1 // <tuple> -*- C++ -*- 2 3 // Copyright (C) 2007-2014 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 /** @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 // Adds a const reference to a non-reference type. 52 template<typename _Tp> 53 struct __add_c_ref 54 { typedef const _Tp& type; }; 55 56 template<typename _Tp> 57 struct __add_c_ref<_Tp&> 58 { typedef _Tp& type; }; 59 60 // Adds a reference to a non-reference type. 61 template<typename _Tp> 62 struct __add_ref 63 { typedef _Tp& type; }; 64 65 template<typename _Tp> 66 struct __add_ref<_Tp&> 67 { typedef _Tp& type; }; 68 69 // Adds an rvalue reference to a non-reference type. 70 template<typename _Tp> 71 struct __add_r_ref 72 { typedef _Tp&& type; }; 73 74 template<typename _Tp> 75 struct __add_r_ref<_Tp&> 76 { typedef _Tp& type; }; 77 78 template<std::size_t _Idx, typename _Head, bool _IsEmptyNotFinal> 79 struct _Head_base; 80 81 template<std::size_t _Idx, typename _Head> 82 struct _Head_base<_Idx, _Head, true> 83 : public _Head 84 { 85 constexpr _Head_base() 86 : _Head() { } 87 88 constexpr _Head_base(const _Head& __h) 89 : _Head(__h) { } 90 91 constexpr _Head_base(const _Head_base&) = default; 92 constexpr _Head_base(_Head_base&&) = default; 93 94 template<typename _UHead> 95 constexpr _Head_base(_UHead&& __h) 96 : _Head(std::forward<_UHead>(__h)) { } 97 98 _Head_base(allocator_arg_t, __uses_alloc0) 99 : _Head() { } 100 101 template<typename _Alloc> 102 _Head_base(allocator_arg_t, __uses_alloc1<_Alloc> __a) 103 : _Head(allocator_arg, *__a._M_a) { } 104 105 template<typename _Alloc> 106 _Head_base(allocator_arg_t, __uses_alloc2<_Alloc> __a) 107 : _Head(*__a._M_a) { } 108 109 template<typename _UHead> 110 _Head_base(__uses_alloc0, _UHead&& __uhead) 111 : _Head(std::forward<_UHead>(__uhead)) { } 112 113 template<typename _Alloc, typename _UHead> 114 _Head_base(__uses_alloc1<_Alloc> __a, _UHead&& __uhead) 115 : _Head(allocator_arg, *__a._M_a, std::forward<_UHead>(__uhead)) { } 116 117 template<typename _Alloc, typename _UHead> 118 _Head_base(__uses_alloc2<_Alloc> __a, _UHead&& __uhead) 119 : _Head(std::forward<_UHead>(__uhead), *__a._M_a) { } 120 121 static constexpr _Head& 122 _M_head(_Head_base& __b) noexcept { return __b; } 123 124 static constexpr const _Head& 125 _M_head(const _Head_base& __b) noexcept { return __b; } 126 }; 127 128 template<std::size_t _Idx, typename _Head> 129 struct _Head_base<_Idx, _Head, false> 130 { 131 constexpr _Head_base() 132 : _M_head_impl() { } 133 134 constexpr _Head_base(const _Head& __h) 135 : _M_head_impl(__h) { } 136 137 constexpr _Head_base(const _Head_base&) = default; 138 constexpr _Head_base(_Head_base&&) = default; 139 140 template<typename _UHead> 141 constexpr _Head_base(_UHead&& __h) 142 : _M_head_impl(std::forward<_UHead>(__h)) { } 143 144 _Head_base(allocator_arg_t, __uses_alloc0) 145 : _M_head_impl() { } 146 147 template<typename _Alloc> 148 _Head_base(allocator_arg_t, __uses_alloc1<_Alloc> __a) 149 : _M_head_impl(allocator_arg, *__a._M_a) { } 150 151 template<typename _Alloc> 152 _Head_base(allocator_arg_t, __uses_alloc2<_Alloc> __a) 153 : _M_head_impl(*__a._M_a) { } 154 155 template<typename _UHead> 156 _Head_base(__uses_alloc0, _UHead&& __uhead) 157 : _M_head_impl(std::forward<_UHead>(__uhead)) { } 158 159 template<typename _Alloc, typename _UHead> 160 _Head_base(__uses_alloc1<_Alloc> __a, _UHead&& __uhead) 161 : _M_head_impl(allocator_arg, *__a._M_a, std::forward<_UHead>(__uhead)) 162 { } 163 164 template<typename _Alloc, typename _UHead> 165 _Head_base(__uses_alloc2<_Alloc> __a, _UHead&& __uhead) 166 : _M_head_impl(std::forward<_UHead>(__uhead), *__a._M_a) { } 167 168 static constexpr _Head& 169 _M_head(_Head_base& __b) noexcept { return __b._M_head_impl; } 170 171 static constexpr const _Head& 172 _M_head(const _Head_base& __b) noexcept { return __b._M_head_impl; } 173 174 _Head _M_head_impl; 175 }; 176 177 /** 178 * Contains the actual implementation of the @c tuple template, stored 179 * as a recursive inheritance hierarchy from the first element (most 180 * derived class) to the last (least derived class). The @c Idx 181 * parameter gives the 0-based index of the element stored at this 182 * point in the hierarchy; we use it to implement a constant-time 183 * get() operation. 184 */ 185 template<std::size_t _Idx, typename... _Elements> 186 struct _Tuple_impl; 187 188 /** 189 * Zero-element tuple implementation. This is the basis case for the 190 * inheritance recursion. 