reactor_op* op);
+
+  // Move descriptor registration from one descriptor_data object to another.
+  ASIO_DECL void move_descriptor(socket_type descriptor,
+      per_descriptor_data& target_descriptor_data,
+      per_descriptor_data& source_descriptor_data);
+
+  // Post a reactor operation for immediate completion.
+  void post_immediate_completion(reactor_op* op, bool is_continuation);
+
+  // Start a new operation. The reactor operation will be performed when the
+  // given descriptor is flagged as ready, or an error has occurred.
+  ASIO_DECL void start_op(int op_type, socket_type descriptor,
+      per_descriptor_data&, reactor_op* op,
+      bool is_continuation, bool allow_speculative);
+
+  // Cancel all operations associated with the given descriptor. The
+  // handlers associated with the descriptor will be invoked with the
+  // operation_aborted error.
+  ASIO_DECL void cancel_ops(socket_type descriptor, per_descriptor_data&);
+
+  // Cancel all operations associated with the given descriptor and key. The
+  // handlers associated with the descriptor will be invoked with the
+  // operation_aborted error.
+  ASIO_DECL void cancel_ops_by_key(socket_type descriptor,
+      per_descriptor_data& descriptor_data,
+      int op_type, void* cancellation_key);
+
+  // Cancel any operations that are running against the descriptor and remove
+  // its registration from the reactor. The reactor resources associated with
+  // the descriptor must be released by calling cleanup_descriptor_data.
+  ASIO_DECL void deregister_descriptor(socket_type descriptor,
+      per_descriptor_data&, bool closing);
+
+  // Remove the descriptor's registration from the reactor. The reactor
+  // resources associated with the descriptor must be released by calling
+  // cleanup_descriptor_data.
+  ASIO_DECL void deregister_internal_descriptor(
+      socket_type descriptor, per_descriptor_data&);
+
+  // Perform any post-deregistration cleanup tasks associated with the
+  // descriptor data.
+  ASIO_DECL void cleanup_descriptor_data(per_descriptor_data&);
+
+  // Add a new timer queue to the reactor.
+  template <typename Time_Traits>
+  void add_timer_queue(timer_queue<Time_Traits>& queue);
+
+  // Remove a timer queue from the reactor.
+  template <typename Time_Traits>
+  void remove_timer_queue(timer_queue<Time_Traits>& queue);
+
+  // Schedule a new operation in the given timer queue to expire at the
+  // specified absolute time.
+  template <typename Time_Traits>
+  void schedule_timer(timer_queue<Time_Traits>& queue,
+      const typename Time_Traits::time_type& time,
+      typename timer_queue<Time_Traits>::per_timer_data& timer, wait_op* op);
+
+  // Cancel the timer operations associated with the given token. Returns the
+  // number of operations that have been posted or dispatched.
+  template <typename Time_Traits>
+  std::size_t cancel_timer(timer_queue<Time_Traits>& queue,
+      typename timer_queue<Time_Traits>::per_timer_data& timer,
+      std::size_t max_cancelled = (std::numeric_limits<std::size_t>::max)());
+
+  // Cancel the timer operations associated with the given key.
+  template <typename Time_Traits>
+  void cancel_timer_by_key(timer_queue<Time_Traits>& queue,
+      typename timer_queue<Time_Traits>::per_timer_data* timer,
+      void* cancellation_key);
+
+  // Move the timer operations associated with the given timer.
+  template <typename Time_Traits>
+  void move_timer(timer_queue<Time_Traits>& queue,
+      typename timer_queue<Time_Traits>::per_timer_data& target,
+      typename timer_queue<Time_Traits>::per_timer_data& source);
+
+  // Run /dev/poll once until interrupted or events are ready to be dispatched.
+  ASIO_DECL void run(long usec, op_queue<operation>& ops);
+
+  // Interrupt the select loop.
+  ASIO_DECL void interrupt();
+
+private:
+  // Create the /dev/poll file descriptor. Throws an exception if the descriptor
+  // cannot be created.
+  ASIO_DECL static int do_dev_poll_create();
+
+  // Helper function to add a new timer queue.
+  ASIO_DECL void do_add_timer_queue(timer_queue_base& queue);
+
+  // Helper function to remove a timer queue.
+  ASIO_DECL void do_remove_timer_queue(timer_queue_base& queue);
+
+  // Get the timeout value for the /dev/poll DP_POLL operation. The timeout
+  // value is returned as a number of milliseconds. A return value of -1
+  // indicates that the poll should block indefinitely.
+  ASIO_DECL int get_timeout(int msec);
+
+  // Cancel all operations associated with the given descriptor. The do_cancel
+  // function of the handler objects will be invoked. This function does not
+  // acquire the dev_poll_reactor's mutex.
+  ASIO_DECL void cancel_ops_unlocked(socket_type descriptor,
+      const asio::error_code& ec);
+
+  // Add a pending event entry for the given descriptor.
+  ASIO_DECL ::pollfd& add_pending_event_change(int descriptor);
+
+  // The scheduler implementation used to post completions.
+  scheduler& scheduler_;
+
+  // Mutex to protect access to internal data.
+  asio::detail::mutex mutex_;
+
+  // The /dev/poll file descriptor.
+  int dev_poll_fd_;
+
+  // Vector of /dev/poll events waiting to be written to the descriptor.
+  std::vector< ::pollfd> pending_event_changes_;
+
+  // Hash map to associate a descriptor with a pending event change index.
+  hash_map<int, std::size_t> pending_event_change_index_;
+
+  // The interrupter is used to break a blocking DP_POLL operation.
+  select_interrupter interrupter_;
+
+  // The queues of read, write and except operations.
+  reactor_op_queue<socket_type> op_queue_[max_ops];
+
+  // The timer queues.
+  timer_queue_set timer_queues_;
+
+  // Whether the service has been shut down.
+  bool shutdown_;
+};
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#include "asio/detail/impl/dev_poll_reactor.hpp"
+#if defined(ASIO_HEADER_ONLY)
+# include "asio/detail/impl/dev_poll_reactor.ipp"
+#endif // defined(ASIO_HEADER_ONLY)
+
+#endif // defined(ASIO_HAS_DEV_POLL)
+
+#endif // ASIO_DETAIL_DEV_POLL_REACTOR_HPP

