| 1 | // <experimental/any> -*- C++ -*- | 
 
 
 
 
 | 2 |  | 
 
 
 
 
 | 3 | // Copyright (C) 2014-2021 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 | /** @file experimental/any | 
 
 
 
 
 | 26 | *  This is a TS C++ Library header. | 
 
 
 
 
 | 27 | *  @ingroup libfund-ts | 
 
 
 
 
 | 28 | */ | 
 
 
 
 
 | 29 |  | 
 
 
 
 
 | 30 | #ifndef _GLIBCXX_EXPERIMENTAL_ANY | 
 
 
 
 
 | 31 | #define _GLIBCXX_EXPERIMENTAL_ANY 1 | 
 
 
 
 
 | 32 |  | 
 
 
 
 
 | 33 | #pragma GCC system_header | 
 
 
 
 
 | 34 |  | 
 
 
 
 
 | 35 | #if __cplusplus >= 201402L | 
 
 
 
 
 | 36 |  | 
 
 
 
 
 | 37 | #include <typeinfo> | 
 
 
 
 
 | 38 | #include <new> | 
 
 
 
 
 | 39 | #include <utility> | 
 
 
 
 
 | 40 | #include <type_traits> | 
 
 
 
 
 | 41 | #include <experimental/bits/lfts_config.h> | 
 
 
 
 
 | 42 |  | 
 
 
 
 
 | 43 | namespace std _GLIBCXX_VISIBILITY(default) | 
 
 
 
 
 | 44 | { | 
 
 
 
 
 | 45 | _GLIBCXX_BEGIN_NAMESPACE_VERSION | 
 
 
 
 
 | 46 |  | 
 
 
 
 
 | 47 | namespace experimental | 
 
 
 
 
 | 48 | { | 
 
 
 
 
 | 49 | inline namespace fundamentals_v1 | 
 
 
 
 
 | 50 | { | 
 
 
 
 
 | 51 | /** | 
 
 
 
 
 | 52 | * @defgroup any Type-safe container of any type | 
 
 
 
 
 | 53 | * @ingroup libfund-ts | 
 
 
 
 
 | 54 | * | 
 
 
 
 
 | 55 | * A type-safe container for single values of value types, as | 
 
 
 
 
 | 56 | * described in n3804 "Any Library Proposal (Revision 3)". | 
 
 
 
 
 | 57 | * | 
 
 
 
 
 | 58 | * @{ | 
 
 
 
 
 | 59 | */ | 
 
 
 
 
 | 60 |  | 
 
 
 
 
 | 61 | #define __cpp_lib_experimental_any 201411 | 
 
 
 
 
 | 62 |  | 
 
 
 
 
 | 63 | /** | 
 
 
 
 
 | 64 | *  @brief Exception class thrown by a failed @c any_cast | 
 
 
 
 
 | 65 | *  @ingroup exceptions | 
 
 
 
 
 | 66 | */ | 
 
 
 
 
 | 67 | class bad_any_cast : public bad_cast | 
 
 
 
 
 | 68 | { | 
 
 
 
 
 | 69 | public: | 
 
 
 
 
 | 70 | virtual const char* what() const noexcept { return "bad any_cast"; } | 
 
 
 
 
 | 71 | }; | 
 
 
 
 
 | 72 |  | 
 
 
 
 
 | 73 | /// @cond undocumented | 
 
 
 
 
 | 74 | [[gnu::noreturn]] inline void __throw_bad_any_cast() | 
 
 
 
 
 | 75 | { | 
 
 
 
 
 | 76 | #if __cpp_exceptions | 
 
 
 
 
 | 77 | throw bad_any_cast{}; | 
 
 
 
 
 | 78 | #else | 
 
 
 
 
 | 79 | __builtin_abort(); | 
 
 
 
 
 | 80 | #endif | 
 
 
 
 
 | 81 | } | 
 
 
 
 
 | 82 | /// @endcond | 
 
 
 
 
 | 83 |  | 
 
 
 
 
 | 84 | /** | 
 
 
 
 
 | 85 | *  @brief A type-safe container of any type. | 
 
 
 
 
 | 86 | * | 
 
 
 
 
 | 87 | *  An @c any object's state is either empty or it stores a contained object | 
 
 
 
 
 | 88 | *  of CopyConstructible type. | 
 
 
 
 
 | 89 | */ | 
 
 
 
 
 | 90 | class any | 
 
 
 
 
 | 91 | { | 
 
 
 
 
 | 92 | // Holds either pointer to a heap object or the contained object itself. | 
 
