MaybeNativeString would be more appropriate?

Naming things :-D

Not sure aboutNativeString. It has connotations to native string type supported on the platform, but this is not it.

It might make sense to have aStrPtr type per encoding for clarity. Then signatures could enforce it. But maybe that would be overengineering.

Do we use any encoding apart from UTF8? I thought allFromString functions nowadays used that.

Indeed, I find exactly one usage withEncoding.ASCII, everything else isUTF8. And the one case that uses ASCII isPyBuffer_SizeFromFormat, which doesn't specify ASCII encoding either, I highly doubt it will break if it's passed UTF8 instead as it will probably just compare bytes directly and bail out on anything that it doesn't understand.

The main thing I find "problematic" is that this object is not a pure pointer, it has ownership over the buffer it points to.

Maybe we should renamePyDict to something likePyDictFacade to make it clear that it doesn't take ownership.

This overload actually does incref internally (which makes sense, since to create a potentially long-livedPyDict object pointing to something we borrowed, we need toIncRef).

Since this pattern is used in a lot of places, we should have a function for this (GetUtf8String or something like that). That could open up potential optimisation paths with caching or preallocated buffers per thread.

At this point it would be a premature optimization. Also, I don't see how we could cache disposablestruct instances easily.

Please makeRuntime apartial class and move this into a separate file.

I can do this just before pushing. Otherwise it would require me to update the roslyn package, that does automatic conversion of [DllImport] into the pattern withDelegates.

Did you generate this via a script? That would be a good addition (although I'd hope we wouldn't need too many changes of this class ;)).

The script convertedDllImport declarations. It did not work on the Python source, headers, or docs. Essentially, signatures are identical to what we had exceptstring parameters and a few minor exceptions where I switched to*Reference types.