lib/asio/include/asio/detail/epoll_reactor.hpp

@@ -0,0 +1,278 @@
+//
+// detail/epoll_reactor.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_EPOLL_REACTOR_HPP
+#define ASIO_DETAIL_EPOLL_REACTOR_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_HAS_EPOLL)
+
+#include "asio/detail/atomic_count.hpp"
+#include "asio/detail/conditionally_enabled_mutex.hpp"
+#include "asio/detail/limits.hpp"
+#include "asio/detail/object_pool.hpp"
+#include "asio/detail/op_queue.hpp"
+#include "asio/detail/reactor_op.hpp"
+#include "asio/detail/scheduler_task.hpp"
+#include "asio/detail/select_interrupter.hpp"
+#include "asio/detail/socket_types.hpp"
+#include "asio/detail/timer_queue_base.hpp"
+#include "asio/detail/timer_queue_set.hpp"
+#include "asio/detail/wait_op.hpp"
+#include "asio/execution_context.hpp"
+
+#if defined(ASIO_HAS_TIMERFD)
+# include <sys/timerfd.h>
+#endif // defined(ASIO_HAS_TIMERFD)
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+class epoll_reactor
+  : public execution_context_service_base<epoll_reactor>,
+    public scheduler_task
+{
+private:
+  // The mutex type used by this reactor.
+  typedef conditionally_enabled_mutex mutex;
+
+public:
+  enum op_types { read_op = 0, write_op = 1,
+    connect_op = 1, except_op = 2, max_ops = 3 };
+
+  // Per-descriptor queues.
+  class descriptor_state : operation
+  {
+    friend class epoll_reactor;
+    friend class object_pool_access;
+
+    descriptor_state* next_;
+    descriptor_state* prev_;
+
+    mutex mutex_;
+    epoll_reactor* reactor_;
+    int descriptor_;
+    uint32_t registered_events_;
+    op_queue<reactor_op> op_queue_[max_ops];
+    bool try_speculative_[max_ops];
+    bool shutdown_;
+
+    ASIO_DECL descriptor_state(bool locking);
+    void set_ready_events(uint32_t events) { task_result_ = events; }
+    void add_ready_events(uint32_t events) { task_result_ |= events; }
+    ASIO_DECL operation* perform_io(uint32_t events);
+    ASIO_DECL static void do_complete(
+        void* owner, operation* base,
+        const asio::error_code& ec, std::size_t bytes_transferred);
+  };
+
+  // Per-descriptor data.
+  typedef descriptor_state* per_descriptor_data;
+
+  // Constructor.
+  ASIO_DECL epoll_reactor(asio::execution_context& ctx);
+
+  // Destructor.
+  ASIO_DECL ~epoll_reactor();
+
+  // Destroy all user-defined handler objects owned by the service.
+  ASIO_DECL void shutdown();
+
+  // Recreate internal descriptors following a fork.
+  ASIO_DECL void notify_fork(
+      asio::execution_context::fork_event fork_ev);
+
+  // Initialise the task.
+  ASIO_DECL void init_task();
+
+  // Register a socket with the reactor. Returns 0 on success, system error
+  // code on failure.
+  ASIO_DECL int register_descriptor(socket_type descriptor,
+      per_descriptor_data& descriptor_data);
+
+  // Register a descriptor with an associated single operation. Returns 0 on
+  // success, system error code on failure.
+  ASIO_DECL int register_internal_descriptor(
+      int op_type, socket_type descriptor,
+      per_descriptor_data& descriptor_data, reactor_op* op);
+
+  // Move descriptor registration from one descriptor_data object to another.
+  ASIO_DECL void move_descriptor(socket_type descriptor,
+      per_descriptor_data& target_descriptor_data,
+      per_descriptor_data& source_descriptor_data);
+
+  // Post a reactor operation for immediate completion.
+  void post_immediate_completion(operation* op, bool is_continuation);
+
+  // Start a new operation. The reactor operation will be performed when the
+  // given descriptor is flagged as ready, or an error has occurred.
+  ASIO_DECL void start_op(int op_type, socket_type descriptor,
+      per_descriptor_data& descriptor_data, reactor_op* op,
+      bool is_continuation, bool allow_speculative);
+
+  // Cancel all operations associated with the given descriptor. The
+  // handlers associated with the descriptor will be invoked with the
+  // operation_aborted error.
+  ASIO_DECL void cancel_ops(socket_type descriptor,
+      per_descriptor_data& descriptor_data);
+
+  // Cancel all operations associated with the given descriptor and key. The
+  // handlers associated with the descriptor will be invoked with the
+  // operation_aborted error.
+  ASIO_DECL void cancel_ops_by_key(socket_type descriptor,
+      per_descriptor_data& descriptor_data,
+      int op_type, void* cancellation_key);
+
+  // Cancel any operations that are running against the descriptor and remove
+  // its registration from the reactor. The reactor resources associated with
+  // the descriptor must be released by calling cleanup_descriptor_data.
+  ASIO_DECL void deregister_descriptor(socket_type descriptor,
+      per_descriptor_data& descriptor_data, bool closing);
+
