tuple revision 1.1.1.5
1 // <tuple> -*- C++ -*- 2 3 // Copyright (C) 2007-2015 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 include/tuple 26 * This is a Standard C++ Library header. 27 */ 28 29 #ifndef _GLIBCXX_TUPLE 30 #define _GLIBCXX_TUPLE 1 31 32 #pragma GCC system_header 33 34 #if __cplusplus < 201103L 35 # include <bits/c++0x_warning.h> 36 #else 37 38 #include <utility> 39 #include <array> 40 #include <bits/uses_allocator.h> 41 42 namespace std _GLIBCXX_VISIBILITY(default) 43 { 44 _GLIBCXX_BEGIN_NAMESPACE_VERSION 45 46 /** 47 * @addtogroup utilities 48 * @{ 49 */ 50 51 template<std::size_t _Idx, typename _Head, bool _IsEmptyNotFinal> 52 struct _Head_base; 53 54 template<std::size_t _Idx, typename _Head> 55 struct _Head_base<_Idx, _Head, true> 56 : public _Head 57 { 58 constexpr _Head_base() 59 : _Head() { } 60 61 constexpr _Head_base(const _Head& __h) 62 : _Head(__h) { } 63 64 constexpr _Head_base(const _Head_base&) = default; 65 constexpr _Head_base(_Head_base&&) = default; 66 67 template<typename _UHead> 68 constexpr _Head_base(_UHead&& __h) 69 : _Head(std::forward<_UHead>(__h)) { } 70 71 _Head_base(allocator_arg_t, __uses_alloc0) 72 : _Head() { } 73 74 template<typename _Alloc> 75 _Head_base(allocator_arg_t, __uses_alloc1<_Alloc> __a) 76 : _Head(allocator_arg, *__a._M_a) { } 77 78 template<typename _Alloc> 79 _Head_base(allocator_arg_t, __uses_alloc2<_Alloc> __a) 80 : _Head(*__a._M_a) { } 81 82 template<typename _UHead> 83 _Head_base(__uses_alloc0, _UHead&& __uhead) 84 : _Head(std::forward<_UHead>(__uhead)) { } 85 86 template<typename _Alloc, typename _UHead> 87 _Head_base(__uses_alloc1<_Alloc> __a, _UHead&& __uhead) 88 : _Head(allocator_arg, *__a._M_a, std::forward<_UHead>(__uhead)) { } 89 90 template<typename _Alloc, typename _UHead> 91 _Head_base(__uses_alloc2<_Alloc> __a, _UHead&& __uhead) 92 : _Head(std::forward<_UHead>(__uhead), *__a._M_a) { } 93 94 static constexpr _Head& 95 _M_head(_Head_base& __b) noexcept { return __b; } 96 97 static constexpr const _Head& 98 _M_head(const _Head_base& __b) noexcept { return __b; } 99 }; 100 101 template<std::size_t _Idx, typename _Head> 102 struct _Head_base<_Idx, _Head, false> 103 { 104 constexpr _Head_base() 105 : _M_head_impl() { } 106 107 constexpr _Head_base(const _Head& __h) 108 : _M_head_impl(__h) { } 109 110 constexpr _Head_base(const _Head_base&) = default; 111 constexpr _Head_base(_Head_base&&) = default; 112 113 template<typename _UHead> 114 constexpr _Head_base(_UHead&& __h) 115 : _M_head_impl(std::forward<_UHead>(__h)) { } 116 117 _Head_base(allocator_arg_t, __uses_alloc0) 118 : _M_head_impl() { } 119 120 template<typename _Alloc> 121 _Head_base(allocator_arg_t, __uses_alloc1<_Alloc> __a) 122 : _M_head_impl(allocator_arg, *__a._M_a) { } 123 124 template<typename _Alloc> 125 _Head_base(allocator_arg_t, __uses_alloc2<_Alloc> __a) 126 : _M_head_impl(*__a._M_a) { } 127 128 template<typename _UHead> 129 _Head_base(__uses_alloc0, _UHead&& __uhead) 130 : _M_head_impl(std::forward<_UHead>(__uhead)) { } 131 132 template<typename _Alloc, typename _UHead> 133 _Head_base(__uses_alloc1<_Alloc> __a, _UHead&& __uhead) 134 : _M_head_impl(allocator_arg, *__a._M_a, std::forward<_UHead>(__uhead)) 135 { } 136 137 template<typename _Alloc, typename _UHead> 138 _Head_base(__uses_alloc2<_Alloc> __a, _UHead&& __uhead) 139 : _M_head_impl(std::forward<_UHead>(__uhead), *__a._M_a) { } 140 141 static constexpr _Head& 142 _M_head(_Head_base& __b) noexcept { return __b._M_head_impl; } 143 144 static constexpr const _Head& 145 _M_head(const _Head_base& __b) noexcept { return __b._M_head_impl; } 146 147 _Head _M_head_impl; 148 }; 149 150 /** 151 * Contains the actual implementation of the @c tuple template, stored 152 * as a recursive inheritance hierarchy from the first element (most 153 * derived class) to the last (least derived class). The @c Idx 154 * parameter gives the 0-based index of the element stored at this 155 * point in the hierarchy; we use it to implement a constant-time 156 * get() operation. 157 */ 158 template<std::size_t _Idx, typename... _Elements> 159 struct _Tuple_impl; 160 161 template<typename _Tp> 162 struct __is_empty_non_tuple : is_empty<_Tp> { }; 163 164 // Using EBO for elements that are tuples causes ambiguous base errors. 165 template<typename _El0, typename... _El> 166 struct __is_empty_non_tuple<tuple<_El0, _El...>> : false_type { }; 167 168 // Use the Empty Base-class Optimization for empty, non-final types. 169 template<typename _Tp> 170 using __empty_not_final 171 = typename conditional<__is_final(_Tp), false_type, 172 __is_empty_non_tuple<_Tp>>::type; 173 174 /** 175 * Recursive tuple implementation. Here we store the @c Head element 176 * and derive from a @c Tuple_impl containing the remaining elements 177 * (which contains the @c Tail). 