 
 
 
 | 93 | union _Storage | 
 
 
 
 
 | 94 | { | 
 
 
 
 
 | 95 | // This constructor intentionally doesn't initialize anything. | 
 
 
 
 
 | 96 | _Storage() = default; | 
 
 
 
 
 | 97 |  | 
 
 
 
 
 | 98 | // Prevent trivial copies of this type, buffer might hold a non-POD. | 
 
 
 
 
 | 99 | _Storage(const _Storage&) = delete; | 
 
 
 
 
 | 100 | _Storage& operator=(const _Storage&) = delete; | 
 
 
 
 
 | 101 |  | 
 
 
 
 
 | 102 | void* _M_ptr; | 
 
 
 
 
 | 103 | aligned_storage<sizeof(_M_ptr), alignof(void*)>::type _M_buffer; | 
 
 
 
 
 | 104 | }; | 
 
 
 
 
 | 105 |  | 
 
 
 
 
 | 106 | template<typename _Tp, typename _Safe = is_nothrow_move_constructible<_Tp>, | 
 
 
 
 
 | 107 | bool _Fits = (sizeof(_Tp) <= sizeof(_Storage)) | 
 
 
 
 
 | 108 | && (alignof(_Tp) <= alignof(_Storage))> | 
 
 
 
 
 | 109 | using _Internal = std::integral_constant<bool, _Safe::value && _Fits>; | 
 
 
 
 
 | 110 |  | 
 
 
 
 
 | 111 | template<typename _Tp> | 
 
 
 
 
 | 112 | struct _Manager_internal; // uses small-object optimization | 
 
 
 
 
 | 113 |  | 
 
 
 
 
 | 114 | template<typename _Tp> | 
 
 
 
 
 | 115 | struct _Manager_external; // creates contained object on the heap | 
 
 
 
 
 | 116 |  | 
 
 
 
 
 | 117 | template<typename _Tp> | 
 
 
 
 
 | 118 | using _Manager = conditional_t<_Internal<_Tp>::value, | 
 
 
 
 
 | 119 | _Manager_internal<_Tp>, | 
 
 
 
 
 | 120 | _Manager_external<_Tp>>; | 
 
 
 
 
 | 121 |  | 
 
 
 
 
 | 122 | template<typename _Tp, typename _Decayed = decay_t<_Tp>> | 
 
 
 
 
 | 123 | using _Decay = enable_if_t<!is_same<_Decayed, any>::value, _Decayed>; | 
 
 
 
 
 | 124 |  | 
 
 
 
 
 | 125 | public: | 
 
 
 
 
 | 126 | // construct/destruct | 
 
 
 
 
 | 127 |  | 
 
 
 
 
 | 128 | /// Default constructor, creates an empty object. | 
 
 
 
 
 | 129 | any() noexcept : _M_manager(nullptr) { } | 
 
 
 
 
 | 130 |  | 
 
 
 
 
 | 131 | /// Copy constructor, copies the state of @p __other | 
 
 
 
 
 | 132 | any(const any& __other) | 
 
 
 
 
 | 133 | { | 
 
 
 
 
 | 134 | if (__other.empty()) | 
 
 
 
 
 | 135 | _M_manager = nullptr; | 
 
 
 
 
 | 136 | else | 
 
 
 
 
 | 137 | { | 
 
 
 
 
 | 138 | _Arg __arg; | 
 
 
 
 
 | 139 | __arg._M_any = this; | 
 
 
 
 
 | 140 | __other._M_manager(_Op_clone, &__other, &__arg); | 
 
 
 
 
 | 141 | } | 
 
 
 
 
 | 142 | } | 
 
 
 
 
 | 143 |  | 
 
 
 
 
 | 144 | /** | 
 
 
 
 
 | 145 | * @brief Move constructor, transfer the state from @p __other | 
 
 
 
 
 | 146 | * | 
 
 
 
 
 | 147 | * @post @c __other.empty() (this postcondition is a GNU extension) | 
 
 
 
 
 | 148 | */ | 
 
 
 
 
 | 149 | any(any&& __other) noexcept | 
 
 
 
 
 | 150 | { | 
 
 
 
 
 | 151 | if (__other.empty()) | 
 
 
 
 
 | 152 | _M_manager = nullptr; | 
 
 
 
 
 | 153 | else | 
 
 
 
 
 | 154 | { | 
 
 
 
 
 | 155 | _Arg __arg; | 
 
 
 
 
 | 156 | __arg._M_any = this; | 
 
 
 
 
 | 157 | __other._M_manager(_Op_xfer, &__other, &__arg); | 
 
 
 
 
 | 158 | } | 
 
 
 
 
 | 159 | } | 
 
 
 
 
 | 160 |  | 
 
 
 
 
 | 161 | /// Construct with a copy of @p __value as the contained object. | 
 
 
 
 
 | 162 | template <typename _ValueType, typename _Tp = _Decay<_ValueType>, | 
 
 
 
