Provide 0.6 implementation of collect for previous releases

README.md

@@ -80,6 +80,8 @@ Currently, the `@compat` macro supports the following syntaxes:
 
 * `@compat Base.IndexStyle(::Type{<:MyArray}) = IndexLinear()` and `@compat Base.IndexStyle(::Type{<:MyArray}) = IndexCartesian()` to define traits for abstract arrays, replacing the former `Base.linearindexing{T<:MyArray}(::Type{T}) = Base.LinearFast()` and `Base.linearindexing{T<:MyArray}(::Type{T}) = Base.LinearSlow()`, respectively.
 
+* `Compat.collect(A)` returns an Array even on 0.5, no matter what indices the array `A` has. [#21257]
+
 ## Module Aliases
 
 * In 0.6, some 0.5 iterator functions have been moved to the `Base.Iterators`
@@ -361,3 +363,4 @@ includes this fix. Find the minimum version from there.
 [#20500]: https://github.com/JuliaLang/julia/issues/20500
 [#18629]: https://github.com/JuliaLang/julia/pull/18629
 [#21346]: https://github.com/JuliaLang/julia/pull/21346
+[#21257]: https://github.com/JuliaLang/julia/pull/21257

src/Compat.jl

@@ -1464,6 +1464,20 @@ if VERSION < v"0.6.0-pre.beta.102"
     Base.bswap(z::Complex) = Complex(bswap(real(z)), bswap(imag(z)))
 end
 
+# https://github.com/JuliaLang/julia/pull/21257
+if v"0.5.0" <= VERSION < v"0.6.0-pre.beta.28"
+    collect(A) = collect_indices(indices(A), A)
+    collect_indices(::Tuple{}, A) = copy!(Array{eltype(A)}(), A)
+    collect_indices(indsA::Tuple{Vararg{Base.OneTo}}, A) =
+        copy!(Array{eltype(A)}(length.(indsA)), A)
+    function collect_indices(indsA, A)
+        B = Array{eltype(A)}(length.(indsA))
+        copy!(B, CartesianRange(indices(B)), A, CartesianRange(indsA))
+    end
+else
+    const collect = Base.collect
+end
+
 include("to-be-deprecated.jl")
 
 end # module Compat

test/REQUIRE

@@ -0,0 +1 @@
+OffsetArrays

test/runtests.jl

@@ -1822,6 +1822,13 @@ let zbuf = IOBuffer([0xbf, 0xc0, 0x00, 0x00, 0x40, 0x20, 0x00, 0x00,
     @test bswap(z2) ===  3.5 - 4.5im
 end
 
+# collect
+if VERSION >= v"0.5.0"
+    using OffsetArrays
+    a = OffsetArray(1:3, -1:1)
+    @test Compat.collect(a) == [1,2,3]
+end
+
 include("to-be-deprecated.jl")
 
 nothing