libstdc++
safe_iterator.tcc
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1// Debugging iterator implementation (out of line) -*- C++ -*-
2
3// Copyright (C) 2003-2024 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 debug/safe_iterator.tcc
26 * This file is a GNU debug extension to the Standard C++ Library.
27 */
28
29#ifndef _GLIBCXX_DEBUG_SAFE_ITERATOR_TCC
30#define _GLIBCXX_DEBUG_SAFE_ITERATOR_TCC 1
31
32#include <bits/stl_algobase.h>
33
34namespace __gnu_debug
35{
36 template<typename _Iterator, typename _Sequence, typename _Category>
37 typename _Distance_traits<_Iterator>::__type
38 _Safe_iterator<_Iterator, _Sequence, _Category>::
39 _M_get_distance_from_begin() const
40 {
41 typedef _Sequence_traits<_Sequence> _SeqTraits;
42
43 // No need to consider before_begin as this function is only used in
44 // _M_can_advance which won't be used for forward_list iterators.
45 if (_M_is_begin())
46 return std::make_pair(0, __dp_exact);
47
48 if (_M_is_end())
49 return _SeqTraits::_S_size(*_M_get_sequence());
50
51 typename _Distance_traits<_Iterator>::__type __res
52 = __get_distance(_M_get_sequence()->_M_base().begin(), base());
53
54 if (__res.second == __dp_equality)
55 return std::make_pair(1, __dp_sign);
56
57 return __res;
58 }
59
60 template<typename _Iterator, typename _Sequence, typename _Category>
61 typename _Distance_traits<_Iterator>::__type
62 _Safe_iterator<_Iterator, _Sequence, _Category>::
63 _M_get_distance_to_end() const
64 {
65 typedef _Sequence_traits<_Sequence> _SeqTraits;
66
67 // No need to consider before_begin as this function is only used in
68 // _M_can_advance which won't be used for forward_list iterators.
69 if (_M_is_begin())
70 return _SeqTraits::_S_size(*_M_get_sequence());
71
72 if (_M_is_end())
73 return std::make_pair(0, __dp_exact);
74
75 typename _Distance_traits<_Iterator>::__type __res
76 = __get_distance(base(), _M_get_sequence()->_M_base().end());
77
78 if (__res.second == __dp_equality)
79 return std::make_pair(1, __dp_sign);
80
81 return __res;
82 }
83
84 template<typename _Iterator, typename _Sequence, typename _Category>
85 bool
86 _Safe_iterator<_Iterator, _Sequence, _Category>::
87 _M_can_advance(difference_type __n, bool __strict) const
88 {
89 if (this->_M_singular())
90 return false;
91
92 if (__n == 0)
93 return true;
94
96 ? _M_get_distance_from_begin()
97 : _M_get_distance_to_end();
98
99 if (__n < 0)
100 __n = -__n;
101
102 return __dist.second > __dp_sign
103 ? __dist.first >= __n
104 : !__strict && __dist.first > 0;
105 }
106
107 template<typename _Iterator, typename _Sequence, typename _Category>
108 template<typename _Diff>
109 bool
110 _Safe_iterator<_Iterator, _Sequence, _Category>::
111 _M_can_advance(const std::pair<_Diff, _Distance_precision>& __dist,
112 int __way) const
113 {
114 return __dist.second == __dp_exact
115 ? _M_can_advance(__way * __dist.first)
116 : _M_can_advance(__way * (__dist.first == 0
117 ? 0
118 : __dist.first < 0 ? -1 : 1));
119 }
120
121 template<typename _Iterator, typename _Sequence, typename _Category>
122 typename _Distance_traits<_Iterator>::__type
123 _Safe_iterator<_Iterator, _Sequence, _Category>::
124 _M_get_distance_to(const _Safe_iterator& __rhs) const