 
 | 163 | typename _Mgr = _Manager<_Tp>, | 
 
 
 
 
 | 164 | typename enable_if<is_constructible<_Tp, _ValueType&&>::value, | 
 
 
 
 
 | 165 | bool>::type = true> | 
 
 
 
 
 | 166 | any(_ValueType&& __value) | 
 
 
 
 
 | 167 | : _M_manager(&_Mgr::_S_manage) | 
 
 
 
 
 | 168 | { | 
 
 
 
 
 | 169 | _Mgr::_S_create(_M_storage, std::forward<_ValueType>(__value)); | 
 
 
 
 
 | 170 | static_assert(is_copy_constructible<_Tp>::value, | 
 
 
 
 
 | 171 | "The contained object must be CopyConstructible"); | 
 
 
 
 
 | 172 | } | 
 
 
 
 
 | 173 |  | 
 
 
 
 
 | 174 | /// Construct with a copy of @p __value as the contained object. | 
 
 
 
 
 | 175 | template <typename _ValueType, typename _Tp = _Decay<_ValueType>, | 
 
 
 
 
 | 176 | typename _Mgr = _Manager<_Tp>, | 
 
 
 
 
 | 177 | typename enable_if<!is_constructible<_Tp, _ValueType&&>::value, | 
 
 
 
 
 | 178 | bool>::type = false> | 
 
 
 
 
 | 179 | any(_ValueType&& __value) | 
 
 
 
 
 | 180 | : _M_manager(&_Mgr::_S_manage) | 
 
 
 
 
 | 181 | { | 
 
 
 
 
 | 182 | _Mgr::_S_create(_M_storage, __value); | 
 
 
 
 
 | 183 | static_assert(is_copy_constructible<_Tp>::value, | 
 
 
 
 
 | 184 | "The contained object must be CopyConstructible"); | 
 
 
 
 
 | 185 | } | 
 
 
 
 
 | 186 |  | 
 
 
 
 
 | 187 | /// Destructor, calls @c clear() | 
 
 
 
 
 | 188 | ~any() { clear(); } | 
 
 
 
 
 | 189 |  | 
 
 
 
 
 | 190 | // assignments | 
 
 
 
 
 | 191 |  | 
 
 
 
 
 | 192 | /// Copy the state of another object. | 
 
 
 
 
 | 193 | any& operator=(const any& __rhs) | 
 
 
 
 
 | 194 | { | 
 
 
 
 
 | 195 | *this = any(__rhs); | 
 
 
 
 
 | 196 | return *this; | 
 
 
 
 
 | 197 | } | 
 
 
 
 
 | 198 |  | 
 
 
 
 
 | 199 | /** | 
 
 
 
 
 | 200 | * @brief Move assignment operator | 
 
 
 
 
 | 201 | * | 
 
 
 
 
 | 202 | * @post @c __rhs.empty() (not guaranteed for other implementations) | 
 
 
 
 
 | 203 | */ | 
 
 
 
 
 | 204 | any& operator=(any&& __rhs) noexcept | 
 
 
 
 
 | 205 | { | 
 
 
 
 
 | 206 | if (__rhs.empty()) | 
 
 
 
 
 | 207 | clear(); | 
 
 
 
 
 | 208 | else if (this != &__rhs) | 
 
 
 
 
 | 209 | { | 
 
 
 
 
 | 210 | clear(); | 
 
 
 
 
 | 211 | _Arg __arg; | 
 
 
 
 
 | 212 | __arg._M_any = this; | 
 
 
 
 
 | 213 | __rhs._M_manager(_Op_xfer, &__rhs, &__arg); | 
 
 
 
 
 | 214 | } | 
 
 
 
 
 | 215 | return *this; | 
 
 
 
 
 | 216 | } | 
 
 
 
 
 | 217 |  | 
 
 
 
 
 | 218 | /// Store a copy of @p __rhs as the contained object. | 
 
 
 
 
 | 219 | template<typename _ValueType> | 
 
 
 
 
 | 220 | enable_if_t<!is_same<any, decay_t<_ValueType>>::value, any&> | 
 
 
 
 
 | 221 | operator=(_ValueType&& __rhs) | 
 
 
 
 
 | 222 | { | 
 
 
 
 
 | 223 | *this = any(std::forward<_ValueType>(__rhs)); | 
 
 
 
 
 | 224 | return *this; | 
 
 
 
 
 | 225 | } | 
 
 
 
 
 | 226 |  | 
 
 
 
 
 | 227 | // modifiers | 
 
 
 
 
 | 228 |  | 
 
 
 
 
 | 229 | /// If not empty, destroy the contained object. | 
 
 
 
 
 | 230 | void clear() noexcept | 
 
 
 
 
 | 231 | { | 
 
 
 
