| // -*- C++ -*- |
| |
| // Copyright (C) 2005, 2006 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 2, 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 COPYING. If not, write to |
| // the Free Software Foundation, 59 Temple Place - Suite 330, Boston, |
| // MA 02111-1307, USA. |
| |
| // As a special exception, you may use this file as part of a free |
| // software library without restriction. Specifically, if other files |
| // instantiate templates or use macros or inline functions from this |
| // file, or you compile this file and link it with other files to |
| // produce an executable, this file does not by itself cause the |
| // resulting executable to be covered by the GNU General Public |
| // License. This exception does not however invalidate any other |
| // reasons why the executable file might be covered by the GNU General |
| // Public License. |
| |
| // 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 pb_ds; |
| using namespace pb_ds; |
| |
| // 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; |
| } |