#include <iostream>

 #include <vector>

 #include <queue>

 #include <functional>

 #include <string>

 using namespace std;

 // Empty the priority queue and print its contents.

 template <typename PriorityQueue>

 void dumpContents( const string & msg, PriorityQueue & pq )

 {

     cout << msg << ":" << endl;

     while( !pq.empty( ) )

     {

         cout << pq.top( ) << endl;

         pq.pop( );

     }

 }

 // Do some inserts and removes (done in dumpContents).

 int main( )

 {

     priority_queue<int>                           maxPQ;

     priority_queue<int,vector<int>,greater<int> > minPQ;

     minPQ.push(  ); minPQ.push(  ); minPQ.push(  );

     maxPQ.push(  ); maxPQ.push(  ); maxPQ.push(  );

     dumpContents( "minPQ", minPQ );

     dumpContents( "maxPQ", maxPQ );

     return ;

 }

$ ./a.exe

minPQ:

maxPQ: