libstdc++

tuple
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1 // <tuple> -*- C++ -*-
2
3 // Copyright (C) 2007-2013 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 template<typename _UHead, typename = typename
92 enable_if<!is_convertible<_UHead,
93 __uses_alloc_base>::value>::type>
94 constexpr _Head_base(_UHead&& __h)
95 : _Head(std::forward<_UHead>(__h)) { }
96
97 _Head_base(__uses_alloc0)
98 : _Head() { }
99
100 template<typename _Alloc>
101 _Head_base(__uses_alloc1<_Alloc> __a)
102 : _Head(allocator_arg, *__a._M_a) { }
103
104 template<typename _Alloc>
105 _Head_base(__uses_alloc2<_Alloc> __a)
106 : _Head(*__a._M_a) { }
107
108 template<typename _UHead>
109 _Head_base(__uses_alloc0, _UHead&& __uhead)
110 : _Head(std::forward<_UHead>(__uhead)) { }
111
112 template<typename _Alloc, typename _UHead>
113 _Head_base(__uses_alloc1<_Alloc> __a, _UHead&& __uhead)
114 : _Head(allocator_arg, *__a._M_a, std::forward<_UHead>(__uhead)) { }
115
116 template<typename _Alloc, typename _UHead>
117 _Head_base(__uses_alloc2<_Alloc> __a, _UHead&& __uhead)
118 : _Head(std::forward<_UHead>(__uhead), *__a._M_a) { }
119
120 static constexpr _Head&
121 _M_head(_Head_base& __b) noexcept { return __b; }
122
123 static constexpr const _Head&
124 _M_head(const _Head_base& __b) noexcept { return __b; }
125 };
126
127 template<std::size_t _Idx, typename _Head>
128 struct _Head_base<_Idx, _Head, false>
129 {
130 constexpr _Head_base()
131 : _M_head_impl() { }
132
133 constexpr _Head_base(const _Head& __h)
134 : _M_head_impl(__h) { }
135
136 template<typename _UHead, typename = typename
137 enable_if<!is_convertible<_UHead,
138 __uses_alloc_base>::value>::type>
139 constexpr _Head_base(_UHead&& __h)
140 : _M_head_impl(std::forward<_UHead>(__h)) { }
141
142 _Head_base(__uses_alloc0)
143 : _M_head_impl() { }
144
145 template<typename _Alloc>
146 _Head_base(__uses_alloc1<_Alloc> __a)
147 : _M_head_impl(allocator_arg, *__a._M_a) { }
148
149 template<typename _Alloc>
150 _Head_base(__uses_alloc2<_Alloc> __a)
151 : _M_head_impl(*__a._M_a) { }
152
153 template<typename _UHead>
154 _Head_base(__uses_alloc0, _UHead&& __uhead)
155 : _M_head_impl(std::forward<_UHead>(__uhead)) { }
156
157 template<typename _Alloc, typename _UHead>
158 _Head_base(__uses_alloc1<_Alloc> __a, _UHead&& __uhead)
159 : _M_head_impl(allocator_arg, *__a._M_a, std::forward<_UHead>(__uhead))
160 { }
161
162 template<typename _Alloc, typename _UHead>
163 _Head_base(__uses_alloc2<_Alloc> __a, _UHead&& __uhead)
164 : _M_head_impl(std::forward<_UHead>(__uhead), *__a._M_a) { }
165
166 static constexpr _Head&
167 _M_head(_Head_base& __b) noexcept { return __b._M_head_impl; }
168
169 static constexpr const _Head&
170 _M_head(const _Head_base& __b) noexcept { return __b._M_head_impl; }
171
172 _Head _M_head_impl;
173 };
174
175 /**
176 * Contains the actual implementation of the @c tuple template, stored
177 * as a recursive inheritance hierarchy from the first element (most
178 * derived class) to the last (least derived class). The @c Idx
179 * parameter gives the 0-based index of the element stored at this
180 * point in the hierarchy; we use it to implement a constant-time
181 * get() operation.
182 */
183 template<std::size_t _Idx, typename... _Elements>
184 struct _Tuple_impl;
185
186 /**
187 * Zero-element tuple implementation. This is the basis case for the
188 * inheritance recursion.
189 */
190 template<std::size_t _Idx>
191 struct _Tuple_impl<_Idx>
192 {
193 template<std::size_t, typename...> friend class _Tuple_impl;
194
195 _Tuple_impl() = default;
196
197 template<typename _Alloc>
198 _Tuple_impl(allocator_arg_t, const _Alloc&) { }
199
200 template<typename _Alloc>
201 _Tuple_impl(allocator_arg_t, const _Alloc&, const _Tuple_impl&) { }
202
203 template<typename _Alloc>
204 _Tuple_impl(allocator_arg_t, const _Alloc&, _Tuple_impl&&) { }
205
206 protected:
207 void _M_swap(_Tuple_impl&) noexcept { /* no-op */ }
208 };
209
210 template<typename _Tp>
211 struct __is_empty_non_tuple : is_empty<_Tp> { };
212
213 // Using EBO for elements that are tuples causes ambiguous base errors.
214 template<typename _El0, typename... _El>
215 struct __is_empty_non_tuple<tuple<_El0, _El...>> : false_type { };
216
217 // Use the Empty Base-class Optimization for empty, non-final types.