+  // Remove the descriptor's registration from the reactor. The reactor
+  // resources associated with the descriptor must be released by calling
+  // cleanup_descriptor_data.
+  ASIO_DECL void deregister_internal_descriptor(
+      socket_type descriptor, per_descriptor_data& descriptor_data);
+
+  // Perform any post-deregistration cleanup tasks associated with the
+  // descriptor data.
+  ASIO_DECL void cleanup_descriptor_data(
+      per_descriptor_data& descriptor_data);
+
+  // Add a new timer queue to the reactor.
+  template <typename Time_Traits>
+  void add_timer_queue(timer_queue<Time_Traits>& timer_queue);
+
+  // Remove a timer queue from the reactor.
+  template <typename Time_Traits>
+  void remove_timer_queue(timer_queue<Time_Traits>& timer_queue);
+
+  // Schedule a new operation in the given timer queue to expire at the
+  // specified absolute time.
+  template <typename Time_Traits>
+  void schedule_timer(timer_queue<Time_Traits>& queue,
+      const typename Time_Traits::time_type& time,
+      typename timer_queue<Time_Traits>::per_timer_data& timer, wait_op* op);
+
+  // Cancel the timer operations associated with the given token. Returns the
+  // number of operations that have been posted or dispatched.
+  template <typename Time_Traits>
+  std::size_t cancel_timer(timer_queue<Time_Traits>& queue,
+      typename timer_queue<Time_Traits>::per_timer_data& timer,
+      std::size_t max_cancelled = (std::numeric_limits<std::size_t>::max)());
+
+  // Cancel the timer operations associated with the given key.
+  template <typename Time_Traits>
+  void cancel_timer_by_key(timer_queue<Time_Traits>& queue,
+      typename timer_queue<Time_Traits>::per_timer_data* timer,
+      void* cancellation_key);
+
+  // Move the timer operations associated with the given timer.
+  template <typename Time_Traits>
+  void move_timer(timer_queue<Time_Traits>& queue,
+      typename timer_queue<Time_Traits>::per_timer_data& target,
+      typename timer_queue<Time_Traits>::per_timer_data& source);
+
+  // Run epoll once until interrupted or events are ready to be dispatched.
+  ASIO_DECL void run(long usec, op_queue<operation>& ops);
+
+  // Interrupt the select loop.
+  ASIO_DECL void interrupt();
+
+private:
+  // The hint to pass to epoll_create to size its data structures.
+  enum { epoll_size = 20000 };
+
+  // Create the epoll file descriptor. Throws an exception if the descriptor
+  // cannot be created.
+  ASIO_DECL static int do_epoll_create();
+
+  // Create the timerfd file descriptor. Does not throw.
+  ASIO_DECL static int do_timerfd_create();
+
+  // Allocate a new descriptor state object.
+  ASIO_DECL descriptor_state* allocate_descriptor_state();
+
+  // Free an existing descriptor state object.
+  ASIO_DECL void free_descriptor_state(descriptor_state* s);
+
+  // Helper function to add a new timer queue.
+  ASIO_DECL void do_add_timer_queue(timer_queue_base& queue);
+
+  // Helper function to remove a timer queue.
+  ASIO_DECL void do_remove_timer_queue(timer_queue_base& queue);
+
+  // Called to recalculate and update the timeout.
+  ASIO_DECL void update_timeout();
+
+  // Get the timeout value for the epoll_wait call. The timeout value is
+  // returned as a number of milliseconds. A return value of -1 indicates
+  // that epoll_wait should block indefinitely.
+  ASIO_DECL int get_timeout(int msec);
+
+#if defined(ASIO_HAS_TIMERFD)
+  // Get the timeout value for the timer descriptor. The return value is the
+  // flag argument to be used when calling timerfd_settime.
+  ASIO_DECL int get_timeout(itimerspec& ts);
+#endif // defined(ASIO_HAS_TIMERFD)
+
+  // The scheduler implementation used to post completions.
+  scheduler& scheduler_;
+
+  // Mutex to protect access to internal data.
+  mutex mutex_;
+
+  // The interrupter is used to break a blocking epoll_wait call.
+  select_interrupter interrupter_;
+
+  // The epoll file descriptor.
+  int epoll_fd_;
+
+  // The timer file descriptor.
+  int timer_fd_;
+
+  // The timer queues.
+  timer_queue_set timer_queues_;
+
+  // Whether the service has been shut down.
+  bool shutdown_;
+
+  // Mutex to protect access to the registered descriptors.
+  mutex registered_descriptors_mutex_;
+
+  // Keep track of all registered descriptors.
+  object_pool<descriptor_state> registered_descriptors_;
+
+  // Helper class to do post-perform_io cleanup.
+  struct perform_io_cleanup_on_block_exit;
+  friend struct perform_io_cleanup_on_block_exit;
+};
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#include "asio/detail/impl/epoll_reactor.hpp"
+#if defined(ASIO_HEADER_ONLY)
+# include "asio/detail/impl/epoll_reactor.ipp"
+#endif // defined(ASIO_HEADER_ONLY)
+
+#endif // defined(ASIO_HAS_EPOLL)
+
+#endif // ASIO_DETAIL_EPOLL_REACTOR_HPP

