3 // Copyright (C) 2007-2016 Free Software Foundation, Inc.
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)
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.
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.
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/>.
25 /** @file include/tuple
26 * This is a Standard C++ Library header.
29 #ifndef _GLIBCXX_TUPLE
30 #define _GLIBCXX_TUPLE 1
32 #pragma GCC system_header
34 #if __cplusplus < 201103L
35 # include <bits/c++0x_warning.h>
40 #include <bits/uses_allocator.h>
42 namespace std _GLIBCXX_VISIBILITY(default)
44 _GLIBCXX_BEGIN_NAMESPACE_VERSION
47 * @addtogroup utilities
51 template<std::size_t _Idx, typename _Head, bool _IsEmptyNotFinal>
54 template<std::size_t _Idx, typename _Head>
55 struct _Head_base<_Idx, _Head, true>
58 constexpr _Head_base()
61 constexpr _Head_base(const _Head& __h)
64 constexpr _Head_base(const _Head_base&) = default;
65 constexpr _Head_base(_Head_base&&) = default;
67 template<typename _UHead>
68 constexpr _Head_base(_UHead&& __h)
69 : _Head(std::forward<_UHead>(__h)) { }
71 _Head_base(allocator_arg_t, __uses_alloc0)
74 template<typename _Alloc>
75 _Head_base(allocator_arg_t, __uses_alloc1<_Alloc> __a)
76 : _Head(allocator_arg, *__a._M_a) { }
78 template<typename _Alloc>
79 _Head_base(allocator_arg_t, __uses_alloc2<_Alloc> __a)
80 : _Head(*__a._M_a) { }
82 template<typename _UHead>
83 _Head_base(__uses_alloc0, _UHead&& __uhead)
84 : _Head(std::forward<_UHead>(__uhead)) { }
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)) { }
90 template<typename _Alloc, typename _UHead>
91 _Head_base(__uses_alloc2<_Alloc> __a, _UHead&& __uhead)
92 : _Head(std::forward<_UHead>(__uhead), *__a._M_a) { }
94 static constexpr _Head&
95 _M_head(_Head_base& __b) noexcept { return __b; }
97 static constexpr const _Head&
98 _M_head(const _Head_base& __b) noexcept { return __b; }
101 template<std::size_t _Idx, typename _Head>
102 struct _Head_base<_Idx, _Head, false>
104 constexpr _Head_base()
107 constexpr _Head_base(const _Head& __h)
108 : _M_head_impl(__h) { }
110 constexpr _Head_base(const _Head_base&) = default;
111 constexpr _Head_base(_Head_base&&) = default;
113 template<typename _UHead>
114 constexpr _Head_base(_UHead&& __h)
115 : _M_head_impl(std::forward<_UHead>(__h)) { }
117 _Head_base(allocator_arg_t, __uses_alloc0)
120 template<typename _Alloc>
121 _Head_base(allocator_arg_t, __uses_alloc1<_Alloc> __a)
122 : _M_head_impl(allocator_arg, *__a._M_a) { }
124 template<typename _Alloc>
125 _Head_base(allocator_arg_t, __uses_alloc2<_Alloc> __a)
126 : _M_head_impl(*__a._M_a) { }
128 template<typename _UHead>
129 _Head_base(__uses_alloc0, _UHead&& __uhead)
130 : _M_head_impl(std::forward<_UHead>(__uhead)) { }
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))
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) { }
141 static constexpr _Head&
142 _M_head(_Head_base& __b) noexcept { return __b._M_head_impl; }
144 static constexpr const _Head&
145 _M_head(const _Head_base& __b) noexcept { return __b._M_head_impl; }
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
158 template<std::size_t _Idx, typename... _Elements>
161 template<typename _Tp>
162 struct __is_empty_non_tuple : is_empty<_Tp> { };
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 { };
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;
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).
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>
184 template<std::size_t, typename...> friend class _Tuple_impl;
186 typedef _Tuple_impl<_Idx + 1, _Tail...> _Inherited;
187 typedef _Head_base<_Idx, _Head, __empty_not_final<_Head>::value> _Base;
189 static constexpr _Head&
190 _M_head(_Tuple_impl& __t) noexcept { return _Base::_M_head(__t); }
192 static constexpr const _Head&
193 _M_head(const _Tuple_impl& __t) noexcept { return _Base::_M_head(__t); }
195 static constexpr _Inherited&
196 _M_tail(_Tuple_impl& __t) noexcept { return __t; }
198 static constexpr const _Inherited&
199 _M_tail(const _Tuple_impl& __t) noexcept { return __t; }
201 constexpr _Tuple_impl()
202 : _Inherited(), _Base() { }
205 constexpr _Tuple_impl(const _Head& __head, const _Tail&... __tail)
206 : _Inherited(__tail...), _Base(__head) { }
208 template<typename _UHead, typename... _UTail, typename = typename
209 enable_if<sizeof...(_Tail) == sizeof...(_UTail)>::type>
211 constexpr _Tuple_impl(_UHead&& __head, _UTail&&... __tail)
212 : _Inherited(std::forward<_UTail>(__tail)...),
213 _Base(std::forward<_UHead>(__head)) { }
215 constexpr _Tuple_impl(const _Tuple_impl&) = default;
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))) { }
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)) { }
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))) { }
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)) { }
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) { }
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)) { }
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)) { }
262 template<typename _Alloc>
263 _Tuple_impl(allocator_arg_t __tag, const _Alloc& __a,
265 : _Inherited(__tag, __a, std::move(_M_tail(__in))),
266 _Base(__use_alloc<_Head, _Alloc, _Head>(__a),
267 std::forward<_Head>(_M_head(__in))) { }
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)) { }
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),
284 (_Tuple_impl<_Idx, _UHead, _UTails...>::_M_head(__in))) { }
287 operator=(const _Tuple_impl& __in)
289 _M_head(*this) = _M_head(__in);
290 _M_tail(*this) = _M_tail(__in);
295 operator=(_Tuple_impl&& __in)
296 noexcept(__and_<is_nothrow_move_assignable<_Head>,
297 is_nothrow_move_assignable<_Inherited>>::value)
299 _M_head(*this) = std::forward<_Head>(_M_head(__in));
300 _M_tail(*this) = std::move(_M_tail(__in));
304 template<typename... _UElements>
306 operator=(const _Tuple_impl<_Idx, _UElements...>& __in)
308 _M_head(*this) = _Tuple_impl<_Idx, _UElements...>::_M_head(__in);
309 _M_tail(*this) = _Tuple_impl<_Idx, _UElements...>::_M_tail(__in);
313 template<typename _UHead, typename... _UTails>
315 operator=(_Tuple_impl<_Idx, _UHead, _UTails...>&& __in)
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));
326 _M_swap(_Tuple_impl& __in)
327 noexcept(__is_nothrow_swappable<_Head>::value
328 && noexcept(_M_tail(__in)._M_swap(_M_tail(__in))))
331 swap(_M_head(*this), _M_head(__in));
332 _Inherited::_M_swap(_M_tail(__in));
336 // Basis case of inheritance recursion.
