libstdc++
|
00001 // Pair implementation -*- C++ -*- 00002 00003 // Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 00004 // 2010, 2011, 2012 00005 // Free Software Foundation, Inc. 00006 // 00007 // This file is part of the GNU ISO C++ Library. This library is free 00008 // software; you can redistribute it and/or modify it under the 00009 // terms of the GNU General Public License as published by the 00010 // Free Software Foundation; either version 3, or (at your option) 00011 // any later version. 00012 00013 // This library is distributed in the hope that it will be useful, 00014 // but WITHOUT ANY WARRANTY; without even the implied warranty of 00015 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00016 // GNU General Public License for more details. 00017 00018 // Under Section 7 of GPL version 3, you are granted additional 00019 // permissions described in the GCC Runtime Library Exception, version 00020 // 3.1, as published by the Free Software Foundation. 00021 00022 // You should have received a copy of the GNU General Public License and 00023 // a copy of the GCC Runtime Library Exception along with this program; 00024 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 00025 // <http://www.gnu.org/licenses/>. 00026 00027 /* 00028 * 00029 * Copyright (c) 1994 00030 * Hewlett-Packard Company 00031 * 00032 * Permission to use, copy, modify, distribute and sell this software 00033 * and its documentation for any purpose is hereby granted without fee, 00034 * provided that the above copyright notice appear in all copies and 00035 * that both that copyright notice and this permission notice appear 00036 * in supporting documentation. Hewlett-Packard Company makes no 00037 * representations about the suitability of this software for any 00038 * purpose. It is provided "as is" without express or implied warranty. 00039 * 00040 * 00041 * Copyright (c) 1996,1997 00042 * Silicon Graphics Computer Systems, Inc. 00043 * 00044 * Permission to use, copy, modify, distribute and sell this software 00045 * and its documentation for any purpose is hereby granted without fee, 00046 * provided that the above copyright notice appear in all copies and 00047 * that both that copyright notice and this permission notice appear 00048 * in supporting documentation. Silicon Graphics makes no 00049 * representations about the suitability of this software for any 00050 * purpose. It is provided "as is" without express or implied warranty. 00051 */ 00052 00053 /** @file bits/stl_pair.h 00054 * This is an internal header file, included by other library headers. 00055 * Do not attempt to use it directly. @headername{utility} 00056 */ 00057 00058 #ifndef _STL_PAIR_H 00059 #define _STL_PAIR_H 1 00060 00061 #include <bits/move.h> // for std::move / std::forward, and std::swap 00062 00063 #ifdef __GXX_EXPERIMENTAL_CXX0X__ 00064 #include <type_traits> // for std::__decay_and_strip too 00065 #endif 00066 00067 namespace std _GLIBCXX_VISIBILITY(default) 00068 { 00069 _GLIBCXX_BEGIN_NAMESPACE_VERSION 00070 00071 #ifdef __GXX_EXPERIMENTAL_CXX0X__ 00072 /// piecewise_construct_t 00073 struct piecewise_construct_t { }; 00074 00075 /// piecewise_construct 00076 constexpr piecewise_construct_t piecewise_construct = piecewise_construct_t(); 00077 00078 // Forward declarations. 00079 template<typename...> 00080 class tuple; 00081 00082 template<std::size_t...