 
 | 232 | if (!empty()) | 
 
 
 
 
 | 233 | { | 
 
 
 
 
 | 234 | _M_manager(_Op_destroy, this, nullptr); | 
 
 
 
 
 | 235 | _M_manager = nullptr; | 
 
 
 
 
 | 236 | } | 
 
 
 
 
 | 237 | } | 
 
 
 
 
 | 238 |  | 
 
 
 
 
 | 239 | /// Exchange state with another object. | 
 
 
 
 
 | 240 | void swap(any& __rhs) noexcept | 
 
 
 
 
 | 241 | { | 
 
 
 
 
 | 242 | if (empty() && __rhs.empty()) | 
 
 
 
 
 | 243 | return; | 
 
 
 
 
 | 244 |  | 
 
 
 
 
 | 245 | if (!empty() && !__rhs.empty()) | 
 
 
 
 
 | 246 | { | 
 
 
 
 
 | 247 | if (this == &__rhs) | 
 
 
 
 
 | 248 | return; | 
 
 
 
 
 | 249 |  | 
 
 
 
 
 | 250 | any __tmp; | 
 
 
 
 
 | 251 | _Arg __arg; | 
 
 
 
 
 | 252 | __arg._M_any = &__tmp; | 
 
 
 
 
 | 253 | __rhs._M_manager(_Op_xfer, &__rhs, &__arg); | 
 
 
 
 
 | 254 | __arg._M_any = &__rhs; | 
 
 
 
 
 | 255 | _M_manager(_Op_xfer, this, &__arg); | 
 
 
 
 
 | 256 | __arg._M_any = this; | 
 
 
 
 
 | 257 | __tmp._M_manager(_Op_xfer, &__tmp, &__arg); | 
 
 
 
 
 | 258 | } | 
 
 
 
 
 | 259 | else | 
 
 
 
 
 | 260 | { | 
 
 
 
 
 | 261 | any* __empty = empty() ? this : &__rhs; | 
 
 
 
 
 | 262 | any* __full = empty() ? &__rhs : this; | 
 
 
 
 
 | 263 | _Arg __arg; | 
 
 
 
 
 | 264 | __arg._M_any = __empty; | 
 
 
 
 
 | 265 | __full->_M_manager(_Op_xfer, __full, &__arg); | 
 
 
 
 
 | 266 | } | 
 
 
 
 
 | 267 | } | 
 
 
 
 
 | 268 |  | 
 
 
 
 
 | 269 | // observers | 
 
 
 
 
 | 270 |  | 
 
 
 
 
 | 271 | /// Reports whether there is a contained object or not. | 
 
 
 
 
 | 272 | _GLIBCXX_NODISCARD bool empty() const noexcept { return _M_manager == nullptr; } | 
 
 
 
 
 | 273 |  | 
 
 
 
 
 | 274 | #if __cpp_rtti | 
 
 
 
 
 | 275 | /// The @c typeid of the contained object, or @c typeid(void) if empty. | 
 
 
 
 
 | 276 | const type_info& type() const noexcept | 
 
 
 
 
 | 277 | { | 
 
 
 
 
 | 278 | if (empty()) | 
 
 
 
 
 | 279 | return typeid(void); | 
 
 
 
 
 | 280 | _Arg __arg; | 
 
 
 
 
 | 281 | _M_manager(_Op_get_type_info, this, &__arg); | 
 
 
 
 
 | 282 | return *__arg._M_typeinfo; | 
 
 
 
 
 | 283 | } | 
 
 
 
 
 | 284 | #endif | 
 
 
 
 
 | 285 |  | 
 
 
 
 
 | 286 | template<typename _Tp> | 
 
 
 
 
 | 287 | static constexpr bool __is_valid_cast() | 
 
 
 
 
 | 288 | { return __or_<is_reference<_Tp>, is_copy_constructible<_Tp>>::value; } | 
 
 
 
 
 | 289 |  | 
 
 
 
 
 | 290 | private: | 
 
 
 
 
 | 291 | enum _Op { | 
 
 
 
 
 | 292 | _Op_access, _Op_get_type_info, _Op_clone, _Op_destroy, _Op_xfer | 
 
 
 
 
 | 293 | }; | 
 
 
 
 
 | 294 |  | 
 
 
 
 
 | 295 | union _Arg | 
 
 
 
 
 | 296 | { | 
 
 
 
 
 | 297 | void* _M_obj; | 
 
 
 
 
 | 298 | const std::type_info* _M_typeinfo; | 
 
 
 
 
 | 299 | any* _M_any; | 
 
 
 
 
 | 300 | }; | 
 
 
 
 
 | 301 |  | 
 
 
 
 
 | 302 | void (*_M_manager)(_Op, const any*, _Arg*); | 
 
 
 
 
 | 303 | _Storage _M_storage; | 
 
 
 
 
 | 304 |  | 
 
 
 
 
 | 305 | template<typename _Tp> | 
 
 
 
 
 | 306 | friend enable_if_t<is_object<_Tp>::value, void*> | 
 
 
 
 
 | 307 | __any_caster(const any* __any); | 
 
 
 
 
 | 308 |  | 
 
 
 
 
 | 309 | // Manage in-place contained object. | 
 
 
 
 
 | 310 | template<typename _Tp> | 
 
 
 
 
 | 311 | struct _Manager_internal | 
 
 
 
 
 | 312 | { | 
 
 
 
 
 | 313 | static void | 
 
 
 
 
 | 314 | _S_manage(_Op __which, const any* __anyp, _Arg* __arg); | 
 
 
 
 
 | 315 |  | 
 
 
 
 
 | 316 | template<typename _Up> | 
 
 
 
 
 | 317 | static void | 
 
 
 
 
 | 318 | _S_create(_Storage& __storage, _Up&& __value) | 
 
 
 
 
 | 319 | { | 
 
 
 
 
 | 320 | void* __addr = &__storage._M_buffer; | 
 
 
 
 
 | 321 | ::new (__addr) _Tp(std::forward<_Up>(__value)); | 
 
 
 
 
 | 322 | } | 
 
 
 
 
 | 323 | }; | 
 
 
 
 
 | 324 |  | 
 
 
 
 
 | 325 | // Manage external contained object. | 
 
 
 
 
 | 326 | template<typename _Tp> | 
 
 
 
 
 | 327 | struct _Manager_external | 
 
 
 
 
 | 328 | { | 
 
 
 
 
 | 329 | static void | 
 
 
 
 
 | 330 | _S_manage(_Op __which, const any* __anyp, _Arg* __arg); | 
 
 
 
 
 | 331 |  | 
 
 
 
 
 | 332 | template<typename _Up> | 
 
 
 
 
 | 333 | static void | 
 
 
 
 
 | 334 | _S_create(_Storage& __storage, _Up&& __value) | 
 
 
 
 
 | 335 | { | 
 
 
 
 
 | 336 | __storage._M_ptr = new _Tp(std::forward<_Up>(__value)); | 
 
 
 
 
 | 337 | } | 
 
 
 
 
 | 338 | }; | 
 
 
 
 
 | 339 | }; | 
 
 
 
 
 | 340 |  | 
 
 
 
 
 | 341 | /// Exchange the states of two @c any objects. | 
 
 
 
 
 | 342 | inline void swap(any& __x, any& __y) noexcept { __x.swap(__y); } | 
 
 
 
 
 | 343 |  | 
 
 
 
 
 | 344 | /** | 
 
 
 
 
 | 345 | * @brief Access the contained object. | 
 
 
 
 
 | 346 | * | 
 
 
 
 
 | 347 | * @tparam  _ValueType  A const-reference or CopyConstructible type. | 
 
 
 
 
 | 348 | * @param   __any       The object to access. | 
 
 
 
 
 | 349 | * @return  The contained object. | 
 
 
 
 
 | 350 | * @throw   bad_any_cast If <code> | 
 
 
 
 
 | 351 | *          __any.type() != typeid(remove_reference_t<_ValueType>) | 
 
 
 
 
 | 352 | *          </code> | 
 
 
 
 
 | 353 | */ | 
 
 
 
 
 | 354 | template<typename _ValueType> | 
 
 
 
 
 | 355 | inline _ValueType any_cast(const any& __any) | 
 
 
 
 
 | 356 | { | 
 
 
 
 
 | 357 | static_assert(any::__is_valid_cast<_ValueType>(), | 
 
 
 
 
 | 358 | "Template argument must be a reference or CopyConstructible type"); | 
 
 
 
 
 | 359 | auto __p = any_cast<add_const_t<remove_reference_t<_ValueType>>>(&__any); | 
 
 
 
 
 | 360 | if (__p) | 
 
 
 
 
 | 361 | return *__p; | 
 
 
 
 
 | 362 | __throw_bad_any_cast(); | 
 
 
 
 
 | 363 | } | 
 
 
 
 
 | 364 |  | 
 
 
 
 
 | 365 | /** | 
 
 
 
 
 | 366 | * @brief Access the contained object. | 
 
 
 
 
 | 367 | * | 
 
 
 
 
 | 368 | * @tparam  _ValueType  A reference or CopyConstructible type. | 
 
 
 
 
 | 369 | * @param   __any       The object to access. | 
 
 
 
 
 | 370 | * @return  The contained object. | 
 
 
 
 
 | 371 | * @throw   bad_any_cast If <code> | 
 
 
 