337 template<std::size_t _Idx, typename _Head>
338 struct _Tuple_impl<_Idx, _Head>
339 : private _Head_base<_Idx, _Head, __empty_not_final<_Head>::value>
341 template<std::size_t, typename...> friend class _Tuple_impl;
343 typedef _Head_base<_Idx, _Head, __empty_not_final<_Head>::value> _Base;
345 static constexpr _Head&
346 _M_head(_Tuple_impl& __t) noexcept { return _Base::_M_head(__t); }
348 static constexpr const _Head&
349 _M_head(const _Tuple_impl& __t) noexcept { return _Base::_M_head(__t); }
351 constexpr _Tuple_impl()
355 constexpr _Tuple_impl(const _Head& __head)
358 template<typename _UHead>
360 constexpr _Tuple_impl(_UHead&& __head)
361 : _Base(std::forward<_UHead>(__head)) { }
363 constexpr _Tuple_impl(const _Tuple_impl&) = default;
366 _Tuple_impl(_Tuple_impl&& __in)
367 noexcept(is_nothrow_move_constructible<_Head>::value)
368 : _Base(std::forward<_Head>(_M_head(__in))) { }
370 template<typename _UHead>
371 constexpr _Tuple_impl(const _Tuple_impl<_Idx, _UHead>& __in)
372 : _Base(_Tuple_impl<_Idx, _UHead>::_M_head(__in)) { }
374 template<typename _UHead>
375 constexpr _Tuple_impl(_Tuple_impl<_Idx, _UHead>&& __in)
376 : _Base(std::forward<_UHead>(_Tuple_impl<_Idx, _UHead>::_M_head(__in)))
379 template<typename _Alloc>
380 _Tuple_impl(allocator_arg_t __tag, const _Alloc& __a)
381 : _Base(__tag, __use_alloc<_Head>(__a)) { }
383 template<typename _Alloc>
384 _Tuple_impl(allocator_arg_t __tag, const _Alloc& __a,
386 : _Base(__use_alloc<_Head, _Alloc, _Head>(__a), __head) { }
388 template<typename _Alloc, typename _UHead>
389 _Tuple_impl(allocator_arg_t __tag, const _Alloc& __a,
391 : _Base(__use_alloc<_Head, _Alloc, _UHead>(__a),
392 std::forward<_UHead>(__head)) { }
394 template<typename _Alloc>
395 _Tuple_impl(allocator_arg_t __tag, const _Alloc& __a,
396 const _Tuple_impl& __in)
397 : _Base(__use_alloc<_Head, _Alloc, _Head>(__a), _M_head(__in)) { }
399 template<typename _Alloc>
400 _Tuple_impl(allocator_arg_t __tag, const _Alloc& __a,
402 : _Base(__use_alloc<_Head, _Alloc, _Head>(__a),
403 std::forward<_Head>(_M_head(__in))) { }
405 template<typename _Alloc, typename _UHead>
406 _Tuple_impl(allocator_arg_t __tag, const _Alloc& __a,
407 const _Tuple_impl<_Idx, _UHead>& __in)
408 : _Base(__use_alloc<_Head, _Alloc, _Head>(__a),
409 _Tuple_impl<_Idx, _UHead>::_M_head(__in)) { }
411 template<typename _Alloc, typename _UHead>
412 _Tuple_impl(allocator_arg_t __tag, const _Alloc& __a,
413 _Tuple_impl<_Idx, _UHead>&& __in)
414 : _Base(__use_alloc<_Head, _Alloc, _UHead>(__a),
415 std::forward<_UHead>(_Tuple_impl<_Idx, _UHead>::_M_head(__in)))
419 operator=(const _Tuple_impl& __in)
421 _M_head(*this) = _M_head(__in);
426 operator=(_Tuple_impl&& __in)
427 noexcept(is_nothrow_move_assignable<_Head>::value)
429 _M_head(*this) = std::forward<_Head>(_M_head(__in));
433 template<typename _UHead>
435 operator=(const _Tuple_impl<_Idx, _UHead>& __in)
437 _M_head(*this) = _Tuple_impl<_Idx, _UHead>::_M_head(__in);
441 template<typename _UHead>
443 operator=(_Tuple_impl<_Idx, _UHead>&& __in)
446 = std::forward<_UHead>(_Tuple_impl<_Idx, _UHead>::_M_head(__in));
452 _M_swap(_Tuple_impl& __in)
453 noexcept(__is_nothrow_swappable<_Head>::value)
456 swap(_M_head(*this), _M_head(__in));
460 template<typename... _Elements>
463 // Concept utility functions, reused in conditionally-explicit
465 template<bool, typename... _Elements>
468 template<typename... _UElements>
469 static constexpr bool _ConstructibleTuple()
471 return __and_<is_constructible<_Elements, const _UElements&>...>::value;
474 template<typename... _UElements>
475 static constexpr bool _ImplicitlyConvertibleTuple()
477 return __and_<is_convertible<const _UElements&, _Elements>...>::value;
480 template<typename... _UElements>
481 static constexpr bool _MoveConstructibleTuple()
483 return __and_<is_constructible<_Elements, _UElements&&>...>::value;
486 template<typename... _UElements>
487 static constexpr bool _ImplicitlyMoveConvertibleTuple()
489 return __and_<is_convertible<_UElements&&, _Elements>...>::value;
492 template<typename _SrcTuple>
493 static constexpr bool _NonNestedTuple()
495 return __and_<__not_<is_same<tuple<_Elements...>,
497 typename remove_reference<_SrcTuple>::type
499 __not_<is_convertible<_SrcTuple, _Elements...>>,
500 __not_<is_constructible<_Elements..., _SrcTuple>>
503 template<typename... _UElements>
504 static constexpr bool _NotSameTuple()
506 return __not_<is_same<tuple<_Elements...>,
507 typename remove_const<
508 typename remove_reference<_UElements...>::type
513 template<typename... _Elements>
514 struct _TC<false, _Elements...>
516 template<typename... _UElements>
517 static constexpr bool _ConstructibleTuple()
522 template<typename... _UElements>
523 static constexpr bool _ImplicitlyConvertibleTuple()
528 template<typename... _UElements>
529 static constexpr bool _MoveConstructibleTuple()
534 template<typename... _UElements>
535 static constexpr bool _ImplicitlyMoveConvertibleTuple()
540 template<typename... _UElements>
541 static constexpr bool _NonNestedTuple()
545 template<typename... _UElements>
546 static constexpr bool _NotSameTuple()
552 /// Primary class template, tuple
553 template<typename... _Elements>
554 class tuple : public _Tuple_impl<0, _Elements...>
556 typedef _Tuple_impl<0, _Elements...> _Inherited;
558 // Used for constraining the default constructor so
559 // that it becomes dependent on the constraints.