lib/asio/include/asio/detail/event.hpp

@@ -0,0 +1,48 @@
+//
+// detail/event.hpp
+// ~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_EVENT_HPP
+#define ASIO_DETAIL_EVENT_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if !defined(ASIO_HAS_THREADS)
+# include "asio/detail/null_event.hpp"
+#elif defined(ASIO_WINDOWS)
+# include "asio/detail/win_event.hpp"
+#elif defined(ASIO_HAS_PTHREADS)
+# include "asio/detail/posix_event.hpp"
+#elif defined(ASIO_HAS_STD_MUTEX_AND_CONDVAR)
+# include "asio/detail/std_event.hpp"
+#else
+# error Only Windows, POSIX and std::condition_variable are supported!
+#endif
+
+namespace asio {
+namespace detail {
+
+#if !defined(ASIO_HAS_THREADS)
+typedef null_event event;
+#elif defined(ASIO_WINDOWS)
+typedef win_event event;
+#elif defined(ASIO_HAS_PTHREADS)
+typedef posix_event event;
+#elif defined(ASIO_HAS_STD_MUTEX_AND_CONDVAR)
+typedef std_event event;
+#endif
+
+} // namespace detail
+} // namespace asio
+
+#endif // ASIO_DETAIL_EVENT_HPP

lib/asio/include/asio/detail/eventfd_select_interrupter.hpp

@@ -0,0 +1,83 @@
+//
+// detail/eventfd_select_interrupter.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+// Copyright (c) 2008 Roelof Naude (roelof.naude at gmail dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_EVENTFD_SELECT_INTERRUPTER_HPP
+#define ASIO_DETAIL_EVENTFD_SELECT_INTERRUPTER_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_HAS_EVENTFD)
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+class eventfd_select_interrupter
+{
+public:
+  // Constructor.
+  ASIO_DECL eventfd_select_interrupter();
+
+  // Destructor.
+  ASIO_DECL ~eventfd_select_interrupter();
+
+  // Recreate the interrupter's descriptors. Used after a fork.
+  ASIO_DECL void recreate();
+
+  // Interrupt the select call.
+  ASIO_DECL void interrupt();
+
+  // Reset the select interrupter. Returns true if the reset was successful.
+  ASIO_DECL bool reset();
+
+  // Get the read descriptor to be passed to select.
+  int read_descriptor() const
+  {
+    return read_descriptor_;
+  }
+
+private:
+  // Open the descriptors. Throws on error.
+  ASIO_DECL void open_descriptors();
+
+  // Close the descriptors.
+  ASIO_DECL void close_descriptors();
+
+  // The read end of a connection used to interrupt the select call. This file
+  // descriptor is passed to select such that when it is time to stop, a single
+  // 64bit value will be written on the other end of the connection and this
+  // descriptor will become readable.
+  int read_descriptor_;
+
+  // The write end of a connection used to interrupt the select call. A single
+  // 64bit non-zero value may be written to this to wake up the select which is
+  // waiting for the other end to become readable. This descriptor will only
+  // differ from the read descriptor when a pipe is used.
+  int write_descriptor_;
+};
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#if defined(ASIO_HEADER_ONLY)
+# include "asio/detail/impl/eventfd_select_interrupter.ipp"
+#endif // defined(ASIO_HEADER_ONLY)
+
+#endif // defined(ASIO_HAS_EVENTFD)
+
+#endif // ASIO_DETAIL_EVENTFD_SELECT_INTERRUPTER_HPP