 
 | 372 | *          __any.type() != typeid(remove_reference_t<_ValueType>) | 
 
 
 
 
 | 373 | *          </code> | 
 
 
 
 
 | 374 | * | 
 
 
 
 
 | 375 | * @{ | 
 
 
 
 
 | 376 | */ | 
 
 
 
 
 | 377 | template<typename _ValueType> | 
 
 
 
 
 | 378 | inline _ValueType any_cast(any& __any) | 
 
 
 
 
 | 379 | { | 
 
 
 
 
 | 380 | static_assert(any::__is_valid_cast<_ValueType>(), | 
 
 
 
 
 | 381 | "Template argument must be a reference or CopyConstructible type"); | 
 
 
 
 
 | 382 | auto __p = any_cast<remove_reference_t<_ValueType>>(&__any); | 
 
 
 
 
 | 383 | if (__p) | 
 
 
 
 
 | 384 | return *__p; | 
 
 
 
 
 | 385 | __throw_bad_any_cast(); | 
 
 
 
 
 | 386 | } | 
 
 
 
 
 | 387 |  | 
 
 
 
 
 | 388 | template<typename _ValueType, | 
 
 
 
 
 | 389 | typename enable_if<!is_move_constructible<_ValueType>::value | 
 
 
 
 
 | 390 | || is_lvalue_reference<_ValueType>::value, | 
 
 
 
 
 | 391 | bool>::type = true> | 
 
 
 
 
 | 392 | inline _ValueType any_cast(any&& __any) | 
 
 
 
 
 | 393 | { | 
 
 
 
 
 | 394 | static_assert(any::__is_valid_cast<_ValueType>(), | 
 
 
 
 
 | 395 | "Template argument must be a reference or CopyConstructible type"); | 
 
 
 
 
 | 396 | auto __p = any_cast<remove_reference_t<_ValueType>>(&__any); | 
 
 
 
 
 | 397 | if (__p) | 
 
 
 
 
 | 398 | return *__p; | 
 
 
 
 
 | 399 | __throw_bad_any_cast(); | 
 
 
 
 
 | 400 | } | 
 
 
 
 
 | 401 |  | 
 
 
 
 
 | 402 | template<typename _ValueType, | 
 
 
 
 
 | 403 | typename enable_if<is_move_constructible<_ValueType>::value | 
 
 
 
 
 | 404 | && !is_lvalue_reference<_ValueType>::value, | 
 
 
 
 
 | 405 | bool>::type = false> | 
 
 
 
 
 | 406 | inline _ValueType any_cast(any&& __any) | 
 
 
 
 
 | 407 | { | 
 
 
 
 
 | 408 | static_assert(any::__is_valid_cast<_ValueType>(), | 
 
 
 
 
 | 409 | "Template argument must be a reference or CopyConstructible type"); | 
 
 
 
 
 | 410 | auto __p = any_cast<remove_reference_t<_ValueType>>(&__any); | 
 
 
 
 
 | 411 | if (__p) | 
 
 
 
 
 | 412 | return std::move(*__p); | 
 
 
 
 
 | 413 | __throw_bad_any_cast(); | 
 
 
 
 
 | 414 | } | 
 
 
 
 
 | 415 | /// @} | 
 
 
 
 
 | 416 |  | 
 
 
 
 
 | 417 | /// @cond undocumented | 
 
 
 
 
 | 418 | template<typename _Tp> | 
 
 
 
 
 | 419 | enable_if_t<is_object<_Tp>::value, void*> | 
 
 
 
 
 | 420 | __any_caster(const any* __any) | 
 
 
 
 
 | 421 | { | 
 
 
 
 
 | 422 | // any_cast<T> returns non-null if __any->type() == typeid(T) and | 
 
 
 
 
 | 423 | // typeid(T) ignores cv-qualifiers so remove them: | 
 
 
 
 
 | 424 | using _Up = remove_cv_t<_Tp>; | 
 
 
 
 
 | 425 | // The contained value has a decayed type, so if decay_t<U> is not U, | 
 
 
 
 
 | 426 | // then it's not possible to have a contained value of type U. | 
 
 
 
 
 | 427 | using __does_not_decay = is_same<decay_t<_Up>, _Up>; | 
 
 
 
 
 | 428 | // Only copy constructible types can be used for contained values. | 
 
 
 
 
 | 429 | using __is_copyable = is_copy_constructible<_Up>; | 
 
 
 
 
 | 430 | // If the type _Tp could never be stored in an any we don't want to | 
 
 
 
 
 | 431 | // instantiate _Manager<_Tp>, so use _Manager<any::_Op> instead, which | 
 
 
 
 
 | 432 | // is explicitly specialized and has a no-op _S_manage function. | 
 
 
 
 
 | 433 | using _Vp = conditional_t<__and_<__does_not_decay, __is_copyable>::value, | 
 