178 */ 179 template<std::size_t _Idx, typename _Head, typename... _Tail> 180 struct _Tuple_impl<_Idx, _Head, _Tail...> 181 : public _Tuple_impl<_Idx + 1, _Tail...>, 182 private _Head_base<_Idx, _Head, __empty_not_final<_Head>::value> 183 { 184 template<std::size_t, typename...> friend class _Tuple_impl; 185 186 typedef _Tuple_impl<_Idx + 1, _Tail...> _Inherited; 187 typedef _Head_base<_Idx, _Head, __empty_not_final<_Head>::value> _Base; 188 189 static constexpr _Head& 190 _M_head(_Tuple_impl& __t) noexcept { return _Base::_M_head(__t); } 191 192 static constexpr const _Head& 193 _M_head(const _Tuple_impl& __t) noexcept { return _Base::_M_head(__t); } 194 195 static constexpr _Inherited& 196 _M_tail(_Tuple_impl& __t) noexcept { return __t; } 197 198 static constexpr const _Inherited& 199 _M_tail(const _Tuple_impl& __t) noexcept { return __t; } 200 201 constexpr _Tuple_impl() 202 : _Inherited(), _Base() { } 203 204 explicit 205 constexpr _Tuple_impl(const _Head& __head, const _Tail&... __tail) 206 : _Inherited(__tail...), _Base(__head) { } 207 208 template<typename _UHead, typename... _UTail, typename = typename 209 enable_if<sizeof...(_Tail) == sizeof...(_UTail)>::type> 210 explicit 211 constexpr _Tuple_impl(_UHead&& __head, _UTail&&... __tail) 212 : _Inherited(std::forward<_UTail>(__tail)...), 213 _Base(std::forward<_UHead>(__head)) { } 214 215 constexpr _Tuple_impl(const _Tuple_impl&) = default; 216 217 constexpr 218 _Tuple_impl(_Tuple_impl&& __in) 219 noexcept(__and_<is_nothrow_move_constructible<_Head>, 220 is_nothrow_move_constructible<_Inherited>>::value) 221 : _Inherited(std::move(_M_tail(__in))), 222 _Base(std::forward<_Head>(_M_head(__in))) { } 223 224 template<typename... _UElements> 225 constexpr _Tuple_impl(const _Tuple_impl<_Idx, _UElements...>& __in) 226 : _Inherited(_Tuple_impl<_Idx, _UElements...>::_M_tail(__in)), 227 _Base(_Tuple_impl<_Idx, _UElements...>::_M_head(__in)) { } 228 229 template<typename _UHead, typename... _UTails> 230 constexpr _Tuple_impl(_Tuple_impl<_Idx, _UHead, _UTails...>&& __in) 231 : _Inherited(std::move 232 (_Tuple_impl<_Idx, _UHead, _UTails...>::_M_tail(__in))), 233 _Base(std::forward<_UHead> 234 (_Tuple_impl<_Idx, _UHead, _UTails...>::_M_head(__in))) { } 235 236 template<typename _Alloc> 237 _Tuple_impl(allocator_arg_t __tag, const _Alloc& __a) 238 : _Inherited(__tag, __a), 239 _Base(__tag, __use_alloc<_Head>(__a)) { } 240 241 template<typename _Alloc> 242 _Tuple_impl(allocator_arg_t __tag, const _Alloc& __a, 243 const _Head& __head, const _Tail&... __tail) 244 : _Inherited(__tag, __a, __tail...), 245 _Base(__use_alloc<_Head, _Alloc, _Head>(__a), __head) { } 246 247 template<typename _Alloc, typename _UHead, typename... _UTail, 248 typename = typename enable_if<sizeof...(_Tail) 249 == sizeof...(_UTail)>::type> 250 _Tuple_impl(allocator_arg_t __tag, const _Alloc& __a, 251 _UHead&& __head, _UTail&&... __tail) 252 : _Inherited(__tag, __a, std::forward<_UTail>(__tail)...), 253 _Base(__use_alloc<_Head, _Alloc, _UHead>(__a), 254 std::forward<_UHead>(__head)) { } 255 256 template<typename _Alloc> 257 _Tuple_impl(allocator_arg_t __tag, const _Alloc& __a, 258 const _Tuple_impl& __in) 259 : _Inherited(__tag, __a, _M_tail(__in)), 260 _Base(__use_alloc<_Head, _Alloc, _Head>(__a), _M_head(__in)) { } 261 262 template<typename _Alloc> 263 _Tuple_impl(allocator_arg_t __tag, const _Alloc& __a, 264 _Tuple_impl&& __in) 265 : _Inherited(__tag, __a, std::move(_M_tail(__in))), 266 _Base(__use_alloc<_Head, _Alloc, _Head>(__a), 267 std::forward<_Head>(_M_head(__in))) { } 268 269 template<typename _Alloc, typename... _UElements> 270 _Tuple_impl(allocator_arg_t __tag, const _Alloc& __a, 271 const _Tuple_impl<_Idx, _UElements...>& __in) 272 : _Inherited(__tag, __a, 273 _Tuple_impl<_Idx, _UElements...>::_M_tail(__in)), 274 _Base(__use_alloc<_Head, _Alloc, _Head>(__a), 275 _Tuple_impl<_Idx, _UElements...>::_M_head(__in)) { } 276 277 template<typename _Alloc, typename _UHead, typename... _UTails> 278 _Tuple_impl(allocator_arg_t __tag, const _Alloc& __a, 279 _Tuple_impl<_Idx, _UHead, _UTails...>&& __in) 280 : _Inherited(__tag, __a, std::move 281 (_Tuple_impl<_Idx, _UHead, _UTails...>::_M_tail(__in))), 282 _Base(__use_alloc<_Head, _Alloc, _UHead>(__a), 283 std::forward<_UHead> 284 (_Tuple_impl<_Idx, _UHead, _UTails...>::_M_head(__in))) { } 285 286 _Tuple_impl& 287 operator=(const _Tuple_impl& __in) 288 { 289 _M_head(*this) = _M_head(__in); 290 _M_tail(*this) = _M_tail(__in); 291 return *this; 292 } 293 294 _Tuple_impl& 295 operator=(_Tuple_impl&& __in) 296 noexcept(__and_<is_nothrow_move_assignable<_Head>, 297 is_nothrow_move_assignable<_Inherited>>::value) 298 { 299 _M_head(*this) = std::forward<_Head>(_M_head(__in)); 300 _M_tail(*this) = std::move(_M_tail(__in)); 301 return *this; 302 } 303 304 template<typename... _UElements> 305 _Tuple_impl& 306 operator=(const _Tuple_impl<_Idx, _UElements...