125 {
126 typedef typename _Distance_traits<_Iterator>::__type _Dist;
127 typedef _Sequence_traits<_Sequence> _SeqTraits;
128
129 _Dist __base_dist = __get_distance(this->base(), __rhs.base());
130 if (__base_dist.second == __dp_exact)
131 return __base_dist;
132
133 _Dist __seq_dist = _SeqTraits::_S_size(*this->_M_get_sequence());
134 if (this->_M_is_before_begin())
135 {
136 if (__rhs._M_is_begin())
137 return std::make_pair(1, __dp_exact);
138
139 return __seq_dist.second == __dp_exact
140 ? std::make_pair(__seq_dist.first + 1, __dp_exact)
141 : __seq_dist;
142 }
143
144 if (this->_M_is_begin())
145 {
146 if (__rhs._M_is_before_begin())
147 return std::make_pair(-1, __dp_exact);
148
149 if (__rhs._M_is_end())
150 return __seq_dist;
151
152 return std::make_pair(__seq_dist.first,
153 __seq_dist.second == __dp_exact
154 ? __dp_sign_max_size : __seq_dist.second);
155 }
156
157 if (this->_M_is_end())
158 {
159 if (__rhs._M_is_before_begin())
160 return __seq_dist.second == __dp_exact
161 ? std::make_pair(-__seq_dist.first - 1, __dp_exact)
162 : std::make_pair(-__seq_dist.first, __dp_sign);
163
164 if (__rhs._M_is_begin())
165 return std::make_pair(-__seq_dist.first, __seq_dist.second);
166
167 return std::make_pair(-__seq_dist.first,
168 __seq_dist.second == __dp_exact
169 ? __dp_sign_max_size : __seq_dist.second);
170 }
171
172 if (__rhs._M_is_before_begin())
173 return __seq_dist.second == __dp_exact
174 ? std::make_pair(__seq_dist.first - 1, __dp_exact)
175 : std::make_pair(-__seq_dist.first, __dp_sign);
176
177 if (__rhs._M_is_begin())
178 return std::make_pair(-__seq_dist.first,
179 __seq_dist.second == __dp_exact
180 ? __dp_sign_max_size : __seq_dist.second);
181
182 if (__rhs._M_is_end())
183 return std::make_pair(__seq_dist.first,
184 __seq_dist.second == __dp_exact
185 ? __dp_sign_max_size : __seq_dist.second);
186
187 return std::make_pair(1, __dp_equality);
188 }
189
190 template<typename _Iterator, typename _Sequence, typename _Category>
191 bool
192 _Safe_iterator<_Iterator, _Sequence, _Category>::
193 _M_valid_range(const _Safe_iterator& __rhs,
195 bool __check_dereferenceable) const
196 {
197 if (_M_singular() || __rhs._M_singular() || !_M_can_compare(__rhs))
198 return false;
199
200 /* Determine iterators order */
201 __dist = _M_get_distance_to(__rhs);
202 if (__dist.second != __dp_equality)
203 {
204 // If range is not empty first iterator must be dereferenceable.
205 return __dist.first == 0
206 || (__dist.first > 0
207 && (!__check_dereferenceable || _M_dereferenceable()));
208 }
209
210 // Assume that this is a valid range; we can't check anything else.
211 return true;
212 }
213
214 template<typename _Iterator, typename _Sequence>
215 bool
216 _Safe_iterator<_Iterator, _Sequence, std::random_access_iterator_tag>::
217 _M_valid_range(const _Safe_iterator& __rhs,
218 std::pair<difference_type,
219 _Distance_precision>& __dist) const
220 {
221 if (this->_M_singular() || __rhs._M_singular()
222 || !this->_M_can_compare(__rhs))
223 return false;
224
225 /* Determine iterators order */
226 __dist = std::make_pair(__rhs.base() - this->base(), __dp_exact);
227
228 // If range is not empty first iterator must be dereferenceable.