 
 
 
 | 434 | _Up, any::_Op>; | 
 
 
 
 
 | 435 | // First try comparing function addresses, which works without RTTI | 
 
 
 
 
 | 436 | if (__any->_M_manager == &any::_Manager<_Vp>::_S_manage | 
 
 
 
 
 | 437 | #if __cpp_rtti | 
 
 
 
 
 | 438 | || __any->type() == typeid(_Tp) | 
 
 
 
 
 | 439 | #endif | 
 
 
 
 
 | 440 | ) | 
 
 
 
 
 | 441 | { | 
 
 
 
 
 | 442 | any::_Arg __arg; | 
 
 
 
 
 | 443 | __any->_M_manager(any::_Op_access, __any, &__arg); | 
 
 
 
 
 | 444 | return __arg._M_obj; | 
 
 
 
 
 | 445 | } | 
 
 
 
 
 | 446 | return nullptr; | 
 
 
 
 
 | 447 | } | 
 
 
 
 
 | 448 |  | 
 
 
 
 
 | 449 | // This overload exists so that std::any_cast<void(*)()>(a) is well-formed. | 
 
 
 
 
 | 450 | template<typename _Tp> | 
 
 
 
 
 | 451 | enable_if_t<!is_object<_Tp>::value, _Tp*> | 
 
 
 
 
 | 452 | __any_caster(const any*) noexcept | 
 
 
 
 
 | 453 | { return nullptr; } | 
 
 
 
 
 | 454 | /// @endcond | 
 
 
 
 
 | 455 |  | 
 
 
 
 
 | 456 | /** | 
 
 
 
 
 | 457 | * @brief Access the contained object. | 
 
 
 
 
 | 458 | * | 
 
 
 
 
 | 459 | * @tparam  _ValueType  The type of the contained object. | 
 
 
 
 
 | 460 | * @param   __any       A pointer to the object to access. | 
 
 
 
 
 | 461 | * @return  The address of the contained object if <code> | 
 
 
 
 
 | 462 | *          __any != nullptr && __any.type() == typeid(_ValueType) | 
 
 
 
 
 | 463 | *          </code>, otherwise a null pointer. | 
 
 
 
 
 | 464 | * | 
 
 
 
 
 | 465 | * @{ | 
 
 
 
 
 | 466 | */ | 
 
 
 
 
 | 467 | template<typename _ValueType> | 
 
 
 
 
 | 468 | inline const _ValueType* any_cast(const any* __any) noexcept | 
 
 
 
 
 | 469 | { | 
 
 
 
 
 | 470 | if (__any) | 
 
 
 
 
 | 471 | return static_cast<_ValueType*>(__any_caster<_ValueType>(__any)); | 
 
 
 
 
 | 472 | return nullptr; | 
 
 
 
 
 | 473 | } | 
 
 
 
 
 | 474 |  | 
 
 
 
 
 | 475 | template<typename _ValueType> | 
 
 
 
 
 | 476 | inline _ValueType* any_cast(any* __any) noexcept | 
 
 
 
 
 | 477 | { | 
 
 
 
 
 | 478 | if (__any) | 
 
 
 
 
 | 479 | return static_cast<_ValueType*>(__any_caster<_ValueType>(__any)); | 
 
 
 
 
 | 480 | return nullptr; | 
 
 
 
 
 | 481 | } | 
 
 
 
 
 | 482 | /// @} | 
 
 
 
 
 | 483 |  | 
 
 
 
 
 | 484 | template<typename _Tp> | 
 
 
 
 
 | 485 | void | 
 
 
 
 
 | 486 | any::_Manager_internal<_Tp>:: | 
 
 
 
 
 | 487 | _S_manage(_Op __which, const any* __any, _Arg* __arg) | 
 
 
 
 
 | 488 | { | 
 
 
 
 
 | 489 | // The contained object is in _M_storage._M_buffer | 
 
 
 
 
 | 490 | auto __ptr = reinterpret_cast<const _Tp*>(&__any->_M_storage._M_buffer); | 
 
