libstdc++
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00001 // Pair implementation -*- C++ -*- 00002 00003 // Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 00004 // Free Software Foundation, Inc. 00005 // 00006 // This file is part of the GNU ISO C++ Library. This library is free 00007 // software; you can redistribute it and/or modify it under the 00008 // terms of the GNU General Public License as published by the 00009 // Free Software Foundation; either version 3, or (at your option) 00010 // any later version. 00011 00012 // This library is distributed in the hope that it will be useful, 00013 // but WITHOUT ANY WARRANTY; without even the implied warranty of 00014 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00015 // GNU General Public License for more details. 00016 00017 // Under Section 7 of GPL version 3, you are granted additional 00018 // permissions described in the GCC Runtime Library Exception, version 00019 // 3.1, as published by the Free Software Foundation. 00020 00021 // You should have received a copy of the GNU General Public License and 00022 // a copy of the GCC Runtime Library Exception along with this program; 00023 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 00024 // <http://www.gnu.org/licenses/>. 00025 00026 /* 00027 * 00028 * Copyright (c) 1994 00029 * Hewlett-Packard Company 00030 * 00031 * Permission to use, copy, modify, distribute and sell this software 00032 * and its documentation for any purpose is hereby granted without fee, 00033 * provided that the above copyright notice appear in all copies and 00034 * that both that copyright notice and this permission notice appear 00035 * in supporting documentation. Hewlett-Packard Company makes no 00036 * representations about the suitability of this software for any 00037 * purpose. It is provided "as is" without express or implied warranty. 00038 * 00039 * 00040 * Copyright (c) 1996,1997 00041 * Silicon Graphics Computer Systems, Inc. 00042 * 00043 * Permission to use, copy, modify, distribute and sell this software 00044 * and its documentation for any purpose is hereby granted without fee, 00045 * provided that the above copyright notice appear in all copies and 00046 * that both that copyright notice and this permission notice appear 00047 * in supporting documentation. Silicon Graphics makes no 00048 * representations about the suitability of this software for any 00049 * purpose. It is provided "as is" without express or implied warranty. 00050 */ 00051 00052 /** @file stl_pair.h 00053 * This is an internal header file, included by other library headers. 00054 * You should not attempt to use it directly. 00055 */ 00056 00057 #ifndef _STL_PAIR_H 00058 #define _STL_PAIR_H 1 00059 00060 #include <bits/move.h> // for std::move / std::forward, std::decay, and 00061 // std::swap 00062 00063 _GLIBCXX_BEGIN_NAMESPACE(std) 00064 00065 /// pair holds two objects of arbitrary type. 00066 template<class _T1, class _T2> 00067 struct pair 00068 { 00069 typedef _T1 first_type; ///< @c first_type is the first bound type 00070 typedef _T2 second_type; ///< @c second_type is the second bound type 00071 00072 _T1 first; ///< @c first is a copy of the first object 00073 _T2 second; ///< @c second is a copy of the second object 00074 00075 // _GLIBCXX_RESOLVE_LIB_DEFECTS 00076 // 265. std::pair::pair() effects overly restrictive 00077 /** The default constructor creates @c first and @c second using their 00078 * respective default constructors. */ 00079 pair() 00080 : first(), second() { } 00081 00082 /** Two objects may be passed to a @c pair constructor to be copied. */ 00083 pair(const _T1& __a, const _T2& __b) 00084 : first(__a), second(__b) { } 00085 00086 #ifdef __GXX_EXPERIMENTAL_CXX0X__ 00087 template<class _U1, class _U2> 00088 pair(_U1&& __x, _U2&& __y) 00089 : first(std::forward<_U1>(__x)), 00090 second(std::forward<_U2>(__y)) { } 00091 00092 pair(pair&& __p) 00093 : first(std::move(__p.first)), 00094 second(std::move(__p.second)) { } 00095 #endif 00096 00097 /** There is also a templated copy ctor for the @c pair class itself. */ 00098 template<class _U1, class _U2> 00099 pair(const pair<_U1, _U2>& __p) 00100 : first(__p.first), 00101 second(__p.second) { } 00102 00103 #ifdef __GXX_EXPERIMENTAL_CXX0X__ 00104 template<class _U1, class _U2> 00105 pair(pair<_U1, _U2>&& __p) 00106 : first(std::move(__p.first)), 00107 second(std::move(__p.second)) { } 00108 00109 // http://gcc.gnu.org/ml/libstdc++/2007-08/msg00052.html 00110 template<class _U1, class _Arg0, class... _Args> 00111 pair(_U1&& __x, _Arg0&& __arg0, _Args&&... __args) 00112 : first(std::forward<_U1>(__x)), 00113 second(std::forward<_Arg0>(__arg0), 00114 std::forward<_Args>(__args)...) { } 00115 00116 pair& 00117 operator=(pair&& __p) 00118 { 00119 first = std::move(__p.first); 00120 second = std::move(__p.second); 00121 return *this; 00122 } 00123 00124 template<class _U1, class _U2> 00125 pair& 00126 operator=(pair<_U1, _U2>&& __p) 00127 { 00128 first = std::move(__p.first); 00129 second = std::move(__p.second); 00130 return *this; 00131 } 00132 00133 void 00134 swap(pair&& __p) 00135 { 00136 using std::swap; 00137 swap(first, __p.first); 00138 swap(second, __p.second); 00139 } 00140 #endif 00141 }; 00142 00143 /// Two pairs of the same type are equal iff their members are equal. 00144 template<class _T1, class _T2> 00145 inline bool 00146 operator==(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y) 00147 { return __x.first == __y.first && __x.second == __y.second; } 00148 00149 /// <http://gcc.gnu.org/onlinedocs/libstdc++/manual/utilities.html> 00150 template<class _T1, class _T2> 00151 inline bool 00152 operator<(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y) 00153 { return __x.first < __y.first 00154 || (!(__y.first < __x.first) && __x.second < __y.second); } 00155 00156 /// Uses @c operator== to find the result. 00157 template<class _T1, class _T2> 00158 inline bool 00159 operator!=(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y) 00160 { return !(__x == __y); } 00161 00162 /// Uses @c operator< to find the result. 00163 template<class _T1, class _T2> 00164 inline bool 00165 operator>(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y) 00166 { return __y < __x; } 00167 00168 /// Uses @c operator< to find the result. 00169 template<class _T1, class _T2> 00170 inline bool 00171 operator<=(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y) 00172 { return !(__y < __x); } 00173 00174 /// Uses @c operator< to find the result. 00175 template<class _T1, class _T2> 00176 inline bool 00177 operator>=(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y) 00178 { return !(__x < __y); } 00179 00180 #ifdef __GXX_EXPERIMENTAL_CXX0X__ 00181 /// See std::pair::swap(). 00182 // Note: no std::swap overloads in C++03 mode, this has performance 00183 // implications, see, eg, libstdc++/38466. 00184 template<class _T1, class _T2> 00185 inline void 00186 swap(pair<_T1, _T2>& __x, pair<_T1, _T2>& __y) 00187 { __x.swap(__y); } 00188 00189 template<class _T1, class _T2> 00190 inline void 00191 swap(pair<_T1, _T2>&& __x, pair<_T1, _T2>& __y) 00192 { __x.swap(__y); } 00193 00194 template<class _T1, class _T2> 00195 inline void 00196 swap(pair<_T1, _T2>& __x, pair<_T1, _T2>&& __y) 00197 { __x.swap(__y); } 00198 #endif 00199 00200 /** 00201 * @brief A convenience wrapper for creating a pair from two objects. 00202 * @param x The first object. 00203 * @param y The second object. 00204 * @return A newly-constructed pair<> object of the appropriate type. 00205 * 00206 * The standard requires that the objects be passed by reference-to-const, 00207 * but LWG issue #181 says they should be passed by const value. We follow 00208 * the LWG by default. 00209 */ 00210 // _GLIBCXX_RESOLVE_LIB_DEFECTS 00211 // 181. make_pair() unintended behavior 00212 #ifndef __GXX_EXPERIMENTAL_CXX0X__ 00213 template<class _T1, class _T2> 00214 inline pair<_T1, _T2> 00215 make_pair(_T1 __x, _T2 __y) 00216 { return pair<_T1, _T2>(__x, __y); } 00217 #else 00218 template<typename _Tp> 00219 class reference_wrapper; 00220 00221 // Helper which adds a reference to a type when given a reference_wrapper 00222 template<typename _Tp> 00223 struct __strip_reference_wrapper 00224 { 00225 typedef _Tp __type; 00226 }; 00227 00228 template<typename _Tp> 00229 struct __strip_reference_wrapper<reference_wrapper<_Tp> > 00230 { 00231 typedef _Tp& __type; 00232 }; 00233 00234 template<typename _Tp> 00235 struct __strip_reference_wrapper<const reference_wrapper<_Tp> > 00236 { 00237 typedef _Tp& __type; 00238 }; 00239 00240 template<typename _Tp> 00241 struct __decay_and_strip 00242 { 00243 typedef typename __strip_reference_wrapper< 00244 typename decay<_Tp>::type>::__type __type; 00245 }; 00246 00247 // NB: DR 706. 00248 template<class _T1, class _T2> 00249 inline pair<typename __decay_and_strip<_T1>::__type, 00250 typename __decay_and_strip<_T2>::__type> 00251 make_pair(_T1&& __x, _T2&& __y) 00252 { 00253 return pair<typename __decay_and_strip<_T1>::__type, 00254 typename __decay_and_strip<_T2>::__type> 00255 (std::forward<_T1>(__x), std::forward<_T2>(__y)); 00256 } 00257 #endif 00258 00259 _GLIBCXX_END_NAMESPACE 00260 00261 #endif /* _STL_PAIR_H */