Drop Travis, improve device(<:SubArray}

Author: chriselrod

.travis.yml

@@ -567,13 +567,8 @@ device(::Type) = nothing
 device(::Type{<:Tuple}) = CPUIndex()
 # Relies on overloading for GPUArrays that have subtyped `StridedArray`.
 device(::Type{<:StridedArray}) = CPUPointer()
-function device(::Type{T}) where {T <: SubArray}
-    if T <: StridedArray
-        device(parent_type(T))
-    else
-        CPUIndex()
-    end
-end
+device(::Type{<:SubArray{T,N,A,I}}) where {T,N,A,I<:Tuple{Vararg{Union{Integer,AbstractRange}}}} = device(A)
+device(::Type{<:SubArray}) = CPUIndex()
 function device(::Type{T}) where {T <: AbstractArray}
     P = parent_type(T)
     T === P ? CPUIndex() : device(P)

src/ArrayInterface.jl

@@ -267,16 +267,17 @@ Base.getindex(::DummyZeros{T}, inds...) where {T} = zero(T)
     A = zeros(3,4,5);
     D1 = view(A, 1:2:3, :, :)  # first dimension is discontiguous
     D2 = view(A, :, 2:2:4, :)  # first dimension is contiguous
-    @test device(A) === ArrayInterface.CPUPointer()
-    @test device((1,2,3)) === ArrayInterface.CPUIndex()
-    @test device(PermutedDimsArray(A,(3,1,2))) === ArrayInterface.CPUPointer()
-    @test device(view(A, 1, :, 2:4)) === ArrayInterface.CPUPointer()
-    @test device(view(A, 1, :, 2:4)') === ArrayInterface.CPUPointer()
-    @test device(view(A, 1, :, [2,3,4])) === ArrayInterface.CPUIndex()
-    @test device(view(A, 1, :, [2,3,4])') === ArrayInterface.CPUIndex()
-    @test device(@SArray(zeros(2,2,2))) === ArrayInterface.CPUIndex()
-    @test device(@view(@SArray(zeros(2,2,2))[1,1:2,:])) === ArrayInterface.CPUIndex()
-    @test device(@MArray(zeros(2,2,2))) === ArrayInterface.CPUPointer()
+    @test @inferred(device(A)) === ArrayInterface.CPUPointer()
+    @test @inferred(device((1,2,3))) === ArrayInterface.CPUIndex()
+    @test @inferred(device(PermutedDimsArray(A,(3,1,2)))) === ArrayInterface.CPUPointer()
+    @test @inferred(device(view(A, 1, :, 2:4))) === ArrayInterface.CPUPointer()
+    @test @inferred(device(view(A, 1, :, 2:4)')) === ArrayInterface.CPUPointer()
+    @test @inferred(device(view(PermutedDimsArray(A, (3,1,2)), 1, :, 2:4)')) === ArrayInterface.CPUPointer()
+    @test @inferred(device(view(A, 1, :, [2,3,4]))) === ArrayInterface.CPUIndex()
+    @test @inferred(device(view(A, 1, :, [2,3,4])')) === ArrayInterface.CPUIndex()
+    @test @inferred(device(@SArray(zeros(2,2,2)))) === ArrayInterface.CPUIndex()
+    @test @inferred(device(@view(@SArray(zeros(2,2,2))[1,1:2,:]))) === ArrayInterface.CPUIndex()
+    @test @inferred(device(@MArray(zeros(2,2,2)))) === ArrayInterface.CPUPointer()
     @test isnothing(device("Hello, world!"))
 
     @test @inferred(contiguous_axis(@SArray(zeros(2,2,2)))) === ArrayInterface.Contiguous(1)