Use promote_eltype_op for ./, .\, and .^ (fixes #14725)

Author: martinholters

base/arraymath.jl

@@ -43,18 +43,12 @@ promote_array_type{S<:Integer}(F, ::Type{S}, ::Type{Bool}) = S
 promote_array_type(F, ::Type{Bool}, ::Type{Bool}) = promote_op(F, Bool, Bool)
 
 # Handle operations that return different types
-./(x::Number, Y::AbstractArray) =
-    reshape([ x ./ y for y in Y ], size(Y))
-./(X::AbstractArray, y::Number) =
-    reshape([ x ./ y for x in X ], size(X))
-.\(x::Number, Y::AbstractArray) =
-    reshape([ x .\ y for y in Y ], size(Y))
-.\(X::AbstractArray, y::Number) =
-    reshape([ x .\ y for x in X ], size(X))
-.^(x::Number, Y::AbstractArray) =
-    reshape([ x ^ y for y in Y ], size(Y))
-.^(X::AbstractArray, y::Number      ) =
-    reshape([ x ^ y for x in X ], size(X))
+for f in (:./, :.\, :.^)
+    @eval ($f)(x::Number, Y::AbstractArray) =
+            reshape((promote_eltype_op($f, x, Y))[ ($f)(x, y) for y in Y ], size(Y))
+    @eval ($f)(X::AbstractArray, y::Number) =
+            reshape((promote_eltype_op($f, X, y))[ ($f)(x, y) for x in X ], size(X))
+end
 
 for f in (:+, :-, :div, :mod, :&, :|, :$)
     @eval begin

base/complex.jl

@@ -32,6 +32,10 @@ promote_op{T<:Real,S<:Real}(op, ::Type{Complex{T}}, ::Type{S}) =
     Complex{promote_op(op,T,S)}
 promote_op{T<:Real,S<:Real}(op, ::Type{T}, ::Type{Complex{S}}) =
     Complex{promote_op(op,T,S)}
+promote_op{T<:Integer,S<:Integer}(::typeof(^), ::Type{T}, ::Type{Complex{S}}) =
+    Complex{Float64}
+promote_op{T<:Integer,S<:Integer}(::typeof(.^), ::Type{T}, ::Type{Complex{S}}) =
+    Complex{Float64}
 
 widen{T}(::Type{Complex{T}}) = Complex{widen(T)}
 

test/broadcast.jl

@@ -116,3 +116,14 @@ rt = Base.return_types(broadcast, Tuple{Function, Array{Float64, 3}, Array{Int,
 @test length(rt) == 1 && rt[1] == Array{Float64, 3}
 rt = Base.return_types(broadcast!, Tuple{Function, Array{Float64, 3}, Array{Float64, 3}, Array{Int, 1}})
 @test length(rt) == 1 && rt[1] == Array{Float64, 3}
+
+# issue 14725
+let a = Number[2, 2.0, 4//2, 2+0im] / 2
+    @test eltype(a) == Number
+end
+let a = Real[2, 2.0, 4//2] / 2
+    @test eltype(a) == Real
+end
+let a = Real[2, 2.0, 4//2] / 2.0
+    @test eltype(a) <: Real # promotion to Float64 would also be possible
+end