Allocator-aware @safe reference counting is still not possible

[Paul Backus]

On Monday, 23 January 2023 at 08:49:50 UTC, Richard (Rikki) 
Andrew Cattermole wrote:
> Basically right now we're missing the lifetime checks 
> surrounding borrowed & function parameter. Everything else is 
> do-able right now, even if it isn't as cheap as it could be 
> (like RC eliding).

Have you seen the borrow method [1] used by SafeRefCounted? It is 
already possible, in the current D language, to prevent a 
container or smart pointer from leaking references. The syntax is 
awkward, because you have to use a callback, but it can be done.

Lifetime issues are not the blocker here. The blocker is being 
able to give deallocate/free a safe interface, so that it can be 
used safely in a generic or polymorphic context, where the 
specific implementation is not known in advance.

[1]: https://dlang.org/library/std/typecons/borrow.html