1 // Pair implementation -*- C++ -*- 2 3 // Copyright (C) 2001 Free Software Foundation, Inc. 4 // 5 // This file is part of the GNU ISO C++ Library. This library is free 6 // software; you can redistribute it and/or modify it under the 7 // terms of the GNU General Public License as published by the 8 // Free Software Foundation; either version 2, or (at your option) 9 // any later version. 10 11 // This library is distributed in the hope that it will be useful, 12 // but WITHOUT ANY WARRANTY; without even the implied warranty of 13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 // GNU General Public License for more details. 15 16 // You should have received a copy of the GNU General Public License along 17 // with this library; see the file COPYING. If not, write to the Free 18 // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, 19 // USA. 20 21 // As a special exception, you may use this file as part of a free software 22 // library without restriction. Specifically, if other files instantiate 23 // templates or use macros or inline functions from this file, or you compile 24 // this file and link it with other files to produce an executable, this 25 // file does not by itself cause the resulting executable to be covered by 26 // the GNU General Public License. This exception does not however 27 // invalidate any other reasons why the executable file might be covered by 28 // the GNU General Public License. 29 30 /* 31 * 32 * Copyright (c) 1994 33 * Hewlett-Packard Company 34 * 35 * Permission to use, copy, modify, distribute and sell this software 36 * and its documentation for any purpose is hereby granted without fee, 37 * provided that the above copyright notice appear in all copies and 38 * that both that copyright notice and this permission notice appear 39 * in supporting documentation. Hewlett-Packard Company makes no 40 * representations about the suitability of this software for any 41 * purpose. It is provided "as is" without express or implied warranty. 42 * 43 * 44 * Copyright (c) 1996,1997 45 * Silicon Graphics Computer Systems, Inc. 46 * 47 * Permission to use, copy, modify, distribute and sell this software 48 * and its documentation for any purpose is hereby granted without fee, 49 * provided that the above copyright notice appear in all copies and 50 * that both that copyright notice and this permission notice appear 51 * in supporting documentation. Silicon Graphics makes no 52 * representations about the suitability of this software for any 53 * purpose. It is provided "as is" without express or implied warranty. 54 */ 55 56 /** @file stl_pair.h 57 * This is an internal header file, included by other library headers. 58 * You should not attempt to use it directly. 59 */ 60 61 #ifndef __GLIBCPP_INTERNAL_PAIR_H 62 #define __GLIBCPP_INTERNAL_PAIR_H 63 64 namespace std 65 { 66 67 /// pair holds two objects of arbitrary type. 68 template <class _T1, class _T2> 69 struct pair { 70 typedef _T1 first_type; ///< @c first_type is the first bound type 71 typedef _T2 second_type; ///< @c second_type is the second bound type 72 73 _T1 first; ///< @c first is a copy of the first object 74 _T2 second; ///< @c second is a copy of the second object 75 #ifdef _GLIBCPP_RESOLVE_LIB_DEFECTS 76 //265. std::pair::pair() effects overly restrictive 77 /** The default constructor creates @c first and @c second using their 78 * respective default constructors. */ 79 pair() : first(), second() {} 80 #else 81 pair() : first(_T1()), second(_T2()) {} 82 #endif 83 /** Two objects may be passed to a @c pair constructor to be copied. */ 84 pair(const _T1& __a, const _T2& __b) : first(__a), second(__b) {} 85 86 /** There is also a templated copy ctor for the @c pair class itself. */ 87 template <class _U1, class _U2> 88 pair(const pair<_U1, _U2>& __p) : first(__p.first), second(__p.second) {} 89 }; 90 91 /// Two pairs of the same type are equal iff their members are equal. 92 template <class _T1, class _T2> 93 inline bool operator==(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y) 94 { 95 return __x.first == __y.first && __x.second == __y.second; 96 } 97 98 /// <http://gcc.gnu.org/onlinedocs/libstdc++/20_util/howto.html#pairlt> 99 template <class _T1, class _T2> 100 inline bool operator<(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y) 101 { 102 return __x.first < __y.first || 103 (!(__y.first < __x.first) && __x.second < __y.second); 104 } 105 106 /// Uses @c operator== to find the result. 107 template <class _T1, class _T2> 108 inline bool operator!=(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y) { 109 return !(__x == __y); 110 } 111 112 /// Uses @c operator< to find the result. 113 template <class _T1, class _T2> 114 inline bool operator>(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y) { 115 return __y < __x; 116 } 117 118 /// Uses @c operator< to find the result. 119 template <class _T1, class _T2> 120 inline bool operator<=(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y) { 121 return !(__y < __x); 122 } 123 124 /// Uses @c operator< to find the result. 125 template <class _T1, class _T2> 126 inline bool operator>=(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y) { 127 return !(__x < __y); 128 } 129 130 /** 131 * @brief A convenience wrapper for creating a pair from two objects. 132 * @param x The first object. 133 * @param y The second object. 134 * @return A newly-constructed pair<> object of the appropriate type. 135 * 136 * The standard requires that the objects be passed by reference-to-const, 137 * but LWG issue #181 says they should be passed by const value. We follow 138 * the LWG by default. 139 */ 140 template <class _T1, class _T2> 141 #ifdef _GLIBCPP_RESOLVE_LIB_DEFECTS 142 //181. make_pair() unintended behavior 143 inline pair<_T1, _T2> make_pair(_T1 __x, _T2 __y) 144 #else 145 inline pair<_T1, _T2> make_pair(const _T1& __x, const _T2& __y) 146 #endif 147 { 148 return pair<_T1, _T2>(__x, __y); 149 } 150 151 } // namespace std 152 153 #endif /* __GLIBCPP_INTERNAL_PAIR_H */ 154 155 // Local Variables: 156 // mode:C++ 157 // End: 158