560 template<typename _Dummy>
563 static constexpr bool _DefaultConstructibleTuple()
565 return __and_<is_default_constructible<_Elements>...>::value;
567 static constexpr bool _ImplicitlyDefaultConstructibleTuple()
569 return __and_<__is_implicitly_default_constructible<_Elements>...>
575 template<typename _Dummy = void,
576 typename enable_if<_TC2<_Dummy>::
577 _ImplicitlyDefaultConstructibleTuple(),
582 template<typename _Dummy = void,
583 typename enable_if<_TC2<_Dummy>::
584 _DefaultConstructibleTuple()
587 _ImplicitlyDefaultConstructibleTuple(),
589 explicit constexpr tuple()
592 // Shortcut for the cases where constructors taking _Elements...
593 // need to be constrained.
594 template<typename _Dummy> using _TCC =
595 _TC<is_same<_Dummy, void>::value,
598 template<typename _Dummy = void,
600 _TCC<_Dummy>::template
601 _ConstructibleTuple<_Elements...>()
602 && _TCC<_Dummy>::template
603 _ImplicitlyConvertibleTuple<_Elements...>()
604 && (sizeof...(_Elements) >= 1),
606 constexpr tuple(const _Elements&... __elements)
607 : _Inherited(__elements...) { }
609 template<typename _Dummy = void,
611 _TCC<_Dummy>::template
612 _ConstructibleTuple<_Elements...>()
613 && !_TCC<_Dummy>::template
614 _ImplicitlyConvertibleTuple<_Elements...>()
615 && (sizeof...(_Elements) >= 1),
617 explicit constexpr tuple(const _Elements&... __elements)
618 : _Inherited(__elements...) { }
620 // Shortcut for the cases where constructors taking _UElements...
621 // need to be constrained.
622 template<typename... _UElements> using _TMC =
623 _TC<(sizeof...(_Elements) == sizeof...(_UElements)),
626 template<typename... _UElements, typename
628 _TC<sizeof...(_UElements) == 1, _Elements...>::template
629 _NotSameTuple<_UElements...>()
630 && _TMC<_UElements...>::template
631 _MoveConstructibleTuple<_UElements...>()
632 && _TMC<_UElements...>::template
633 _ImplicitlyMoveConvertibleTuple<_UElements...>()
634 && (sizeof...(_Elements) >= 1),
636 constexpr tuple(_UElements&&... __elements)
637 : _Inherited(std::forward<_UElements>(__elements)...) { }
639 template<typename... _UElements, typename
641 _TC<sizeof...(_UElements) == 1, _Elements...>::template
642 _NotSameTuple<_UElements...>()
643 && _TMC<_UElements...>::template
644 _MoveConstructibleTuple<_UElements...>()
645 && !_TMC<_UElements...>::template
646 _ImplicitlyMoveConvertibleTuple<_UElements...>()
647 && (sizeof...(_Elements) >= 1),
649 explicit constexpr tuple(_UElements&&... __elements)
650 : _Inherited(std::forward<_UElements>(__elements)...) { }
652 constexpr tuple(const tuple&) = default;
654 constexpr tuple(tuple&&) = default;
656 // Shortcut for the cases where constructors taking tuples
657 // must avoid creating temporaries.
658 template<typename _Dummy> using _TNTC =
659 _TC<is_same<_Dummy, void>::value && sizeof...(_Elements) == 1,
662 template<typename... _UElements, typename _Dummy = void, typename
663 enable_if<_TMC<_UElements...>::template
664 _ConstructibleTuple<_UElements...>()
665 && _TMC<_UElements...>::template
666 _ImplicitlyConvertibleTuple<_UElements...>()
667 && _TNTC<_Dummy>::template
668 _NonNestedTuple<const tuple<_UElements...>&>(),
670 constexpr tuple(const tuple<_UElements...>& __in)
671 : _Inherited(static_cast<const _Tuple_impl<0, _UElements...>&>(__in))
674 template<typename... _UElements, typename _Dummy = void, typename
675 enable_if<_TMC<_UElements...>::template
676 _ConstructibleTuple<_UElements...>()
677 && !_TMC<_UElements...>::template
678 _ImplicitlyConvertibleTuple<_UElements...>()
679 && _TNTC<_Dummy>::template
680 _NonNestedTuple<const tuple<_UElements...>&>(),
682 explicit constexpr tuple(const tuple<_UElements...>& __in)
683 : _Inherited(static_cast<const _Tuple_impl<0, _UElements...>&>(__in))
686 template<typename... _UElements, typename _Dummy = void, typename
687 enable_if<_TMC<_UElements...>::template
688 _MoveConstructibleTuple<_UElements...>()
689 && _TMC<_UElements...>::template
690 _ImplicitlyMoveConvertibleTuple<_UElements...>()
691 && _TNTC<_Dummy>::template
692 _NonNestedTuple<tuple<_UElements...>&&>(),
694 constexpr tuple(tuple<_UElements...>&& __in)
695 : _Inherited(static_cast<_Tuple_impl<0, _UElements...>&&>(__in)) { }
697 template<typename... _UElements, typename _Dummy = void, typename
698 enable_if<_TMC<_UElements...>::template
699 _MoveConstructibleTuple<_UElements...>()
700 && !_TMC<_UElements...>::template
701 _ImplicitlyMoveConvertibleTuple<_UElements...>()
702 && _TNTC<_Dummy>::template
703 _NonNestedTuple<tuple<_UElements...>&&>(),
705 explicit constexpr tuple(tuple<_UElements...>&& __in)
706 : _Inherited(static_cast<_Tuple_impl<0, _UElements...>&&>(__in)) { }
708 // Allocator-extended constructors.
