long use_count() const noexcept;
(since C++11)

Returns the number of shared_ptr instances that share ownership of the managed object, or ​0​ if the managed object has already been deleted, i.e. *this is empty.



Return value

The number of shared_ptr instances sharing the ownership of the managed object at the instant of the call.


expired() may be faster than use_count(). This function is inherently racy, if the managed object is shared among threads that might be creating and destroying copies of the shared_ptr: then, the result is reliable only if it matches the number of copies uniquely owned by the calling thread, or zero; any other value may become stale before it can be used.


See also

checks whether the referenced object was already deleted
(public member function)

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