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
42namespace 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