It seems great to have something that is C but cleaned up, although clay had all that with templates and move semantics.

I think leaving out move semantics and destructors is inexcusable at this point. It is not only fundamental, but doesn't affect things like standard libraries, runtimes, or ABIs.

But it of course move semantics and destructors affect all things. If the goal is to call and be callable from C without special constructs, how would you make the C code respect the move semantics and destructors?