std::weak_ptr<T>::reset

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< cpp‎ | memory‎ | weak ptr
 
 
Utilities library
General utilities
Relational operators (deprecated in C++20)
 
Dynamic memory management
Uninitialized memory algorithms
Constrained uninitialized memory algorithms
Allocators
Garbage collection support
(C++11)(until C++23)
(C++11)(until C++23)
(C++11)(until C++23)
(C++11)(until C++23)
(C++11)(until C++23)
(C++11)(until C++23)



 
 
void reset() noexcept;
(since C++11)

Releases the reference to the managed object. After the call *this manages no object.

Parameters

(none)

Return value

(none)

Example

#include <iostream>
#include <memory>
 
int main()
{
    auto shared = std::make_shared<int>(), shared2 = shared, shared3 = shared2;
 
    auto weak = std::weak_ptr<int>{shared};
 
    std::cout << std::boolalpha 
              << "shared.use_count(): " << shared.use_count() << '\n'
              << "weak.use_count(): " << weak.use_count() << '\n'
              << "weak.expired(): " << weak.expired() << '\n';
 
    weak.reset();
 
    std::cout << "weak.reset();\n"
              << "shared.use_count(): " << shared.use_count() << '\n'
              << "weak.use_count(): " << weak.use_count() << '\n'
              << "weak.expired(): " << weak.expired() << '\n';
}

Output:

shared.use_count(): 3
weak.use_count(): 3
weak.expired(): false
weak.reset();
shared.use_count(): 3
weak.use_count(): 0
weak.expired(): true

See also

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