Fix eachindex for more than one ReshapedReinterpretArray (JuliaLang#3…

…7999)

base/reinterpretarray.jl

@@ -205,7 +205,12 @@ struct SCartesianIndices2{K,R<:AbstractUnitRange{Int}} <: AbstractMatrix{SCartes
 end
 SCartesianIndices2{K}(indices2::AbstractUnitRange{Int}) where {K} = (@assert K::Int > 1; SCartesianIndices2{K,typeof(indices2)}(indices2))
 
-eachindex(::IndexSCartesian2{K}, A::AbstractArray) where {K} = SCartesianIndices2{K}(eachindex(IndexLinear(), parent(A)))
+eachindex(::IndexSCartesian2{K}, A::ReshapedReinterpretArray) where {K} = SCartesianIndices2{K}(eachindex(IndexLinear(), parent(A)))
+@inline function eachindex(style::IndexSCartesian2{K}, A::AbstractArray, B::AbstractArray...) where {K}
+ iter = eachindex(style, A)
+ Base._all_match_first(C->eachindex(style, C), iter, B...) || Base.throw_eachindex_mismatch_indices(IndexSCartesian2{K}(), axes(A), axes.(B)...)
+ return iter
+end
 
 size(iter::SCartesianIndices2{K}) where K = (K, length(iter.indices2))
 axes(iter::SCartesianIndices2{K}) where K = (Base.OneTo(K), iter.indices2)
@@ -265,7 +270,7 @@ function _setindex!(::IndexSCartesian2, A::AbstractArray{T,N}, v, ind::SCartesia
  J = _ind2sub(tail(axes(A)), ind.j)
  setindex!(A, v, ind.i, J...)
 end
-
+eachindex(style::IndexSCartesian2, A::AbstractArray) = eachindex(style, parent(A))
 
 ## AbstractArray interface
 

test/reinterpretarray.jl

@@ -136,6 +136,7 @@ Azr = reinterpret(reshape, UInt8, Az)
 W = WrapperArray(Azr)
 copyto!(W, fill(0x01, 3, 2, 2))
 @test all(isequal((0x01, 0x01, 0x01)), Az)
+@test eachindex(W, W) == eachindex(W)
 
 # ensure that reinterpret arrays aren't erroneously classified as strided
 let A = reshape(1:20, 5, 4)
@@ -238,6 +239,12 @@ let a = fill(1.0, 5, 3)
  r[goodinds...] = -5
  @test r[goodinds...] == -5
  end
+
+ ar = [(1,2), (3,4)]
+ arr = reinterpret(reshape, Int, ar)
+ @test @inferred(IndexStyle(arr)) == Base.IndexSCartesian2{2}()
+ @test @inferred(eachindex(arr)) == Base.SCartesianIndices2{2}(Base.OneTo(2))
+ @test @inferred(eachindex(arr, arr)) == Base.SCartesianIndices2{2}(Base.OneTo(2))
 end
 
 # Error on reinterprets that would expose padding