From 27e0b03b3c8cfb205c170689b20c6b0f37295196 Mon Sep 17 00:00:00 2001
From: kalmar <kalmar@amu.edu.pl>
Date: Tue, 11 Jul 2017 15:58:02 +0200
Subject: [PATCH] move type-related functions to one location

---
 src/GroupRings.jl | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/src/GroupRings.jl b/src/GroupRings.jl
index caede0c..5686c9e 100644
--- a/src/GroupRings.jl
+++ b/src/GroupRings.jl
@@ -65,8 +65,16 @@ elem_type(::GroupRing) = GroupRingElem
 parent_type(::GroupRingElem) = GroupRing
 parent_type(::Type{GroupRingElem}) = GroupRing
 
+eltype(X::GroupRingElem) = eltype(X.coeffs)
+
 parent{T}(g::GroupRingElem{T}) = g.parent
 
+Base.promote_rule{T<:Number,S<:Number}(::Type{GroupRingElem{T}}, ::Type{GroupRingElem{S}}) = GroupRingElem{promote_type(T,S)}
+
+function convert{T<:Number}(::Type{T}, X::GroupRingElem)
+   return GroupRingElem(convert(AbstractVector{T}, X.coeffs), parent(X))
+end
+
 ###############################################################################
 #
 #   GroupRing / GroupRingElem constructors
@@ -77,10 +85,6 @@ function GroupRingElem{T<:Number}(c::AbstractVector{T}, RG::GroupRing)
    return GroupRingElem{T}(c, RG)
 end
 
-function convert{T<:Number}(::Type{T}, X::GroupRingElem)
-   return GroupRingElem(convert(AbstractVector{T}, X.coeffs), parent(X))
-end
-
 function GroupRing(G::Group, pm::Array{Int,2})
    size(pm,1) == size(pm,2) || throw("pm must be square, got $(size(pm))")
    RG = GroupRing(G, initialise=false)