[musjleman]

> More like UAF ? Also, you can't. That was the idea. But it seems a bad one, according to you and user rom1v.

Well in your code if you bft_free OWN with outstanding REFs, nothing happens and the bft_free on last REF does nothing as well so it becomes just a leak.

> I'll try to make it so. This aspect is new to me. Anyway I hear it's quite hard, beyond that, to have a thread-safe lib, so I'll advertize it as non-TS.

IMO thread-safe should be the default with an easy opt-out by defining a single macro or something like that.

> Maybe that's the price for compacting str+str_view into a single type ?

Kind of. Without the VUE functionality I think you could refactor it into 2 states - SBO or REF.

  struct Buffet {
    union {
      struct {          // | u32 refcnt | char data[] |
        void*     ptr;  // --------------^ points to data. at offset -4 is refcount / start of alloc
        SIZE_TYPE size;
      } large;                                        // cap > sizeof(void*) + sizeof(SIZE_TYPE)
      char small[sizeof(void*) + sizeof(SIZE_TYPE)];  // cap <= sizeof(void*) + sizeof(SIZE_TYPE)
    } storage;
    SIZE_TYPE cap; // on big endian this value could also function as the null terminating byte
  }

[alcover]

> if you bft_free OWN with outstanding REFs, nothing happens and the bft_free on last REF does nothing as well so it becomes just a leak.

I seem to have solved this with a `wantfree` flag. https://github.com/alcover/buffet/commit/ade05630aafdf5c940e...