Fix slicing of PtrArrays

src/ptr_array.jl

@@ -994,16 +994,18 @@ end
   pstore!(pointer(A) + (i - oneunit(i)) * static_sizeof(T), v)
   v
 end
-@inline function unsafe_getindex(A::PtrVector{T}, i::Integer) where {T}
+@inline function unsafe_getindex(A::PtrVector{T}, i::Vararg{Integer}) where {T}
+  i_ = first(i)
   pload(
     pointer(A) +
-    (i - ArrayInterface.offset1(A)) * only(LayoutPointers.bytestrides(A))
+    (i_ - ArrayInterface.offset1(A)) * only(LayoutPointers.bytestrides(A))
   )
 end
-@inline function unsafe_setindex!(A::PtrVector{T}, v, i::Integer) where {T}
+@inline function unsafe_setindex!(A::PtrVector{T}, v, i::Vararg{Integer}) where {T}
+  i_ = first(i)
   pstore!(
     pointer(A) +
-    (i - ArrayInterface.offset1(A)) * only(LayoutPointers.bytestrides(A)),
+    (i_ - ArrayInterface.offset1(A)) * only(LayoutPointers.bytestrides(A)),
     v
   )
   v

src/views.jl

@@ -2,18 +2,23 @@
   A::AbstractPtrArray{T,N},
   i::Vararg{Union{Integer,AbstractRange,Colon},N}
 ) where {T,N}
-  PtrArray(SubArray(A, Base.to_indices(A, i)))
+  j = Base.to_indices(A, i)
+  @boundscheck checkbounds(A, j...)
+  PtrArray(SubArray(A, j))
 end
 @inline function Base.view(
   A::AbstractPtrArray{T,N},
   i::AbstractUnitRange
 ) where {T,N}
-  view(vec(A), i)
+  V = vec(A)
+  @boundscheck checkbounds(V, i)
+  view(V, i)
 end
 @inline function Base.view(
   A::AbstractPtrArray{T,1},
   i::AbstractUnitRange
 ) where {T}
+  @boundscheck checkbounds(A, i)
   sx = only(static_strides(A))
   if sx === static(1)
     p = pointer(A) + (first(i) - first(offsets(A))) * sizeof(T)

test/runtests.jl

@@ -449,4 +449,42 @@ end
       @test A == B
     end
   end
+
+  @testset "PtrArray slicing" begin
+    # Testing for the bug in https://github.com/JuliaSIMD/StrideArrays.jl/issues/88
+    x = [1 3; 2 4]
+    GC.@preserve x begin
+      ptrarrays = (
+        StrideArraysCore.PtrArray(pointer(x), (2, 2)),
+        StrideArraysCore.PtrArray(pointer(x), (StaticInt(2), StaticInt(2))),
+      )
+      for y in ptrarrays
+        # This triggered the bug, a 2D index into a Vector, which is used by display/show
+        y1 = y[1, :]
+        @test y1[2, 1] == x[1, 2]
+
+        # Some general tests with slicing and bounds checking
+        @test y[1, 1] == x[1, 1]
+        @test y[2, 1] == x[2, 1]
+        @test y[1, 2] == x[1, 2]
+        @test y[2, 2] == x[2, 2]
+        @test y1[1] == x[1, 1]
+        @test y1[2] == x[1, 2]
+        y2 = y[2, :]
+        @test y2[1] == x[2, 1]
+        @test y2[2] == x[2, 2]
+        y3 = y[:, 1]
+        @test y3[1] == x[1, 1]
+        @test y3[2] == x[2, 1]
+        @test_throws BoundsError y[1:5]
+        @test_throws BoundsError y[3, :]
+        @test_throws BoundsError y[:, 3]
+        @test_throws BoundsError y[2:3, :]
+        @test_throws BoundsError y1[3]
+        @test_throws BoundsError y1[1:3]
+        @test_throws BoundsError y2[3]
+        @test_throws BoundsError y2[1:3]
+      end
+    end
+  end
 end