>& __in) 307 { 308 _M_head(*this) = _Tuple_impl<_Idx, _UElements...>::_M_head(__in); 309 _M_tail(*this) = _Tuple_impl<_Idx, _UElements...>::_M_tail(__in); 310 return *this; 311 } 312 313 template<typename _UHead, typename... _UTails> 314 _Tuple_impl& 315 operator=(_Tuple_impl<_Idx, _UHead, _UTails...>&& __in) 316 { 317 _M_head(*this) = std::forward<_UHead> 318 (_Tuple_impl<_Idx, _UHead, _UTails...>::_M_head(__in)); 319 _M_tail(*this) = std::move 320 (_Tuple_impl<_Idx, _UHead, _UTails...>::_M_tail(__in)); 321 return *this; 322 } 323 324 protected: 325 void 326 _M_swap(_Tuple_impl& __in) 327 noexcept(noexcept(swap(std::declval<_Head&>(), 328 std::declval<_Head&>())) 329 && noexcept(_M_tail(__in)._M_swap(_M_tail(__in)))) 330 { 331 using std::swap; 332 swap(_M_head(*this), _M_head(__in)); 333 _Inherited::_M_swap(_M_tail(__in)); 334 } 335 }; 336 337 // Basis case of inheritance recursion. 338 template<std::size_t _Idx, typename _Head> 339 struct _Tuple_impl<_Idx, _Head> 340 : private _Head_base<_Idx, _Head, __empty_not_final<_Head>::value> 341 { 342 template<std::size_t, typename...> friend class _Tuple_impl; 343 344 typedef _Head_base<_Idx, _Head, __empty_not_final<_Head>::value> _Base; 345 346 static constexpr _Head& 347 _M_head(_Tuple_impl& __t) noexcept { return _Base::_M_head(__t); } 348 349 static constexpr const _Head& 350 _M_head(const _Tuple_impl& __t) noexcept { return _Base::_M_head(__t); } 351 352 constexpr _Tuple_impl() 353 : _Base() { } 354 355 explicit 356 constexpr _Tuple_impl(const _Head& __head) 357 : _Base(__head) { } 358 359 template<typename _UHead> 360 explicit 361 constexpr _Tuple_impl(_UHead&& __head) 362 : _Base(std::forward<_UHead>(__head)) { } 363 364 constexpr _Tuple_impl(const _Tuple_impl&) = default; 365 366 constexpr 367 _Tuple_impl(_Tuple_impl&& __in) 368 noexcept(is_nothrow_move_constructible<_Head>::value) 369 : _Base(std::forward<_Head>(_M_head(__in))) { } 370 371 template<typename _UHead> 372 constexpr _Tuple_impl(const _Tuple_impl<_Idx, _UHead>& __in) 373 : _Base(_Tuple_impl<_Idx, _UHead>::_M_head(__in)) { } 374 375 template<typename _UHead> 376 constexpr _Tuple_impl(_Tuple_impl<_Idx, _UHead>&& __in) 377 : _Base(std::forward<_UHead>(_Tuple_impl<_Idx, _UHead>::_M_head(__in))) 378 { } 379 380 template<typename _Alloc> 381 _Tuple_impl(allocator_arg_t __tag, const _Alloc& __a) 382 : _Base(__tag, __use_alloc<_Head>(__a)) { } 383 384 template<typename _Alloc> 385 _Tuple_impl(allocator_arg_t __tag, const _Alloc& __a, 386 const _Head& __head) 387 : _Base(__use_alloc<_Head, _Alloc, _Head>(__a), __head) { } 388 389 template<typename _Alloc, typename _UHead> 390 _Tuple_impl(allocator_arg_t __tag, const _Alloc& __a, 391 _UHead&& __head) 392 : _Base(__use_alloc<_Head, _Alloc, _UHead>(__a), 393 std::forward<_UHead>(__head)) { } 394 395 template<typename _Alloc> 396 _Tuple_impl(allocator_arg_t __tag, const _Alloc& __a, 397 const _Tuple_impl& __in) 398 : _Base(__use_alloc<_Head, _Alloc, _Head>(__a), _M_head(__in)) { } 399 400 template<typename _Alloc> 401 _Tuple_impl(allocator_arg_t __tag, const _Alloc& __a, 402 _Tuple_impl&& __in) 403 : _Base(__use_alloc<_Head, _Alloc, _Head>(__a), 404 std::forward<_Head>(_M_head(__in))) { } 405 406 template<typename _Alloc, typename _UHead> 407 _Tuple_impl(allocator_arg_t __tag, const _Alloc& __a, 408 const _Tuple_impl<_Idx, _UHead>& __in) 409 : _Base(__use_alloc<_Head, _Alloc, _Head>(__a), 410 _Tuple_impl<_Idx, _UHead>::_M_head(__in)) { } 411 412 template<typename _Alloc, typename _UHead> 413 _Tuple_impl(allocator_arg_t __tag, const _Alloc& __a, 414 _Tuple_impl<_Idx, _UHead>&& __in) 415 : _Base(__use_alloc<_Head, _Alloc, _UHead>(__a), 416 std::forward<_UHead>(_Tuple_impl<_Idx, _UHead>::_M_head(__in))) 417 { } 418 419 _Tuple_impl& 420 operator=(const _Tuple_impl& __in) 421 { 422 _M_head(*this) = _M_head(__in); 423 return *this; 424 } 425 426 _Tuple_impl& 427 operator=(_Tuple_impl&& __in) 428 noexcept(is_nothrow_move_assignable<_Head>::value) 429 { 430 _M_head(*this) = std::forward<_Head>(_M_head(__in)); 431 return *this; 432 } 433 434 template<typename _UHead> 435 _Tuple_impl& 436 operator=(const _Tuple_impl<_Idx, _UHead>& __in) 437 { 438 _M_head(*this) = _Tuple_impl<_Idx, _UHead>::_M_head(__in); 439 return *this; 440 } 441 442 template<typename _UHead> 443 _Tuple_impl& 444 operator=(_Tuple_impl<_Idx, _UHead>&& __in) 445 { 446 _M_head(*this) 447 = std::forward<_UHead>(_Tuple_impl<_Idx, _UHead>::_M_head(__in)); 448 return *this; 449 } 450 451 protected: 452 void 453 _M_swap(_Tuple_impl& __in) 454 noexcept(noexcept(swap(std::declval<_Head&>(), std::declval<_Head&>()))) 455 { 456 using std::swap; 457 swap(_M_head(*this), _M_head(__in)); 458 } 459 }; 460 461 /// Primary class template, tuple 462 template<typename... _Elements> 463 class tuple : public _Tuple_impl<0, _Elements...> 464 { 465 typedef _Tuple_impl<0, _Elements...> _Inherited; 466 467 public: 468 constexpr tuple() 469 : _Inherited() { } 470 471 explicit 472 constexpr tuple(const _Elements&... __elements) 473 : _Inherited(__elements...) { } 474 475 template<typename... _UElements, typename = typename 476 enable_if<__and_<is_convertible<_UElements, 477 _Elements>...>::value>::type> 478 explicit 479 constexpr tuple(_UElements&&... __elements) 480 : _Inherited(std::forward<_UElements>(__elements)...) { } 481 482 constexpr tuple(const tuple&) = default; 483 484 constexpr tuple(tuple&&) = default; 485 486 template<typename... _UElements, typename = typename 487 enable_if<__and_<is_convertible<const _UElements&, 488 _Elements>...>::value>::type> 489 constexpr tuple(const tuple<_UElements...>& __in) 490 : _Inherited(static_cast<const _Tuple_impl<0, _UElements...>&>(__in)) 491 { } 492 493 template<typename... _UElements, typename = typename 494 enable_if<__and_<is_convertible<_UElements, 495 _Elements>...>::value>::type> 496 constexpr tuple(tuple<_UElements...>&& __in) 497 : _Inherited(static_cast<_Tuple_impl<0, _UElements...>&&>(__in)) { } 498 499 // Allocator-extended constructors. 500 501 template<typename _Alloc> 502 tuple(allocator_arg_t __tag, const _Alloc& __a) 503 : _Inherited(__tag, __a) { } 504 505 template<typename _Alloc> 506 tuple(allocator_arg_t __tag, const _Alloc& __a, 507 const _Elements&... __elements) 508 : _Inherited(__tag, __a, __elements...) { } 509 510 template<typename _Alloc, typename... _UElements, typename = typename 511 enable_if<sizeof...(_UElements) 512 == sizeof...(_Elements)>::type> 513 tuple(allocator_arg_t __tag, const _Alloc& __a, 514 _UElements&&... __elements) 515 : _Inherited(__tag, __a, std::forward<_UElements>(__elements)...) 516 { } 517 518 template<typename _Alloc> 519 tuple(allocator_arg_t __tag, const _Alloc& __a, const tuple& __in) 520 : _Inherited(__tag, __a, static_cast<const _Inherited&>(__in)) { } 521 522 template<typename _Alloc> 523 tuple(allocator_arg_t __tag, const _Alloc& __a, tuple&& __in) 524 : _Inherited(__tag, __a, static_cast<_Inherited&&>(__in)) { } 525 526 template<typename _Alloc, typename... _UElements, typename = typename 527 enable_if<sizeof...(_UElements) 528 == sizeof...(_Elements)>::type> 529 tuple(allocator_arg_t __tag, const _Alloc& __a, 530 const tuple<_UElements...>& __in) 531 : _Inherited(__tag, __a, 532 static_cast<const _Tuple_impl<0, _UElements...>&>(__in)) 533 { } 534 535 template<typename _Alloc, typename... _UElements, typename = typename 536 enable_if<sizeof...(_UElements) 537 == sizeof...(_Elements)>::type> 538 tuple(allocator_arg_t __tag, const _Alloc& __a, 539 tuple<_UElements...>&& __in) 540 : _Inherited(__tag, __a, 541 static_cast<_Tuple_impl<0, _UElements...>&&>(__in)) 542 { } 543 544 tuple& 545 operator=(const tuple& __in) 546 { 547 static_cast<_Inherited&>(*this) = __in; 548 return *this; 549 } 550 551 tuple& 552 operator=(tuple&& __in) 553 noexcept(is_nothrow_move_assignable<_Inherited>::value) 554 { 555 static_cast<_Inherited&>(*this) = std::move(__in); 556 return *this; 557 } 558 559 template<typename... _UElements, typename = typename 560 enable_if<sizeof...(_UElements) 561 == sizeof...(_Elements)>::type> 562 tuple& 563 operator=(const tuple<_UElements...>& __in) 564 { 565 static_cast<_Inherited&>(*this) = __in; 566 return *this; 567 } 568 569 template<typename... _UElements, typename = typename 570 enable_if<sizeof...(_UElements) 571 == sizeof...(_Elements)>::type> 572 tuple& 573 operator=(tuple<_UElements...>&& __in) 574 { 575 static_cast<_Inherited&>(*this) = std::move(__in); 576 return *this; 577 } 578 579 void 580 swap(tuple& __in) 581 noexcept(noexcept(__in._M_swap(__in))) 582 { _Inherited::_M_swap(__in); } 583 }; 584 585 // Explicit specialization, zero-element tuple. 586 template<> 587 class tuple<> 588 { 589 public: 590 void swap(tuple&) noexcept { /* no-op */ } 591 }; 592 593 /// Partial specialization, 2-element tuple. 