std::weak_ptr<T>::reset

自 C++11 起

void reset() noexcept;

释放对托管对象的引用。调用后*this不再管理任何对象。

参数

(无)

返回值

(无)

示例

#include <memory>
#include <iostream>
 
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';
}

结果

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