191 */ 192 template<std::size_t _Idx> 193 struct _Tuple_impl<_Idx> 194 { 195 template<std::size_t, typename...> friend class _Tuple_impl; 196 197 _Tuple_impl() = default; 198 199 template<typename _Alloc> 200 _Tuple_impl(allocator_arg_t, const _Alloc&) { } 201 202 template<typename _Alloc> 203 _Tuple_impl(allocator_arg_t, const _Alloc&, const _Tuple_impl&) { } 204 205 template<typename _Alloc> 206 _Tuple_impl(allocator_arg_t, const _Alloc&, _Tuple_impl&&) { } 207 208 protected: 209 void _M_swap(_Tuple_impl&) noexcept { /* no-op */ } 210 }; 211 212 template<typename _Tp> 213 struct __is_empty_non_tuple : is_empty<_Tp> { }; 214 215 // Using EBO for elements that are tuples causes ambiguous base errors. 216 template<typename _El0, typename... _El> 217 struct __is_empty_non_tuple<tuple<_El0, _El...>> : false_type { }; 218 219 // Use the Empty Base-class Optimization for empty, non-final types. 220 template<typename _Tp> 221 using __empty_not_final 222 = typename conditional<__is_final(_Tp), false_type, 223 __is_empty_non_tuple<_Tp>>::type; 224 225 /** 226 * Recursive tuple implementation. Here we store the @c Head element 227 * and derive from a @c Tuple_impl containing the remaining elements 228 * (which contains the @c Tail). 229 */ 230 template<std::size_t _Idx, typename _Head, typename... _Tail> 231 struct _Tuple_impl<_Idx, _Head, _Tail...> 232 : public _Tuple_impl<_Idx + 1, _Tail...>, 233 private _Head_base<_Idx, _Head, __empty_not_final<_Head>::value> 234 { 235 template<std::size_t, typename...> friend class _Tuple_impl; 236 237 typedef _Tuple_impl<_Idx + 1, _Tail...> _Inherited; 238 typedef _Head_base<_Idx, _Head, __empty_not_final<_Head>::value> _Base; 239 240 static constexpr _Head& 241 _M_head(_Tuple_impl& __t) noexcept { return _Base::_M_head(__t); } 242 243 static constexpr const _Head& 244 _M_head(const _Tuple_impl& __t) noexcept { return _Base::_M_head(__t); } 245 246 static constexpr _Inherited& 247 _M_tail(_Tuple_impl& __t) noexcept { return __t; } 248 249 static constexpr const _Inherited& 250 _M_tail(const _Tuple_impl& __t) noexcept { return __t; } 251 252 constexpr _Tuple_impl() 253 : _Inherited(), _Base() { } 254 255 explicit 256 constexpr _Tuple_impl(const _Head& __head, const _Tail&... __tail) 257 : _Inherited(__tail...), _Base(__head) { } 258 259 template<typename _UHead, typename... _UTail, typename = typename 260 enable_if<sizeof...(_Tail) == sizeof...(_UTail)>::type> 261 explicit 262 constexpr _Tuple_impl(_UHead&& __head, _UTail&&... __tail) 263 : _Inherited(std::forward<_UTail>(__tail)...), 264 _Base(std::forward<_UHead>(__head)) { } 265 266 constexpr _Tuple_impl(const _Tuple_impl&) = default; 267 268 constexpr 269 _Tuple_impl(_Tuple_impl&& __in) 270 noexcept(__and_<is_nothrow_move_constructible<_Head>, 271 is_nothrow_move_constructible<_Inherited>>::value) 272 : _Inherited(std::move(_M_tail(__in))), 273 _Base(std::forward<_Head>(_M_head(__in))) { } 274 275 template<typename... _UElements> 276 constexpr _Tuple_impl(const _Tuple_impl<_Idx, _UElements...>& __in) 277 : _Inherited(_Tuple_impl<_Idx, _UElements...>::_M_tail(__in)), 278 _Base(_Tuple_impl<_Idx, _UElements...>::_M_head(__in)) { } 279 280 template<typename _UHead, typename... _UTails> 281 constexpr _Tuple_impl(_Tuple_impl<_Idx, _UHead, _UTails...>&& __in) 282 : _Inherited(std::move 283 (_Tuple_impl<_Idx, _UHead, _UTails...>::_M_tail(__in))), 284 _Base(std::forward<_UHead> 285 (_Tuple_impl<_Idx, _UHead, _UTails...>::_M_head(__in))) { } 286 287 template<typename _Alloc> 288 _Tuple_impl(allocator_arg_t __tag, const _Alloc& __a) 289 : _Inherited(__tag, __a), 290 _Base(__tag, __use_alloc<_Head>(__a)) { } 291 292 template<typename _Alloc> 293 _Tuple_impl(allocator_arg_t __tag, const _Alloc& __a, 294 const _Head& __head, const _Tail&... __tail) 295 : _Inherited(__tag, __a, __tail...), 296 _Base(__use_alloc<_Head, _Alloc, _Head>(__a), __head) { } 297 298 template<typename _Alloc, typename _UHead, typename... _UTail, 299 typename = typename enable_if<sizeof...(_Tail) 300 == sizeof...