Broken-why?

<..ex-prqueue.cxx ..>

#include <priority_queue>
#include <iostream>
using namespace std;

int main() {
   priority_queue<int> s;
   s.push(1);  s.push(3);  s.push(2);
   while( ! s.empty() ){
     cout << s.top() << ' ';
     s.pop();
   }
   cout << endl;
   return 0;
}

-_-_-