weak_ptr::swap
Swaps two weak_ptr objects.
void swap(weak_ptr& wp);
Parameters
- wp
The weak pointer to swap with.
Remarks
The member function leaves the resource originally pointed to by *this subsequently pointed to by wp, and the resource originally pointed to by wp subsequently pointed to by *this. The function does not change the reference counts for the two resources and it does not throw any exceptions.
Example
// std_tr1__memory__weak_ptr_swap.cpp
// compile with: /EHsc
#include <memory>
#include <iostream>
struct deleter
{
void operator()(int *p)
{
delete p;
}
};
int main()
{
std::shared_ptr<int> sp1(new int(5));
std::shared_ptr<int> sp2(new int(10));
std::cout << "*sp1 == " << *sp1 << std::endl;
sp1.swap(sp2);
std::cout << "*sp1 == " << *sp1 << std::endl;
swap(sp1, sp2);
std::cout << "*sp1 == " << *sp1 << std::endl;
std::cout << std::endl;
std::weak_ptr<int> wp1(sp1);
std::weak_ptr<int> wp2(sp2);
std::cout << "*wp1 == " << *wp1.lock() << std::endl;
wp1.swap(wp2);
std::cout << "*wp1 == " << *wp1.lock() << std::endl;
swap(wp1, wp2);
std::cout << "*wp1 == " << *wp1.lock() << std::endl;
return (0);
}
*sp1 == 5 *sp1 == 10 *sp1 == 5 *wp1 == 5 *wp1 == 10 *wp1 == 5
Requirements
Header: <memory>
Namespace: std