struct classCompare

{

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

   {

       return lhs < rhs ;

   }

};

int main(void)

{

  set<int, classCompare> aSet ;

  system("pause") ;

  return 0 ;

}

bool fncmp(int lhs, int rhs)

{

  return lhs < rhs ;

}

int main(void)

{

  bool(*fn_pt)(int, int) = fncmp ;

  set<int, bool(*)(int, int)> aSet(fn_pt) ;

  system("pause") ;

  return 0 ;

}