218 template<typename _Tp>
219 using __empty_not_final
220 = typename conditional<__is_final(_Tp), false_type,
221 __is_empty_non_tuple<_Tp>>::type;
222
223 /**
224 * Recursive tuple implementation. Here we store the @c Head element
225 * and derive from a @c Tuple_impl containing the remaining elements
226 * (which contains the @c Tail).
227 */
228 template<std::size_t _Idx, typename _Head, typename... _Tail>
229 struct _Tuple_impl<_Idx, _Head, _Tail...>
230 : public _Tuple_impl<_Idx + 1, _Tail...>,
231 private _Head_base<_Idx, _Head, __empty_not_final<_Head>::value>
232 {
233 template<std::size_t, typename...> friend class _Tuple_impl;
234
235 typedef _Tuple_impl<_Idx + 1, _Tail...> _Inherited;
236 typedef _Head_base<_Idx, _Head, __empty_not_final<_Head>::value> _Base;
237
238 static constexpr _Head&
239 _M_head(_Tuple_impl& __t) noexcept { return _Base::_M_head(__t); }
240
241 static constexpr const _Head&
242 _M_head(const _Tuple_impl& __t) noexcept { return _Base::_M_head(__t); }
243
244 static constexpr _Inherited&
245 _M_tail(_Tuple_impl& __t) noexcept { return __t; }
246
247 static constexpr const _Inherited&
248 _M_tail(const _Tuple_impl& __t) noexcept { return __t; }
249
250 constexpr _Tuple_impl()
251 : _Inherited(), _Base() { }
252
253 explicit
254 constexpr _Tuple_impl(const _Head& __head, const _Tail&... __tail)
255 : _Inherited(__tail...), _Base(__head) { }
256
257 template<typename _UHead, typename... _UTail, typename = typename
258 enable_if<sizeof...(_Tail) == sizeof...(_UTail)>::type>
259 explicit
260 constexpr _Tuple_impl(_UHead&& __head, _UTail&&... __tail)
261 : _Inherited(std::forward<_UTail>(__tail)...),
262 _Base(std::forward<_UHead>(__head)) { }
263
264 constexpr _Tuple_impl(const _Tuple_impl&) = default;
265
266 constexpr
267 _Tuple_impl(_Tuple_impl&& __in)
268 noexcept(__and_<is_nothrow_move_constructible<_Head>,
269 is_nothrow_move_constructible<_Inherited>>::value)
270 : _Inherited(std::move(_M_tail(__in))),
271 _Base(std::forward<_Head>(_M_head(__in))) { }
272
273 template<typename... _UElements>
274 constexpr _Tuple_impl(const _Tuple_impl<_Idx, _UElements...>& __in)
275 : _Inherited(_Tuple_impl<_Idx, _UElements...>::_M_tail(__in)),
276 _Base(_Tuple_impl<_Idx, _UElements...>::_M_head(__in)) { }
277
278 template<typename _UHead, typename... _UTails>
279 constexpr _Tuple_impl(_Tuple_impl<_Idx, _UHead, _UTails...>&& __in)
280 : _Inherited(std::move
281 (_Tuple_impl<_Idx, _UHead, _UTails...>::_M_tail(__in))),
282 _Base(std::forward<_UHead>
283 (_Tuple_impl<_Idx, _UHead, _UTails...>::_M_head(__in))) { }
284
285 template<typename _Alloc>
286 _Tuple_impl(allocator_arg_t __tag, const _Alloc& __a)
287 : _Inherited(__tag, __a),
288 _Base(__use_alloc<_Head>(__a)) { }
289
290 template<typename _Alloc>
291 _Tuple_impl(allocator_arg_t __tag, const _Alloc& __a,
292 const _Head& __head, const _Tail&... __tail)
293 : _Inherited(__tag, __a, __tail...),
294 _Base(__use_alloc<_Head, _Alloc, _Head>(__a), __head) { }
295
296 template<typename _Alloc, typename _UHead, typename... _UTail,
297 typename = typename enable_if<sizeof...(_Tail)
298 == sizeof...(_UTail)>::type>
299 _Tuple_impl(allocator_arg_t __tag, const _Alloc& __a,
300 _UHead&& __head, _UTail&&... __tail)
301 : _Inherited(__tag, __a, std::forward<_UTail>(__tail)...),
302 _Base(__use_alloc<_Head, _Alloc, _UHead>(__a),
303 std::forward<_UHead>(__head)) { }
304
305 template<typename _Alloc>
306 _Tuple_impl(allocator_arg_t __tag, const _Alloc& __a,
307 const _Tuple_impl& __in)
308 : _Inherited(__tag, __a, _M_tail(__in)),
309 _Base(__use_alloc<_Head, _Alloc, _Head>(__a), _M_head(__in)) { }
310
311 template<typename _Alloc>
312 _Tuple_impl(allocator_arg_t __tag, const _Alloc& __a,
313 _Tuple_impl&& __in)
314 : _Inherited(__tag, __a, std::move(_M_tail(__in))),
315 _Base(__use_alloc<_Head, _Alloc, _Head>(__a),
316 std::forward<_Head>(_M_head(__in))) { }
317
318 template<typename _Alloc, typename... _UElements>
319 _Tuple_impl(allocator_arg_t __tag, const _Alloc& __a,