(_UTail)>::type> 301 _Tuple_impl(allocator_arg_t __tag, const _Alloc& __a, 302 _UHead&& __head, _UTail&&... __tail) 303 : _Inherited(__tag, __a, std::forward<_UTail>(__tail)...), 304 _Base(__use_alloc<_Head, _Alloc, _UHead>(__a), 305 std::forward<_UHead>(__head)) { } 306 307 template<typename _Alloc> 308 _Tuple_impl(allocator_arg_t __tag, const _Alloc& __a, 309 const _Tuple_impl& __in) 310 : _Inherited(__tag, __a, _M_tail(__in)), 311 _Base(__use_alloc<_Head, _Alloc, _Head>(__a), _M_head(__in)) { } 312 313 template<typename _Alloc> 314 _Tuple_impl(allocator_arg_t __tag, const _Alloc& __a, 315 _Tuple_impl&& __in) 316 : _Inherited(__tag, __a, std::move(_M_tail(__in))), 317 _Base(__use_alloc<_Head, _Alloc, _Head>(__a), 318 std::forward<_Head>(_M_head(__in))) { } 319 320 template<typename _Alloc, typename... _UElements> 321 _Tuple_impl(allocator_arg_t __tag, const _Alloc& __a, 322 const _Tuple_impl<_Idx, _UElements...>& __in) 323 : _Inherited(__tag, __a, 324 _Tuple_impl<_Idx, _UElements...>::_M_tail(__in)), 325 _Base(__use_alloc<_Head, _Alloc, _Head>(__a), 326 _Tuple_impl<_Idx, _UElements...>::_M_head(__in)) { } 327 328 template<typename _Alloc, typename _UHead, typename... _UTails> 329 _Tuple_impl(allocator_arg_t __tag, const _Alloc& __a, 330 _Tuple_impl<_Idx, _UHead, _UTails...>&& __in) 331 : _Inherited(__tag, __a, std::move 332 (_Tuple_impl<_Idx, _UHead, _UTails...>::_M_tail(__in))), 333 _Base(__use_alloc<_Head, _Alloc, _UHead>(__a), 334 std::forward<_UHead> 335 (_Tuple_impl<_Idx, _UHead, _UTails...>::_M_head(__in))) { } 336 337 _Tuple_impl& 338 operator=(const _Tuple_impl& __in) 339 { 340 _M_head(*this) = _M_head(__in); 341 _M_tail(*this) = _M_tail(__in); 342 return *this; 343 } 344 345 _Tuple_impl& 346 operator=(_Tuple_impl&& __in) 347 noexcept(__and_<is_nothrow_move_assignable<_Head>, 348 is_nothrow_move_assignable<_Inherited>>::value) 349 { 350 _M_head(*this) = std::forward<_Head>(_M_head(__in)); 351 _M_tail(*this) = std::move(_M_tail(__in)); 352 return *this; 353 } 354 355 template<typename... _UElements> 356 _Tuple_impl& 357 operator=(const _Tuple_impl<_Idx, _UElements...>& __in) 358 { 359 _M_head(*this) = _Tuple_impl<_Idx, _UElements...>::_M_head(__in); 360 _M_tail(*this) = _Tuple_impl<_Idx, _UElements...>::_M_tail(__in); 361 return *this; 362 } 363 364 template<typename _UHead, typename... _UTails> 365 _Tuple_impl& 366 operator=(_Tuple_impl<_Idx, _UHead, _UTails...>&& __in) 367 { 368 _M_head(*this) = std::forward<_UHead> 369 (_Tuple_impl<_Idx, _UHead, _UTails...>::_M_head(__in)); 370 _M_tail(*this) = std::move 371 (_Tuple_impl<_Idx, _UHead, _UTails...>::_M_tail(__in)); 372 return *this; 373 } 374 375 protected: 376 void 377 _M_swap(_Tuple_impl& __in) 378 noexcept(noexcept(swap(std::declval<_Head&>(), 379 std::declval<_Head&>())) 380 && noexcept(_M_tail(__in)._M_swap(_M_tail(__in)))) 381 { 382 using std::swap; 383 swap(_M_head(*this), _M_head(__in)); 384 _Inherited::_M_swap(_M_tail(__in)); 385 } 386 }; 387 388 /// Primary class template, tuple 389 template<typename... _Elements> 390 class tuple : public _Tuple_impl<0, _Elements...> 391 { 392 typedef _Tuple_impl<0, _Elements...> _Inherited; 393 394 public: 395 constexpr tuple() 396 : _Inherited() { } 397 398 explicit 399 constexpr tuple(const _Elements&... __elements) 400 : _Inherited(__elements...) { } 401 402 template<typename... _UElements, typename = typename 403 enable_if<__and_<is_convertible<_UElements, 404 _Elements>...>::value>::type> 405 explicit 406 constexpr tuple(_UElements&&... __elements) 407 : _Inherited(std::forward<_UElements>(__elements)...) { } 408 409 constexpr tuple(const tuple&) = default; 410 411 constexpr tuple(tuple&&) = default; 412 413 template<typename... _UElements, typename = typename 414 enable_if<__and_<is_convertible<const _UElements&, 415 _Elements>...>::value>::type> 416 constexpr tuple(const tuple<_UElements...>& __in) 417 : _Inherited(static_cast<const _Tuple_impl<0, _UElements...>&>(__in)) 418 { } 419 420 template<typename... _UElements, typename = typename 421 enable_if<__and_<is_convertible<_UElements, 422 _Elements>...>::value>::type> 423 constexpr tuple(tuple<_UElements...>&& __in) 424 : _Inherited(static_cast<_Tuple_impl<0, _UElements...>&&>(__in)) { } 425 426 // Allocator-extended constructors. 427 428 template<typename _Alloc> 429 tuple(allocator_arg_t __tag, const _Alloc& __a) 430 : _Inherited(__tag, __a) { } 431 432 template<typename _Alloc> 433 tuple(allocator_arg_t __tag, const _Alloc& __a, 434 const _Elements&... __elements) 435 : _Inherited(__tag, __a, __elements...) { } 436 437 template<typename _Alloc, typename... _UElements, typename = typename 438 enable_if<sizeof...(_UElements) 439 == sizeof...