710 template<typename _Alloc>
711 tuple(allocator_arg_t __tag, const _Alloc& __a)
712 : _Inherited(__tag, __a) { }
714 template<typename _Alloc, typename _Dummy = void,
716 _TCC<_Dummy>::template
717 _ConstructibleTuple<_Elements...>()
718 && _TCC<_Dummy>::template
719 _ImplicitlyConvertibleTuple<_Elements...>(),
721 tuple(allocator_arg_t __tag, const _Alloc& __a,
722 const _Elements&... __elements)
723 : _Inherited(__tag, __a, __elements...) { }
725 template<typename _Alloc, typename _Dummy = void,
727 _TCC<_Dummy>::template
728 _ConstructibleTuple<_Elements...>()
729 && !_TCC<_Dummy>::template
730 _ImplicitlyConvertibleTuple<_Elements...>(),
732 explicit tuple(allocator_arg_t __tag, const _Alloc& __a,
733 const _Elements&... __elements)
734 : _Inherited(__tag, __a, __elements...) { }
736 template<typename _Alloc, typename... _UElements, typename
737 enable_if<_TMC<_UElements...>::template
738 _MoveConstructibleTuple<_UElements...>()
739 && _TMC<_UElements...>::template
740 _ImplicitlyMoveConvertibleTuple<_UElements...>(),
742 tuple(allocator_arg_t __tag, const _Alloc& __a,
743 _UElements&&... __elements)
744 : _Inherited(__tag, __a, std::forward<_UElements>(__elements)...)
747 template<typename _Alloc, typename... _UElements, typename
748 enable_if<_TMC<_UElements...>::template
749 _MoveConstructibleTuple<_UElements...>()
750 && !_TMC<_UElements...>::template
751 _ImplicitlyMoveConvertibleTuple<_UElements...>(),
753 explicit tuple(allocator_arg_t __tag, const _Alloc& __a,
754 _UElements&&... __elements)
755 : _Inherited(__tag, __a, std::forward<_UElements>(__elements)...)
758 template<typename _Alloc>
759 tuple(allocator_arg_t __tag, const _Alloc& __a, const tuple& __in)
760 : _Inherited(__tag, __a, static_cast<const _Inherited&>(__in)) { }
762 template<typename _Alloc>
763 tuple(allocator_arg_t __tag, const _Alloc& __a, tuple&& __in)
764 : _Inherited(__tag, __a, static_cast<_Inherited&&>(__in)) { }
766 template<typename _Alloc, typename... _UElements, typename
767 enable_if<_TMC<_UElements...>::template
768 _ConstructibleTuple<_UElements...>()
769 && _TMC<_UElements...>::template
770 _ImplicitlyConvertibleTuple<_UElements...>(),
772 tuple(allocator_arg_t __tag, const _Alloc& __a,
773 const tuple<_UElements...>& __in)
774 : _Inherited(__tag, __a,
775 static_cast<const _Tuple_impl<0, _UElements...>&>(__in))
778 template<typename _Alloc, typename... _UElements, typename
779 enable_if<_TMC<_UElements...>::template
780 _ConstructibleTuple<_UElements...>()
781 && !_TMC<_UElements...>::template
782 _ImplicitlyConvertibleTuple<_UElements...>(),
784 explicit tuple(allocator_arg_t __tag, const _Alloc& __a,
785 const tuple<_UElements...>& __in)
786 : _Inherited(__tag, __a,
787 static_cast<const _Tuple_impl<0, _UElements...>&>(__in))
790 template<typename _Alloc, typename... _UElements, typename
791 enable_if<_TMC<_UElements...>::template
792 _MoveConstructibleTuple<_UElements...>()
793 && _TMC<_UElements...>::template
794 _ImplicitlyMoveConvertibleTuple<_UElements...>(),
796 tuple(allocator_arg_t __tag, const _Alloc& __a,
797 tuple<_UElements...>&& __in)
798 : _Inherited(__tag, __a,
799 static_cast<_Tuple_impl<0, _UElements...>&&>(__in))
802 template<typename _Alloc, typename... _UElements, typename
803 enable_if<_TMC<_UElements...>::template
804 _MoveConstructibleTuple<_UElements...>()
805 && !_TMC<_UElements...>::template
806 _ImplicitlyMoveConvertibleTuple<_UElements...>(),
808 explicit tuple(allocator_arg_t __tag, const _Alloc& __a,
809 tuple<_UElements...>&& __in)
810 : _Inherited(__tag, __a,
811 static_cast<_Tuple_impl<0, _UElements...>&&>(__in))
815 operator=(const tuple& __in)
817 static_cast<_Inherited&>(*this) = __in;
822 operator=(tuple&& __in)
823 noexcept(is_nothrow_move_assignable<_Inherited>::value)
825 static_cast<_Inherited&>(*this) = std::move(__in);
829 template<typename... _UElements, typename = typename
830 enable_if<sizeof...(_UElements)
831 == sizeof...(_Elements)>::type>
833 operator=(const tuple<_UElements...>& __in)
835 static_cast<_Inherited&>(*this) = __in;
839 template<typename... _UElements, typename = typename
840 enable_if<sizeof...(_UElements)
841 == sizeof...(_Elements)>::type>
843 operator=(tuple<_UElements...>&& __in)
845 static_cast<_Inherited&>(*this) = std::move(__in);
851 noexcept(noexcept(__in._M_swap(__in)))
852 { _Inherited::_M_swap(__in); }
855 // Explicit specialization, zero-element tuple.
860 void swap(tuple&) noexcept { /* no-op */ }
863 /// Partial specialization, 2-element tuple.
864 /// Includes construction and assignment from a pair.
865 template<typename _T1, typename _T2>
866 class tuple<_T1, _T2> : public _Tuple_impl<0, _T1, _T2>
868 typedef _Tuple_impl<0, _T1, _T2> _Inherited;
871 template <typename _U1 = _T1,
873 typename enable_if<__and_<
874 __is_implicitly_default_constructible<_U1>,
875 __is_implicitly_default_constructible<_U2>>
876 ::value, bool>::type = true>
881 template <typename _U1 = _T1,
885 is_default_constructible<_U1>,
886 is_default_constructible<_U2>,
888 __and_<__is_implicitly_default_constructible<_U1>,
889 __is_implicitly_default_constructible<_U2>>>>
890 ::value, bool>::type = false>
892 explicit constexpr tuple()
895 // Shortcut for the cases where constructors taking _T1, _T2
896 // need to be constrained.
897 template<typename _Dummy> using _TCC =
898 _TC<is_same<_Dummy, void>::value, _T1, _T2>;
900 template<typename _Dummy = void, typename
901 enable_if<_TCC<_Dummy>::template
902 _ConstructibleTuple<_T1, _T2>()
903 && _TCC<_Dummy>::template
904 _ImplicitlyConvertibleTuple<_T1, _T2>(),
906 constexpr tuple(const _T1& __a1, const _T2& __a2)
907 : _Inherited(__a1, __a2) { }
909 template<typename _Dummy = void, typename
910 enable_if<_TCC<_Dummy>::template
911 _ConstructibleTuple<_T1, _T2>()
912 && !_TCC<_Dummy>::template
913 _ImplicitlyConvertibleTuple<_T1, _T2>(),
915 explicit constexpr tuple(const _T1& __a1, const _T2& __a2)
916 : _Inherited(__a1, __a2) { }
918 // Shortcut for the cases where constructors taking _U1, _U2
919 // need to be constrained.