320 const _Tuple_impl<_Idx, _UElements...>& __in)
321 : _Inherited(__tag, __a,
322 _Tuple_impl<_Idx, _UElements...>::_M_tail(__in)),
323 _Base(__use_alloc<_Head, _Alloc, _Head>(__a),
324 _Tuple_impl<_Idx, _UElements...>::_M_head(__in)) { }
325
326 template<typename _Alloc, typename _UHead, typename... _UTails>
327 _Tuple_impl(allocator_arg_t __tag, const _Alloc& __a,
328 _Tuple_impl<_Idx, _UHead, _UTails...>&& __in)
329 : _Inherited(__tag, __a, std::move
330 (_Tuple_impl<_Idx, _UHead, _UTails...>::_M_tail(__in))),
331 _Base(__use_alloc<_Head, _Alloc, _UHead>(__a),
332 std::forward<_UHead>
333 (_Tuple_impl<_Idx, _UHead, _UTails...>::_M_head(__in))) { }
334
335 _Tuple_impl&
336 operator=(const _Tuple_impl& __in)
337 {
338 _M_head(*this) = _M_head(__in);
339 _M_tail(*this) = _M_tail(__in);
340 return *this;
341 }
342
343 _Tuple_impl&
344 operator=(_Tuple_impl&& __in)
345 noexcept(__and_<is_nothrow_move_assignable<_Head>,
346 is_nothrow_move_assignable<_Inherited>>::value)
347 {
348 _M_head(*this) = std::forward<_Head>(_M_head(__in));
349 _M_tail(*this) = std::move(_M_tail(__in));
350 return *this;
351 }
352
353 template<typename... _UElements>
354 _Tuple_impl&
355 operator=(const _Tuple_impl<_Idx, _UElements...>& __in)
356 {
357 _M_head(*this) = _Tuple_impl<_Idx, _UElements...>::_M_head(__in);
358 _M_tail(*this) = _Tuple_impl<_Idx, _UElements...>::_M_tail(__in);
359 return *this;
360 }
361
362 template<typename _UHead, typename... _UTails>
363 _Tuple_impl&
364 operator=(_Tuple_impl<_Idx, _UHead, _UTails...>&& __in)
365 {
366 _M_head(*this) = std::forward<_UHead>
367 (_Tuple_impl<_Idx, _UHead, _UTails...>::_M_head(__in));
368 _M_tail(*this) = std::move
369 (_Tuple_impl<_Idx, _UHead, _UTails...>::_M_tail(__in));
370 return *this;
371 }
372
373 protected:
374 void
375 _M_swap(_Tuple_impl& __in)
376 noexcept(noexcept(swap(std::declval<_Head&>(),
377 std::declval<_Head&>()))
378 && noexcept(_M_tail(__in)._M_swap(_M_tail(__in))))
379 {
380 using std::swap;
381 swap(_M_head(*this), _M_head(__in));
382 _Inherited::_M_swap(_M_tail(__in));
383 }
384 };
385
386 /// Primary class template, tuple
387 template<typename... _Elements>
388 class tuple : public _Tuple_impl<0, _Elements...>
389 {
390 typedef _Tuple_impl<0, _Elements...> _Inherited;
391
392 public:
393 constexpr tuple()
394 : _Inherited() { }
395
396 explicit
397 constexpr tuple(const _Elements&... __elements)
398 : _Inherited(__elements...) { }
399
400 template<typename... _UElements, typename = typename
401 enable_if<__and_<is_convertible<_UElements,
402 _Elements>...>::value>::type>
403 explicit
404 constexpr tuple(_UElements&&... __elements)
405 : _Inherited(std::forward<_UElements>(__elements)...) { }
406
407 constexpr tuple(const tuple&) = default;
408
409 constexpr tuple(tuple&&) = default;
410
411 template<typename... _UElements, typename = typename
412 enable_if<__and_<is_convertible<const _UElements&,
413 _Elements>...>::value>::type>
414 constexpr tuple(const tuple<_UElements...>& __in)
415 : _Inherited(static_cast<const _Tuple_impl<0, _UElements...>&>(__in))
416 { }
417
418 template<typename... _UElements, typename = typename
419 enable_if<__and_<is_convertible<_UElements,
420 _Elements>...>::value>::type>
421 constexpr tuple(tuple<_UElements...>&& __in)
422 : _Inherited(static_cast<_Tuple_impl<0, _UElements...>&&>(__in)) { }
423
424 // Allocator-extended constructors.
425
426 template<typename _Alloc>
427 tuple(allocator_arg_t __tag, const _Alloc& __a)
428 : _Inherited(__tag, __a) { }
429
430 template<typename _Alloc>
431 tuple(allocator_arg_t __tag, const _Alloc& __a,
432 const _Elements&... __elements)
433 : _Inherited(__tag, __a, __elements...) { }
434
435 template<typename _Alloc, typename... _UElements, typename = typename
436 enable_if<sizeof...(_UElements)
437 == sizeof...(_Elements)>::type>
438 tuple(allocator_arg_t __tag, const _Alloc& __a,
439 _UElements&&... __elements)
440 : _Inherited(__tag, __a, std::forward<_UElements>(__elements)...)