(_Elements)>::type> 440 tuple(allocator_arg_t __tag, const _Alloc& __a, 441 _UElements&&... __elements) 442 : _Inherited(__tag, __a, std::forward<_UElements>(__elements)...) 443 { } 444 445 template<typename _Alloc> 446 tuple(allocator_arg_t __tag, const _Alloc& __a, const tuple& __in) 447 : _Inherited(__tag, __a, static_cast<const _Inherited&>(__in)) { } 448 449 template<typename _Alloc> 450 tuple(allocator_arg_t __tag, const _Alloc& __a, tuple&& __in) 451 : _Inherited(__tag, __a, static_cast<_Inherited&&>(__in)) { } 452 453 template<typename _Alloc, typename... _UElements, typename = typename 454 enable_if<sizeof...(_UElements) 455 == sizeof...(_Elements)>::type> 456 tuple(allocator_arg_t __tag, const _Alloc& __a, 457 const tuple<_UElements...>& __in) 458 : _Inherited(__tag, __a, 459 static_cast<const _Tuple_impl<0, _UElements...>&>(__in)) 460 { } 461 462 template<typename _Alloc, typename... _UElements, typename = typename 463 enable_if<sizeof...(_UElements) 464 == sizeof...(_Elements)>::type> 465 tuple(allocator_arg_t __tag, const _Alloc& __a, 466 tuple<_UElements...>&& __in) 467 : _Inherited(__tag, __a, 468 static_cast<_Tuple_impl<0, _UElements...>&&>(__in)) 469 { } 470 471 tuple& 472 operator=(const tuple& __in) 473 { 474 static_cast<_Inherited&>(*this) = __in; 475 return *this; 476 } 477 478 tuple& 479 operator=(tuple&& __in) 480 noexcept(is_nothrow_move_assignable<_Inherited>::value) 481 { 482 static_cast<_Inherited&>(*this) = std::move(__in); 483 return *this; 484 } 485 486 template<typename... _UElements, typename = typename 487 enable_if<sizeof...(_UElements) 488 == sizeof...(_Elements)>::type> 489 tuple& 490 operator=(const tuple<_UElements...>& __in) 491 { 492 static_cast<_Inherited&>(*this) = __in; 493 return *this; 494 } 495 496 template<typename... _UElements, typename = typename 497 enable_if<sizeof...(_UElements) 498 == sizeof...(_Elements)>::type> 499 tuple& 500 operator=(tuple<_UElements...>&& __in) 501 { 502 static_cast<_Inherited&>(*this) = std::move(__in); 503 return *this; 504 } 505 506 void 507 swap(tuple& __in) 508 noexcept(noexcept(__in._M_swap(__in))) 509 { _Inherited::_M_swap(__in); } 510 }; 511 512 // Explicit specialization, zero-element tuple. 513 template<> 514 class tuple<> 515 { 516 public: 517 void swap(tuple&) noexcept { /* no-op */ } 518 }; 519 520 /// Partial specialization, 2-element tuple. 521 /// Includes construction and assignment from a pair. 522 template<typename _T1, typename _T2> 523 class tuple<_T1, _T2> : public _Tuple_impl<0, _T1, _T2> 524 { 525 typedef _Tuple_impl<0, _T1, _T2> _Inherited; 526 527 public: 528 constexpr tuple() 529 : _Inherited() { } 530 531 explicit 532 constexpr tuple(const _T1& __a1, const _T2& __a2) 533 : _Inherited(__a1, __a2) { } 534 535 template<typename _U1, typename _U2, typename = typename 536 enable_if<__and_<is_convertible<_U1, _T1>, 537 is_convertible<_U2, _T2>>::value>::type> 538 explicit 539 constexpr tuple(_U1&& __a1, _U2&& __a2) 540 : _Inherited(std::forward<_U1>(__a1), std::forward<_U2>(__a2)) { } 541 542 constexpr tuple(const tuple&) = default; 543 544 constexpr tuple(tuple&&) = default; 545 546 template<typename _U1, typename _U2, typename = typename 547 enable_if<__and_<is_convertible<const _U1&, _T1>, 548 is_convertible<const _U2&, _T2>>::value>::type> 549 constexpr tuple(const tuple<_U1, _U2>& __in) 550 : _Inherited(static_cast<const _Tuple_impl<0, _U1, _U2>&>(__in)) { } 551 552 template<typename _U1, typename _U2, typename = typename 553 enable_if<__and_<is_convertible<_U1, _T1>, 554 is_convertible<_U2, _T2>>::value>::type> 555 constexpr tuple(tuple<_U1, _U2>&& __in) 556 : _Inherited(static_cast<_Tuple_impl<0, _U1, _U2>&&>(__in)) { } 557 558 template<typename _U1, typename _U2, typename = typename 559 enable_if<__and_<is_convertible<const _U1&, _T1>, 560 is_convertible<const _U2&, _T2>>::value>::type> 561 constexpr tuple(const pair<_U1, _U2>& __in) 562 : _Inherited(__in.first, __in.second) { } 563 564 template<typename _U1, typename _U2, typename = typename 565 enable_if<__and_<is_convertible<_U1, _T1>, 566 is_convertible<_U2, _T2>>::value>::type> 567 constexpr tuple(pair<_U1, _U2>&& __in) 568 : _Inherited(std::forward<_U1>(__in.first), 569 std::forward<_U2>(__in.second)) { } 570 571 // Allocator-extended constructors. 