594 /// Includes construction and assignment from a pair. 595 template<typename _T1, typename _T2> 596 class tuple<_T1, _T2> : public _Tuple_impl<0, _T1, _T2> 597 { 598 typedef _Tuple_impl<0, _T1, _T2> _Inherited; 599 600 public: 601 constexpr tuple() 602 : _Inherited() { } 603 604 explicit 605 constexpr tuple(const _T1& __a1, const _T2& __a2) 606 : _Inherited(__a1, __a2) { } 607 608 template<typename _U1, typename _U2, typename = typename 609 enable_if<__and_<is_convertible<_U1, _T1>, 610 is_convertible<_U2, _T2>>::value>::type> 611 explicit 612 constexpr tuple(_U1&& __a1, _U2&& __a2) 613 : _Inherited(std::forward<_U1>(__a1), std::forward<_U2>(__a2)) { } 614 615 constexpr tuple(const tuple&) = default; 616 617 constexpr tuple(tuple&&) = default; 618 619 template<typename _U1, typename _U2, typename = typename 620 enable_if<__and_<is_convertible<const _U1&, _T1>, 621 is_convertible<const _U2&, _T2>>::value>::type> 622 constexpr tuple(const tuple<_U1, _U2>& __in) 623 : _Inherited(static_cast<const _Tuple_impl<0, _U1, _U2>&>(__in)) { } 624 625 template<typename _U1, typename _U2, typename = typename 626 enable_if<__and_<is_convertible<_U1, _T1>, 627 is_convertible<_U2, _T2>>::value>::type> 628 constexpr tuple(tuple<_U1, _U2>&& __in) 629 : _Inherited(static_cast<_Tuple_impl<0, _U1, _U2>&&>(__in)) { } 630 631 template<typename _U1, typename _U2, typename = typename 632 enable_if<__and_<is_convertible<const _U1&, _T1>, 633 is_convertible<const _U2&, _T2>>::value>::type> 634 constexpr tuple(const pair<_U1, _U2>& __in) 635 : _Inherited(__in.first, __in.second) { } 636 637 template<typename _U1, typename _U2, typename = typename 638 enable_if<__and_<is_convertible<_U1, _T1>, 639 is_convertible<_U2, _T2>>::value>::type> 640 constexpr tuple(pair<_U1, _U2>&& __in) 641 : _Inherited(std::forward<_U1>(__in.first), 642 std::forward<_U2>(__in.second)) { } 643 644 // Allocator-extended constructors. 645 646 template<typename _Alloc> 647 tuple(allocator_arg_t __tag, const _Alloc& __a) 648 : _Inherited(__tag, __a) { } 649 650 template<typename _Alloc> 651 tuple(allocator_arg_t __tag, const _Alloc& __a, 652 const _T1& __a1, const _T2& __a2) 653 : _Inherited(__tag, __a, __a1, __a2) { } 654 655 template<typename _Alloc, typename _U1, typename _U2> 656 tuple(allocator_arg_t __tag, const _Alloc& __a, _U1&& __a1, _U2&& __a2) 657 : _Inherited(__tag, __a, std::forward<_U1>(__a1), 658 std::forward<_U2>(__a2)) { } 659 660 template<typename _Alloc> 661 tuple(allocator_arg_t __tag, const _Alloc& __a, const tuple& __in) 662 : _Inherited(__tag, __a, static_cast<const _Inherited&>(__in)) { } 663 664 template<typename _Alloc> 665 tuple(allocator_arg_t __tag, const _Alloc& __a, tuple&& __in) 666 : _Inherited(__tag, __a, static_cast<_Inherited&&>(__in)) { } 667 668 template<typename _Alloc, typename _U1, typename _U2> 669 tuple(allocator_arg_t __tag, const _Alloc& __a, 670 const tuple<_U1, _U2>& __in) 671 : _Inherited(__tag, __a, 672 static_cast<const _Tuple_impl<0, _U1, _U2>&>(__in)) 673 { } 674 675 template<typename _Alloc, typename _U1, typename _U2> 676 tuple(allocator_arg_t __tag, const _Alloc& __a, tuple<_U1, _U2>&& __in) 677 : _Inherited(__tag, __a, static_cast<_Tuple_impl<0, _U1, _U2>&&>(__in)) 678 { } 679 680 template<typename _Alloc, typename _U1, typename _U2> 681 tuple(allocator_arg_t __tag, const _Alloc& __a, 682 const pair<_U1, _U2>& __in) 683 : _Inherited(__tag, __a, __in.first, __in.second) { } 684 685 template<typename _Alloc, typename _U1, typename _U2> 686 tuple(allocator_arg_t __tag, const _Alloc& __a, pair<_U1, _U2>&& __in) 687 : _Inherited(__tag, __a, std::forward<_U1>(__in.first), 688 std::forward<_U2>(__in.second)) { } 689 690 tuple& 691 operator=(const tuple& __in) 692 { 693 static_cast<_Inherited&>(*this) = __in; 694 return *this; 695 } 696 697 tuple& 698 operator=(tuple&& __in) 699 noexcept(is_nothrow_move_assignable<_Inherited>::value) 700 { 701 static_cast<_Inherited&>(*this) = std::move(__in); 702 return *this; 703 } 704 705 template<typename _U1, typename _U2> 706 tuple& 707 operator=(const tuple<_U1, _U2>& __in) 708 { 709 static_cast<_Inherited&>(*this) = __in; 710 return *this; 711 } 712 713 template<typename _U1, typename _U2> 714 tuple& 715 operator=(tuple<_U1, _U2>&& __in) 716 { 717 static_cast<_Inherited&>(*this) = std::move(__in); 718 return *this; 719 } 720 721 template<typename _U1, typename _U2> 722 tuple& 723 operator=(const pair<_U1, _U2>& __in) 724 { 725 this->_M_head(*this) = __in.first; 726 this->_M_tail(*this)._M_head(*this) = __in.second; 727 return *this; 728 } 729 730 template<typename _U1, typename _U2> 731 tuple& 732 operator=(pair<_U1, _U2>&& __in) 733 { 734 this->_M_head(*this) = std::forward<_U1>(__in.first); 735 this->_M_tail(*this)._M_head(*this) = std::forward<_U2>(__in.second); 736 return *this; 737 } 738 739 void 740 swap(tuple& __in) 741 noexcept(noexcept(__in._M_swap(__in))) 742 { _Inherited::_M_swap(__in); } 743 }; 744 745 746 /// Gives the type of the ith element of a given tuple type. 747 template<std::size_t __i, typename _Tp> 748 struct tuple_element; 749 750 /** 751 * Recursive case for tuple_element: strip off the first element in 752 * the tuple and retrieve the (i-1)th element of the remaining tuple. 753 */ 754 template<std::size_t __i, typename _Head, typename... _Tail> 755 struct tuple_element<__i, tuple<_Head, _Tail...> > 756 : tuple_element<__i - 1, tuple<_Tail...