441 { }
442
443 template<typename _Alloc>
444 tuple(allocator_arg_t __tag, const _Alloc& __a, const tuple& __in)
445 : _Inherited(__tag, __a, static_cast<const _Inherited&>(__in)) { }
446
447 template<typename _Alloc>
448 tuple(allocator_arg_t __tag, const _Alloc& __a, tuple&& __in)
449 : _Inherited(__tag, __a, static_cast<_Inherited&&>(__in)) { }
450
451 template<typename _Alloc, typename... _UElements, typename = typename
452 enable_if<sizeof...(_UElements)
453 == sizeof...(_Elements)>::type>
454 tuple(allocator_arg_t __tag, const _Alloc& __a,
455 const tuple<_UElements...>& __in)
456 : _Inherited(__tag, __a,
457 static_cast<const _Tuple_impl<0, _UElements...>&>(__in))
458 { }
459
460 template<typename _Alloc, typename... _UElements, typename = typename
461 enable_if<sizeof...(_UElements)
462 == sizeof...(_Elements)>::type>
463 tuple(allocator_arg_t __tag, const _Alloc& __a,
464 tuple<_UElements...>&& __in)
465 : _Inherited(__tag, __a,
466 static_cast<_Tuple_impl<0, _UElements...>&&>(__in))
467 { }
468
469 tuple&
470 operator=(const tuple& __in)
471 {
472 static_cast<_Inherited&>(*this) = __in;
473 return *this;
474 }
475
476 tuple&
477 operator=(tuple&& __in)
478 noexcept(is_nothrow_move_assignable<_Inherited>::value)
479 {
480 static_cast<_Inherited&>(*this) = std::move(__in);
481 return *this;
482 }
483
484 template<typename... _UElements, typename = typename
485 enable_if<sizeof...(_UElements)
486 == sizeof...(_Elements)>::type>
487 tuple&
488 operator=(const tuple<_UElements...>& __in)
489 {
490 static_cast<_Inherited&>(*this) = __in;
491 return *this;
492 }
493
494 template<typename... _UElements, typename = typename
495 enable_if<sizeof...(_UElements)
496 == sizeof...(_Elements)>::type>
497 tuple&
498 operator=(tuple<_UElements...>&& __in)
499 {
500 static_cast<_Inherited&>(*this) = std::move(__in);
501 return *this;
502 }
503
504 void
505 swap(tuple& __in)
506 noexcept(noexcept(__in._M_swap(__in)))
507 { _Inherited::_M_swap(__in); }
508 };
509
510 // Explicit specialization, zero-element tuple.
511 template<>
512 class tuple<>
513 {
514 public:
515 void swap(tuple&) noexcept { /* no-op */ }
516 };
517
518 /// Partial specialization, 2-element tuple.
519 /// Includes construction and assignment from a pair.
520 template<typename _T1, typename _T2>
521 class tuple<_T1, _T2> : public _Tuple_impl<0, _T1, _T2>
522 {
523 typedef _Tuple_impl<0, _T1, _T2> _Inherited;
524
525 public:
526 constexpr tuple()
527 : _Inherited() { }
528
529 explicit
530 constexpr tuple(const _T1& __a1, const _T2& __a2)
531 : _Inherited(__a1, __a2) { }
532
533 template<typename _U1, typename _U2, typename = typename
534 enable_if<__and_<is_convertible<_U1, _T1>,
535 is_convertible<_U2, _T2>>::value>::type>
536 explicit
537 constexpr tuple(_U1&& __a1, _U2&& __a2)
538 : _Inherited(std::forward<_U1>(__a1), std::forward<_U2>(__a2)) { }
539
540 constexpr tuple(const tuple&) = default;
541
542 constexpr tuple(tuple&&) = default;
543
544 template<typename _U1, typename _U2, typename = typename
545 enable_if<__and_<is_convertible<const _U1&, _T1>,
546 is_convertible<const _U2&, _T2>>::value>::type>
547 constexpr tuple(const tuple<_U1, _U2>& __in)
548 : _Inherited(static_cast<const _Tuple_impl<0, _U1, _U2>&>(__in)) { }
549
550 template<typename _U1, typename _U2, typename = typename
551 enable_if<__and_<is_convertible<_U1, _T1>,
552 is_convertible<_U2, _T2>>::value>::type>
553 constexpr tuple(tuple<_U1, _U2>&& __in)
554 : _Inherited(static_cast<_Tuple_impl<0, _U1, _U2>&&>(__in)) { }
555
556 template<typename _U1, typename _U2, typename = typename
557 enable_if<__and_<is_convertible<const _U1&, _T1>,
558 is_convertible<const _U2&, _T2>>::value>::type>
559 constexpr tuple(const pair<_U1, _U2>& __in)
560 : _Inherited(__in.first, __in.second) { }
561
562 template<typename _U1, typename _U2, typename = typename
563 enable_if<__and_<is_convertible<_U1, _T1>,
564 is_convertible<_U2, _T2>>::value>::type>
565 constexpr tuple(pair<_U1, _U2>&& __in)
566 : _Inherited(std::forward<_U1>(__in.first),
567 std::forward<_U2>(__in.second)) { }
568
569 // Allocator-extended constructors.