229 return __dist.first == 0
230 || (__dist.first > 0 && this->_M_dereferenceable());
231 }
232} // namespace __gnu_debug
233
234namespace std _GLIBCXX_VISIBILITY(default)
235{
236_GLIBCXX_BEGIN_NAMESPACE_VERSION
237
238 template<typename _Ite, typename _Seq>
239 _GLIBCXX20_CONSTEXPR
240 _Ite
241 __niter_base(const ::__gnu_debug::_Safe_iterator<_Ite, _Seq,
243 { return __it.base(); }
244
245 template<bool _IsMove,
246 typename _Ite, typename _Seq, typename _Cat, typename _OI>
247 _GLIBCXX20_CONSTEXPR
248 _OI
249 __copy_move_a(
250 const ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>& __first,
251 const ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>& __last,
252 _OI __result)
253 {
254 typename ::__gnu_debug::_Distance_traits<_Ite>::__type __dist;
255 __glibcxx_check_valid_range2(__first, __last, __dist);
256 __glibcxx_check_can_increment_dist(__result, __dist, 1);
257
258 if (__dist.second > ::__gnu_debug::__dp_equality)
259 return std::__copy_move_a<_IsMove>(__first.base(), __last.base(),
260 __result);
261
262 return std::__copy_move_a1<_IsMove>(__first, __last, __result);
263 }
264
265 template<bool _IsMove,
266 typename _II, typename _Ite, typename _Seq, typename _Cat>
267 _GLIBCXX20_CONSTEXPR
269 __copy_move_a(_II __first, _II __last,
270 const ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>& __result)
271 {
272 typename ::__gnu_debug::_Distance_traits<_II>::__type __dist;
273 __glibcxx_check_valid_range2(__first, __last, __dist);
274 __glibcxx_check_can_increment_dist(__result, __dist, 1);
275
276 if (__dist.second > ::__gnu_debug::__dp_sign
277 && __result._M_can_advance(__dist.first, true))
278 return ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>(
279 std::__copy_move_a<_IsMove>(__first, __last, __result.base()),
280 __result._M_sequence);
281
282 return std::__copy_move_a1<_IsMove>(__first, __last, __result);
283 }
284
285 template<bool _IsMove,
286 typename _IIte, typename _ISeq, typename _ICat,
287 typename _OIte, typename _OSeq, typename _OCat>
288 _GLIBCXX20_CONSTEXPR
289 ::__gnu_debug::_Safe_iterator<_OIte, _OSeq, _OCat>
290 __copy_move_a(
291 const ::__gnu_debug::_Safe_iterator<_IIte, _ISeq, _ICat>& __first,
292 const ::__gnu_debug::_Safe_iterator<_IIte, _ISeq, _ICat>& __last,
293 const ::__gnu_debug::_Safe_iterator<_OIte, _OSeq, _OCat>& __result)
294 {
295 typename ::__gnu_debug::_Distance_traits<_IIte>::__type __dist;
296 __glibcxx_check_valid_range2(__first, __last, __dist);
297 __glibcxx_check_can_increment_dist(__result, __dist, 1);
298
299 if (__dist.second > ::__gnu_debug::__dp_equality)
300 {
301 if (__dist.second > ::__gnu_debug::__dp_sign
302 && __result._M_can_advance(__dist.first, true))
303 return ::__gnu_debug::_Safe_iterator<_OIte, _OSeq, _OCat>(
304 std::__copy_move_a<_IsMove>(__first.base(), __last.base(),
305 __result.base()),
306 __result._M_sequence);
307
308 return std::__copy_move_a<_IsMove>(__first.base(), __last.base(),
309 __result);
310 }
311
312 return std::__copy_move_a1<_IsMove>(__first, __last, __result);
313 }
314
315 template<bool _IsMove,
316 typename _Ite, typename _Seq, typename _Cat, typename _OI>
317 _GLIBCXX20_CONSTEXPR
318 _OI
319 __copy_move_backward_a(
320 const ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>& __first,
321 const ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>& __last,
