# std::weak_ptr::use_count

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< cpp‎ | memory‎ | weak ptr

long use_count() const; |  | (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.

### Parameters

(none)

### Return value

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

### Exceptions

`noexcept` specification:
noexcept

### Notes

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.

### Example

| This section is incomplete Reason: no example

### See also

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

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