570
571 template<typename _Alloc>
572 tuple(allocator_arg_t __tag, const _Alloc& __a)
573 : _Inherited(__tag, __a) { }
574
575 template<typename _Alloc>
576 tuple(allocator_arg_t __tag, const _Alloc& __a,
577 const _T1& __a1, const _T2& __a2)
578 : _Inherited(__tag, __a, __a1, __a2) { }
579
580 template<typename _Alloc, typename _U1, typename _U2>
581 tuple(allocator_arg_t __tag, const _Alloc& __a, _U1&& __a1, _U2&& __a2)
582 : _Inherited(__tag, __a, std::forward<_U1>(__a1),
583 std::forward<_U2>(__a2)) { }
584
585 template<typename _Alloc>
586 tuple(allocator_arg_t __tag, const _Alloc& __a, const tuple& __in)
587 : _Inherited(__tag, __a, static_cast<const _Inherited&>(__in)) { }
588
589 template<typename _Alloc>
590 tuple(allocator_arg_t __tag, const _Alloc& __a, tuple&& __in)
591 : _Inherited(__tag, __a, static_cast<_Inherited&&>(__in)) { }
592
593 template<typename _Alloc, typename _U1, typename _U2>
594 tuple(allocator_arg_t __tag, const _Alloc& __a,
595 const tuple<_U1, _U2>& __in)
596 : _Inherited(__tag, __a,
597 static_cast<const _Tuple_impl<0, _U1, _U2>&>(__in))
598 { }
599
600 template<typename _Alloc, typename _U1, typename _U2>
601 tuple(allocator_arg_t __tag, const _Alloc& __a, tuple<_U1, _U2>&& __in)
602 : _Inherited(__tag, __a, static_cast<_Tuple_impl<0, _U1, _U2>&&>(__in))
603 { }
604
605 template<typename _Alloc, typename _U1, typename _U2>
606 tuple(allocator_arg_t __tag, const _Alloc& __a,
607 const pair<_U1, _U2>& __in)
608 : _Inherited(__tag, __a, __in.first, __in.second) { }
609
610 template<typename _Alloc, typename _U1, typename _U2>
611 tuple(allocator_arg_t __tag, const _Alloc& __a, pair<_U1, _U2>&& __in)
612 : _Inherited(__tag, __a, std::forward<_U1>(__in.first),
613 std::forward<_U2>(__in.second)) { }
614
615 tuple&
616 operator=(const tuple& __in)
617 {
618 static_cast<_Inherited&>(*this) = __in;
619 return *this;
620 }
621
622 tuple&
623 operator=(tuple&& __in)
624 noexcept(is_nothrow_move_assignable<_Inherited>::value)
625 {
626 static_cast<_Inherited&>(*this) = std::move(__in);
627 return *this;
628 }
629
630 template<typename _U1, typename _U2>
631 tuple&
632 operator=(const tuple<_U1, _U2>& __in)
633 {
634 static_cast<_Inherited&>(*this) = __in;
635 return *this;
636 }
637
638 template<typename _U1, typename _U2>
639 tuple&
640 operator=(tuple<_U1, _U2>&& __in)
641 {
642 static_cast<_Inherited&>(*this) = std::move(__in);
643 return *this;
644 }
645
646 template<typename _U1, typename _U2>
647 tuple&
648 operator=(const pair<_U1, _U2>& __in)
649 {
650 this->_M_head(*this) = __in.first;
651 this->_M_tail(*this)._M_head(*this) = __in.second;
652 return *this;
653 }
654
655 template<typename _U1, typename _U2>
656 tuple&
657 operator=(pair<_U1, _U2>&& __in)
658 {
659 this->_M_head(*this) = std::forward<_U1>(__in.first);
660 this->_M_tail(*this)._M_head(*this) = std::forward<_U2>(__in.second);
661 return *this;
662 }
663
664 void
665 swap(tuple& __in)
666 noexcept(noexcept(__in._M_swap(__in)))
667 { _Inherited::_M_swap(__in); }
668 };
669
670
671 /// Gives the type of the ith element of a given tuple type.
672 template<std::size_t __i, typename _Tp>
673 struct tuple_element;
674
675 /**
676 * Recursive case for tuple_element: strip off the first element in
677 * the tuple and retrieve the (i-1)th element of the remaining tuple.
678 */
679 template<std::size_t __i, typename _Head, typename... _Tail>
680 struct tuple_element<__i, tuple<_Head, _Tail...> >
681 : tuple_element<__i - 1, tuple<_Tail...> > { };
682
683 /**
684 * Basis case for tuple_element: The first element is the one we're seeking.
685 */
686 template<typename _Head, typename... _Tail>
687 struct tuple_element<0, tuple<_Head, _Tail...> >
688 {
689 typedef _Head type;
690 };
691
692 template<std::size_t __i, typename _Tp>
693 struct tuple_element<__i, const _Tp>
694 {
695 typedef typename
696 add_const<typename tuple_element<__i, _Tp>::type>::type type;
697 };
698
699 template<std::size_t __i, typename _Tp>
700 struct tuple_element<__i, volatile _Tp>
701 {
702 typedef typename
703 add_volatile<typename tuple_element<__i, _Tp>::type>::type type;
704 };
705
706 template<std::size_t __i, typename _Tp>
707 struct tuple_element<__i, const volatile _Tp>
708 {
709 typedef typename
710 add_cv<typename tuple_element<__i, _Tp>::type>::type type;
711 };
712
713 /// Finds the size of a given tuple type.
