`Window` type is not memory safe

[JeffBezanson]

StaticKernels.jl/src/types.jl

Line 42 in d08b602

parent_ptr::Ptr{T}

This is not a valid use of Ptr --- it will drop references to a and cause crashes. Please do not do this. I had to lie down for five minutes after seeing this code.

[stev47]

Yes, I am aware of this and taking the risk in the same way UnsafeArrays does (don't look at it if you do not want to lie down for another five minutes). It is another instance of JuliaLang/julia#14955
User-facing code is safe as long as one does not store the window references. All looping operations use GC.@preserve.

But if you have a better suggestion to achieve the same behaviour while staying allocation-free, I'm open to suggestions.

[JeffBezanson]

Fortunately this should be fixed in julia 1.5 (JuliaLang/julia#34126).
At least the name of UnsafeArrays is pretty clear :)

[stev47]

Thank you, that looks promising indeed!
You are right, I'll add an appropriate warning for now.

[RoyiAvital]

Is it closed because a warning was added or because it was reimplemented safely?

[stev47]

Yes it was implemented safely as soon as I realized the workaround wasn't even necessary in julia 1.4. Since julia 1.5 the situation only got better.
Also the referenced commit b884686 above is titled: "make Window memory safe"