322 _OI __result)
323 {
324 typename ::__gnu_debug::_Distance_traits<_Ite>::__type __dist;
325 __glibcxx_check_valid_range2(__first, __last, __dist);
326 __glibcxx_check_can_increment_dist(__result, __dist, -1);
327
328 if (__dist.second > ::__gnu_debug::__dp_equality)
329 return std::__copy_move_backward_a<_IsMove>(
330 __first.base(), __last.base(), __result);
331
332 return std::__copy_move_backward_a1<_IsMove>(__first, __last, __result);
333 }
334
335 template<bool _IsMove,
336 typename _II, typename _Ite, typename _Seq, typename _Cat>
337 _GLIBCXX20_CONSTEXPR
339 __copy_move_backward_a(_II __first, _II __last,
340 const ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>& __result)
341 {
342 typename ::__gnu_debug::_Distance_traits<_II>::__type __dist;
343 __glibcxx_check_valid_range2(__first, __last, __dist);
344 __glibcxx_check_can_increment_dist(__result, __dist, -1);
345
346 if (__dist.second > ::__gnu_debug::__dp_sign
347 && __result._M_can_advance(-__dist.first, true))
348 return ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>(
349 std::__copy_move_backward_a<_IsMove>(__first, __last,
350 __result.base()),
351 __result._M_sequence);
352
353 return std::__copy_move_backward_a1<_IsMove>(__first, __last, __result);
354 }
355
356 template<bool _IsMove,
357 typename _IIte, typename _ISeq, typename _ICat,
358 typename _OIte, typename _OSeq, typename _OCat>
359 _GLIBCXX20_CONSTEXPR
360 ::__gnu_debug::_Safe_iterator<_OIte, _OSeq, _OCat>
361 __copy_move_backward_a(
362 const ::__gnu_debug::_Safe_iterator<_IIte, _ISeq, _ICat>& __first,
363 const ::__gnu_debug::_Safe_iterator<_IIte, _ISeq, _ICat>& __last,
364 const ::__gnu_debug::_Safe_iterator<_OIte, _OSeq, _OCat>& __result)
365 {
366 typename ::__gnu_debug::_Distance_traits<_IIte>::__type __dist;
367 __glibcxx_check_valid_range2(__first, __last, __dist);
368 __glibcxx_check_can_increment_dist(__result, __dist, -1);
369
370 if (__dist.second > ::__gnu_debug::__dp_equality)
371 {
372 if (__dist.second > ::__gnu_debug::__dp_sign
373 && __result._M_can_advance(-__dist.first, true))
374 return ::__gnu_debug::_Safe_iterator<_OIte, _OSeq, _OCat>(
375 std::__copy_move_backward_a<_IsMove>(__first.base(), __last.base(),
376 __result.base()),
377 __result._M_sequence);
378
379 return std::__copy_move_backward_a<_IsMove>(
380 __first.base(), __last.base(), __result);
381 }
382
383 return std::__copy_move_backward_a1<_IsMove>(__first, __last, __result);
384 }
385
386 template<typename _Ite, typename _Seq, typename _Cat, typename _Tp>
387 _GLIBCXX20_CONSTEXPR
388 void
389 __fill_a(const ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>& __first,
390 const ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>& __last,
391 const _Tp& __value)
392 {
393 typename ::__gnu_debug::_Distance_traits<_Ite>::__type __dist;
394 __glibcxx_check_valid_range2(__first, __last, __dist);
395
396 if (__dist.second > ::__gnu_debug::__dp_equality)
397 std::__fill_a(__first.base(), __last.base(), __value);
398
399 std::__fill_a1(__first, __last, __value);
400 }
401
402 template<typename _Ite, typename _Seq, typename _Cat, typename _Size,
403 typename _Tp>
404 _GLIBCXX20_CONSTEXPR
405 ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>
406 __fill_n_a(const ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>& __first,