714 template<typename _Tp>
715 struct tuple_size;
716
717 template<typename _Tp>
718 struct tuple_size<const _Tp>
719 : public integral_constant<
720 typename remove_cv<decltype(tuple_size<_Tp>::value)>::type,
721 tuple_size<_Tp>::value> { };
722
723 template<typename _Tp>
724 struct tuple_size<volatile _Tp>
725 : public integral_constant<
726 typename remove_cv<decltype(tuple_size<_Tp>::value)>::type,
727 tuple_size<_Tp>::value> { };
728
729 template<typename _Tp>
730 struct tuple_size<const volatile _Tp>
731 : public integral_constant<
732 typename remove_cv<decltype(tuple_size<_Tp>::value)>::type,
733 tuple_size<_Tp>::value> { };
734
735 /// class tuple_size
736 template<typename... _Elements>
737 struct tuple_size<tuple<_Elements...>>
738 : public integral_constant<std::size_t, sizeof...(_Elements)> { };
739
740 template<std::size_t __i, typename _Head, typename... _Tail>
741 constexpr typename __add_ref<_Head>::type
742 __get_helper(_Tuple_impl<__i, _Head, _Tail...>& __t) noexcept
743 { return _Tuple_impl<__i, _Head, _Tail...>::_M_head(__t); }
744
745 template<std::size_t __i, typename _Head, typename... _Tail>
746 constexpr typename __add_c_ref<_Head>::type
747 __get_helper(const _Tuple_impl<__i, _Head, _Tail...>& __t) noexcept
748 { return _Tuple_impl<__i, _Head, _Tail...>::_M_head(__t); }
749
750 // Return a reference (const reference, rvalue reference) to the ith element
751 // of a tuple. Any const or non-const ref elements are returned with their
752 // original type.
753 template<std::size_t __i, typename... _Elements>
754 constexpr typename __add_ref<
755 typename tuple_element<__i, tuple<_Elements...>>::type
756 >::type
757 get(tuple<_Elements...>& __t) noexcept
758 { return __get_helper<__i>(__t); }
759
760 template<std::size_t __i, typename... _Elements>
761 constexpr typename __add_c_ref<
762 typename tuple_element<__i, tuple<_Elements...>>::type
763 >::type
764 get(const tuple<_Elements...>& __t) noexcept
765 { return __get_helper<__i>(__t); }
766
767 template<std::size_t __i, typename... _Elements>
768 constexpr typename __add_r_ref<
769 typename tuple_element<__i, tuple<_Elements...>>::type
770 >::type
771 get(tuple<_Elements...>&& __t) noexcept
772 { return std::forward<typename tuple_element<__i,
773 tuple<_Elements...>>::type&&>(get<__i>(__t)); }
774
775 // This class helps construct the various comparison operations on tuples
776 template<std::size_t __check_equal_size, std::size_t __i, std::size_t __j,
777 typename _Tp, typename _Up>
778 struct __tuple_compare;
779
780 template<std::size_t __i, std::size_t __j, typename _Tp, typename _Up>
781 struct __tuple_compare<0, __i, __j, _Tp, _Up>
782 {
783 static constexpr bool
784 __eq(const _Tp& __t, const _Up& __u)
785 {
786 return (get<__i>(__t) == get<__i>(__u) &&
787 __tuple_compare<0, __i + 1, __j, _Tp, _Up>::__eq(__t, __u));
788 }
789
790 static constexpr bool
791 __less(const _Tp& __t, const _Up& __u)
792 {
793 return ((get<__i>(__t) < get<__i>(__u))
794 || !(get<__i>(__u) < get<__i>(__t)) &&
795 __tuple_compare<0, __i + 1, __j, _Tp, _Up>::__less(__t, __u));
796 }
797 };
798
799 template<std::size_t __i, typename _Tp, typename _Up>
800 struct __tuple_compare<0, __i, __i, _Tp, _Up>
801 {
802 static constexpr bool
803 __eq(const _Tp&, const _Up&) { return true; }
804
805 static constexpr bool
806 __less(const _Tp&, const _Up&) { return false; }
807 };
808
809 template<typename... _TElements, typename... _UElements>
810 constexpr bool
811 operator==(const tuple<_TElements...>& __t,
812 const tuple<_UElements...>& __u)
813 {
814 typedef tuple<_TElements...> _Tp;
815 typedef tuple<_UElements...> _Up;
816 return bool(__tuple_compare<tuple_size<_Tp>::value - tuple_size<_Up>::value,
817 0, tuple_size<_Tp>::value, _Tp, _Up>::__eq(__t, __u));
818 }
819
820 template<typename... _TElements, typename... _UElements>
821 constexpr bool
822 operator<(const tuple<_TElements...>& __t,
823 const tuple<_UElements...>& __u)
824 {
825 typedef tuple<_TElements...> _Tp;
826 typedef tuple<_UElements...> _Up;
827 return bool(__tuple_compare<tuple_size<_Tp>::value - tuple_size<_Up>::value,
828 0, tuple_size<_Tp>::value, _Tp, _Up>::__less(__t, __u));
829 }
830
831 template<typename... _TElements, typename... _UElements>
832 inline constexpr bool
833 operator!=(const tuple<_TElements...>& __t,
834 const tuple<_UElements...>& __u)
835 { return !(__t == __u); }
836
837 template<typename... _TElements, typename... _UElements>
838 inline constexpr bool
839 operator>(const tuple<_TElements...>& __t,
840 const tuple<_UElements...>& __u)
841 { return __u < __t; }
842
843 template<typename... _TElements, typename... _UElements>
844 inline constexpr bool
845 operator<=(const tuple<_TElements...>& __t,
846 const tuple<_UElements...>& __u)
847 { return !(__u < __t); }
848
849 template<typename... _TElements, typename... _UElements>
850 inline constexpr bool
851 operator>=(const tuple<_TElements...>& __t,
852 const tuple<_UElements...>& __u)
853 { return !(__t < __u); }
854
855 // NB: DR 705.
