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// -*- C++ -*-

// Copyright (C) 2005, 2006, 2009 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 erase_if_example.cpp

 * A basic example showing how to use erase_if.

 */

/**

 * The following example shows how to use a conditional-erase

 * method of associative containers to erase some of their entries.

 */

#include <iostream>

#include <cassert>

#include <ext/pb_ds/assoc_container.hpp>

using namespace std;

using namespace __gnu_pbds;

// The following functor takes a map's value-type object and returns

// whether its key is between two numbers.

struct between : public unary_function<pair<const int, char>, bool>

{

  // Constructor taking two numbers determining a range.

  between(int b, int e) : m_b(b), m_e(e)

  { assert(m_b < m_e); }

  // Operator determining whether a value-type object's key is within

  // the range.

  inline bool

  operator()(const pair<const int, char>& r_val)

  { return r_val.first >= m_b&&  r_val.first < m_e; }

private:

  const int m_b;

  const int m_e;

};

/**

 * The following function performs a sequence of operations on an

 * associative container object mapping integers to characters. Specifically

 * it inserts 100 values and then uses a conditional-erase method to erase

 * the values whose key is between 10 and 90.

 */

template<class Cntnr>

void

some_op_sequence(Cntnr r_c)

{

  assert(r_c.empty());

  assert(r_c.size() == 0);

  for (int i = 0; i < 100; ++i)

    r_c.insert(make_pair(i, static_cast<char>(i)));

  assert(r_c.size() == 100);

  // Erase all values whose key is between 10 (inclusive) and 90

  // (non-inclusive).

  r_c.erase_if(between(10 , 90));

  assert(!r_c.empty());

  assert(r_c.size() == 20);

}

int main()

{

  // Perform operations on a list-update set.

  some_op_sequence(list_update<int, char>());

  // Perform operations on a collision-chaining hash set.

  some_op_sequence(cc_hash_table<int, char>());

  // Perform operations on a general-probing hash set.

  some_op_sequence(gp_hash_table<int, char>());

  // Perform operations on a red-black tree set.

  some_op_sequence(tree<int, char>());

  // Perform operations on a splay tree set.

  some_op_sequence(tree<

                   int,

                   char,

                   less<int>,

                   splay_tree_tag>());

  // Perform operations on a splay tree set.

  some_op_sequence(tree<

                   int,

                   char,

                   less<int>,

                   ov_tree_tag>());

  return 0;

}