407 _Size __n, const _Tp& __value,
409 {
410#if __cplusplus >= 201103L
411 static_assert(is_integral<_Size>{}, "fill_n must pass integral size");
412#endif
413
414 if (__n <= 0)
415 return __first;
416
417 __glibcxx_check_can_increment(__first, __n);
418 if (__first._M_can_advance(__n, true))
419 return ::__gnu_debug::_Safe_iterator<_Ite, _Seq, _Cat>(
420 std::__fill_n_a(__first.base(), __n, __value, _Cat()),
421 __first._M_sequence);
422
423 return std::__fill_n_a1(__first, __n, __value);
424 }
425
426 template<typename _II1, typename _Seq1, typename _Cat1, typename _II2>
427 _GLIBCXX20_CONSTEXPR
428 bool
429 __equal_aux(
430 const ::__gnu_debug::_Safe_iterator<_II1, _Seq1, _Cat1>& __first1,
431 const ::__gnu_debug::_Safe_iterator<_II1, _Seq1, _Cat1>& __last1,
432 _II2 __first2)
433 {
434 typename ::__gnu_debug::_Distance_traits<_II1>::__type __dist;
435 __glibcxx_check_valid_range2(__first1, __last1, __dist);
436 __glibcxx_check_can_increment_dist(__first2, __dist, 1);
437
438 if (__dist.second > ::__gnu_debug::__dp_equality)
439 return std::__equal_aux(__first1.base(), __last1.base(), __first2);
440
441 return std::__equal_aux1(__first1, __last1, __first2);
442 }
443
444 template<typename _II1, typename _II2, typename _Seq2, typename _Cat2>
445 _GLIBCXX20_CONSTEXPR
446 bool
447 __equal_aux(_II1 __first1, _II1 __last1,
448 const ::__gnu_debug::_Safe_iterator<_II2, _Seq2, _Cat2>& __first2)
449 {
450 typename ::__gnu_debug::_Distance_traits<_II1>::__type __dist;
451 __glibcxx_check_valid_range2(__first1, __last1, __dist);
452 __glibcxx_check_can_increment_dist(__first2, __dist, 1);
453
454 if (__dist.second > ::__gnu_debug::__dp_sign
455 && __first2._M_can_advance(__dist.first, true))
456 return std::__equal_aux(__first1, __last1, __first2.base());
457
458 return std::__equal_aux1(__first1, __last1, __first2);
459 }
460
461 template<typename _II1, typename _Seq1, typename _Cat1,
462 typename _II2, typename _Seq2, typename _Cat2>
463 _GLIBCXX20_CONSTEXPR
464 bool
465 __equal_aux(
466 const ::__gnu_debug::_Safe_iterator<_II1, _Seq1, _Cat1>& __first1,
467 const ::__gnu_debug::_Safe_iterator<_II1, _Seq1, _Cat1>& __last1,
468 const ::__gnu_debug::_Safe_iterator<_II2, _Seq2, _Cat2>& __first2)
469 {
470 typename ::__gnu_debug::_Distance_traits<_II1>::__type __dist;
471 __glibcxx_check_valid_range2(__first1, __last1, __dist);
472 __glibcxx_check_can_increment_dist(__first2, __dist, 1);
473
474 if (__dist.second > ::__gnu_debug::__dp_equality)
475 {
476 if (__dist.second > ::__gnu_debug::__dp_sign &&
477 __first2._M_can_advance(__dist.first, true))
478 return std::__equal_aux(__first1.base(), __last1.base(),
479 __first2.base());
480 return std::__equal_aux(__first1.base(), __last1.base(), __first2);
481 }
482
483 return __equal_aux1(__first1, __last1, __first2);
484 }
485
486 template<typename _Ite1, typename _Seq1, typename _Cat1,
487 typename _II2>
488 _GLIBCXX20_CONSTEXPR
489 bool
490 __lexicographical_compare_aux(
491 const ::__gnu_debug::_Safe_iterator<_Ite1, _Seq1, _Cat1>& __first1,
492 const ::__gnu_debug::_Safe_iterator<_Ite1, _Seq1, _Cat1>& __last1,
493 _II2 __first2, _II2 __last2)
494 {
495 typename ::__gnu_debug::_Distance_traits<_Ite1>::__type __dist1;
496 __glibcxx_check_valid_range2(__first1, __last1, __dist1);
