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std::bad_weak_ptr

Defined in header <memory> 
class bad_weak_ptr;
 (since C++11)

std::bad_weak_ptr is the type of the object thrown as exceptions by the constructors of std::shared_ptr that take std::weak_ptr as the argument, when the std::weak_ptr refers to an already deleted object.

cpp/error/exceptionstd-bad weak ptr-inheritance.svg

Inheritance diagram.

Member functions

 constructs the bad_weak_ptr object
(public member function)

Inherited from std::exception

Member functions

[virtual]
 destructs the exception object
(virtual public member function of std::exception)
[virtual]
 returns an explanatory string
(virtual public member function of std::exception)

Example

#include <memory>
#include <iostream>
int main()
{
    std::shared_ptr<int> p1(new int(42));
    std::weak_ptr<int> wp(p1);
    p1.reset();
    try {
        std::shared_ptr<int> p2(wp);
    } catch(const std::bad_weak_ptr& e) {
        std::cout << e.what() << '\n';
    }
}

Output:

std::bad_weak_ptr

See also

(C++11)
 smart pointer with shared object ownership semantics
(class template)
(C++11)
 weak reference to an object managed by std::shared_ptr
(class template)

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