> > { }; 757 758 /** 759 * Basis case for tuple_element: The first element is the one we're seeking. 760 */ 761 template<typename _Head, typename... _Tail> 762 struct tuple_element<0, tuple<_Head, _Tail...> > 763 { 764 typedef _Head type; 765 }; 766 767 // Duplicate of C++14's tuple_element_t for internal use in C++11 mode 768 template<std::size_t __i, typename _Tp> 769 using __tuple_element_t = typename tuple_element<__i, _Tp>::type; 770 771 template<std::size_t __i, typename _Tp> 772 struct tuple_element<__i, const _Tp> 773 { 774 typedef typename add_const<__tuple_element_t<__i, _Tp>>::type type; 775 }; 776 777 template<std::size_t __i, typename _Tp> 778 struct tuple_element<__i, volatile _Tp> 779 { 780 typedef typename add_volatile<__tuple_element_t<__i, _Tp>>::type type; 781 }; 782 783 template<std::size_t __i, typename _Tp> 784 struct tuple_element<__i, const volatile _Tp> 785 { 786 typedef typename add_cv<__tuple_element_t<__i, _Tp>>::type type; 787 }; 788 789 #if __cplusplus > 201103L 790 #define __cpp_lib_tuple_element_t 201402 791 792 template<std::size_t __i, typename _Tp> 793 using tuple_element_t = typename tuple_element<__i, _Tp>::type; 794 #endif 795 796 /// Finds the size of a given tuple type. 797 template<typename _Tp> 798 struct tuple_size; 799 800 // _GLIBCXX_RESOLVE_LIB_DEFECTS 801 // 2313. tuple_size should always derive from integral_constant<size_t, N> 802 template<typename _Tp> 803 struct tuple_size<const _Tp> 804 : integral_constant<size_t, tuple_size<_Tp>::value> { }; 805 806 template<typename _Tp> 807 struct tuple_size<volatile _Tp> 808 : integral_constant<size_t, tuple_size<_Tp>::value> { }; 809 810 template<typename _Tp> 811 struct tuple_size<const volatile _Tp> 812 : integral_constant<size_t, tuple_size<_Tp>::value> { }; 813 814 /// class tuple_size 815 template<typename... _Elements> 816 struct tuple_size<tuple<_Elements...>> 817 : public integral_constant<std::size_t, sizeof...(_Elements)> { }; 818 819 template<std::size_t __i, typename _Head, typename... _Tail> 820 constexpr _Head& 821 __get_helper(_Tuple_impl<__i, _Head, _Tail...>& __t) noexcept 822 { return _Tuple_impl<__i, _Head, _Tail...>::_M_head(__t); } 823 824 template<std::size_t __i, typename _Head, typename... _Tail> 825 constexpr const _Head& 826 __get_helper(const _Tuple_impl<__i, _Head, _Tail...>& __t) noexcept 827 { return _Tuple_impl<__i, _Head, _Tail...>::_M_head(__t); } 828 829 /// Return a reference to the ith element of a tuple. 830 template<std::size_t __i, typename... _Elements> 831 constexpr __tuple_element_t<__i, tuple<_Elements...>>& 832 get(tuple<_Elements...>& __t) noexcept 833 { return std::__get_helper<__i>(__t); } 834 835 /// Return a const reference to the ith element of a const tuple. 836 template<std::size_t __i, typename... _Elements> 837 constexpr const __tuple_element_t<__i, tuple<_Elements...>>& 838 get(const tuple<_Elements...>& __t) noexcept 839 { return std::__get_helper<__i>(__t); } 840 841 /// Return an rvalue reference to the ith element of a tuple rvalue. 842 template<std::size_t __i, typename... _Elements> 843 constexpr __tuple_element_t<__i, tuple<_Elements...>>&& 844 get(tuple<_Elements...>&& __t) noexcept 845 { 846 typedef __tuple_element_t<__i, tuple<_Elements...>> __element_type; 847 return std::forward<__element_type&&>(std::get<__i>(__t)); 848 } 849 850 #if __cplusplus > 201103L 851 852 #define __cpp_lib_tuples_by_type 201304 853 854 template<typename _Head, size_t __i, typename... _Tail> 855 constexpr _Head& 856 __get_helper2(_Tuple_impl<__i, _Head, _Tail...>& __t) noexcept 857 { return _Tuple_impl<__i, _Head, _Tail...>::_M_head(__t); } 858 859 template<typename _Head, size_t __i, typename... _Tail> 860 constexpr const _Head& 861 __get_helper2(const _Tuple_impl<__i, _Head, _Tail...>& __t) noexcept 862 { return _Tuple_impl<__i, _Head, _Tail...>::_M_head(__t); } 863 864 /// Return a reference to the unique element of type _Tp of a tuple. 865 template <typename _Tp, typename... _Types> 866 constexpr _Tp& 867 get(tuple<_Types...>& __t) noexcept 868 { return std::__get_helper2<_Tp>(__t); } 869 870 /// Return a reference to the unique element of type _Tp of a tuple rvalue. 871 template <typename _Tp, typename... _Types> 872 constexpr _Tp&& 873 get(tuple<_Types...>&& __t) noexcept 874 { return std::forward<_Tp&&>(std::__get_helper2<_Tp>(__t)); } 875 876 /// Return a const reference to the unique element of type _Tp of a tuple. 877 template <typename _Tp, typename... _Types> 878 constexpr const _Tp& 879 get(const tuple<_Types...