572 573 template<typename _Alloc> 574 tuple(allocator_arg_t __tag, const _Alloc& __a) 575 : _Inherited(__tag, __a) { } 576 577 template<typename _Alloc> 578 tuple(allocator_arg_t __tag, const _Alloc& __a, 579 const _T1& __a1, const _T2& __a2) 580 : _Inherited(__tag, __a, __a1, __a2) { } 581 582 template<typename _Alloc, typename _U1, typename _U2> 583 tuple(allocator_arg_t __tag, const _Alloc& __a, _U1&& __a1, _U2&& __a2) 584 : _Inherited(__tag, __a, std::forward<_U1>(__a1), 585 std::forward<_U2>(__a2)) { } 586 587 template<typename _Alloc> 588 tuple(allocator_arg_t __tag, const _Alloc& __a, const tuple& __in) 589 : _Inherited(__tag, __a, static_cast<const _Inherited&>(__in)) { } 590 591 template<typename _Alloc> 592 tuple(allocator_arg_t __tag, const _Alloc& __a, tuple&& __in) 593 : _Inherited(__tag, __a, static_cast<_Inherited&&>(__in)) { } 594 595 template<typename _Alloc, typename _U1, typename _U2> 596 tuple(allocator_arg_t __tag, const _Alloc& __a, 597 const tuple<_U1, _U2>& __in) 598 : _Inherited(__tag, __a, 599 static_cast<const _Tuple_impl<0, _U1, _U2>&>(__in)) 600 { } 601 602 template<typename _Alloc, typename _U1, typename _U2> 603 tuple(allocator_arg_t __tag, const _Alloc& __a, tuple<_U1, _U2>&& __in) 604 : _Inherited(__tag, __a, static_cast<_Tuple_impl<0, _U1, _U2>&&>(__in)) 605 { } 606 607 template<typename _Alloc, typename _U1, typename _U2> 608 tuple(allocator_arg_t __tag, const _Alloc& __a, 609 const pair<_U1, _U2>& __in) 610 : _Inherited(__tag, __a, __in.first, __in.second) { } 611 612 template<typename _Alloc, typename _U1, typename _U2> 613 tuple(allocator_arg_t __tag, const _Alloc& __a, pair<_U1, _U2>&& __in) 614 : _Inherited(__tag, __a, std::forward<_U1>(__in.first), 615 std::forward<_U2>(__in.second)) { } 616 617 tuple& 618 operator=(const tuple& __in) 619 { 620 static_cast<_Inherited&>(*this) = __in; 621 return *this; 622 } 623 624 tuple& 625 operator=(tuple&& __in) 626 noexcept(is_nothrow_move_assignable<_Inherited>::value) 627 { 628 static_cast<_Inherited&>(*this) = std::move(__in); 629 return *this; 630 } 631 632 template<typename _U1, typename _U2> 633 tuple& 634 operator=(const tuple<_U1, _U2>& __in) 635 { 636 static_cast<_Inherited&>(*this) = __in; 637 return *this; 638 } 639 640 template<typename _U1, typename _U2> 641 tuple& 642 operator=(tuple<_U1, _U2>&& __in) 643 { 644 static_cast<_Inherited&>(*this) = std::move(__in); 645 return *this; 646 } 647 648 template<typename _U1, typename _U2> 649 tuple& 650 operator=(const pair<_U1, _U2>& __in) 651 { 652 this->_M_head(*this) = __in.first; 653 this->_M_tail(*this)._M_head(*this) = __in.second; 654 return *this; 655 } 656 657 template<typename _U1, typename _U2> 658 tuple& 659 operator=(pair<_U1, _U2>&& __in) 660 { 661 this->_M_head(*this) = std::forward<_U1>(__in.first); 662 this->_M_tail(*this)._M_head(*this) = std::forward<_U2>(__in.second); 663 return *this; 664 } 665 666 void 667 swap(tuple& __in) 668 noexcept(noexcept(__in._M_swap(__in))) 669 { _Inherited::_M_swap(__in); } 670 }; 671 672 673 /// Gives the type of the ith element of a given tuple type. 674 template<std::size_t __i, typename _Tp> 675 struct tuple_element; 676 677 /** 678 * Recursive case for tuple_element: strip off the first element in 679 * the tuple and retrieve the (i-1)th element of the remaining tuple. 680 */ 681 template<std::size_t __i, typename _Head, typename... _Tail> 682 struct tuple_element<__i, tuple<_Head, _Tail...> > 683 : tuple_element<__i - 1, tuple<_Tail...> > { }; 684 685 /** 686 * Basis case for tuple_element: The first element is the one we're seeking. 687 */ 688 template<typename _Head, typename... _Tail> 689 struct tuple_element<0, tuple<_Head, _Tail...> > 690 { 691 typedef _Head type; 692 }; 693 694 template<std::size_t __i, typename _Tp> 695 struct tuple_element<__i, const _Tp> 696 { 697 typedef typename 698 add_const<typename tuple_element<__i, _Tp>::type>::type type; 699 }; 700 701 template<std::size_t __i, typename _Tp> 702 struct tuple_element<__i, volatile _Tp> 703 { 704 typedef typename 705 add_volatile<typename tuple_element<__i, _Tp>::type>::type type; 706 }; 707 708 template<std::size_t __i, typename _Tp> 709 struct tuple_element<__i, const volatile _Tp> 710 { 711 typedef typename 712 add_cv<typename tuple_element<__i, _Tp>::type>::type type; 713 }; 714 715 #if __cplusplus > 201103L 716 template<std::size_t __i, typename _Tp> 717 using tuple_element_t = typename tuple_element<__i, _Tp>::type; 718 #endif 719 720 /// Finds the size of a given tuple type. 721 template<typename _Tp> 722 struct tuple_size; 723 724 // _GLIBCXX_RESOLVE_LIB_DEFECTS 725 // 2313. tuple_size should always derive from integral_constant<size_t, N> 726 template<typename _Tp> 727 struct tuple_size<const _Tp> 728 : public integral_constant<size_t, tuple_size<_Tp>::value> { }; 729 730 template<typename _Tp> 731 struct tuple_size<volatile _Tp> 732 : public integral_constant<size_t, tuple_size<_Tp>::value> { }; 733 734 template<typename _Tp> 735 struct tuple_size<const volatile _Tp> 736 : public integral_constant<size_t, tuple_size<_Tp>::value> { }; 737 738 /// class tuple_size 739 template<typename... _Elements> 740 struct tuple_size<tuple<_Elements...