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std::weak_ptr::use_count

From cppreference.com
< cpp‎ | memory‎ | weak ptr
 
 
 
Dynamic memory management
Uninitialized storage
(C++17)
(deprecated since c++17)
(deprecated since c++17)
(deprecated since c++17)
Garbage collection support
Miscellaneous
(C++11)
(C++11)
C Library
Low level memory management
 
 
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.

Contents

[edit] Parameters

(none)

[edit] Return value

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

[edit] 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.

[edit] Example

[edit] See also

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