libstdc++
|
00001 // <utility> -*- C++ -*- 00002 00003 // Copyright (C) 2001-2018 Free Software Foundation, Inc. 00004 // 00005 // This file is part of the GNU ISO C++ Library. This library is free 00006 // software; you can redistribute it and/or modify it under the 00007 // terms of the GNU General Public License as published by the 00008 // Free Software Foundation; either version 3, or (at your option) 00009 // any later version. 00010 00011 // This library is distributed in the hope that it will be useful, 00012 // but WITHOUT ANY WARRANTY; without even the implied warranty of 00013 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00014 // GNU General Public License for more details. 00015 00016 // Under Section 7 of GPL version 3, you are granted additional 00017 // permissions described in the GCC Runtime Library Exception, version 00018 // 3.1, as published by the Free Software Foundation. 00019 00020 // You should have received a copy of the GNU General Public License and 00021 // a copy of the GCC Runtime Library Exception along with this program; 00022 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 00023 // <http://www.gnu.org/licenses/>. 00024 00025 /* 00026 * 00027 * Copyright (c) 1994 00028 * Hewlett-Packard Company 00029 * 00030 * Permission to use, copy, modify, distribute and sell this software 00031 * and its documentation for any purpose is hereby granted without fee, 00032 * provided that the above copyright notice appear in all copies and 00033 * that both that copyright notice and this permission notice appear 00034 * in supporting documentation. Hewlett-Packard Company makes no 00035 * representations about the suitability of this software for any 00036 * purpose. It is provided "as is" without express or implied warranty. 00037 * 00038 * 00039 * Copyright (c) 1996,1997 00040 * Silicon Graphics Computer Systems, Inc. 00041 * 00042 * Permission to use, copy, modify, distribute and sell this software 00043 * and its documentation for any purpose is hereby granted without fee, 00044 * provided that the above copyright notice appear in all copies and 00045 * that both that copyright notice and this permission notice appear 00046 * in supporting documentation. Silicon Graphics makes no 00047 * representations about the suitability of this software for any 00048 * purpose. It is provided "as is" without express or implied warranty. 00049 */ 00050 00051 /** @file include/utility 00052 * This is a Standard C++ Library header. 00053 */ 00054 00055 #ifndef _GLIBCXX_UTILITY 00056 #define _GLIBCXX_UTILITY 1 00057 00058 #pragma GCC system_header 00059 00060 /** 00061 * @defgroup utilities Utilities 00062 * 00063 * Components deemed generally useful. Includes pair, tuple, 00064 * forward/move helpers, ratio, function object, metaprogramming and 00065 * type traits, time, date, and memory functions. 00066 */ 00067 00068 #include <bits/c++config.h> 00069 #include <bits/stl_relops.h> 00070 #include <bits/stl_pair.h> 00071 00072 #if __cplusplus >= 201103L 00073 00074 #include <type_traits> 00075 #include <bits/move.h> 00076 #include <initializer_list> 00077 00078 namespace std _GLIBCXX_VISIBILITY(default) 00079 { 00080 _GLIBCXX_BEGIN_NAMESPACE_VERSION 00081 00082 /// Finds the size of a given tuple type. 00083 template<typename _Tp> 00084 struct tuple_size; 00085 00086 // _GLIBCXX_RESOLVE_LIB_DEFECTS 00087 // 2313. tuple_size should always