920 using _TMC = _TC<true, _T1, _T2>;
922 template<typename _U1, typename _U2, typename
923 enable_if<_TMC::template
924 _MoveConstructibleTuple<_U1, _U2>()
926 _ImplicitlyMoveConvertibleTuple<_U1, _U2>(),
928 constexpr tuple(_U1&& __a1, _U2&& __a2)
929 : _Inherited(std::forward<_U1>(__a1), std::forward<_U2>(__a2)) { }
931 template<typename _U1, typename _U2, typename
932 enable_if<_TMC::template
933 _MoveConstructibleTuple<_U1, _U2>()
935 _ImplicitlyMoveConvertibleTuple<_U1, _U2>(),
937 explicit constexpr tuple(_U1&& __a1, _U2&& __a2)
938 : _Inherited(std::forward<_U1>(__a1), std::forward<_U2>(__a2)) { }
940 constexpr tuple(const tuple&) = default;
942 constexpr tuple(tuple&&) = default;
944 template<typename _U1, typename _U2, typename
945 enable_if<_TMC::template
946 _ConstructibleTuple<_U1, _U2>()
948 _ImplicitlyConvertibleTuple<_U1, _U2>(),
950 constexpr tuple(const tuple<_U1, _U2>& __in)
951 : _Inherited(static_cast<const _Tuple_impl<0, _U1, _U2>&>(__in)) { }
953 template<typename _U1, typename _U2, typename
954 enable_if<_TMC::template
955 _ConstructibleTuple<_U1, _U2>()
957 _ImplicitlyConvertibleTuple<_U1, _U2>(),
959 explicit constexpr tuple(const tuple<_U1, _U2>& __in)
960 : _Inherited(static_cast<const _Tuple_impl<0, _U1, _U2>&>(__in)) { }
962 template<typename _U1, typename _U2, typename
963 enable_if<_TMC::template
964 _MoveConstructibleTuple<_U1, _U2>()
966 _ImplicitlyMoveConvertibleTuple<_U1, _U2>(),
968 constexpr tuple(tuple<_U1, _U2>&& __in)
969 : _Inherited(static_cast<_Tuple_impl<0, _U1, _U2>&&>(__in)) { }
971 template<typename _U1, typename _U2, typename
972 enable_if<_TMC::template
973 _MoveConstructibleTuple<_U1, _U2>()
975 _ImplicitlyMoveConvertibleTuple<_U1, _U2>(),
977 explicit constexpr tuple(tuple<_U1, _U2>&& __in)
978 : _Inherited(static_cast<_Tuple_impl<0, _U1, _U2>&&>(__in)) { }
980 template<typename _U1, typename _U2, typename
981 enable_if<_TMC::template
982 _ConstructibleTuple<_U1, _U2>()
984 _ImplicitlyConvertibleTuple<_U1, _U2>(),
986 constexpr tuple(const pair<_U1, _U2>& __in)
987 : _Inherited(__in.first, __in.second) { }
989 template<typename _U1, typename _U2, typename
990 enable_if<_TMC::template
991 _ConstructibleTuple<_U1, _U2>()
993 _ImplicitlyConvertibleTuple<_U1, _U2>(),
995 explicit constexpr tuple(const pair<_U1, _U2>& __in)
996 : _Inherited(__in.first, __in.second) { }
998 template<typename _U1, typename _U2, typename
999 enable_if<_TMC::template
1000 _MoveConstructibleTuple<_U1, _U2>()
1002 _ImplicitlyMoveConvertibleTuple<_U1, _U2>(),
1004 constexpr tuple(pair<_U1, _U2>&& __in)
1005 : _Inherited(std::forward<_U1>(__in.first),
1006 std::forward<_U2>(__in.second)) { }
1008 template<typename _U1, typename _U2, typename
1009 enable_if<_TMC::template
1010 _MoveConstructibleTuple<_U1, _U2>()
1012 _ImplicitlyMoveConvertibleTuple<_U1, _U2>(),
1013 bool>::type = false>
1014 explicit constexpr tuple(pair<_U1, _U2>&& __in)
1015 : _Inherited(std::forward<_U1>(__in.first),
1016 std::forward<_U2>(__in.second)) { }
1018 // Allocator-extended constructors.
1020 template<typename _Alloc>
1021 tuple(allocator_arg_t __tag, const _Alloc& __a)
1022 : _Inherited(__tag, __a) { }
1024 template<typename _Alloc, typename _Dummy = void,
1026 _TCC<_Dummy>::template
1027 _ConstructibleTuple<_T1, _T2>()
1028 && _TCC<_Dummy>::template
1029 _ImplicitlyConvertibleTuple<_T1, _T2>(),
1032 tuple(allocator_arg_t __tag, const _Alloc& __a,
1033 const _T1& __a1, const _T2& __a2)
1034 : _Inherited(__tag, __a, __a1, __a2) { }
1036 template<typename _Alloc, typename _Dummy = void,
1038 _TCC<_Dummy>::template
1039 _ConstructibleTuple<_T1, _T2>()
1040 && !_TCC<_Dummy>::template
1041 _ImplicitlyConvertibleTuple<_T1, _T2>(),
1044 explicit tuple(allocator_arg_t __tag, const _Alloc& __a,
1045 const _T1& __a1, const _T2& __a2)
1046 : _Inherited(__tag, __a, __a1, __a2) { }
1048 template<typename _Alloc, typename _U1, typename _U2, typename
1049 enable_if<_TMC::template
1050 _MoveConstructibleTuple<_U1, _U2>()
1052 _ImplicitlyMoveConvertibleTuple<_U1, _U2>(),
1054 tuple(allocator_arg_t __tag, const _Alloc& __a, _U1&& __a1, _U2&& __a2)
1055 : _Inherited(__tag, __a, std::forward<_U1>(__a1),
1056 std::forward<_U2>(__a2)) { }
1058 template<typename _Alloc, typename _U1, typename _U2, typename
1059 enable_if<_TMC::template
1060 _MoveConstructibleTuple<_U1, _U2>()
1062 _ImplicitlyMoveConvertibleTuple<_U1, _U2>(),
1063 bool>::type = false>
1064 explicit tuple(allocator_arg_t __tag, const _Alloc& __a,
1065 _U1&& __a1, _U2&& __a2)
1066 : _Inherited(__tag, __a, std::forward<_U1>(__a1),
1067 std::forward<_U2>(__a2)) { }
1069 template<typename _Alloc>