856 template<typename... _Elements>
857 constexpr tuple<typename __decay_and_strip<_Elements>::__type...>
858 make_tuple(_Elements&&... __args)
859 {
860 typedef tuple<typename __decay_and_strip<_Elements>::__type...>
861 __result_type;
862 return __result_type(std::forward<_Elements>(__args)...);
863 }
864
865 template<typename... _Elements>
866 tuple<_Elements&&...>
867 forward_as_tuple(_Elements&&... __args) noexcept
868 { return tuple<_Elements&&...>(std::forward<_Elements>(__args)...); }
869
870 template<typename>
871 struct __is_tuple_like_impl : false_type
872 { };
873
874 template<typename... _Tps>
875 struct __is_tuple_like_impl<tuple<_Tps...>> : true_type
876 { };
877
878 template<typename _T1, typename _T2>
879 struct __is_tuple_like_impl<pair<_T1, _T2>> : true_type
880 { };
881
882 template<typename _Tp, std::size_t _Nm>
883 struct __is_tuple_like_impl<array<_Tp, _Nm>> : true_type
884 { };
885
886 // Internal type trait that allows us to sfinae-protect tuple_cat.
887 template<typename _Tp>
888 struct __is_tuple_like
889 : public __is_tuple_like_impl<typename std::remove_cv
890 <typename std::remove_reference<_Tp>::type>::type>::type
891 { };
892
893 // Stores a tuple of indices. Also used by bind() to extract the elements
894 // in a tuple.
895 template<std::size_t... _Indexes>
896 struct _Index_tuple
897 {
898 typedef _Index_tuple<_Indexes..., sizeof...(_Indexes)> __next;
899 };
900
901 // Builds an _Index_tuple<0, 1, 2, ..., _Num-1>.
902 template<std::size_t _Num>
903 struct _Build_index_tuple
904 {
905 typedef typename _Build_index_tuple<_Num - 1>::__type::__next __type;
906 };
907
908 template<>
909 struct _Build_index_tuple<0>
910 {
911 typedef _Index_tuple<> __type;
912 };
913
914 template<std::size_t, typename, typename, std::size_t>
915 struct __make_tuple_impl;
916
917 template<std::size_t _Idx, typename _Tuple, typename... _Tp,
918 std::size_t _Nm>
919 struct __make_tuple_impl<_Idx, tuple<_Tp...>, _Tuple, _Nm>
920 {
921 typedef typename __make_tuple_impl<_Idx + 1, tuple<_Tp...,
922 typename std::tuple_element<_Idx, _Tuple>::type>, _Tuple, _Nm>::__type
923 __type;
924 };
925
926 template<std::size_t _Nm, typename _Tuple, typename... _Tp>
927 struct __make_tuple_impl<_Nm, tuple<_Tp...>, _Tuple, _Nm>
928 {
929 typedef tuple<_Tp...> __type;
930 };
931
932 template<typename _Tuple>
933 struct __do_make_tuple
934 : public __make_tuple_impl<0, tuple<>, _Tuple,
935 std::tuple_size<_Tuple>::value>
936 { };
937
938 // Returns the std::tuple equivalent of a tuple-like type.
939 template<typename _Tuple>
940 struct __make_tuple
941 : public __do_make_tuple<typename std::remove_cv
942 <typename std::remove_reference<_Tuple>::type>::type>
943 { };
944
945 // Combines several std::tuple's into a single one.
946 template<typename...>
947 struct __combine_tuples;
948
949 template<>
950 struct __combine_tuples<>
951 {
952 typedef tuple<> __type;
953 };
954
955 template<typename... _Ts>
956 struct __combine_tuples<tuple<_Ts...>>
957 {
958 typedef tuple<_Ts...> __type;
959 };
960
961 template<typename... _T1s, typename... _T2s, typename... _Rem>
962 struct __combine_tuples<tuple<_T1s...>, tuple<_T2s...>, _Rem...>
963 {
964 typedef typename __combine_tuples<tuple<_T1s..., _T2s...>,
965 _Rem...>::__type __type;
966 };
967
968 // Computes the result type of tuple_cat given a set of tuple-like types.
