sorry, which only your weak_ptr (ptr_to_unique) has. -----Ursprüngliche Nachricht----- Von:Sebastian Wittmeier <wittmeier_at_[hidden]> The difference between your weak_ptr (ptr_to_unique) and your shared_ptr (notifying_unique_ptr) is at construction and destruction time and the ability to copy, which only your shared_ptr (notifying_unique_ptr) has.