>> 741 : public integral_constant<std::size_t, sizeof...(_Elements)> { }; 742 743 template<std::size_t __i, typename _Head, typename... _Tail> 744 constexpr typename __add_ref<_Head>::type 745 __get_helper(_Tuple_impl<__i, _Head, _Tail...>& __t) noexcept 746 { return _Tuple_impl<__i, _Head, _Tail...>::_M_head(__t); } 747 748 template<std::size_t __i, typename _Head, typename... _Tail> 749 constexpr typename __add_c_ref<_Head>::type 750 __get_helper(const _Tuple_impl<__i, _Head, _Tail...>& __t) noexcept 751 { return _Tuple_impl<__i, _Head, _Tail...>::_M_head(__t); } 752 753 /// Return a reference to the ith element of a tuple. 754 template<std::size_t __i, typename... _Elements> 755 constexpr typename __add_ref< 756 typename tuple_element<__i, tuple<_Elements...>>::type 757 >::type 758 get(tuple<_Elements...>& __t) noexcept 759 { return std::__get_helper<__i>(__t); } 760 761 /// Return a const reference to the ith element of a const tuple. 762 template<std::size_t __i, typename... _Elements> 763 constexpr typename __add_c_ref< 764 typename tuple_element<__i, tuple<_Elements...>>::type 765 >::type 766 get(const tuple<_Elements...>& __t) noexcept 767 { return std::__get_helper<__i>(__t); } 768 769 /// Return an rvalue reference to the ith element of a tuple rvalue. 770 template<std::size_t __i, typename... _Elements> 771 constexpr typename __add_r_ref< 772 typename tuple_element<__i, tuple<_Elements...>>::type 773 >::type 774 get(tuple<_Elements...>&& __t) noexcept 775 { return std::forward<typename tuple_element<__i, 776 tuple<_Elements...>>::type&&>(get<__i>(__t)); } 777 778 #if __cplusplus > 201103L 779 780 #define __cpp_lib_tuples_by_type 201304 781 782 template<typename _Head, size_t __i, typename... _Tail> 783 constexpr typename __add_ref<_Head>::type 784 __get_helper2(_Tuple_impl<__i, _Head, _Tail...>& __t) noexcept 785 { return _Tuple_impl<__i, _Head, _Tail...>::_M_head(__t); } 786 787 template<typename _Head, size_t __i, typename... _Tail> 788 constexpr typename __add_c_ref<_Head>::type 789 __get_helper2(const _Tuple_impl<__i, _Head, _Tail...>& __t) noexcept 790 { return _Tuple_impl<__i, _Head, _Tail...>::_M_head(__t); } 791 792 /// Return a reference to the unique element of type _Tp of a tuple. 793 template <typename _Tp, typename... _Types> 794 constexpr _Tp& 795 get(tuple<_Types...>& __t) noexcept 796 { return std::__get_helper2<_Tp>(__t); } 797 798 /// Return a reference to the unique element of type _Tp of a tuple rvalue. 799 template <typename _Tp, typename... _Types> 800 constexpr _Tp&& 801 get(tuple<_Types...>&& __t) noexcept 802 { return std::forward<_Tp&&>(std::__get_helper2<_Tp>(__t)); } 803 804 /// Return a const reference to the unique element of type _Tp of a tuple. 805 template <typename _Tp, typename... _Types> 806 constexpr const _Tp& 807 get(const tuple<_Types...>& __t) noexcept 808 { return std::__get_helper2<_Tp>(__t); } 809 #endif 810 811 812 // This class helps construct the various comparison operations on tuples 813 template<std::size_t __check_equal_size, std::size_t __i, std::size_t __j, 814 typename _Tp, typename _Up> 815 struct __tuple_compare; 816 817 template<std::size_t __i, std::size_t __j, typename _Tp, typename _Up> 818 struct __tuple_compare<0, __i, __j, _Tp, _Up> 819 { 820 static constexpr bool 821 __eq(const _Tp& __t, const _Up& __u) 822 { 823 return (get<__i>(__t) == get<__i>(__u) && 824 __tuple_compare<0, __i + 1, __j, _Tp, _Up>::__eq(__t, __u)); 825 } 826 827 static constexpr bool 828 __less(const _Tp& __t, const _Up& __u) 829 { 830 return ((get<__i>(__t) < get<__i>(__u)) 831 || !