1// <utility> -*- C++ -*- 2 3// Copyright (C) 2001-2018 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 74#include <type_traits> 75#include <bits/move.h> 76#include <initializer_list> 77 78#if __cplusplus > 201402L 79#include <exception> 80#endif 81 82namespace std _GLIBCXX_VISIBILITY(default) 83{ 84_GLIBCXX_BEGIN_NAMESPACE_VERSION 85 86 /// Finds the size of a given tuple type. 87 template<typename _Tp> 88 struct tuple_size; 89 90 // _GLIBCXX_RESOLVE_LIB_DEFECTS 91 // 2313. tuple_size should always derive from integral_constant<size_t, N> 92 // 2770. tuple_size<const T> specialization is not SFINAE compatible 93 94 template<typename _Tp, 95 typename _Up = typename remove_cv<_Tp>::type, 96 typename = typename enable_if<is_same<_Tp, _Up>::value>::type, 97 size_t = tuple_size<_Tp>::value> 98 using __enable_if_has_tuple_size = _Tp; 99 100 template<typename _Tp> 101 struct tuple_size<const __enable_if_has_tuple_size<_Tp>> 102 : public tuple_size<_Tp> { }; 103 104 template<typename _Tp> 105 struct tuple_size<volatile __enable_if_has_tuple_size<_Tp>> 106 : public tuple_size<_Tp> { }; 107 108 template<typename _Tp> 109 struct tuple_size<const volatile __enable_if_has_tuple_size<_Tp>> 110 : public tuple_size<_Tp> { }; 111 112 /// Gives the type of the ith element of a given tuple type. 113 template<std::size_t __i, typename _Tp> 114 struct tuple_element; 115 116 // Duplicate of C++14's tuple_element_t for internal use in C++11 mode 117 template<std::size_t __i, typename _Tp> 118 using __tuple_element_t = typename tuple_element<__i, _Tp>::type; 119 120 template<std::size_t __i, typename _Tp> 121 struct tuple_element<__i, const _Tp> 122 { 123 typedef typename add_const<__tuple_element_t<__i, _Tp>>::type type; 124 }; 125 126 template<std::size_t __i, typename _Tp> 127 struct tuple_element<__i, volatile _Tp> 128 { 129 typedef typename add_volatile<__tuple_element_t<__i, _Tp>>::type type; 130 }; 131 132 template<std::size_t __i, typename _Tp> 133 struct tuple_element<__i, const volatile _Tp> 134 { 135 typedef typename add_cv<__tuple_element_t<__i, _Tp>>::type type; 136 }; 137 138#if __cplusplus > 201103L 139#define __cpp_lib_tuple_element_t 201402 140 141 template<std::size_t __i, typename _Tp> 142 using tuple_element_t = typename tuple_element<__i, _Tp>::type; 143#endif 144 145 // Various functions which give std::pair a tuple-like interface. 146 147 /// Partial specialization for std::pair 148 template<typename _T1, typename _T2> 149 struct __is_tuple_like_impl<std::pair<_T1, _T2>> : true_type 150 { }; 151 152 /// Partial specialization for std::pair 153 template<class _Tp1, class _Tp2> 154 struct tuple_size<std::pair<_Tp1, _Tp2>> 155 : public integral_constant<std::size_t, 2> { }; 156 157 /// Partial specialization for std::pair 158 template<class _Tp1, class _Tp2> 159 struct tuple_element<0, std::pair<_Tp1, _Tp2>> 160 { typedef _Tp1 type; }; 161 162 /// Partial specialization for std::pair 163 template<class _Tp1, class _Tp2> 164 struct tuple_element<1, std::pair<_Tp1, _Tp2>> 165 { typedef _Tp2 type; }; 166 167 template<std::size_t _Int> 168 struct __pair_get; 169 170 template<> 171 struct __pair_get<0> 172 { 173 template<typename _Tp1, typename _Tp2> 174 static constexpr _Tp1& 175 __get(std::pair<_Tp1, _Tp2>& __pair) noexcept 176 { return __pair.first; } 177 178 template<typename _Tp1, typename _Tp2> 179 static