lib/asio/include/asio/detail/executor_function.hpp

@@ -0,0 +1,204 @@
+//
+// detail/executor_function.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_EXECUTOR_FUNCTION_HPP
+#define ASIO_DETAIL_EXECUTOR_FUNCTION_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+#include "asio/detail/handler_alloc_helpers.hpp"
+#include "asio/detail/handler_invoke_helpers.hpp"
+#include "asio/detail/memory.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+#if defined(ASIO_HAS_MOVE)
+
+// Lightweight, move-only function object wrapper.
+class executor_function
+{
+public:
+  template <typename F, typename Alloc>
+  explicit executor_function(F f, const Alloc& a)
+  {
+    // Allocate and construct an object to wrap the function.
+    typedef impl<F, Alloc> impl_type;
+    typename impl_type::ptr p = {
+      detail::addressof(a), impl_type::ptr::allocate(a), 0 };
+    impl_ = new (p.v) impl_type(ASIO_MOVE_CAST(F)(f), a);
+    p.v = 0;
+  }
+
+  executor_function(executor_function&& other) ASIO_NOEXCEPT
+    : impl_(other.impl_)
+  {
+    other.impl_ = 0;
+  }
+
+  ~executor_function()
+  {
+    if (impl_)
+      impl_->complete_(impl_, false);
+  }
+
+  void operator()()
+  {
+    if (impl_)
+    {
+      impl_base* i = impl_;
+      impl_ = 0;
+      i->complete_(i, true);
+    }
+  }
+
+private:
+  // Base class for polymorphic function implementations.
+  struct impl_base
+  {
+    void (*complete_)(impl_base*, bool);
+  };
+
+  // Polymorphic function implementation.
+  template <typename Function, typename Alloc>
+  struct impl : impl_base
+  {
+    ASIO_DEFINE_TAGGED_HANDLER_ALLOCATOR_PTR(
+        thread_info_base::executor_function_tag, impl);
+
+    template <typename F>
+    impl(ASIO_MOVE_ARG(F) f, const Alloc& a)
+      : function_(ASIO_MOVE_CAST(F)(f)),
+        allocator_(a)
+    {
+      complete_ = &executor_function::complete<Function, Alloc>;
+    }
+
+    Function function_;
+    Alloc allocator_;
+  };
+
+  // Helper to complete function invocation.
+  template <typename Function, typename Alloc>
+  static void complete(impl_base* base, bool call)
+  {
+    // Take ownership of the function object.
+    impl<Function, Alloc>* i(static_cast<impl<Function, Alloc>*>(base));
+    Alloc allocator(i->allocator_);
+    typename impl<Function, Alloc>::ptr p = {
+      detail::addressof(allocator), i, i };
+
+    // Make a copy of the function so that the memory can be deallocated before
+    // the upcall is made. Even if we're not about to make an upcall, a
+    // sub-object of the function may be the true owner of the memory
+    // associated with the function. Consequently, a local copy of the function
+    // is required to ensure that any owning sub-object remains valid until
+    // after we have deallocated the memory here.
+    Function function(ASIO_MOVE_CAST(Function)(i->function_));
+    p.reset();
+
+    // Make the upcall if required.
+    if (call)
+    {
+      asio_handler_invoke_helpers::invoke(function, function);
+    }
+  }
+
+  impl_base* impl_;
+};
+
+#else // defined(ASIO_HAS_MOVE)
+
+// Not so lightweight, copyable function object wrapper.
+class executor_function
+{
+public:
+  template <typename F, typename Alloc>
+  explicit executor_function(const F& f, const Alloc&)
+    : impl_(new impl<typename decay<F>::type>(f))
+  {
+  }
+
+  void operator()()
+  {
+    impl_->complete_(impl_.get());
+  }
+
+private:
+  // Base class for polymorphic function implementations.
+  struct impl_base
+  {
+    void (*complete_)(impl_base*);
+  };
+
+  // Polymorphic function implementation.
+  template <typename F>
+  struct impl : impl_base
+  {
+    impl(const F& f)
+      : function_(f)
+    {
+      complete_ = &executor_function::complete<F>;
+    }
+
+    F function_;
+  };
+
+  // Helper to complete function invocation.
+  template <typename F>
+  static void complete(impl_base* i)
+  {
+    static_cast<impl<F>*>(i)->function_();
+  }
+
+  shared_ptr<impl_base> impl_;
+};
+
+#endif // defined(ASIO_HAS_MOVE)
+
+// Lightweight, non-owning, copyable function object wrapper.
+class executor_function_view
+{
+public:
+  template <typename F>
+  explicit executor_function_view(F& f) ASIO_NOEXCEPT
+    : complete_(&executor_function_view::complete<F>),
+      function_(&f)
+  {
+  }
+
+  void operator()()
+  {
+    complete_(function_);
+  }
+
+private:
+  // Helper to complete function invocation.
+  template <typename F>
+  static void complete(void* f)
+  {
+    (*static_cast<F*>(f))();
+  }
+
+  void (*complete_)(void*);
+  void* function_;
+};
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // ASIO_DETAIL_EXECUTOR_FUNCTION_HPP

lib/asio/include/asio/detail/executor_op.hpp

@@ -0,0 +1,84 @@
+//
+// detail/executor_op.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_EXECUTOR_OP_HPP
+#define ASIO_DETAIL_EXECUTOR_OP_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+#include "asio/detail/fenced_block.hpp"
+#include "asio/detail/handler_alloc_helpers.hpp"
+#include "asio/detail/handler_invoke_helpers.hpp"
+#include "asio/detail/scheduler_operation.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+template <typename Handler, typename Alloc,
+    typename Operation = scheduler_operation>
+class executor_op : public Operation
+{
+public:
+  ASIO_DEFINE_HANDLER_ALLOCATOR_PTR(executor_op);
+
+  template <typename H>
+  executor_op(ASIO_MOVE_ARG(H) h, const Alloc& allocator)
+    : Operation(&executor_op::do_complete),
+      handler_(ASIO_MOVE_CAST(H)(h)),
+      allocator_(allocator)
+  {
+  }
+
+  static void do_complete(void* owner, Operation* base,
+      const asio::error_code& /*ec*/,
+      std::size_t /*bytes_transferred*/)
+  {
+    // Take ownership of the handler object.
+    executor_op* o(static_cast<executor_op*>(base));
+    Alloc allocator(o->allocator_);
+    ptr p = { detail::addressof(allocator), o, o };
+
+    ASIO_HANDLER_COMPLETION((*o));
+
+    // Make a copy of the handler so that the memory can be deallocated before
+    // the upcall is made. Even if we're not about to make an upcall, a
+    // sub-object of the handler may be the true owner of the memory associated
+    // with the handler. Consequently, a local copy of the handler is required
+    // to ensure that any owning sub-object remains valid until after we have
+    // deallocated the memory here.
+    Handler handler(ASIO_MOVE_CAST(Handler)(o->handler_));
+    p.reset();
+
+    // Make the upcall if required.
+    if (owner)
+    {
+      fenced_block b(fenced_block::half);
+      ASIO_HANDLER_INVOCATION_BEGIN(());
+      asio_handler_invoke_helpers::invoke(handler, handler);
+      ASIO_HANDLER_INVOCATION_END;
+    }
+  }
+
+private:
+  Handler handler_;
+  Alloc allocator_;
+};
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // ASIO_DETAIL_EXECUTOR_OP_HPP

