example use of @inbounds in the @inbounds documentation uses it incorrectly

[yurivish]

It appears that the example use of @inbounds given in the documentation for @inbounds is not a safe use of @inbounds:

The paragraph above the example implies that it is meant as an example to be followed, not one to be avoided. However, the warning immediately below the example strongly recommends only using @inbounds when it is certain from the information locally available that all accesses are in bounds.

This is not the case in the example, whose method signature explicitly allows all AbstractArrays, including those which do not use one-based indexing.

I verified that the example silently produces incorrect results due to out-of-bounds memory access on Julia 1.5.3:

julia> function sum(A::AbstractArray)
           r = zero(eltype(A))
           for i = 1:length(A)
               @inbounds r += A[i]
           end
           return r
       end
sum (generic function with 1 method)

julia> using OffsetArrays

julia> sum(OffsetArray(collect(1:11), -5:5))
8858289599