1 // <utility> -*- C++ -*- 2 3 // Copyright (C) 2001-2014 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 3, 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 // Under Section 7 of GPL version 3, you are granted additional 17 // permissions described in the GCC Runtime Library Exception, version 18 // 3.1, as published by the Free Software Foundation. 19 20 // You should have received a copy of the GNU General Public License and 21 // a copy of the GCC Runtime Library Exception along with this program; 22 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 23 // <http://www.gnu.org/licenses/>. 24 25 /* 26 * 27 * Copyright (c) 1994 28 * Hewlett-Packard Company 29 * 30 * Permission to use, copy, modify, distribute and sell this software 31 * and its documentation for any purpose is hereby granted without fee, 32 * provided that the above copyright notice appear in all copies and 33 * that both that copyright notice and this permission notice appear 34 * in supporting documentation. Hewlett-Packard Company makes no 35 * representations about the suitability of this software for any 36 * purpose. It is provided "as is" without express or implied warranty. 37 * 38 * 39 * Copyright (c) 1996,1997 40 * Silicon Graphics Computer Systems, Inc. 41 * 42 * Permission to use, copy, modify, distribute and sell this software 43 * and its documentation for any purpose is hereby granted without fee, 44 * provided that the above copyright notice appear in all copies and 45 * that both that copyright notice and this permission notice appear 46 * in supporting documentation. Silicon Graphics makes no 47 * representations about the suitability of this software for any 48 * purpose. It is provided "as is" without express or implied warranty. 49 */ 50 51 /** @file include/utility 52 * This is a Standard C++ Library header. 53 */ 54 55 #ifndef _GLIBCXX_UTILITY 56 #define _GLIBCXX_UTILITY 1 57 58 #pragma GCC system_header 59 60 /** 61 * @defgroup utilities Utilities 62 * 63 * Components deemed generally useful. Includes pair, tuple, 64 * forward/move helpers, ratio, function object, metaprogramming and 65 * type traits, time, date, and memory functions. 66 */ 67 68 #include <bits/c++config.h> 69 #include <bits/stl_relops.h> 70 #include <bits/stl_pair.h> 71 72 #if __cplusplus >= 201103L 73 #include <bits/move.h> 74 #include <initializer_list> 75 76 namespace std _GLIBCXX_VISIBILITY(default) 77 { 78 _GLIBCXX_BEGIN_NAMESPACE_VERSION 79 80 template<class _Tp> 81 class tuple_size; 82 83 template<std::size_t _Int, class _Tp> 84 class tuple_element; 85 86 // Various functions which give std::pair a tuple-like interface. 87 template<class _Tp1, class _Tp2> 88 struct tuple_size<std::pair<_Tp1, _Tp2>> 89 : public integral_constant<std::size_t, 2> { }; 90 91 template<class _Tp1, class _Tp2> 92 struct tuple_element<0, std::pair<_Tp1, _Tp2>> 93 { typedef _Tp1 type; }; 94 95 template<class _Tp1, class _Tp2> 96 struct tuple_element<1, std::pair<_Tp1, _Tp2>> 97 { typedef _Tp2 type; }; 98 99 template<std::size_t _Int> 100 struct __pair_get; 101 102 template<> 103 struct __pair_get<0> 104 { 105 template<typename _Tp1, typename _Tp2> 106 static constexpr _Tp1& 107 __get(std::pair<_Tp1, _Tp2>& __pair) noexcept 108 { return __pair.first; } 109 110 template<typename _Tp1, typename _Tp2> 111 static constexpr _Tp1&& 112 __move_get(std::pair<_Tp1, _Tp2>&& __pair) noexcept 113 { return std::forward<_Tp1>(__pair.first); } 114 115 template<typename _Tp1, typename _Tp2> 116 static constexpr const _Tp1& 117 __const_get(const std::pair<_Tp1, _Tp2>& __pair) noexcept 118 { return __pair.first; } 119 }; 120 121 template<> 122 struct __pair_get<1> 123 { 124 template<typename _Tp1, typename _Tp2> 125 static constexpr _Tp2& 126 __get(std::pair<_Tp1, _Tp2>& __pair) noexcept 127 { return __pair.second; } 128 129 template<typename _Tp1, typename _Tp2> 130 static constexpr _Tp2&& 131 __move_get(std::pair<_Tp1, _Tp2>&& __pair) noexcept 132 { return std::forward<_Tp2>(__pair.second); } 133 