derive from integral_constant<size_t, N> 00088 // 2770. tuple_size<const T> specialization is not SFINAE compatible 00089 00090 template<typename _Tp, 00091 typename _Up = typename remove_cv<_Tp>::type, 00092 typename = typename enable_if<is_same<_Tp, _Up>::value>::type, 00093 size_t = tuple_size<_Tp>::value> 00094 using __enable_if_has_tuple_size = _Tp; 00095 00096 template<typename _Tp> 00097 struct tuple_size<const __enable_if_has_tuple_size<_Tp>> 00098 : public tuple_size<_Tp> { }; 00099 00100 template<typename _Tp> 00101 struct tuple_size<volatile __enable_if_has_tuple_size<_Tp>> 00102 : public tuple_size<_Tp> { }; 00103 00104 template<typename _Tp> 00105 struct tuple_size<const volatile __enable_if_has_tuple_size<_Tp>> 00106 : public tuple_size<_Tp> { }; 00107 00108 /// Gives the type of the ith element of a given tuple type. 00109 template<std::size_t __i, typename _Tp> 00110 struct tuple_element; 00111 00112 // Duplicate of C++14's tuple_element_t for internal use in C++11 mode 00113 template<std::size_t __i, typename _Tp> 00114 using __tuple_element_t = typename tuple_element<__i, _Tp>::type; 00115 00116 template<std::size_t __i, typename _Tp> 00117 struct tuple_element<__i, const _Tp> 00118 { 00119 typedef typename add_const<__tuple_element_t<__i, _Tp>>::type type; 00120 }; 00121 00122 template<std::size_t __i, typename _Tp> 00123 struct tuple_element<__i, volatile _Tp> 00124 { 00125 typedef typename add_volatile<__tuple_element_t<__i, _Tp>>::type type; 00126 }; 00127 00128 template<std::size_t __i, typename _Tp> 00129 struct tuple_element<__i, const volatile _Tp> 00130 { 00131 typedef typename add_cv<__tuple_element_t<__i, _Tp>>::type type; 00132 }; 00133 00134 #if __cplusplus > 201103L 00135 #define __cpp_lib_tuple_element_t 201402 00136 00137 template<std::size_t __i, typename _Tp> 00138 using tuple_element_t = typename tuple_element<__i, _Tp>::type; 00139 #endif 00140 00141 // Various functions which give std::pair a tuple-like interface. 00142 00143 /// Partial specialization for std::pair 00144 template<typename _T1, typename _T2> 00145 struct __is_tuple_like_impl<std::pair<_T1, _T2>> : true_type 00146 { }; 00147 00148 /// Partial specialization for std::pair 00149 template<class _Tp1, class _Tp2> 00150 struct tuple_size<std::pair<_Tp1, _Tp2>> 00151 : public integral_constant<std::size_t, 2> { }; 00152 00153 /// Partial specialization for std::pair 00154 template<class _Tp1, class _Tp2> 00155 struct tuple_element<0, std::pair<_Tp1, _Tp2>> 00156 { typedef _Tp1 type; }; 00157 00158 /// Partial specialization for std::pair 00159 template<class _Tp1, class _Tp2> 00160 struct tuple_element<1, std::pair<_Tp1, _Tp2>> 00161 { typedef _Tp2 type; }; 00162 00163 template<std::size_t _Int> 00164 struct __pair_get; 00165 00166 template<> 00167 struct __pair_get<0> 00168 { 00169 template<typename _Tp1, typename _Tp2> 00170 static constexpr _Tp1& 00171 __get(std::pair<_Tp1, _Tp2>& __pair) noexcept 00172 { return __pair.first; } 00173 00174 template<typename _Tp1, typename _Tp2> 00175 static constexpr _Tp1&& 00176 __move_get(std::pair<_Tp1, _Tp2>&& __pair) noexcept 00177 { return std::forward<_Tp1>(__pair.first); } 00178 00179 template<typename _Tp1, typename _Tp2> 00180 static constexpr const _Tp1& 00181 __const_get(const std::pair<_Tp1, _Tp2>& __pair) noexcept 00182 { return __pair.first; } 00183 00184 template<typename _Tp1, typename _Tp2> 00185 static constexpr