constexpr _Tp1&& 180 __move_get(std::pair<_Tp1, _Tp2>&& __pair) noexcept 181 { return std::forward<_Tp1>(__pair.first); } 182 183 template<typename _Tp1, typename _Tp2> 184 static constexpr const _Tp1& 185 __const_get(const std::pair<_Tp1, _Tp2>& __pair) noexcept 186 { return __pair.first; } 187 188 template<typename _Tp1, typename _Tp2> 189 static constexpr const _Tp1&& 190 __const_move_get(const std::pair<_Tp1, _Tp2>&& __pair) noexcept 191 { return std::forward<const _Tp1>(__pair.first); } 192 }; 193 194 template<> 195 struct __pair_get<1> 196 { 197 template<typename _Tp1, typename _Tp2> 198 static constexpr _Tp2& 199 __get(std::pair<_Tp1, _Tp2>& __pair) noexcept 200 { return __pair.second; } 201 202 template<typename _Tp1, typename _Tp2> 203 static constexpr _Tp2&& 204 __move_get(std::pair<_Tp1, _Tp2>&& __pair) noexcept 205 { return std::forward<_Tp2>(__pair.second); } 206 207 template<typename _Tp1, typename _Tp2> 208 static constexpr const _Tp2& 209 __const_get(const std::pair<_Tp1, _Tp2>& __pair) noexcept 210 { return __pair.second; } 211 212 template<typename _Tp1, typename _Tp2> 213 static constexpr const _Tp2&& 214 __const_move_get(const std::pair<_Tp1, _Tp2>&& __pair) noexcept 215 { return std::forward<const _Tp2>(__pair.second); } 216 }; 217 218 template<std::size_t _Int, class _Tp1, class _Tp2> 219 constexpr typename tuple_element<_Int, std::pair<_Tp1, _Tp2>>::type& 220 get(std::pair<_Tp1, _Tp2>& __in) noexcept 221 { return __pair_get<_Int>::__get(__in); } 222 223 template<std::size_t _Int, class _Tp1, class _Tp2> 224 constexpr typename tuple_element<_Int, std::pair<_Tp1, _Tp2>>::type&& 225 get(std::pair<_Tp1, _Tp2>&& __in) noexcept 226 { return __pair_get<_Int>::__move_get(std::move(__in)); } 227 228 template<std::size_t _Int, class _Tp1, class _Tp2> 229 constexpr const typename tuple_element<_Int, std::pair<_Tp1, _Tp2>>::type& 230 get(const std::pair<_Tp1, _Tp2>& __in) noexcept 231 { return __pair_get<_Int>::__const_get(__in); } 232 233 template<std::size_t _Int, class _Tp1, class _Tp2> 234 constexpr const typename tuple_element<_Int, std::pair<_Tp1, _Tp2>>::type&& 235 get(const std::pair<_Tp1, _Tp2>&& __in) noexcept 236 { return __pair_get<_Int>::__const_move_get(std::move(__in)); } 237 238#if __cplusplus > 201103L 239 240#define __cpp_lib_tuples_by_type 201304 241 242 template <typename _Tp, typename _Up> 243 constexpr _Tp& 244 get(pair<_Tp, _Up>& __p) noexcept 245 { return __p.first; } 246 247 template <typename _Tp, typename _Up> 248 constexpr const _Tp& 249 get(const pair<_Tp, _Up>& __p) noexcept 250 { return __p.first; } 251 252 template <typename _Tp, typename _Up> 253 constexpr _Tp&& 254 get(pair<_Tp, _Up>&& __p) noexcept 255 { return std::move(__p.first); } 256 257 template <typename _Tp, typename _Up> 258 constexpr const _Tp&& 259 get(const pair<_Tp, _Up>&& __p) noexcept 260 { return std::move(__p.first); } 261 262 template <typename _Tp, typename _Up> 263 constexpr _Tp& 264 get(pair<_Up, _Tp>& __p) noexcept 265 { return __p.second; } 266 267 template <typename _Tp, typename _Up> 268 constexpr const _Tp& 269 get(const pair<_Up, _Tp>& __p) noexcept 270 { return __p.second; } 271 272 template <typename _Tp, typename _Up> 273 constexpr _Tp&& 274 get(pair<_Up, _Tp>&& __p) noexcept 275 { return std::move(__p.second); } 276 277 template <typename _Tp, typename _Up> 278 constexpr const _Tp&& 279 get(const pair<_Up, _Tp>&& __p) noexcept 280 { return std::move(__p.second); } 281 282#define __cpp_lib_exchange_function 201304 283 284 /// Assign @p __new_val to @p __obj and return its previous value. 