Stores a pointer and a value using unused bits in the pointer

This is like a unique_ptr, taking a general functor to perform the deletion as necessary, while holding an integral value in the remaining bits. A char pointer will have up to 16 bits available, while a pointer to a 64-bit integer will have 19. This depends on alignof(T).

The primary purpose is associating a count with a pointer without paying any additional space or finding values elsewhere.