// priority_queue::swap
#include <iostream> // std::cout
#include <queue> // std::priority_queue
int main ()
{
std::priority_queue<int> foo,bar;
foo.push (15); foo.push(30); foo.push(10);
bar.push (101); bar.push(202);
foo.swap(bar);
std::cout << "size of foo: " << foo.size() << '
';
std::cout << "size of bar: " << bar.size() << '
';
return 0;
}