(get<__i>(__u) < get<__i>(__t)) && 832 __tuple_compare<0, __i + 1, __j, _Tp, _Up>::__less(__t, __u)); 833 } 834 }; 835 836 template<std::size_t __i, typename _Tp, typename _Up> 837 struct __tuple_compare<0, __i, __i, _Tp, _Up> 838 { 839 static constexpr bool 840 __eq(const _Tp&, const _Up&) { return true; } 841 842 static constexpr bool 843 __less(const _Tp&, const _Up&) { return false; } 844 }; 845 846 template<typename... _TElements, typename... _UElements> 847 constexpr bool 848 operator==(const tuple<_TElements...>& __t, 849 const tuple<_UElements...>& __u) 850 { 851 typedef tuple<_TElements...> _Tp; 852 typedef tuple<_UElements...> _Up; 853 return bool(__tuple_compare<tuple_size<_Tp>::value - tuple_size<_Up>::value, 854 0, tuple_size<_Tp>::value, _Tp, _Up>::__eq(__t, __u)); 855 } 856 857 template<typename... _TElements, typename... _UElements> 858 constexpr bool 859 operator<(const tuple<_TElements...>& __t, 860 const tuple<_UElements...>& __u) 861 { 862 typedef tuple<_TElements...> _Tp; 863 typedef tuple<_UElements...> _Up; 864 return bool(__tuple_compare<tuple_size<_Tp>::value - tuple_size<_Up>::value, 865 0, tuple_size<_Tp>::value, _Tp, _Up>::__less(__t, __u)); 866 } 867 868 template<typename... _TElements, typename... _UElements> 869 constexpr bool 870 operator!=(const tuple<_TElements...>& __t, 871 const tuple<_UElements...>& __u) 872 { return !(__t == __u); } 873 874 template<typename... _TElements, typename... _UElements> 875 constexpr bool 876 operator>(const tuple<_TElements...>& __t, 877 const tuple<_UElements...>& __u) 878 { return __u < __t; } 879 880 template<typename... _TElements, typename... _UElements> 881 constexpr bool 882 operator<=(const tuple<_TElements...>& __t, 883 const tuple<_UElements...>& __u) 884 { return !(__u < __t); } 885 886 template<typename... _TElements, typename... _UElements> 887 constexpr bool 888 operator>=(const tuple<_TElements...>& __t, 889 const tuple<_UElements...>& __u) 890 { return !(__t < __u); } 891 892 // NB: DR 705. 893 template<typename... _Elements> 894 constexpr tuple<typename __decay_and_strip<_Elements>::__type...> 895 make_tuple(_Elements&&... __args) 896 { 897 typedef tuple<typename __decay_and_strip<_Elements>::__type...> 898 __result_type; 899 return __result_type(std::forward<_Elements>(__args)...); 900 } 901 902 template<typename... _Elements> 903 tuple<_Elements&&...> 904 forward_as_tuple(_Elements&&... __args) noexcept 905 { return tuple<_Elements&&...>(std::forward<_Elements>(__args)...); } 906 907 template<typename> 908 struct __is_tuple_like_impl : false_type 909 { }; 910 911 template<typename... _Tps> 912 struct __is_tuple_like_impl<tuple<_Tps...>> : true_type 913 { }; 914 915 template<typename _T1, typename _T2> 916 struct __is_tuple_like_impl<pair<_T1, _T2>> : true_type 917 { }; 918 919 template<typename _Tp, std::size_t _Nm> 920 struct __is_tuple_like_impl<array<_Tp, _Nm>> : true_type 921 { }; 922 923 // Internal type trait that allows us to sfinae-protect tuple_cat. 924 template<typename _Tp> 925 struct __is_tuple_like 926 : public __is_tuple_like_impl<typename std::remove_cv 927 <typename std::remove_reference<_Tp>::type>::type>::type 928 { }; 929 930 template<std::size_t, typename, typename, std::size_t> 931 struct __make_tuple_impl; 932 933 template<std::size_t _Idx, typename _Tuple, typename... _Tp, 934 std::size_t _Nm> 935 struct __make_tuple_impl<_Idx, tuple<_Tp...>, _Tuple, _Nm> 936 { 937 typedef typename __make_tuple_impl<_Idx + 1, tuple<_Tp..., 938 typename std::tuple_element<_Idx, _Tuple>::type>, _Tuple, _Nm>::__type 939 __type; 940 }; 941 942 template<std::size_t _Nm, typename _Tuple, typename... _Tp> 943 struct __make_tuple_impl<_Nm, tuple<_Tp...>, _Tuple, _Nm> 944 { 945 typedef tuple<_Tp...> __type; 946 }; 947 948 template<typename _Tuple> 949 struct __do_make_tuple 950 : public __make_tuple_impl<0, tuple<>, _Tuple, 951 std::tuple_size<_Tuple>::value> 952 { }; 953 954 // Returns the std::tuple equivalent of a tuple-like type. 955 template<typename _Tuple> 956 struct __make_tuple 957 : public __do_make_tuple<typename std::remove_cv 958 <typename std::remove_reference<_Tuple>::type>::type> 959 { }; 960 961 // Combines several std::tuple's into a single one. 962 template<typename...> 963 struct __combine_tuples; 964 965 template<> 966 struct __combine_tuples<> 967 { 968 typedef tuple<> __type; 969 }; 970 971 template<typename... _Ts> 972 struct __combine_tuples<tuple<_Ts...>> 973 { 974 typedef tuple<_Ts...> __type; 975 }; 976 977 template<typename... _T1s, typename... _T2s, typename... _Rem> 978 struct __combine_tuples<tuple<_T1s...