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// -*- C++ -*-
// Copyright (C) 2005-2015 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;
}
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