1070 tuple(allocator_arg_t __tag, const _Alloc& __a, const tuple& __in)
1071 : _Inherited(__tag, __a, static_cast<const _Inherited&>(__in)) { }
1073 template<typename _Alloc>
1074 tuple(allocator_arg_t __tag, const _Alloc& __a, tuple&& __in)
1075 : _Inherited(__tag, __a, static_cast<_Inherited&&>(__in)) { }
1077 template<typename _Alloc, typename _U1, typename _U2, typename
1078 enable_if<_TMC::template
1079 _ConstructibleTuple<_U1, _U2>()
1081 _ImplicitlyConvertibleTuple<_U1, _U2>(),
1083 tuple(allocator_arg_t __tag, const _Alloc& __a,
1084 const tuple<_U1, _U2>& __in)
1085 : _Inherited(__tag, __a,
1086 static_cast<const _Tuple_impl<0, _U1, _U2>&>(__in))
1089 template<typename _Alloc, typename _U1, typename _U2, typename
1090 enable_if<_TMC::template
1091 _ConstructibleTuple<_U1, _U2>()
1093 _ImplicitlyConvertibleTuple<_U1, _U2>(),
1094 bool>::type = false>
1095 explicit tuple(allocator_arg_t __tag, const _Alloc& __a,
1096 const tuple<_U1, _U2>& __in)
1097 : _Inherited(__tag, __a,
1098 static_cast<const _Tuple_impl<0, _U1, _U2>&>(__in))
1101 template<typename _Alloc, typename _U1, typename _U2, typename
1102 enable_if<_TMC::template
1103 _MoveConstructibleTuple<_U1, _U2>()
1105 _ImplicitlyMoveConvertibleTuple<_U1, _U2>(),
1107 tuple(allocator_arg_t __tag, const _Alloc& __a, tuple<_U1, _U2>&& __in)
1108 : _Inherited(__tag, __a, static_cast<_Tuple_impl<0, _U1, _U2>&&>(__in))
1111 template<typename _Alloc, typename _U1, typename _U2, typename
1112 enable_if<_TMC::template
1113 _MoveConstructibleTuple<_U1, _U2>()
1115 _ImplicitlyMoveConvertibleTuple<_U1, _U2>(),
1116 bool>::type = false>
1117 explicit tuple(allocator_arg_t __tag, const _Alloc& __a,
1118 tuple<_U1, _U2>&& __in)
1119 : _Inherited(__tag, __a, static_cast<_Tuple_impl<0, _U1, _U2>&&>(__in))
1122 template<typename _Alloc, typename _U1, typename _U2, typename
1123 enable_if<_TMC::template
1124 _ConstructibleTuple<_U1, _U2>()
1126 _ImplicitlyConvertibleTuple<_U1, _U2>(),
1128 tuple(allocator_arg_t __tag, const _Alloc& __a,
1129 const pair<_U1, _U2>& __in)
1130 : _Inherited(__tag, __a, __in.first, __in.second) { }
1132 template<typename _Alloc, typename _U1, typename _U2, typename
1133 enable_if<_TMC::template
1134 _ConstructibleTuple<_U1, _U2>()
1136 _ImplicitlyConvertibleTuple<_U1, _U2>(),
1137 bool>::type = false>
1138 explicit tuple(allocator_arg_t __tag, const _Alloc& __a,
1139 const pair<_U1, _U2>& __in)
1140 : _Inherited(__tag, __a, __in.first, __in.second) { }
1142 template<typename _Alloc, typename _U1, typename _U2, typename
1143 enable_if<_TMC::template
1144 _MoveConstructibleTuple<_U1, _U2>()
1146 _ImplicitlyMoveConvertibleTuple<_U1, _U2>(),
1148 tuple(allocator_arg_t __tag, const _Alloc& __a, pair<_U1, _U2>&& __in)
1149 : _Inherited(__tag, __a, std::forward<_U1>(__in.first),
1150 std::forward<_U2>(__in.second)) { }
1152 template<typename _Alloc, typename _U1, typename _U2, typename
1153 enable_if<_TMC::template
1154 _MoveConstructibleTuple<_U1, _U2>()
1156 _ImplicitlyMoveConvertibleTuple<_U1, _U2>(),
1157 bool>::type = false>
1158 explicit tuple(allocator_arg_t __tag, const _Alloc& __a,
1159 pair<_U1, _U2>&& __in)
1160 : _Inherited(__tag, __a, std::forward<_U1>(__in.first),
1161 std::forward<_U2>(__in.second)) { }
1164 operator=(const tuple& __in)
1166 static_cast<_Inherited&>(*this) = __in;
1171 operator=(tuple&& __in)
1172 noexcept(is_nothrow_move_assignable<_Inherited>::value)
1174 static_cast<_Inherited&>(*this) = std::move(__in);
1178 template<typename _U1, typename _U2>
1180 operator=(const tuple<_U1, _U2>& __in)
1182 static_cast<_Inherited&>(*this) = __in;
1186 template<typename _U1, typename _U2>
1188 operator=(tuple<_U1, _U2>&& __in)
1190 static_cast<_Inherited&>(*this) = std::move(__in);
1194 template<typename _U1, typename _U2>
1196 operator=(const pair<_U1, _U2>& __in)
1198 this->_M_head(*this) = __in.first;
1199 this->_M_tail(*this)._M_head(*this) = __in.second;
1203 template<typename _U1, typename _U2>
1205 operator=(pair<_U1, _U2>&& __in)
1207 this->_M_head(*this) = std::forward<_U1>(__in.first);
1208 this->_M_tail(*this)._M_head(*this) = std::forward<_U2>(__in.second);
1214 noexcept(noexcept(__in._M_swap(__in)))
1215 { _Inherited::_M_swap(__in); }
1220 * Recursive case for tuple_element: strip off the first element in
1221 * the tuple and retrieve the (i-1)th element of the remaining tuple.
1223 template<std::size_t __i, typename _Head, typename... _Tail>
1224 struct tuple_element<__i, tuple<_Head, _Tail...> >
1225 : tuple_element<__i - 1, tuple<_Tail...> > { };
1228 * Basis case for tuple_element: The first element is the one we're seeking.