134 template<typename _Tp1, typename _Tp2> 135 static constexpr const _Tp2& 136 __const_get(const std::pair<_Tp1, _Tp2>& __pair) noexcept 137 { return __pair.second; } 138 }; 139 140 template<std::size_t _Int, class _Tp1, class _Tp2> 141 constexpr typename tuple_element<_Int, std::pair<_Tp1, _Tp2>>::type& 142 get(std::pair<_Tp1, _Tp2>& __in) noexcept 143 { return __pair_get<_Int>::__get(__in); } 144 145 template<std::size_t _Int, class _Tp1, class _Tp2> 146 constexpr typename tuple_element<_Int, std::pair<_Tp1, _Tp2>>::type&& 147 get(std::pair<_Tp1, _Tp2>&& __in) noexcept 148 { return __pair_get<_Int>::__move_get(std::move(__in)); } 149 150 template<std::size_t _Int, class _Tp1, class _Tp2> 151 constexpr const typename tuple_element<_Int, std::pair<_Tp1, _Tp2>>::type& 152 get(const std::pair<_Tp1, _Tp2>& __in) noexcept 153 { return __pair_get<_Int>::__const_get(__in); } 154 155 #if __cplusplus > 201103L 156 template <typename _Tp, typename _Up> 157 constexpr _Tp& 158 get(pair<_Tp, _Up>& __p) noexcept 159 { return __p.first; } 160 161 template <typename _Tp, typename _Up> 162 constexpr const _Tp& 163 get(const pair<_Tp, _Up>& __p) noexcept 164 { return __p.first; } 165 166 template <typename _Tp, typename _Up> 167 constexpr _Tp&& 168 get(pair<_Tp, _Up>&& __p) noexcept 169 { return std::move(__p.first); } 170 171 template <typename _Tp, typename _Up> 172 constexpr _Tp& 173 get(pair<_Up, _Tp>& __p) noexcept 174 { return __p.second; } 175 176 template <typename _Tp, typename _Up> 177 constexpr const _Tp& 178 get(const pair<_Up, _Tp>& __p) noexcept 179 { return __p.second; } 180 181 template <typename _Tp, typename _Up> 182 constexpr _Tp&& 183 get(pair<_Up, _Tp>&& __p) noexcept 184 { return std::move(__p.second); } 185 186 /// Assign @p __new_val to @p __obj and return its previous value. 187 template <typename _Tp, typename _Up = _Tp> 188 inline _Tp 189 exchange(_Tp& __obj, _Up&& __new_val) 190 { 191 _Tp __old_val = std::move(__obj); 192 __obj = std::forward<_Up>(__new_val); 193 return __old_val; 194 } 195 #endif 196 197 // Stores a tuple of indices. Used by tuple and pair, and by bind() to 198 // extract the elements in a tuple. 199 template<size_t... _Indexes> 200 struct _Index_tuple 201 { 202 typedef _Index_tuple<_Indexes..., sizeof...(_Indexes)> __next; 203 }; 204 205 // Builds an _Index_tuple<0, 1, 2, ..., _Num-1>. 206 template<size_t _Num> 207 struct _Build_index_tuple 208 { 209 typedef typename _Build_index_tuple<_Num - 1>::__type::__next __type; 210 }; 211 212 template<> 213 struct _Build_index_tuple<0> 214 { 215 typedef _Index_tuple<> __type; 216 }; 217 218 #if __cplusplus > 201103L 219 /// Class template integer_sequence 220 template<typename _Tp, _Tp... _Idx> 221 struct integer_sequence 222 { 223 typedef _Tp value_type; 224 static constexpr size_t size() { return sizeof...(_Idx); } 225 }; 226 227 template<typename _Tp, _Tp _Num, 228 typename _ISeq = typename _Build_index_tuple<_Num>::__type> 229 struct _Make_integer_sequence; 230 231 template<typename _Tp, _Tp _Num, size_t... _Idx> 232 struct _Make_integer_sequence<_Tp, _Num, _Index_tuple<_Idx...>> 233 { 234 static_assert( _Num >= 0, 235 "Cannot make integer sequence of negative length" ); 236 237 typedef integer_sequence<_Tp, static_cast<_Tp>(_Idx)...> __type; 238 }; 239 240 /// Alias template make_integer_sequence 241 template<typename _Tp, _Tp _Num> 242 using make_integer_sequence 243 = typename _Make_integer_sequence<_Tp, _Num>::__type; 244 245 /// Alias template index_sequence 246 template<size_t... _Idx> 247 using index_sequence = integer_sequence<size_t, _Idx...>; 248 249 /// Alias template make_index_sequence 250 template<size_t _Num> 251 using make_index_sequence = make_integer_sequence<size_t, _Num>; 252 253 /// Alias template index_sequence_for 254 template<typename... _Types> 255 using index_sequence_for = make_index_sequence<sizeof...(_Types)>; 256 #endif 257 258 _GLIBCXX_END_NAMESPACE_VERSION 259 } // namespace 260 261 #endif 262 263 #endif /* _GLIBCXX_UTILITY */ 264
