text: // -*- C++ -*-
  
  // Copyright (C) 2005-2017 Free Software Foundation, Inc.
  //
  // This file is part of the GNU ISO C++ Library.  This library is free
  // software; you can redistribute it and/or modify it under the terms
  // of the GNU General Public License as published by the Free Software
  // Foundation; either version 3, or (at your option) any later
  // version.
  
  // This library is distributed in the hope that it will be useful, but
  // WITHOUT ANY WARRANTY; without even the implied warranty of
  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  // General Public License for more details.
  
  // You should have received a copy of the GNU General Public License
  // along with this library; see the file COPYING3.  If not see
  // <http://www.gnu.org/licenses/>.
  
  
  // Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL.
  
  // Permission to use, copy, modify, sell, and distribute this software
  // is hereby granted without fee, provided that the above copyright
  // notice appears in all copies, and that both that copyright notice
  // and this permission notice appear in supporting documentation. None
  // of the above authors, nor IBM Haifa Research Laboratories, make any
  // representation about the suitability of this software for any
  // purpose. It is provided "as is" without express or implied
  // warranty.
  
  /**
   * @file priority_queue_erase_if.cpp
   * Example showing how to conditionally erase values from a priority queue.
   */
  
  /**
   * This example shows how to erase from a priority queue using erase_if.
   */
  
  #include <functional>
  #include <iostream>
  #include <cassert>
  #include <ext/pb_ds/priority_queue.hpp>
  
  using namespace std;
  using namespace __gnu_pbds;
  
  int
  main()
  {
    __gnu_pbds::priority_queue<int> p;
  
    // First we insert some values into the container.
    for (int i = 0; i < 1000; ++i)
      p.push(i);
  
    assert(p.top() == 999);
  
    // Now we erase all values that satisfy some predicate, in this case
    // one that returns true for all those larger than 500.
    p.erase_if(bind1st(less<int>(), 500));
  
    // The largest value should be now 500.
    assert(p.top() == 500);
  }
  
  