>& __t) noexcept 880 { return std::__get_helper2<_Tp>(__t); } 881 #endif 882 883 // This class performs the comparison operations on tuples 884 template<typename _Tp, typename _Up, size_t __i, size_t __size> 885 struct __tuple_compare 886 { 887 static constexpr bool 888 __eq(const _Tp& __t, const _Up& __u) 889 { 890 return bool(std::get<__i>(__t) == std::get<__i>(__u)) 891 && __tuple_compare<_Tp, _Up, __i + 1, __size>::__eq(__t, __u); 892 } 893 894 static constexpr bool 895 __less(const _Tp& __t, const _Up& __u) 896 { 897 return bool(std::get<__i>(__t) < std::get<__i>(__u)) 898 || (!bool(std::get<__i>(__u) < std::get<__i>(__t)) 899 && __tuple_compare<_Tp, _Up, __i + 1, __size>::__less(__t, __u)); 900 } 901 }; 902 903 template<typename _Tp, typename _Up, size_t __size> 904 struct __tuple_compare<_Tp, _Up, __size, __size> 905 { 906 static constexpr bool 907 __eq(const _Tp&, const _Up&) { return true; } 908 909 static constexpr bool 910 __less(const _Tp&, const _Up&) { return false; } 911 }; 912 913 template<typename... _TElements, typename... _UElements> 914 constexpr bool 915 operator==(const tuple<_TElements...>& __t, 916 const tuple<_UElements...>& __u) 917 { 918 static_assert(sizeof...(_TElements) == sizeof...(_UElements), 919 "tuple objects can only be compared if they have equal sizes."); 920 using __compare = __tuple_compare<tuple<_TElements...>, 921 tuple<_UElements...>, 922 0, sizeof...(_TElements)>; 923 return __compare::__eq(__t, __u); 924 } 925 926 template<typename... _TElements, typename... _UElements> 927 constexpr bool 928 operator<(const tuple<_TElements...>& __t, 929 const tuple<_UElements...>& __u) 930 { 931 static_assert(sizeof...(_TElements) == sizeof...(_UElements), 932 "tuple objects can only be compared if they have equal sizes."); 933 using __compare = __tuple_compare<tuple<_TElements...>, 934 tuple<_UElements...>, 935 0, sizeof...(_TElements)>; 936 return __compare::__less(__t, __u); 937 } 938 939 template<typename... _TElements, typename... _UElements> 940 constexpr bool 941 operator!=(const tuple<_TElements...>& __t, 942 const tuple<_UElements...>& __u) 943 { return !(__t == __u); } 944 945 template<typename... _TElements, typename... _UElements> 946 constexpr bool 947 operator>(const tuple<_TElements...>& __t, 948 const tuple<_UElements...>& __u) 949 { return __u < __t; } 950 951 template<typename... _TElements, typename... _UElements> 952 constexpr bool 953 operator<=(const tuple<_TElements...>& __t, 954 const tuple<_UElements...>& __u) 955 { return !(__u < __t); } 956 957 template<typename... _TElements, typename... _UElements> 958 constexpr bool 959 operator>=(const tuple<_TElements...>& __t, 960 const tuple<_UElements...>& __u) 961 { return !(__t < __u); } 962 963 // NB: DR 705. 964 template<typename... _Elements> 965 constexpr tuple<typename __decay_and_strip<_Elements>::__type...> 966 make_tuple(_Elements&&... __args) 967 { 968 typedef tuple<typename __decay_and_strip<_Elements>::__type...> 969 __result_type; 970 return __result_type(std::forward<_Elements>(__args)...); 971 } 972 973 template<typename... _Elements> 974 tuple<_Elements&&...> 975 forward_as_tuple(_Elements&&... __args) noexcept 976 { return tuple<_Elements&&...>(std::forward<_Elements>(__args)...); } 977 978 template<typename> 979 struct __is_tuple_like_impl : false_type 980 { }; 981 982 template<typename... _Tps> 983 struct __is_tuple_like_impl<tuple<_Tps...>> : true_type 984 { }; 985 986 template<typename _T1, typename _T2> 987 struct __is_tuple_like_impl<pair<_T1, _T2>> : true_type 988 { }; 989 990 template<typename _Tp, std::size_t _Nm> 991 struct __is_tuple_like_impl<array<_Tp, _Nm>> : true_type 992 { }; 993 994 // Internal type trait that allows us to sfinae-protect tuple_cat. 995 template<typename _Tp> 996 struct __is_tuple_like 997 : public __is_tuple_like_impl<typename std::remove_cv 998 <typename std::remove_reference<_Tp>::type>::type>::type 999 { }; 1000 1001 template<size_t, typename, typename, size_t> 1002 struct __make_tuple_impl; 1003 1004 template<size_t _Idx, typename _Tuple, typename... _Tp, size_t _Nm> 1005 struct __make_tuple_impl<_Idx, tuple<_Tp...>, _Tuple, _Nm> 1006 : __make_tuple_impl<_Idx + 1, 1007 tuple<_Tp..., __tuple_element_t<_Idx, _Tuple>>, 1008 _Tuple, _Nm> 1009 { }; 1010 1011 template<std::size_t _Nm, typename _Tuple, typename... _Tp> 1012 struct __make_tuple_impl<_Nm, tuple<_Tp...>, _Tuple, _Nm> 1013 { 1014 typedef tuple<_Tp...> __type; 1015 }; 1016 1017 template<typename _Tuple> 1018 struct __do_make_tuple 1019 : __make_tuple_impl<0, tuple<>, _Tuple, std::tuple_size<_Tuple>::value> 1020 { }; 1021 1022 // Returns the std::tuple equivalent of a tuple-like type. 1023 template<typename _Tuple> 1024 struct __make_tuple 1025 : public __do_make_tuple<typename std::remove_cv 1026 <typename std::remove_reference<_Tuple>::type>::type> 1027 { }; 1028 1029 // Combines several std::tuple's into a single one. 1030 template<typename...