 
 
 
 | 491 | switch (__which) | 
 
 
 
 
 | 492 | { | 
 
 
 
 
 | 493 | case _Op_access: | 
 
 
 
 
 | 494 | __arg->_M_obj = const_cast<_Tp*>(__ptr); | 
 
 
 
 
 | 495 | break; | 
 
 
 
 
 | 496 | case _Op_get_type_info: | 
 
 
 
 
 | 497 | #if __cpp_rtti | 
 
 
 
 
 | 498 | __arg->_M_typeinfo = &typeid(_Tp); | 
 
 
 
 
 | 499 | #endif | 
 
 
 
 
 | 500 | break; | 
 
 
 
 
 | 501 | case _Op_clone: | 
 
 
 
 
 | 502 | ::new(&__arg->_M_any->_M_storage._M_buffer) _Tp(*__ptr); | 
 
 
 
 
 | 503 | __arg->_M_any->_M_manager = __any->_M_manager; | 
 
 
 
 
 | 504 | break; | 
 
 
 
 
 | 505 | case _Op_destroy: | 
 
 
 
 
 | 506 | __ptr->~_Tp(); | 
 
 
 
 
 | 507 | break; | 
 
 
 
 
 | 508 | case _Op_xfer: | 
 
 
 
 
 | 509 | ::new(&__arg->_M_any->_M_storage._M_buffer) _Tp | 
 
 
 
 
 | 510 | (std::move(*const_cast<_Tp*>(__ptr))); | 
 
 
 
 
 | 511 | __ptr->~_Tp(); | 
 
 
 
 
 | 512 | __arg->_M_any->_M_manager = __any->_M_manager; | 
 
 
 
 
 | 513 | const_cast<any*>(__any)->_M_manager = nullptr; | 
 
 
 
 
 | 514 | break; | 
 
 
 
 
 | 515 | } | 
 
 
 
 
 | 516 | } | 
 
 
 
 
 | 517 |  | 
 
 
 
 
 | 518 | template<typename _Tp> | 
 
 
 
 
 | 519 | void | 
 
 
 
 
 | 520 | any::_Manager_external<_Tp>:: | 
 
 
 
 
 | 521 | _S_manage(_Op __which, const any* __any, _Arg* __arg) | 
 
 
 
 
 | 522 | { | 
 
 
 
 
 | 523 | // The contained object is *_M_storage._M_ptr | 
 
 
 
 
 | 524 | auto __ptr = static_cast<const _Tp*>(__any->_M_storage._M_ptr); | 
 
 
 
 
 | 525 | switch (__which) | 
 
 
 
 
 | 526 | { | 
 
 
 
 
 | 527 | case _Op_access: | 
 
 
 
 
 | 528 | __arg->_M_obj = const_cast<_Tp*>(__ptr); | 
 
 
 
 
 | 529 | break; | 
 
 
 
 
 | 530 | case _Op_get_type_info: | 
 
 
 
 
 | 531 | #if __cpp_rtti | 
 
 
 
 
 | 532 | __arg->_M_typeinfo = &typeid(_Tp); | 
 
 
 
 
 | 533 | #endif | 
 
 
 
 
 | 534 | break; | 
 
 
 
 
 | 535 | case _Op_clone: | 
 
 
 
 
 | 536 | __arg->_M_any->_M_storage._M_ptr = new _Tp(*__ptr); | 
 
 
 
 
 | 537 | __arg->_M_any->_M_manager = __any->_M_manager; | 
 
 
 
 
 | 538 | break; | 
 
 
 
 
 | 539 | case _Op_destroy: | 
 
 
 
 
 | 540 | delete __ptr; | 
 
 
 
 
 | 541 | break; | 
 
 
 
 
 | 542 | case _Op_xfer: | 
 
 
 
 
 | 543 | __arg->_M_any->_M_storage._M_ptr = __any->_M_storage._M_ptr; | 
 
 
 
 
 | 544 | __arg->_M_any->_M_manager = __any->_M_manager; | 
 
 
 
 
 | 545 | const_cast<any*>(__any)->_M_manager = nullptr; | 
 
 
 
 
 | 546 | break; | 
 
 
 
 
 | 547 | } | 
 
 
 
 
 | 548 | } | 
 
 
 
 
 | 549 |  | 
 
 
 
 
 | 550 | // Dummy specialization used by __any_caster. | 
 
 
 
 
 | 551 | template<> | 
 
 
 
 
 | 552 | struct any::_Manager_internal<any::_Op> | 
 
 
 
 
 | 553 | { | 
 
 
 
 
 | 554 | static void | 
 
 
 
 
 | 555 | _S_manage(_Op, const any*, _Arg*) { } | 
 
 
 
 
 | 556 | }; | 
 
 
 
 
 | 557 |  | 
 
 
 
 
 | 558 | /// @} group any | 
 
 
 
 
 | 559 | } // namespace fundamentals_v1 | 
 
 
 
 
 | 560 | } // namespace experimental | 
 
 
 
 
 | 561 |  | 
 
 
 
 
 | 562 | _GLIBCXX_END_NAMESPACE_VERSION | 
 
 
 
 
 | 563 | } // namespace std | 
 
 
 
 
 | 564 |  | 
 
 
 
 
 | 565 | #endif // C++14 | 
 
 
 
 
 | 566 |  | 
 
 
 
 
 | 567 | #endif // _GLIBCXX_EXPERIMENTAL_ANY |