1230 template<typename _Head, typename... _Tail>
1231 struct tuple_element<0, tuple<_Head, _Tail...> >
1236 /// class tuple_size
1237 template<typename... _Elements>
1238 struct tuple_size<tuple<_Elements...>>
1239 : public integral_constant<std::size_t, sizeof...(_Elements)> { };
1241 template<std::size_t __i, typename _Head, typename... _Tail>
1243 __get_helper(_Tuple_impl<__i, _Head, _Tail...>& __t) noexcept
1244 { return _Tuple_impl<__i, _Head, _Tail...>::_M_head(__t); }
1246 template<std::size_t __i, typename _Head, typename... _Tail>
1247 constexpr const _Head&
1248 __get_helper(const _Tuple_impl<__i, _Head, _Tail...>& __t) noexcept
1249 { return _Tuple_impl<__i, _Head, _Tail...>::_M_head(__t); }
1251 /// Return a reference to the ith element of a tuple.
1252 template<std::size_t __i, typename... _Elements>
1253 constexpr __tuple_element_t<__i, tuple<_Elements...>>&
1254 get(tuple<_Elements...>& __t) noexcept
1255 { return std::__get_helper<__i>(__t); }
1257 /// Return a const reference to the ith element of a const tuple.
1258 template<std::size_t __i, typename... _Elements>
1259 constexpr const __tuple_element_t<__i, tuple<_Elements...>>&
1260 get(const tuple<_Elements...>& __t) noexcept
1261 { return std::__get_helper<__i>(__t); }
1263 /// Return an rvalue reference to the ith element of a tuple rvalue.
1264 template<std::size_t __i, typename... _Elements>
1265 constexpr __tuple_element_t<__i, tuple<_Elements...>>&&
1266 get(tuple<_Elements...>&& __t) noexcept
1268 typedef __tuple_element_t<__i, tuple<_Elements...>> __element_type;
1269 return std::forward<__element_type&&>(std::get<__i>(__t));
1272 #if __cplusplus > 201103L
1274 #define __cpp_lib_tuples_by_type 201304
1276 template<typename _Head, size_t __i, typename... _Tail>
1278 __get_helper2(_Tuple_impl<__i, _Head, _Tail...>& __t) noexcept
1279 { return _Tuple_impl<__i, _Head, _Tail...>::_M_head(__t); }
1281 template<typename _Head, size_t __i, typename... _Tail>
1282 constexpr const _Head&
1283 __get_helper2(const _Tuple_impl<__i, _Head, _Tail...>& __t) noexcept
1284 { return _Tuple_impl<__i, _Head, _Tail...>::_M_head(__t); }
1286 /// Return a reference to the unique element of type _Tp of a tuple.
1287 template <typename _Tp, typename... _Types>
1289 get(tuple<_Types...>& __t) noexcept
1290 { return std::__get_helper2<_Tp>(__t); }
1292 /// Return a reference to the unique element of type _Tp of a tuple rvalue.
1293 template <typename _Tp, typename... _Types>
1295 get(tuple<_Types...>&& __t) noexcept
1296 { return std::forward<_Tp&&>(std::__get_helper2<_Tp>(__t)); }
1298 /// Return a const reference to the unique element of type _Tp of a tuple.
1299 template <typename _Tp, typename... _Types>
1300 constexpr const _Tp&
1301 get(const tuple<_Types...>& __t) noexcept
1302 { return std::__get_helper2<_Tp>(__t); }
1305 // This class performs the comparison operations on tuples
1306 template<typename _Tp, typename _Up, size_t __i, size_t __size>
1307 struct __tuple_compare
1309 static constexpr bool
1310 __eq(const _Tp& __t, const _Up& __u)
1312 return bool(std::get<__i>(__t) == std::get<__i>(__u))
1313 && __tuple_compare<_Tp, _Up, __i + 1, __size>::__eq(__t, __u);
1316 static constexpr bool
1317 __less(const _Tp& __t, const _Up& __u)
1319 return bool(std::get<__i>(__t) < std::get<__i>(__u))
1320 || (!bool(std::get<__i>(__u) < std::get<__i>(__t))
1321 && __tuple_compare<_Tp, _Up, __i + 1, __size>::__less(__t, __u));
1325 template<typename _Tp, typename _Up, size_t __size>
1326 struct __tuple_compare<_Tp, _Up, __size, __size>
1328 static constexpr bool
1329 __eq(const _Tp&, const _Up&) { return true; }
1331 static constexpr bool
1332 __less(const _Tp&, const _Up&) { return false; }
1335 template<typename... _TElements, typename... _UElements>
1337 operator==(const tuple<_TElements...>& __t,
1338 const tuple<_UElements...>& __u)
1340 static_assert(sizeof...(_TElements) == sizeof...(_UElements),
1341 "tuple objects can only be compared if they have equal sizes.");
1342 using __compare = __tuple_compare<tuple<_TElements...>,
1343 tuple<_UElements...>,
1344 0, sizeof...(_TElements)>;
1345 return __compare::__eq(__t, __u);
1348 template<typename... _TElements, typename... _UElements>
1350 operator<(const tuple<_TElements...>& __t,
1351 const tuple<_UElements...>& __u)
1353 static_assert(sizeof...(_TElements) == sizeof...(_UElements),
1354 "tuple objects can only be compared if they have equal sizes.");
1355 using __compare = __tuple_compare<tuple<_TElements...>,
1356 tuple<_UElements...>,
1357 0, sizeof...(_TElements)>;
1358 return __compare::__less(__t, __u);
1361 template<typename... _TElements, typename... _UElements>
1363 operator!=(const tuple<_TElements...>& __t,
1364 const tuple<_UElements...>& __u)
1365 { return !(__t == __u); }
1367 template<typename... _TElements, typename... _UElements>
1369 operator>(const tuple<_TElements...>& __t,
1370 const tuple<_UElements...>& __u)
1371 { return __u < __t; }
1373 template<typename... _TElements, typename... _UElements>
1375 operator<=(const tuple<_TElements...>& __t,
1376 const tuple<_UElements...>& __u)
1377 { return !(__u < __t); }
1379 template<typename... _TElements, typename... _UElements>
1381 operator>=(const tuple<_TElements...>& __t,
1382 const tuple<_UElements...>& __u)
1383 { return !(__t < __u); }
1386 template<typename... _Elements>
1387 constexpr tuple<typename __decay_and_strip<_Elements>::__type...>
1388 make_tuple(_Elements&&... __args)
1390 typedef tuple<typename __decay_and_strip<_Elements>::__type...>
1392 return __result_type(std::forward<_Elements>(__args)...);
1395 // _GLIBCXX_RESOLVE_LIB_DEFECTS
1396 // 2275. Why is forward_as_tuple not constexpr?
1397 template<typename... _Elements>
1398 constexpr tuple<_Elements&&...>
1399 forward_as_tuple(_Elements&&... __args) noexcept
1400 { return tuple<_Elements&&...>(std::forward<_Elements>(__args)...); }
1402 template<typename... _Tps>
1403 struct __is_tuple_like_impl<tuple<_Tps...>> : true_type
1406 // Internal type trait that allows us to sfinae-protect tuple_cat.
