Contributions regarding C Interface

[liss-h]

Currently metall's C interface is design around the typical malloc usecase, where you have a single global allocator that does all allocations.

This certainly has its uses, particularly if you want to replace malloc. However some applications might want more fine grained control over metall managers and create multiple on their own. This usecase can currently not be served with the C interface.

We have currently implemented our own metall C interface for that purpose (https://github.com/dice-group/metall-ffi).

So question: Would you be interested in integrating this in some way? Either replacing the current interface or (probably preferred) providing something like this as an alternative to the current interface?

[KIwabuchi]

Thanks for suggesting the improvements in the C interface.
The current C interface was made to demonstrate some basic functionalities in Metall for C applications.
So, I'm interested in replacing the current API with yours.