969 template<typename... _Tpls>
970 struct __tuple_cat_result
971 {
972 typedef typename __combine_tuples
973 <typename __make_tuple<_Tpls>::__type...>::__type __type;
974 };
975
976 // Helper to determine the index set for the first tuple-like
977 // type of a given set.
978 template<typename...>
979 struct __make_1st_indices;
980
981 template<>
982 struct __make_1st_indices<>
983 {
984 typedef std::_Index_tuple<> __type;
985 };
986
987 template<typename _Tp, typename... _Tpls>
988 struct __make_1st_indices<_Tp, _Tpls...>
989 {
990 typedef typename std::_Build_index_tuple<std::tuple_size<
991 typename std::remove_reference<_Tp>::type>::value>::__type __type;
992 };
993
994 // Performs the actual concatenation by step-wise expanding tuple-like
995 // objects into the elements, which are finally forwarded into the
996 // result tuple.
997 template<typename _Ret, typename _Indices, typename... _Tpls>
998 struct __tuple_concater;
999
1000 template<typename _Ret, std::size_t... _Is, typename _Tp, typename... _Tpls>
1001 struct __tuple_concater<_Ret, std::_Index_tuple<_Is...>, _Tp, _Tpls...>
1002 {
1003 template<typename... _Us>
1004 static constexpr _Ret
1005 _S_do(_Tp&& __tp, _Tpls&&... __tps, _Us&&... __us)
1006 {
1007 typedef typename __make_1st_indices<_Tpls...>::__type __idx;
1008 typedef __tuple_concater<_Ret, __idx, _Tpls...> __next;
1009 return __next::_S_do(std::forward<_Tpls>(__tps)...,
1010 std::forward<_Us>(__us)...,
1011 std::get<_Is>(std::forward<_Tp>(__tp))...);
1012 }
1013 };
1014
1015 template<typename _Ret>
1016 struct __tuple_concater<_Ret, std::_Index_tuple<>>
1017 {
1018 template<typename... _Us>
1019 static constexpr _Ret
1020 _S_do(_Us&&... __us)
1021 {
1022 return _Ret(std::forward<_Us>(__us)...);
1023 }
1024 };
1025
1026 /// tuple_cat
1027 template<typename... _Tpls, typename = typename
1028 enable_if<__and_<__is_tuple_like<_Tpls>...>::value>::type>
1029 constexpr auto
1030 tuple_cat(_Tpls&&... __tpls)
1031 -> typename __tuple_cat_result<_Tpls...>::__type
1032 {
1033 typedef typename __tuple_cat_result<_Tpls...>::__type __ret;
1034 typedef typename __make_1st_indices<_Tpls...>::__type __idx;
1035 typedef __tuple_concater<__ret, __idx, _Tpls...> __concater;
1036 return __concater::_S_do(std::forward<_Tpls>(__tpls)...);
1037 }
1038
1039 /// tie
1040 template<typename... _Elements>
1041 inline tuple<_Elements&...>
1042 tie(_Elements&... __args) noexcept
1043 { return tuple<_Elements&...>(__args...); }
1044
1045 /// swap
1046 template<typename... _Elements>
1047 inline void
1048 swap(tuple<_Elements...>& __x, tuple<_Elements...>& __y)
1049 noexcept(noexcept(__x.swap(__y)))
1050 { __x.swap(__y); }
1051
1052 // A class (and instance) which can be used in 'tie' when an element
1053 // of a tuple is not required
1054 struct _Swallow_assign
1055 {
1056 template<class _Tp>
1057 const _Swallow_assign&
1058 operator=(const _Tp&) const
1059 { return *this; }
1060 };
1061
1062 const _Swallow_assign ignore{};
1063
1064 /// Partial specialization for tuples
1065 template<typename... _Types, typename _Alloc>
1066 struct uses_allocator<tuple<_Types...>, _Alloc> : true_type { };
1067
1068 // See stl_pair.h...
1069 template<class _T1, class _T2>
1070 template<typename... _Args1, typename... _Args2>
1071 inline
1072 pair<_T1, _T2>::
1073 pair(piecewise_construct_t,
1074 tuple<_Args1...> __first, tuple<_Args2...> __second)
1075 : pair(__first, __second,
1076 typename _Build_index_tuple<sizeof...(_Args1)>::__type(),
1077 typename _Build_index_tuple<sizeof...(_Args2)>::__type())
1078 { }
1079
1080 template<class _T1, class _T2>
1081 template<typename... _Args1, std::size_t... _Indexes1,
1082 typename... _Args2, std::size_t... _Indexes2>
1083 inline
1084 pair<_T1, _T2>::
1085 pair(tuple<_Args1...>& __tuple1, tuple<_Args2...>& __tuple2,
1086 _Index_tuple<_Indexes1...>, _Index_tuple<_Indexes2...>)
1087 : first(std::forward<_Args1>(std::get<_Indexes1>(__tuple1))...),
1088 second(std::forward<_Args2>(std::get<_Indexes2>(__tuple2))...)
1089 { }
1090
1091 /// @}
1092
1093 _GLIBCXX_END_NAMESPACE_VERSION
1094 } // namespace std
1095
1096 #endif // C++11
1097
1098 #endif // _GLIBCXX_TUPLE