lib/asio/include/asio/detail/fd_set_adapter.hpp

@@ -0,0 +1,39 @@
+//
+// detail/fd_set_adapter.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_FD_SET_ADAPTER_HPP
+#define ASIO_DETAIL_FD_SET_ADAPTER_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if !defined(ASIO_WINDOWS_RUNTIME)
+
+#include "asio/detail/posix_fd_set_adapter.hpp"
+#include "asio/detail/win_fd_set_adapter.hpp"
+
+namespace asio {
+namespace detail {
+
+#if defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+typedef win_fd_set_adapter fd_set_adapter;
+#else
+typedef posix_fd_set_adapter fd_set_adapter;
+#endif
+
+} // namespace detail
+} // namespace asio
+
+#endif // !defined(ASIO_WINDOWS_RUNTIME)
+
+#endif // ASIO_DETAIL_FD_SET_ADAPTER_HPP

lib/asio/include/asio/detail/fenced_block.hpp

@@ -0,0 +1,80 @@
+//
+// detail/fenced_block.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_FENCED_BLOCK_HPP
+#define ASIO_DETAIL_FENCED_BLOCK_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if !defined(ASIO_HAS_THREADS) \
+  || defined(ASIO_DISABLE_FENCED_BLOCK)
+# include "asio/detail/null_fenced_block.hpp"
+#elif defined(ASIO_HAS_STD_ATOMIC)
+# include "asio/detail/std_fenced_block.hpp"
+#elif defined(__MACH__) && defined(__APPLE__)
+# include "asio/detail/macos_fenced_block.hpp"
+#elif defined(__sun)
+# include "asio/detail/solaris_fenced_block.hpp"
+#elif defined(__GNUC__) && defined(__arm__) \
+  && !defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4)
+# include "asio/detail/gcc_arm_fenced_block.hpp"
+#elif defined(__GNUC__) && (defined(__hppa) || defined(__hppa__))
+# include "asio/detail/gcc_hppa_fenced_block.hpp"
+#elif defined(__GNUC__) && (defined(__i386__) || defined(__x86_64__))
+# include "asio/detail/gcc_x86_fenced_block.hpp"
+#elif defined(__GNUC__) \
+  && ((__GNUC__ == 4 && __GNUC_MINOR__ >= 1) || (__GNUC__ > 4)) \
+  && !defined(__INTEL_COMPILER) && !defined(__ICL) \
+  && !defined(__ICC) && !defined(__ECC) && !defined(__PATHSCALE__)
+# include "asio/detail/gcc_sync_fenced_block.hpp"
+#elif defined(ASIO_WINDOWS) && !defined(UNDER_CE)
+# include "asio/detail/win_fenced_block.hpp"
+#else
+# include "asio/detail/null_fenced_block.hpp"
+#endif
+
+namespace asio {
+namespace detail {
+
+#if !defined(ASIO_HAS_THREADS) \
+  || defined(ASIO_DISABLE_FENCED_BLOCK)
+typedef null_fenced_block fenced_block;
+#elif defined(ASIO_HAS_STD_ATOMIC)
+typedef std_fenced_block fenced_block;
+#elif defined(__MACH__) && defined(__APPLE__)
+typedef macos_fenced_block fenced_block;
+#elif defined(__sun)
+typedef solaris_fenced_block fenced_block;
+#elif defined(__GNUC__) && defined(__arm__) \
+  && !defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4)
+typedef gcc_arm_fenced_block fenced_block;
+#elif defined(__GNUC__) && (defined(__hppa) || defined(__hppa__))
+typedef gcc_hppa_fenced_block fenced_block;
+#elif defined(__GNUC__) && (defined(__i386__) || defined(__x86_64__))
+typedef gcc_x86_fenced_block fenced_block;
+#elif defined(__GNUC__) \
+  && ((__GNUC__ == 4 && __GNUC_MINOR__ >= 1) || (__GNUC__ > 4)) \
+  && !defined(__INTEL_COMPILER) && !defined(__ICL) \
+  && !defined(__ICC) && !defined(__ECC) && !defined(__PATHSCALE__)
+typedef gcc_sync_fenced_block fenced_block;
+#elif defined(ASIO_WINDOWS) && !defined(UNDER_CE)
+typedef win_fenced_block fenced_block;
+#else
+typedef null_fenced_block fenced_block;
+#endif
+
+} // namespace detail
+} // namespace asio
+
+#endif // ASIO_DETAIL_FENCED_BLOCK_HPP