1407 template<typename _Tp>
1408 struct __is_tuple_like
1409 : public __is_tuple_like_impl<typename std::remove_cv
1410 <typename std::remove_reference<_Tp>::type>::type>::type
1413 template<size_t, typename, typename, size_t>
1414 struct __make_tuple_impl;
1416 template<size_t _Idx, typename _Tuple, typename... _Tp, size_t _Nm>
1417 struct __make_tuple_impl<_Idx, tuple<_Tp...>, _Tuple, _Nm>
1418 : __make_tuple_impl<_Idx + 1,
1419 tuple<_Tp..., __tuple_element_t<_Idx, _Tuple>>,
1423 template<std::size_t _Nm, typename _Tuple, typename... _Tp>
1424 struct __make_tuple_impl<_Nm, tuple<_Tp...>, _Tuple, _Nm>
1426 typedef tuple<_Tp...> __type;
1429 template<typename _Tuple>
1430 struct __do_make_tuple
1431 : __make_tuple_impl<0, tuple<>, _Tuple, std::tuple_size<_Tuple>::value>
1434 // Returns the std::tuple equivalent of a tuple-like type.
1435 template<typename _Tuple>
1437 : public __do_make_tuple<typename std::remove_cv
1438 <typename std::remove_reference<_Tuple>::type>::type>
1441 // Combines several std::tuple's into a single one.
1442 template<typename...>
1443 struct __combine_tuples;
1446 struct __combine_tuples<>
1448 typedef tuple<> __type;
1451 template<typename... _Ts>
1452 struct __combine_tuples<tuple<_Ts...>>
1454 typedef tuple<_Ts...> __type;
1457 template<typename... _T1s, typename... _T2s, typename... _Rem>
1458 struct __combine_tuples<tuple<_T1s...>, tuple<_T2s...>, _Rem...>
1460 typedef typename __combine_tuples<tuple<_T1s..., _T2s...>,
1461 _Rem...>::__type __type;
1464 // Computes the result type of tuple_cat given a set of tuple-like types.
1465 template<typename... _Tpls>
1466 struct __tuple_cat_result
1468 typedef typename __combine_tuples
1469 <typename __make_tuple<_Tpls>::__type...>::__type __type;
1472 // Helper to determine the index set for the first tuple-like
1473 // type of a given set.
1474 template<typename...>
1475 struct __make_1st_indices;
1478 struct __make_1st_indices<>
1480 typedef std::_Index_tuple<> __type;
1483 template<typename _Tp, typename... _Tpls>
1484 struct __make_1st_indices<_Tp, _Tpls...>
1486 typedef typename std::_Build_index_tuple<std::tuple_size<
1487 typename std::remove_reference<_Tp>::type>::value>::__type __type;
1490 // Performs the actual concatenation by step-wise expanding tuple-like
1491 // objects into the elements, which are finally forwarded into the
1493 template<typename _Ret, typename _Indices, typename... _Tpls>
1494 struct __tuple_concater;
1496 template<typename _Ret, std::size_t... _Is, typename _Tp, typename... _Tpls>
1497 struct __tuple_concater<_Ret, std::_Index_tuple<_Is...>, _Tp, _Tpls...>
1499 template<typename... _Us>
1500 static constexpr _Ret
1501 _S_do(_Tp&& __tp, _Tpls&&... __tps, _Us&&... __us)
1503 typedef typename __make_1st_indices<_Tpls...>::__type __idx;
1504 typedef __tuple_concater<_Ret, __idx, _Tpls...> __next;
1505 return __next::_S_do(std::forward<_Tpls>(__tps)...,
1506 std::forward<_Us>(__us)...,
1507 std::get<_Is>(std::forward<_Tp>(__tp))...);
1511 template<typename _Ret>
1512 struct __tuple_concater<_Ret, std::_Index_tuple<>>
1514 template<typename... _Us>
1515 static constexpr _Ret
1516 _S_do(_Us&&... __us)
1518 return _Ret(std::forward<_Us>(__us)...);
1523 template<typename... _Tpls, typename = typename
1524 enable_if<__and_<__is_tuple_like<_Tpls>...>::value>::type>
1526 tuple_cat(_Tpls&&... __tpls)
1527 -> typename __tuple_cat_result<_Tpls...>::__type
1529 typedef typename __tuple_cat_result<_Tpls...>::__type __ret;
1530 typedef typename __make_1st_indices<_Tpls...>::__type __idx;
1531 typedef __tuple_concater<__ret, __idx, _Tpls...> __concater;
1532 return __concater::_S_do(std::forward<_Tpls>(__tpls)...);
1535 // _GLIBCXX_RESOLVE_LIB_DEFECTS
1536 // 2301. Why is tie not constexpr?
1538 template<typename... _Elements>
1539 constexpr tuple<_Elements&...>
1540 tie(_Elements&... __args) noexcept
1541 { return tuple<_Elements&...>(__args...); }
1544 template<typename... _Elements>
1546 swap(tuple<_Elements...>& __x, tuple<_Elements...>& __y)
1547 noexcept(noexcept(__x.swap(__y)))
1550 // A class (and instance) which can be used in 'tie' when an element
1551 // of a tuple is not required
1552 struct _Swallow_assign
1555 const _Swallow_assign&
1556 operator=(const _Tp&) const
1560 const _Swallow_assign ignore{};
1562 /// Partial specialization for tuples
1563 template<typename... _Types, typename _Alloc>
1564 struct uses_allocator<tuple<_Types...>, _Alloc> : true_type { };
1566 // See stl_pair.h...
1567 template<class _T1, class _T2>
1568 template<typename... _Args1, typename... _Args2>
1571 pair(piecewise_construct_t,
1572 tuple<_Args1...> __first, tuple<_Args2...> __second)
1573 : pair(__first, __second,
1574 typename _Build_index_tuple<sizeof...(_Args1)>::__type(),
1575 typename _Build_index_tuple<sizeof...(_Args2)>::__type())
1578 template<class _T1, class _T2>
1579 template<typename... _Args1, std::size_t... _Indexes1,
1580 typename... _Args2, std::size_t... _Indexes2>
1583 pair(tuple<_Args1...>& __tuple1, tuple<_Args2...>& __tuple2,
1584 _Index_tuple<_Indexes1...>, _Index_tuple<_Indexes2...>)
1585 : first(std::forward<_Args1>(std::get<_Indexes1>(__tuple1))...),
1586 second(std::forward<_Args2>(std::get<_Indexes2>(__tuple2))...)
1591 _GLIBCXX_END_NAMESPACE_VERSION
1596 #endif // _GLIBCXX_TUPLE