> 00083 struct _Index_tuple; 00084 #endif 00085 00086 /// Struct holding two objects of arbitrary type. 00087 template<class _T1, class _T2> 00088 struct pair 00089 { 00090 typedef _T1 first_type; /// @c first_type is the first bound type 00091 typedef _T2 second_type; /// @c second_type is the second bound type 00092 00093 _T1 first; /// @c first is a copy of the first object 00094 _T2 second; /// @c second is a copy of the second object 00095 00096 // _GLIBCXX_RESOLVE_LIB_DEFECTS 00097 // 265. std::pair::pair() effects overly restrictive 00098 /** The default constructor creates @c first and @c second using their 00099 * respective default constructors. */ 00100 _GLIBCXX_CONSTEXPR pair() 00101 : first(), second() { } 00102 00103 /** Two objects may be passed to a @c pair constructor to be copied. */ 00104 _GLIBCXX_CONSTEXPR pair(const _T1& __a, const _T2& __b) 00105 : first(__a), second(__b) { } 00106 00107 /** There is also a templated copy ctor for the @c pair class itself. */ 00108 #ifndef __GXX_EXPERIMENTAL_CXX0X__ 00109 template<class _U1, class _U2> 00110 pair(const pair<_U1, _U2>& __p) 00111 : first(__p.first), second(__p.second) { } 00112 #else 00113 template<class _U1, class _U2, class = typename 00114 enable_if<__and_<is_convertible<const _U1&, _T1>, 00115 is_convertible<const _U2&, _T2>>::value>::type> 00116 constexpr pair(const pair<_U1, _U2>& __p) 00117 : first(__p.first), second(__p.second) { } 00118 00119 constexpr pair(const pair&) = default; 00120 constexpr pair(pair&&) = default; 00121 00122 // DR 811. 00123 template<class _U1, class = typename 00124 enable_if<is_convertible<_U1, _T1>::value>::type> 00125 constexpr pair(_U1&& __x, const _T2& __y) 00126 : first(std::forward<_U1>(__x)), second(__y) { } 00127 00128 template<class _U2, class = typename 00129 enable_if<is_convertible<_U2, _T2>::value>::type> 00130 constexpr pair(const _T1& __x, _U2&& __y) 00131 : first(__x), second(std::forward<_U2>(__y)) { } 00132 00133 template<class _U1, class _U2, class = typename 00134 enable_if<__and_<is_convertible<_U1, _T1>, 00135 is_convertible<_U2, _T2>>::value>::type> 00136 constexpr pair(_U1&& __x, _U2&& __y) 00137 : first(std::forward<_U1>(__x)), second(std::forward<_U2>(__y)) { } 00138 00139 template<class _U1, class _U2, class = typename 00140 enable_if<__and_<is_convertible<_U1, _T1>, 00141 is_convertible<_U2, _T2>>::value>::type> 00142 constexpr pair(pair<_U1, _U2>&& __p) 00143 : first(std::forward<_U1>(__p.first)), 00144 second(std::forward<_U2>(__p.second)) { } 00145 00146 template<typename... _Args1, typename... _Args2> 00147 pair(piecewise_construct_t, tuple<_Args1...>, tuple<_Args2...>); 00148 00149 pair& 00150 operator=(const pair& __p) 00151 { 00152 first = __p.first; 00153 second = __p.second; 00154 return *this; 00155 } 00156 00157 pair& 00158 operator=(pair&& __p) 00159 noexcept(__and_<is_nothrow_move_assignable<_T1>, 00160 is_nothrow_move_assignable<_T2>>::value) 00161 { 00162 first = std::forward<first_type>(__p.first); 00163 second = std::forward<second_type>(__p.second); 00164 return *this; 00165 } 00166 00167 template<class _U1, class _U2> 00168 pair& 00169 operator=(const pair<_U1, _U2>& __p) 00170 { 00171 first = __p.first; 00172 second = __p.second; 00173 return *this; 00174 } 00175 00176 template<class _U1, class _U2> 00177 pair& 00178 operator=(pair<_U1, _U2>&& __p) 00179 { 00180 first = std::forward<_U1>(__p.first); 00181 second = std::forward<_U2>(__p.second); 00182 return *this; 00183 } 00184 00185 void 00186 swap(pair& __p) 00187 noexcept(noexcept(swap(first, __p.first)) 00188 && noexcept(swap(second, __p.second))) 00189 { 00190 using std::swap; 00191 swap(first, __p.first); 00192 swap(second, __p.second); 00193 } 00194 00195 private: 00196 template<typename... _Args1, std::size_t... _Indexes1, 00197 typename... _Args2, std::size_t... _Indexes2> 00198 pair(tuple<_Args1...