combine _copy_oftype methods (#250)

* combine _copy_oftype methods * tests for copy
JuliaArrays · May 16, 2023 · 61a1cf9 · 61a1cf9 · jishnub · May 17, 2023
1 parent 549e949
commit 61a1cf9
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Showing 2 changed files with 11 additions and 5 deletions.
diff --git a/src/fillbroadcast.jl b/src/fillbroadcast.jl
@@ -193,10 +193,8 @@ function broadcasted(::DefaultArrayStyle{1}, ::typeof(*), a::AbstractRange{V}, b
     return _range_convert(AbstractVector{promote_type(T,V)}, a)
 end
 
-_copy_oftype(A::AbstractArray{T,N}, ::Type{T}) where {T,N} = copy(A)
-_copy_oftype(A::AbstractArray{T,N}, ::Type{S}) where {T,N,S} = convert(AbstractArray{S,N}, A)
-_copy_oftype(A::AbstractRange{T}, ::Type{T}) where T = copy(A)
-_copy_oftype(A::AbstractRange{T}, ::Type{S}) where {T,S} = map(S, A)
+_copy_oftype(A::AbstractArray, ::Type{S}) where {S} = eltype(A) == S ? copy(A) : AbstractArray{S}(A)
+_copy_oftype(A::AbstractRange, ::Type{S}) where {S} = map(S, A)
 
 for op in (:+, :-)
     @eval begin
@@ -254,4 +252,4 @@ broadcasted(::DefaultArrayStyle{N}, ::typeof(Base.literal_pow), ::Base.RefValue{
 # supports structured broadcast
 if isdefined(LinearAlgebra, :fzero)
     LinearAlgebra.fzero(x::Zeros) = zero(eltype(x))
-end
+end
diff --git a/test/runtests.jl b/test/runtests.jl
@@ -1168,8 +1168,16 @@ end
 
     @test copy(m) ≡ m
     @test copy(D) ≡ D
+    @test FillArrays._copy_oftype(m, eltype(m)) ≡ m
     @test FillArrays._copy_oftype(m, Int) ≡ Eye{Int}(10)
+    @test FillArrays._copy_oftype(D, eltype(D)) ≡ D
     @test FillArrays._copy_oftype(D, Float64) ≡ Diagonal(Fill(2.0,10))
+
+    # test that _copy_oftype does, in fact, copy the array
+    D2 = Diagonal([1,1])
+    @test FillArrays._copy_oftype(D2, Float64) isa Diagonal{Float64}
+    @test FillArrays._copy_oftype(D2, eltype(D2)) == D2
+    @test FillArrays._copy_oftype(D2, eltype(D2)) !== D2
 end
 
 @testset "Issue #31" begin