497 __glibcxx_check_valid_range(__first2, __last2);
498
499 if (__dist1.second > ::__gnu_debug::__dp_equality)
500 return std::__lexicographical_compare_aux(__first1.base(),
501 __last1.base(),
502 __first2, __last2);
503 return std::__lexicographical_compare_aux1(__first1, __last1,
504 __first2, __last2);
505 }
506
507 template<typename _II1,
508 typename _Ite2, typename _Seq2, typename _Cat2>
509 _GLIBCXX20_CONSTEXPR
510 bool
511 __lexicographical_compare_aux(
512 _II1 __first1, _II1 __last1,
513 const ::__gnu_debug::_Safe_iterator<_Ite2, _Seq2, _Cat2>& __first2,
514 const ::__gnu_debug::_Safe_iterator<_Ite2, _Seq2, _Cat2>& __last2)
515 {
516 __glibcxx_check_valid_range(__first1, __last1);
517 typename ::__gnu_debug::_Distance_traits<_II1>::__type __dist2;
518 __glibcxx_check_valid_range2(__first2, __last2, __dist2);
519
520 if (__dist2.second > ::__gnu_debug::__dp_equality)
521 return std::__lexicographical_compare_aux(__first1, __last1,
522 __first2.base(),
523 __last2.base());
524 return std::__lexicographical_compare_aux1(__first1, __last1,
525 __first2, __last2);
526 }
527
528 template<typename _Ite1, typename _Seq1, typename _Cat1,
529 typename _Ite2, typename _Seq2, typename _Cat2>
530 _GLIBCXX20_CONSTEXPR
531 bool
532 __lexicographical_compare_aux(
533 const ::__gnu_debug::_Safe_iterator<_Ite1, _Seq1, _Cat1>& __first1,
534 const ::__gnu_debug::_Safe_iterator<_Ite1, _Seq1, _Cat1>& __last1,
535 const ::__gnu_debug::_Safe_iterator<_Ite2, _Seq2, _Cat2>& __first2,
536 const ::__gnu_debug::_Safe_iterator<_Ite2, _Seq2, _Cat2>& __last2)
537 {
538 typename ::__gnu_debug::_Distance_traits<_Ite1>::__type __dist1;
539 __glibcxx_check_valid_range2(__first1, __last1, __dist1);
540 typename ::__gnu_debug::_Distance_traits<_Ite2>::__type __dist2;
541 __glibcxx_check_valid_range2(__first2, __last2, __dist2);
542
543 if (__dist1.second > ::__gnu_debug::__dp_equality)
544 {
545 if (__dist2.second > ::__gnu_debug::__dp_equality)
546 return std::__lexicographical_compare_aux(__first1.base(),
547 __last1.base(),
548 __first2.base(),
549 __last2.base());
550 return std::__lexicographical_compare_aux(__first1.base(),
551 __last1.base(),
552 __first2, __last2);
553 }
554
555 if (__dist2.second > ::__gnu_debug::__dp_equality)
556 return std::__lexicographical_compare_aux(__first1, __last1,
557 __first2.base(),
558 __last2.base());
559 return std::__lexicographical_compare_aux1(__first1, __last1,
560 __first2, __last2);
561 }
562
563_GLIBCXX_END_NAMESPACE_VERSION
564} // namespace std
565
566#endif
_Tp * end(valarray< _Tp > &__va) noexcept
Return an iterator pointing to one past the last element of the valarray.
Definition valarray:1243
_Tp * begin(valarray< _Tp > &__va) noexcept
Return an iterator pointing to the first element of the valarray.
Definition valarray:1221
ISO C++ entities toplevel namespace is std.
GNU debug classes for public use.
constexpr _Distance_traits< _Iterator >::__type __get_distance(_Iterator __lhs, _Iterator __rhs, std::random_access_iterator_tag)
Safe iterator wrapper.
Struct holding two objects of arbitrary type.
Definition stl_pair.h:188
_T1 first
The first member.
Definition stl_pair.h:192
_T2 second
The second member.
Definition stl_pair.h:193
Marking input iterators.
Random-access iterators support a superset of bidirectional iterator operations.