>&, tuple<_Args2...>&, 00199 _Index_tuple<_Indexes1...>, _Index_tuple<_Indexes2...>); 00200 #endif 00201 }; 00202 00203 /// Two pairs of the same type are equal iff their members are equal. 00204 template<class _T1, class _T2> 00205 inline _GLIBCXX_CONSTEXPR bool 00206 operator==(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y) 00207 { return __x.first == __y.first && __x.second == __y.second; } 00208 00209 /// <http://gcc.gnu.org/onlinedocs/libstdc++/manual/utilities.html> 00210 template<class _T1, class _T2> 00211 inline _GLIBCXX_CONSTEXPR bool 00212 operator<(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y) 00213 { return __x.first < __y.first 00214 || (!(__y.first < __x.first) && __x.second < __y.second); } 00215 00216 /// Uses @c operator== to find the result. 00217 template<class _T1, class _T2> 00218 inline _GLIBCXX_CONSTEXPR bool 00219 operator!=(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y) 00220 { return !(__x == __y); } 00221 00222 /// Uses @c operator< to find the result. 00223 template<class _T1, class _T2> 00224 inline _GLIBCXX_CONSTEXPR bool 00225 operator>(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y) 00226 { return __y < __x; } 00227 00228 /// Uses @c operator< to find the result. 00229 template<class _T1, class _T2> 00230 inline _GLIBCXX_CONSTEXPR bool 00231 operator<=(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y) 00232 { return !(__y < __x); } 00233 00234 /// Uses @c operator< to find the result. 00235 template<class _T1, class _T2> 00236 inline _GLIBCXX_CONSTEXPR bool 00237 operator>=(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y) 00238 { return !(__x < __y); } 00239 00240 #ifdef __GXX_EXPERIMENTAL_CXX0X__ 00241 /// See std::pair::swap(). 00242 // Note: no std::swap overloads in C++03 mode, this has performance 00243 // implications, see, eg, libstdc++/38466. 00244 template<class _T1, class _T2> 00245 inline void 00246 swap(pair<_T1, _T2>& __x, pair<_T1, _T2>& __y) 00247 noexcept(noexcept(__x.swap(__y))) 00248 { __x.swap(__y); } 00249 #endif 00250 00251 /** 00252 * @brief A convenience wrapper for creating a pair from two objects. 00253 * @param __x The first object. 00254 * @param __y The second object. 00255 * @return A newly-constructed pair<> object of the appropriate type. 00256 * 00257 * The standard requires that the objects be passed by reference-to-const, 00258 * but LWG issue #181 says they should be passed by const value. We follow 00259 * the LWG by default. 00260 */ 00261 // _GLIBCXX_RESOLVE_LIB_DEFECTS 00262 // 181. make_pair() unintended behavior 00263 #ifdef __GXX_EXPERIMENTAL_CXX0X__ 00264 // NB: DR 706. 00265 template<class _T1, class _T2> 00266 constexpr pair<typename __decay_and_strip<_T1>::__type, 00267 typename __decay_and_strip<_T2>::__type> 00268 make_pair(_T1&& __x, _T2&& __y) 00269 { 00270 typedef typename __decay_and_strip<_T1>::__type __ds_type1; 00271 typedef typename __decay_and_strip<_T2>::__type __ds_type2; 00272 typedef pair<__ds_type1, __ds_type2> __pair_type; 00273 return __pair_type(std::forward<_T1>(__x), std::forward<_T2>(__y)); 00274 } 00275 #else 00276 template<class _T1, class _T2> 00277 inline pair<_T1, _T2> 00278 make_pair(_T1 __x, _T2 __y) 00279 { return pair<_T1, _T2>(__x, __y); } 00280 #endif 00281 00282 _GLIBCXX_END_NAMESPACE_VERSION 00283 } // namespace 00284 00285 #endif /* _STL_PAIR_H */