const _Tp1&& 00186 __const_move_get(const std::pair<_Tp1, _Tp2>&& __pair) noexcept 00187 { return std::forward<const _Tp1>(__pair.first); } 00188 }; 00189 00190 template<> 00191 struct __pair_get<1> 00192 { 00193 template<typename _Tp1, typename _Tp2> 00194 static constexpr _Tp2& 00195 __get(std::pair<_Tp1, _Tp2>& __pair) noexcept 00196 { return __pair.second; } 00197 00198 template<typename _Tp1, typename _Tp2> 00199 static constexpr _Tp2&& 00200 __move_get(std::pair<_Tp1, _Tp2>&& __pair) noexcept 00201 { return std::forward<_Tp2>(__pair.second); } 00202 00203 template<typename _Tp1, typename _Tp2> 00204 static constexpr const _Tp2& 00205 __const_get(const std::pair<_Tp1, _Tp2>& __pair) noexcept 00206 { return __pair.second; } 00207 00208 template<typename _Tp1, typename _Tp2> 00209 static constexpr const _Tp2&& 00210 __const_move_get(const std::pair<_Tp1, _Tp2>&& __pair) noexcept 00211 { return std::forward<const _Tp2>(__pair.second); } 00212 }; 00213 00214 template<std::size_t _Int, class _Tp1, class _Tp2> 00215 constexpr typename tuple_element<_Int, std::pair<_Tp1, _Tp2>>::type& 00216 get(std::pair<_Tp1, _Tp2>& __in) noexcept 00217 { return __pair_get<_Int>::__get(__in); } 00218 00219 template<std::size_t _Int, class _Tp1, class _Tp2> 00220 constexpr typename tuple_element<_Int, std::pair<_Tp1, _Tp2>>::type&& 00221 get(std::pair<_Tp1, _Tp2>&& __in) noexcept 00222 { return __pair_get<_Int>::__move_get(std::move(__in)); } 00223 00224 template<std::size_t _Int, class _Tp1, class _Tp2> 00225 constexpr const typename tuple_element<_Int, std::pair<_Tp1, _Tp2>>::type& 00226 get(const std::pair<_Tp1, _Tp2>& __in) noexcept 00227 { return __pair_get<_Int>::__const_get(__in); } 00228 00229 template<std::size_t _Int, class _Tp1, class _Tp2> 00230 constexpr const typename tuple_element<_Int, std::pair<_Tp1, _Tp2>>::type&& 00231 get(const std::pair<_Tp1, _Tp2>&& __in) noexcept 00232 { return __pair_get<_Int>::__const_move_get(std::move(__in)); } 00233 00234 #if __cplusplus > 201103L 00235 00236 #define __cpp_lib_tuples_by_type 201304 00237 00238 template <typename _Tp, typename _Up> 00239 constexpr _Tp& 00240 get(pair<_Tp, _Up>& __p) noexcept 00241 { return __p.first; } 00242 00243 template <typename _Tp, typename _Up> 00244 constexpr const _Tp& 00245 get(const pair<_Tp, _Up>& __p) noexcept 00246 { return __p.first; } 00247 00248 template <typename _Tp, typename _Up> 00249 constexpr _Tp&& 00250 get(pair<_Tp, _Up>&& __p) noexcept 00251 { return std::move(__p.first); } 00252 00253 template <typename _Tp, typename _Up> 00254 constexpr const _Tp&& 00255 get(const pair<_Tp, _Up>&& __p) noexcept 00256 { return std::move(__p.first); } 00257 00258 template <typename _Tp, typename _Up> 00259 constexpr _Tp& 00260 get(pair<_Up, _Tp>& __p) noexcept 00261 { return __p.second; } 00262 00263 template <typename _Tp, typename _Up> 00264 constexpr const _Tp& 00265 get(const pair<_Up, _Tp>& __p) noexcept 00266 { return __p.second; } 00267 00268 template <typename _Tp, typename _Up> 00269 constexpr _Tp&& 00270 get(pair<_Up, _Tp>&& __p) noexcept 00271 { return std::move(__p.second); } 00272 00273 template <typename _Tp, typename _Up> 00274 constexpr const _Tp&& 00275 get(const pair<_Up, _Tp>&& __p) noexcept 00276 { return std::move(__p.second); } 00277 00278 #define __cpp_lib_exchange_function 201304 00279 00280 /// Assign @p __new_val to @p __obj and return its previous value. 