Prepare for removal of FillArrays._copy_oftype (#148)

* Prepare for removal of `FillArrays._copy_oftype`

* Remove branch

* Add tests

* Update Project.toml

Author: devmotion

Project.toml

@@ -1,7 +1,7 @@
 name = "ArrayLayouts"
 uuid = "4c555306-a7a7-4459-81d9-ec55ddd5c99a"
 authors = ["Sheehan Olver <[email protected]>"]
-version = "1.0.9"
+version = "1.0.10"
 
 [deps]
 FillArrays = "1a297f60-69ca-5386-bcde-b61e274b549b"

src/ArrayLayouts.jl

@@ -25,7 +25,7 @@ using LinearAlgebra.BLAS: BlasFloat, BlasReal, BlasComplex
 
 AdjointQtype{T} = isdefined(LinearAlgebra, :AdjointQ) ? LinearAlgebra.AdjointQ{T} : Adjoint{T,<:AbstractQ}
 
-using FillArrays: AbstractFill, getindex_value, axes_print_matrix_row, _copy_oftype
+using FillArrays: AbstractFill, getindex_value, axes_print_matrix_row
 
 using Base: require_one_based_indexing
 
@@ -52,6 +52,9 @@ else
     const CNoPivot = NoPivot
 end
 
+# Originally defined in FillArrays
+_copy_oftype(A::AbstractArray, ::Type{S}) where {S} = eltype(A) == S ? copy(A) : AbstractArray{S}(A)
+_copy_oftype(A::AbstractRange, ::Type{S}) where {S} = eltype(A) == S ? copy(A) : map(S, A)
 
 struct ApplyBroadcastStyle <: BroadcastStyle end
 @inline function copyto!(dest::AbstractArray, bc::Broadcasted{ApplyBroadcastStyle})

test/runtests.jl

@@ -3,6 +3,7 @@ import ArrayLayouts: MemoryLayout, @_layoutlmul, triangulardata
 
 Random.seed!(0)
 
+include("test_utils.jl")
 include("test_layouts.jl")
 include("test_muladd.jl")
 include("test_ldiv.jl")

test/test_utils.jl

@@ -0,0 +1,38 @@
+using ArrayLayouts, LinearAlgebra, FillArrays, Test
+
+@testset "_copy_oftype" begin
+    # Copied from original implementation in FillArrays
+    @testset "FillArrays" begin
+        m = Eye(10)
+        D = Diagonal(Fill(2,10))
+
+        @test ArrayLayouts._copy_oftype(m, eltype(m)) ≡ m
+        @test ArrayLayouts._copy_oftype(m, Int) ≡ Eye{Int}(10)
+        @test ArrayLayouts._copy_oftype(D, eltype(D)) ≡ D
+        @test ArrayLayouts._copy_oftype(D, Float64) ≡ Diagonal(Fill(2.0,10))
+
+        # test that _copy_oftype does, in fact, copy the array
+        D2 = Diagonal([1,1])
+        @test ArrayLayouts._copy_oftype(D2, Float64) isa Diagonal{Float64}
+        @test ArrayLayouts._copy_oftype(D2, eltype(D2)) == D2
+        @test ArrayLayouts._copy_oftype(D2, eltype(D2)) !== D2
+    end
+
+    @testset "general" begin
+        for T in (Float32, Float64)
+            u = T(1):T(10)
+            v = collect(u)
+            for S in (Float32, Float64)
+                # Usually an actual copy
+                @test ArrayLayouts._copy_oftype(u, S) isa AbstractRange{S}
+                @test ArrayLayouts._copy_oftype(u, S) == u
+                @test (ArrayLayouts._copy_oftype(u, S) === u) === (T === S && copy(u) === u)
+
+                # Always an actual copy
+                @test ArrayLayouts._copy_oftype(v, S) isa Array{S}
+                @test ArrayLayouts._copy_oftype(v, S) == v
+                @test ArrayLayouts._copy_oftype(v, S) !== v
+            end
+        end
+    end
+end