weak_ptr::use_count
Counts number of designated shared_ptr objects.
long use_count() const;
Remarks
The member function returns the number of shared_ptr objects that own the resource pointed to by *this.
Example
// std_tr1__memory__weak_ptr_use_count.cpp
// compile with: /EHsc
#include <memory>
#include <iostream>
int main()
{
std::shared_ptr<int> sp1(new int(5));
std::weak_ptr<int> wp(sp1);
std::cout << "wp.use_count() == "
<< wp.use_count() << std::endl;
std::shared_ptr<int> sp2(sp1);
std::cout << "wp.use_count() == "
<< wp.use_count() << std::endl;
return (0);
}
wp.use_count() == 1 wp.use_count() == 2
Requirements
Header: <memory>
Namespace: std