00281 template <typename _Tp, typename _Up = _Tp> 00282 inline _Tp 00283 exchange(_Tp& __obj, _Up&& __new_val) 00284 { return std::__exchange(__obj, std::forward<_Up>(__new_val)); } 00285 #endif 00286 00287 // Stores a tuple of indices. Used by tuple and pair, and by bind() to 00288 // extract the elements in a tuple. 00289 template<size_t... _Indexes> struct _Index_tuple { }; 00290 00291 #ifdef __has_builtin 00292 # if __has_builtin(__make_integer_seq) 00293 # define _GLIBCXX_USE_MAKE_INTEGER_SEQ 1 00294 # endif 00295 #endif 00296 00297 // Builds an _Index_tuple<0, 1, 2, ..., _Num-1>. 00298 template<size_t _Num> 00299 struct _Build_index_tuple 00300 { 00301 #if _GLIBCXX_USE_MAKE_INTEGER_SEQ 00302 template<typename, size_t... _Indices> 00303 using _IdxTuple = _Index_tuple<_Indices...>; 00304 00305 using __type = __make_integer_seq<_IdxTuple, size_t, _Num>; 00306 #else 00307 using __type = _Index_tuple<__integer_pack(_Num)...>; 00308 #endif 00309 }; 00310 00311 #if __cplusplus > 201103L 00312 00313 #define __cpp_lib_integer_sequence 201304 00314 00315 /// Class template integer_sequence 00316 template<typename _Tp, _Tp... _Idx> 00317 struct integer_sequence 00318 { 00319 typedef _Tp value_type; 00320 static constexpr size_t size() noexcept { return sizeof...(_Idx); } 00321 }; 00322 00323 /// Alias template make_integer_sequence 00324 template<typename _Tp, _Tp _Num> 00325 using make_integer_sequence 00326 #if _GLIBCXX_USE_MAKE_INTEGER_SEQ 00327 = __make_integer_seq<integer_sequence, _Tp, _Num>; 00328 #else 00329 = integer_sequence<_Tp, __integer_pack(_Num)...>; 00330 #endif 00331 00332 #undef _GLIBCXX_USE_MAKE_INTEGER_SEQ 00333 00334 /// Alias template index_sequence 00335 template<size_t... _Idx> 00336 using index_sequence = integer_sequence<size_t, _Idx...>; 00337 00338 /// Alias template make_index_sequence 00339 template<size_t _Num> 00340 using make_index_sequence = make_integer_sequence<size_t, _Num>; 00341 00342 /// Alias template index_sequence_for 00343 template<typename... _Types> 00344 using index_sequence_for = make_index_sequence<sizeof...(_Types)>; 00345 #endif 00346 00347 #if __cplusplus > 201402L 00348 00349 struct in_place_t { 00350 explicit in_place_t() = default; 00351 }; 00352 00353 inline constexpr in_place_t in_place{}; 00354 00355 template<typename _Tp> struct in_place_type_t 00356 { 00357 explicit in_place_type_t() = default; 00358 }; 00359 00360 template<typename _Tp> 00361 inline constexpr in_place_type_t<_Tp> in_place_type{}; 00362 00363 template<size_t _Idx> struct in_place_index_t 00364 { 00365 explicit in_place_index_t() = default; 00366 }; 00367 00368 template<size_t _Idx> 00369 inline constexpr in_place_index_t<_Idx> in_place_index{}; 00370 00371 template<typename> 00372 struct __is_in_place_type_impl : false_type 00373 { }; 00374 00375 template<typename _Tp> 00376 struct __is_in_place_type_impl<in_place_type_t<_Tp>> : true_type 00377 { }; 00378 00379 template<typename _Tp> 00380 struct __is_in_place_type 00381 : public __is_in_place_type_impl<_Tp> 00382 { }; 00383 00384 #define __cpp_lib_as_const 201510 00385 template<typename _Tp> 00386 constexpr add_const_t<_Tp>& as_const(_Tp& __t) noexcept { return __t; } 00387 00388 template<typename _Tp> 00389 void as_const(const _Tp&&) = delete; 00390 00391 #endif // C++17 00392 00393 _GLIBCXX_END_NAMESPACE_VERSION 00394 } // namespace 00395 00396 #endif 00397 00398 #endif /* _GLIBCXX_UTILITY */