lib/asio/include/asio/detail/functional.hpp

@@ -0,0 +1,44 @@
+//
+// detail/functional.hpp
+// ~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_FUNCTIONAL_HPP
+#define ASIO_DETAIL_FUNCTIONAL_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#include <functional>
+
+#if !defined(ASIO_HAS_STD_FUNCTION)
+# include <boost/function.hpp>
+#endif // !defined(ASIO_HAS_STD_FUNCTION)
+
+namespace asio {
+namespace detail {
+
+#if defined(ASIO_HAS_STD_FUNCTION)
+using std::function;
+#else // defined(ASIO_HAS_STD_FUNCTION)
+using boost::function;
+#endif // defined(ASIO_HAS_STD_FUNCTION)
+
+} // namespace detail
+
+#if defined(ASIO_HAS_STD_REFERENCE_WRAPPER)
+using std::ref;
+using std::reference_wrapper;
+#endif // defined(ASIO_HAS_STD_REFERENCE_WRAPPER)
+
+} // namespace asio
+
+#endif // ASIO_DETAIL_FUNCTIONAL_HPP

lib/asio/include/asio/detail/future.hpp

@@ -0,0 +1,33 @@
+//
+// detail/future.hpp
+// ~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_FUTURE_HPP
+#define ASIO_DETAIL_FUTURE_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+#if defined(ASIO_HAS_STD_FUTURE)
+# include <future>
+// Even though the future header is available, libstdc++ may not implement the
+// std::future class itself. However, we need to have already included the
+// future header to reliably test for _GLIBCXX_HAS_GTHREADS.
+# if defined(__GNUC__) && !defined(ASIO_HAS_CLANG_LIBCXX)
+#  if defined(_GLIBCXX_HAS_GTHREADS)
+#   define ASIO_HAS_STD_FUTURE_CLASS 1
+#  endif // defined(_GLIBCXX_HAS_GTHREADS)
+# else // defined(__GNUC__) && !defined(ASIO_HAS_CLANG_LIBCXX)
+#  define ASIO_HAS_STD_FUTURE_CLASS 1
+# endif // defined(__GNUC__) && !defined(ASIO_HAS_CLANG_LIBCXX)
+#endif // defined(ASIO_HAS_STD_FUTURE)
+
+#endif // ASIO_DETAIL_FUTURE_HPP

lib/asio/include/asio/detail/gcc_arm_fenced_block.hpp

@@ -0,0 +1,91 @@
+//
+// detail/gcc_arm_fenced_block.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_GCC_ARM_FENCED_BLOCK_HPP
+#define ASIO_DETAIL_GCC_ARM_FENCED_BLOCK_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(__GNUC__) && defined(__arm__)
+
+#include "asio/detail/noncopyable.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+class gcc_arm_fenced_block
+  : private noncopyable
+{
+public:
+  enum half_t { half };
+  enum full_t { full };
+
+  // Constructor for a half fenced block.
+  explicit gcc_arm_fenced_block(half_t)
+  {
+  }
+
+  // Constructor for a full fenced block.
+  explicit gcc_arm_fenced_block(full_t)
+  {
+    barrier();
+  }
+
+  // Destructor.
+  ~gcc_arm_fenced_block()
+  {
+    barrier();
+  }
+
+private:
+  static void barrier()
+  {
+#if defined(__ARM_ARCH_4__) \
+    || defined(__ARM_ARCH_4T__) \
+    || defined(__ARM_ARCH_5__) \
+    || defined(__ARM_ARCH_5E__) \
+    || defined(__ARM_ARCH_5T__) \
+    || defined(__ARM_ARCH_5TE__) \
+    || defined(__ARM_ARCH_5TEJ__) \
+    || defined(__ARM_ARCH_6__) \
+    || defined(__ARM_ARCH_6J__) \
+    || defined(__ARM_ARCH_6K__) \
+    || defined(__ARM_ARCH_6Z__) \
+    || defined(__ARM_ARCH_6ZK__) \
+    || defined(__ARM_ARCH_6T2__)
+# if defined(__thumb__)
+    // This is just a placeholder and almost certainly not sufficient.
+    __asm__ __volatile__ ("" : : : "memory");
+# else // defined(__thumb__)
+    int a = 0, b = 0;
+    __asm__ __volatile__ ("swp %0, %1, [%2]"
+        : "=&r"(a) : "r"(1), "r"(&b) : "memory", "cc");
+# endif // defined(__thumb__)
+#else
+    // ARMv7 and later.
+    __asm__ __volatile__ ("dmb" : : : "memory");
+#endif
+  }
+};
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // defined(__GNUC__) && defined(__arm__)
+
+#endif // ASIO_DETAIL_GCC_ARM_FENCED_BLOCK_HPP