285 template <typename _Tp, typename _Up = _Tp> 286 inline _Tp 287 exchange(_Tp& __obj, _Up&& __new_val) 288 { return std::__exchange(__obj, std::forward<_Up>(__new_val)); } 289#endif 290 291 // Stores a tuple of indices. Used by tuple and pair, and by bind() to 292 // extract the elements in a tuple. 293 template<size_t... _Indexes> struct _Index_tuple { }; 294 295#ifdef __has_builtin 296# if __has_builtin(__make_integer_seq) 297# define _GLIBCXX_USE_MAKE_INTEGER_SEQ 1 298# endif 299#endif 300 301 // Builds an _Index_tuple<0, 1, 2, ..., _Num-1>. 302 template<size_t _Num> 303 struct _Build_index_tuple 304 { 305#if _GLIBCXX_USE_MAKE_INTEGER_SEQ 306 template<typename, size_t... _Indices> 307 using _IdxTuple = _Index_tuple<_Indices...>; 308 309 using __type = __make_integer_seq<_IdxTuple, size_t, _Num>; 310#else 311 using __type = _Index_tuple<__integer_pack(_Num)...>; 312#endif 313 }; 314 315#if __cplusplus > 201103L 316 317#define __cpp_lib_integer_sequence 201304 318 319 /// Class template integer_sequence 320 template<typename _Tp, _Tp... _Idx> 321 struct integer_sequence 322 { 323 typedef _Tp value_type; 324 static constexpr size_t size() noexcept { return sizeof...(_Idx); } 325 }; 326 327 /// Alias template make_integer_sequence 328 template<typename _Tp, _Tp _Num> 329 using make_integer_sequence 330#if _GLIBCXX_USE_MAKE_INTEGER_SEQ 331 = __make_integer_seq<integer_sequence, _Tp, _Num>; 332#else 333 = integer_sequence<_Tp, __integer_pack(_Num)...>; 334#endif 335 336#undef _GLIBCXX_USE_MAKE_INTEGER_SEQ 337 338 /// Alias template index_sequence 339 template<size_t... _Idx> 340 using index_sequence = integer_sequence<size_t, _Idx...>; 341 342 /// Alias template make_index_sequence 343 template<size_t _Num> 344 using make_index_sequence = make_integer_sequence<size_t, _Num>; 345 346 /// Alias template index_sequence_for 347 template<typename... _Types> 348 using index_sequence_for = make_index_sequence<sizeof...(_Types)>; 349#endif 350 351#if __cplusplus > 201402L 352 353 struct in_place_t { 354 explicit in_place_t() = default; 355 }; 356 357 inline constexpr in_place_t in_place{}; 358 359 template<typename _Tp> struct in_place_type_t 360 { 361 explicit in_place_type_t() = default; 362 }; 363 364 template<typename _Tp> 365 inline constexpr in_place_type_t<_Tp> in_place_type{}; 366 367 template<size_t _Idx> struct in_place_index_t 368 { 369 explicit in_place_index_t() = default; 370 }; 371 372 template<size_t _Idx> 373 inline constexpr in_place_index_t<_Idx> in_place_index{}; 374 375 template<typename> 376 struct __is_in_place_type_impl : false_type 377 { }; 378 379 template<typename _Tp> 380 struct __is_in_place_type_impl<in_place_type_t<_Tp>> : true_type 381 { }; 382 383 template<typename _Tp> 384 struct __is_in_place_type 385 : public __is_in_place_type_impl<_Tp> 386 { }; 387 388#define __cpp_lib_as_const 201510 389 template<typename _Tp> 390 constexpr add_const_t<_Tp>& as_const(_Tp& __t) noexcept { return __t; } 391 392 template<typename _Tp> 393 void as_const(const _Tp&&) = delete; 394 395#endif // C++17 396 397_GLIBCXX_END_NAMESPACE_VERSION 398} // namespace 399 400#endif 401 402#endif /* _GLIBCXX_UTILITY */ 403