2nd approach for when you ignore the first) you use a type that doesn't "own" the pointer, and have the FFI side that allocated it free it
3rd approach for when you find out you can't do the 2nd) hope that the "owned" type is actually generic over the allocator used, and make an allocator that doesn't free (or even better, calls the correct free over the FFI boundary). `allocator-api` is the effort in this direction.
2nd approach for when you ignore the first) you use a type that doesn't "own" the pointer, and have the FFI side that allocated it free it
3rd approach for when you find out you can't do the 2nd) hope that the "owned" type is actually generic over the allocator used, and make an allocator that doesn't free (or even better, calls the correct free over the FFI boundary). `allocator-api` is the effort in this direction.