lib/asio/include/asio/detail/gcc_hppa_fenced_block.hpp

@@ -0,0 +1,68 @@
+//
+// detail/gcc_hppa_fenced_block.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_GCC_HPPA_FENCED_BLOCK_HPP
+#define ASIO_DETAIL_GCC_HPPA_FENCED_BLOCK_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(__GNUC__) && (defined(__hppa) || defined(__hppa__))
+
+#include "asio/detail/noncopyable.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+class gcc_hppa_fenced_block
+  : private noncopyable
+{
+public:
+  enum half_t { half };
+  enum full_t { full };
+
+  // Constructor for a half fenced block.
+  explicit gcc_hppa_fenced_block(half_t)
+  {
+  }
+
+  // Constructor for a full fenced block.
+  explicit gcc_hppa_fenced_block(full_t)
+  {
+    barrier();
+  }
+
+  // Destructor.
+  ~gcc_hppa_fenced_block()
+  {
+    barrier();
+  }
+
+private:
+  static void barrier()
+  {
+    // This is just a placeholder and almost certainly not sufficient.
+    __asm__ __volatile__ ("" : : : "memory");
+  }
+};
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // defined(__GNUC__) && (defined(__hppa) || defined(__hppa__))
+
+#endif // ASIO_DETAIL_GCC_HPPA_FENCED_BLOCK_HPP

lib/asio/include/asio/detail/gcc_sync_fenced_block.hpp

@@ -0,0 +1,65 @@
+//
+// detail/gcc_sync_fenced_block.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_GCC_SYNC_FENCED_BLOCK_HPP
+#define ASIO_DETAIL_GCC_SYNC_FENCED_BLOCK_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(__GNUC__) \
+  && ((__GNUC__ == 4 && __GNUC_MINOR__ >= 1) || (__GNUC__ > 4)) \
+  && !defined(__INTEL_COMPILER) && !defined(__ICL) \
+  && !defined(__ICC) && !defined(__ECC) && !defined(__PATHSCALE__)
+
+#include "asio/detail/noncopyable.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+class gcc_sync_fenced_block
+  : private noncopyable
+{
+public:
+  enum half_or_full_t { half, full };
+
+  // Constructor.
+  explicit gcc_sync_fenced_block(half_or_full_t)
+    : value_(0)
+  {
+    __sync_lock_test_and_set(&value_, 1);
+  }
+
+  // Destructor.
+  ~gcc_sync_fenced_block()
+  {
+    __sync_lock_release(&value_);
+  }
+
+private:
+  int value_;
+};
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // defined(__GNUC__)
+       // && ((__GNUC__ == 4 && __GNUC_MINOR__ >= 1) || (__GNUC__ > 4))
+       // && !defined(__INTEL_COMPILER) && !defined(__ICL)
+       // && !defined(__ICC) && !defined(__ECC) && !defined(__PATHSCALE__)
+
+#endif // ASIO_DETAIL_GCC_SYNC_FENCED_BLOCK_HPP

lib/asio/include/asio/detail/gcc_x86_fenced_block.hpp

@@ -0,0 +1,99 @@
+//
+// detail/gcc_x86_fenced_block.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_GCC_X86_FENCED_BLOCK_HPP
+#define ASIO_DETAIL_GCC_X86_FENCED_BLOCK_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(__GNUC__) && (defined(__i386__) || defined(__x86_64__))
+
+#include "asio/detail/noncopyable.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+class gcc_x86_fenced_block
+  : private noncopyable
+{
+public:
+  enum half_t { half };
+  enum full_t { full };
+
+  // Constructor for a half fenced block.
+  explicit gcc_x86_fenced_block(half_t)
+  {
+  }
+
+  // Constructor for a full fenced block.
+  explicit gcc_x86_fenced_block(full_t)
+  {
+    lbarrier();
+  }
+
+  // Destructor.
+  ~gcc_x86_fenced_block()
+  {
+    sbarrier();
+  }
+
+private:
+  static int barrier()
+  {
+    int r = 0, m = 1;
+    __asm__ __volatile__ (
+        "xchgl %0, %1" :
+        "=r"(r), "=m"(m) :
+        "0"(1), "m"(m) :
+        "memory", "cc");
+    return r;
+  }
+
+  static void lbarrier()
+  {
+#if defined(__SSE2__)
+# if (__GNUC__ >= 4) && !defined(__INTEL_COMPILER) && !defined(__ICL)
+    __builtin_ia32_lfence();
+# else // (__GNUC__ >= 4) && !defined(__INTEL_COMPILER) && !defined(__ICL)
+    __asm__ __volatile__ ("lfence" ::: "memory");
+# endif // (__GNUC__ >= 4) && !defined(__INTEL_COMPILER) && !defined(__ICL)
+#else // defined(__SSE2__)
+    barrier();
+#endif // defined(__SSE2__)
+  }
+
+  static void sbarrier()
+  {
+#if defined(__SSE2__)
+# if (__GNUC__ >= 4) && !defined(__INTEL_COMPILER) && !defined(__ICL)
+    __builtin_ia32_sfence();
+# else // (__GNUC__ >= 4) && !defined(__INTEL_COMPILER) && !defined(__ICL)
+    __asm__ __volatile__ ("sfence" ::: "memory");
+# endif // (__GNUC__ >= 4) && !defined(__INTEL_COMPILER) && !defined(__ICL)
+#else // defined(__SSE2__)
+    barrier();
+#endif // defined(__SSE2__)
+  }
+};
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // defined(__GNUC__) && (defined(__i386__) || defined(__x86_64__))
+
+#endif // ASIO_DETAIL_GCC_X86_FENCED_BLOCK_HPP