Generalize strides for ReshapedArray

Update abstractarray.jl

base/reinterpretarray.jl

@@ -176,6 +176,8 @@ function _checked_strides(stp, N)
     map(first, drs)
 end
 
+_checkcontiguous(::Type{Bool}, A::ReinterpretArray) = _checkcontiguous(Bool, parent(A))
+
 similar(a::ReinterpretArray, T::Type, d::Dims) = similar(a.parent, T, d)
 
 function check_readable(a::ReinterpretArray{T, N, S} where N) where {T,S}

base/reshapedarray.jl

@@ -292,3 +292,16 @@ substrides(strds::NTuple{N,Int}, I::Tuple{ReshapedUnitRange, Vararg{Any}}) where
     (size_to_strides(strds[1], size(I[1])...)..., substrides(tail(strds), tail(I))...)
 unsafe_convert(::Type{Ptr{T}}, V::SubArray{T,N,P,<:Tuple{Vararg{Union{RangeIndex,ReshapedUnitRange}}}}) where {T,N,P} =
     unsafe_convert(Ptr{T}, V.parent) + (first_index(V)-1)*sizeof(T)
+
+
+_checkcontiguous(::Type{Bool}, A::AbstractArray) = size_to_strides(1, size(A)...) == strides(A)
+_checkcontiguous(::Type{Bool}, A::DenseArray) = true
+_checkcontiguous(::Type{Bool}, A::ReshapedArray) = _checkcontiguous(Bool, parent(A))
+_checkcontiguous(::Type{Bool}, A::FastContiguousSubArray) = _checkcontiguous(Bool, parent(A))
+
+function strides(a::ReshapedArray)
+    # We can handle non-contiguous parent if it's a StridedVector
+    ndims(parent(a)) == 1 && return size_to_strides(only(strides(parent(a))), size(a)...)
+    _checkcontiguous(Bool, a) || throw(ArgumentError("Parent must be contiguous."))
+    size_to_strides(1, size(a)...)
+end

test/abstractarray.jl

@@ -1561,3 +1561,24 @@ end
     r = Base.IdentityUnitRange(3:4)
     @test reshape(r, :) === reshape(r, (:,)) === r
 end
+
+@testset "strides for ReshapedArray" begin
+    # Type-based contiguous check
+    a = vec(reinterpret(reshape,Int16,reshape(view(reinterpret(Int32,randn(Float64,100)),2:11),5,:)))
+    @test only(only(code_typed(Base._checkcontiguous, Base.typesof(Bool, a))).first.code).val
+    @test strides(a) == (1,)
+    # General contiguous check
+    a = view(rand(10,10), 1:10, 1:10)
+    @test strides(vec(a)) == (1,)
+    b = view(parent(a), 1:9, 1:10)
+    @test_throws "Parent must be contiguous." strides(vec(b))
+    # StridedVector parent
+    for n in 1:3
+        a = view(collect(1:60n), 1:n:60n)
+        @test strides(reshape(a, 3, 4, 5)) == (n, 3n, 12n)
+        @test strides(reshape(a, 5, 6, 2)) == (n, 5n, 30n)
+        b = view(parent(a), 60n:-n:1)
+        @test strides(reshape(b, 3, 4, 5)) == (-n, -3n, -12n)
+        @test strides(reshape(b, 5, 6, 2)) == (-n, -5n, -30n)
+    end
+end