// constructing priority queues

#include <iostream>       // std::cout

#include <queue>          // std::priority_queue

#include <vector>         // std::vector

#include <functional>     // std::greater

class mycomparison

{

  bool reverse;

public:

  mycomparison(const bool& revparam=false)

    {reverse=revparam;}

  bool operator() (const int& lhs, const int&rhs) const

  {

    if (reverse) return (lhs>rhs);

    else return (lhs<rhs);

  }

};

int main ()

{

  int myints[]= {,,,};

  std::priority_queue<int> first;

  std::priority_queue<int> second (myints,myints+);

  std::priority_queue<int, std::vector<int>, std::greater<int> >

                            third (myints,myints+);

  // using mycomparison:

  typedef std::priority_queue<int,std::vector<int>,mycomparison> mypq_type;

  mypq_type fourth;                       // less-than comparison

  mypq_type fifth (mycomparison(true));   // greater-than comparison

  return ;

}