>, tuple<_T2s...>, _Rem...> 979 { 980 typedef typename __combine_tuples<tuple<_T1s..., _T2s...>, 981 _Rem...>::__type __type; 982 }; 983 984 // Computes the result type of tuple_cat given a set of tuple-like types. 985 template<typename... _Tpls> 986 struct __tuple_cat_result 987 { 988 typedef typename __combine_tuples 989 <typename __make_tuple<_Tpls>::__type...>::__type __type; 990 }; 991 992 // Helper to determine the index set for the first tuple-like 993 // type of a given set. 994 template<typename...> 995 struct __make_1st_indices; 996 997 template<> 998 struct __make_1st_indices<> 999 { 1000 typedef std::_Index_tuple<> __type; 1001 }; 1002 1003 template<typename _Tp, typename... _Tpls> 1004 struct __make_1st_indices<_Tp, _Tpls...> 1005 { 1006 typedef typename std::_Build_index_tuple<std::tuple_size< 1007 typename std::remove_reference<_Tp>::type>::value>::__type __type; 1008 }; 1009 1010 // Performs the actual concatenation by step-wise expanding tuple-like 1011 // objects into the elements, which are finally forwarded into the 1012 // result tuple. 1013 template<typename _Ret, typename _Indices, typename... _Tpls> 1014 struct __tuple_concater; 1015 1016 template<typename _Ret, std::size_t... _Is, typename _Tp, typename... _Tpls> 1017 struct __tuple_concater<_Ret, std::_Index_tuple<_Is...>, _Tp, _Tpls...> 1018 { 1019 template<typename... _Us> 1020 static constexpr _Ret 1021 _S_do(_Tp&& __tp, _Tpls&&... __tps, _Us&&... __us) 1022 { 1023 typedef typename __make_1st_indices<_Tpls...>::__type __idx; 1024 typedef __tuple_concater<_Ret, __idx, _Tpls...> __next; 1025 return __next::_S_do(std::forward<_Tpls>(__tps)..., 1026 std::forward<_Us>(__us)..., 1027 std::get<_Is>(std::forward<_Tp>(__tp))...); 1028 } 1029 }; 1030 1031 template<typename _Ret> 1032 struct __tuple_concater<_Ret, std::_Index_tuple<>> 1033 { 1034 template<typename... _Us> 1035 static constexpr _Ret 1036 _S_do(_Us&&... __us) 1037 { 1038 return _Ret(std::forward<_Us>(__us)...); 1039 } 1040 }; 1041 1042 /// tuple_cat 1043 template<typename... _Tpls, typename = typename 1044 enable_if<__and_<__is_tuple_like<_Tpls>...>::value>::type> 1045 constexpr auto 1046 tuple_cat(_Tpls&&... __tpls) 1047 -> typename __tuple_cat_result<_Tpls...>::__type 1048 { 1049 typedef typename __tuple_cat_result<_Tpls...>::__type __ret; 1050 typedef typename __make_1st_indices<_Tpls...>::__type __idx; 1051 typedef __tuple_concater<__ret, __idx, _Tpls...> __concater; 1052 return __concater::_S_do(std::forward<_Tpls>(__tpls)...); 1053 } 1054 1055 /// tie 1056 template<typename... _Elements> 1057 inline tuple<_Elements&...> 1058 tie(_Elements&... __args) noexcept 1059 { return tuple<_Elements&...>(__args...); } 1060 1061 /// swap 1062 template<typename... _Elements> 1063 inline void 1064 swap(tuple<_Elements...>& __x, tuple<_Elements...>& __y) 1065 noexcept(noexcept(__x.swap(__y))) 1066 { __x.swap(__y); } 1067 1068 // A class (and instance) which can be used in 'tie' when an element 1069 // of a tuple is not required 1070 struct _Swallow_assign 1071 { 1072 template<class _Tp> 1073 const _Swallow_assign& 1074 operator=(const _Tp&) const 1075 { return *this; } 1076 }; 1077 1078 const _Swallow_assign ignore{}; 1079 1080 /// Partial specialization for tuples 1081 template<typename... _Types, typename _Alloc> 1082 struct uses_allocator<tuple<_Types...>, _Alloc> : true_type { }; 1083 1084 // See stl_pair.h... 1085 template<class _T1, class _T2> 1086 template<typename... _Args1, typename... _Args2> 1087 inline 1088 pair<_T1, _T2>:: 1089 pair(piecewise_construct_t, 1090 tuple<_Args1...> __first, tuple<_Args2...> __second) 1091 : pair(__first, __second, 1092 typename _Build_index_tuple<sizeof...(_Args1)>::__type(), 1093 typename _Build_index_tuple<sizeof...(_Args2)>::__type()) 1094 { } 1095 1096 template<class _T1, class _T2> 1097 template<typename... _Args1, std::size_t... _Indexes1, 1098 typename... _Args2, std::size_t... _Indexes2> 1099 inline 1100 pair<_T1, _T2>:: 1101 pair(tuple<_Args1...>& __tuple1, tuple<_Args2...>& __tuple2, 1102 _Index_tuple<_Indexes1...>, _Index_tuple<_Indexes2...>) 1103 : first(std::forward<_Args1>(std::get<_Indexes1>(__tuple1))...), 1104 second(std::forward<_Args2>(std::get<_Indexes2>(__tuple2))...) 1105 { } 1106 1107 /// @} 1108 1109 _GLIBCXX_END_NAMESPACE_VERSION 1110 } // namespace std 1111 1112 #endif // C++11 1113 1114 #endif // _GLIBCXX_TUPLE 1115