> 1031 struct __combine_tuples; 1032 1033 template<> 1034 struct __combine_tuples<> 1035 { 1036 typedef tuple<> __type; 1037 }; 1038 1039 template<typename... _Ts> 1040 struct __combine_tuples<tuple<_Ts...>> 1041 { 1042 typedef tuple<_Ts...> __type; 1043 }; 1044 1045 template<typename... _T1s, typename... _T2s, typename... _Rem> 1046 struct __combine_tuples<tuple<_T1s...>, tuple<_T2s...>, _Rem...> 1047 { 1048 typedef typename __combine_tuples<tuple<_T1s..., _T2s...>, 1049 _Rem...>::__type __type; 1050 }; 1051 1052 // Computes the result type of tuple_cat given a set of tuple-like types. 1053 template<typename... _Tpls> 1054 struct __tuple_cat_result 1055 { 1056 typedef typename __combine_tuples 1057 <typename __make_tuple<_Tpls>::__type...>::__type __type; 1058 }; 1059 1060 // Helper to determine the index set for the first tuple-like 1061 // type of a given set. 1062 template<typename...> 1063 struct __make_1st_indices; 1064 1065 template<> 1066 struct __make_1st_indices<> 1067 { 1068 typedef std::_Index_tuple<> __type; 1069 }; 1070 1071 template<typename _Tp, typename... _Tpls> 1072 struct __make_1st_indices<_Tp, _Tpls...> 1073 { 1074 typedef typename std::_Build_index_tuple<std::tuple_size< 1075 typename std::remove_reference<_Tp>::type>::value>::__type __type; 1076 }; 1077 1078 // Performs the actual concatenation by step-wise expanding tuple-like 1079 // objects into the elements, which are finally forwarded into the 1080 // result tuple. 1081 template<typename _Ret, typename _Indices, typename... _Tpls> 1082 struct __tuple_concater; 1083 1084 template<typename _Ret, std::size_t... _Is, typename _Tp, typename... _Tpls> 1085 struct __tuple_concater<_Ret, std::_Index_tuple<_Is...>, _Tp, _Tpls...> 1086 { 1087 template<typename... _Us> 1088 static constexpr _Ret 1089 _S_do(_Tp&& __tp, _Tpls&&... __tps, _Us&&... __us) 1090 { 1091 typedef typename __make_1st_indices<_Tpls...>::__type __idx; 1092 typedef __tuple_concater<_Ret, __idx, _Tpls...> __next; 1093 return __next::_S_do(std::forward<_Tpls>(__tps)..., 1094 std::forward<_Us>(__us)..., 1095 std::get<_Is>(std::forward<_Tp>(__tp))...); 1096 } 1097 }; 1098 1099 template<typename _Ret> 1100 struct __tuple_concater<_Ret, std::_Index_tuple<>> 1101 { 1102 template<typename... _Us> 1103 static constexpr _Ret 1104 _S_do(_Us&&... __us) 1105 { 1106 return _Ret(std::forward<_Us>(__us)...); 1107 } 1108 }; 1109 1110 /// tuple_cat 1111 template<typename... _Tpls, typename = typename 1112 enable_if<__and_<__is_tuple_like<_Tpls>...>::value>::type> 1113 constexpr auto 1114 tuple_cat(_Tpls&&... __tpls) 1115 -> typename __tuple_cat_result<_Tpls...>::__type 1116 { 1117 typedef typename __tuple_cat_result<_Tpls...>::__type __ret; 1118 typedef typename __make_1st_indices<_Tpls...>::__type __idx; 1119 typedef __tuple_concater<__ret, __idx, _Tpls...> __concater; 1120 return __concater::_S_do(std::forward<_Tpls>(__tpls)...); 1121 } 1122 1123 /// tie 1124 template<typename... _Elements> 1125 inline tuple<_Elements&...> 1126 tie(_Elements&... __args) noexcept 1127 { return tuple<_Elements&...>(__args...); } 1128 1129 /// swap 1130 template<typename... _Elements> 1131 inline void 1132 swap(tuple<_Elements...>& __x, tuple<_Elements...>& __y) 1133 noexcept(noexcept(__x.swap(__y))) 1134 { __x.swap(__y); } 1135 1136 // A class (and instance) which can be used in 'tie' when an element 1137 // of a tuple is not required 1138 struct _Swallow_assign 1139 { 1140 template<class _Tp> 1141 const _Swallow_assign& 1142 operator=(const _Tp&) const 1143 { return *this; } 1144 }; 1145 1146 const _Swallow_assign ignore{}; 1147 1148 /// Partial specialization for tuples 1149 template<typename... _Types, typename _Alloc> 1150 struct uses_allocator<tuple<_Types...>, _Alloc> : true_type { }; 1151 1152 // See stl_pair.h... 1153 template<class _T1, class _T2> 1154 template<typename... _Args1, typename... _Args2> 1155 inline 1156 pair<_T1, _T2>:: 1157 pair(piecewise_construct_t, 1158 tuple<_Args1...> __first, tuple<_Args2...> __second) 1159 : pair(__first, __second, 1160 typename _Build_index_tuple<sizeof...(_Args1)>::__type(), 1161 typename _Build_index_tuple<sizeof...(_Args2)>::__type()) 1162 { } 1163 1164 template<class _T1, class _T2> 1165 template<typename... _Args1, std::size_t... _Indexes1, 1166 typename... _Args2, std::size_t... _Indexes2> 1167 inline 1168 pair<_T1, _T2>:: 1169 pair(tuple<_Args1...>& __tuple1, tuple<_Args2...>& __tuple2, 1170 _Index_tuple<_Indexes1...>, _Index_tuple<_Indexes2...>) 1171 : first(std::forward<_Args1>(std::get<_Indexes1>(__tuple1))...), 1172 second(std::forward<_Args2>(std::get<_Indexes2>(__tuple2))...) 1173 { } 1174 1175 /// @} 1176 1177 _GLIBCXX_END_NAMESPACE_VERSION 1178 } // namespace std 1179 1180 #endif // C++11 1181 1182 #endif // _GLIBCXX_TUPLE 1183
Indexes created Wed Apr 29 00:23:26 UTC 2026