1// Debugging support implementation -*- C++ -*-
2
3// Copyright (C) 2003-2026 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/macros.h
26 * This file is a GNU debug extension to the Standard C++ Library.
27 */
28
29#ifndef _GLIBCXX_DEBUG_MACROS_H
30#define _GLIBCXX_DEBUG_MACROS_H 1
31
32/**
33 * Macros used by the implementation to verify certain
34 * properties. These macros may only be used directly by the debug
35 * wrappers. Note that these are macros (instead of the more obviously
36 * @a correct choice of making them functions) because we need line and
37 * file information at the call site, to minimize the distance between
38 * the user error and where the error is reported.
39 *
40 */
41
42#define _GLIBCXX_DEBUG_VERIFY_AT_F(_Cond,_ErrMsg,_File,_Line,_Func) \
43 do { \
44 if (__builtin_expect(!bool(_Cond), false)) \
45 __gnu_debug::_Error_formatter::_S_at(_File, _Line, _Func) \
46 ._ErrMsg._M_error(); \
47 } while (false)
48
49#define _GLIBCXX_DEBUG_VERIFY_AT(_Cond,_ErrMsg,_File,_Line) \
50 _GLIBCXX_DEBUG_VERIFY_AT_F(_Cond,_ErrMsg,_File,_Line,__PRETTY_FUNCTION__)
51
52#define _GLIBCXX_DEBUG_VERIFY(_Cond,_ErrMsg) \
53 _GLIBCXX_DEBUG_VERIFY_AT_F(_Cond, _ErrMsg, __FILE__, __LINE__, \
54 __PRETTY_FUNCTION__)
55
56// Verify that [_First, _Last) forms a valid iterator range.
57#define __glibcxx_check_valid_range(_First,_Last) \
58_GLIBCXX_DEBUG_VERIFY(__gnu_debug::__valid_range(_First, _Last), \
59 _M_message(__gnu_debug::__msg_valid_range) \
60 ._M_iterator(_First, #_First) \
61 ._M_iterator(_Last, #_Last))
62
63#define __glibcxx_check_valid_range_at(_First,_Last,_File,_Line,_Func) \
64_GLIBCXX_DEBUG_VERIFY_AT_F(__gnu_debug::__valid_range(_First, _Last), \
65 _M_message(__gnu_debug::__msg_valid_range) \
66 ._M_iterator(_First, #_First) \
67 ._M_iterator(_Last, #_Last), \
68 _File,_Line,_Func)
69
70#define __glibcxx_check_valid_range2(_First,_Last,_Dist) \
71_GLIBCXX_DEBUG_VERIFY(__gnu_debug::__valid_range(_First, _Last, _Dist), \
72 _M_message(__gnu_debug::__msg_valid_range) \
73 ._M_iterator(_First, #_First) \
74 ._M_iterator(_Last, #_Last))
75
76#define __glibcxx_check_valid_constructor_range(_First,_Last) \
77 __gnu_debug::__check_valid_range(_First, _Last, \
78 __FILE__, __LINE__, __PRETTY_FUNCTION__)
79
80// Verify that [_First, _Last) forms a non-empty iterator range.
81#define __glibcxx_check_non_empty_range(_First,_Last) \
82_GLIBCXX_DEBUG_VERIFY(_First != _Last, \
83 _M_message(__gnu_debug::__msg_non_empty_range) \
84 ._M_iterator(_First, #_First) \
85 ._M_iterator(_Last, #_Last))
86
87// Verify that [_First, _First + _Size) forms a valid range.
88#define __glibcxx_check_can_increment(_First,_Size) \
89_GLIBCXX_DEBUG_VERIFY(__gnu_debug::__can_advance(_First, _Size), \
90 _M_message(__gnu_debug::__msg_iter_subscript_oob) \
91 ._M_iterator(_First, #_First) \
92 ._M_integer(_Size, #_Size))
93
94#define __glibcxx_check_can_increment_dist(_First,_Dist,_Way) \
95 _GLIBCXX_DEBUG_VERIFY(__gnu_debug::__can_advance(_First, _Dist, _Way), \
96 _M_message(__gnu_debug::__msg_iter_subscript_oob) \
97 ._M_iterator(_First, #_First) \
98 ._M_integer(_Way * _Dist.first, #_Dist))
99
100#define __glibcxx_check_can_increment_range(_First1,_Last1,_First2) \
101 do \
102 { \
103 typename __gnu_debug::_Distance_traits<__decltype(_First1)>::__type __dist;\
104 _GLIBCXX_DEBUG_VERIFY_AT_F( \
105 __gnu_debug::__valid_range(_First1, _Last1, __dist),\
106 _M_message(__gnu_debug::__msg_valid_range) \
107 ._M_iterator(_First1, #_First1) \
108 ._M_iterator(_Last1, #_Last1), \
109 __FILE__,__LINE__,__PRETTY_FUNCTION__); \
110 _GLIBCXX_DEBUG_VERIFY_AT_F( \
111 __gnu_debug::__can_advance(_First2, __dist, 1), \
112 _M_message(__gnu_debug::__msg_iter_subscript_oob)\
113 ._M_iterator(_First2, #_First2) \
114 ._M_integer(__dist.first), \
115 __FILE__,__LINE__,__PRETTY_FUNCTION__); \
116 } while(false)
117
118#define __glibcxx_check_can_decrement_range(_First1,_Last1,_First2) \
119 do \
120 { \
121 typename __gnu_debug::_Distance_traits<__decltype(_First1)>::__type __dist;\
122 _GLIBCXX_DEBUG_VERIFY_AT_F( \
123 __gnu_debug::__valid_range(_First1, _Last1, __dist),\
124 _M_message(__gnu_debug::__msg_valid_range) \
125 ._M_iterator(_First1, #_First1) \
126 ._M_iterator(_Last1, #_Last1), \
127 __FILE__,__LINE__,__PRETTY_FUNCTION__); \
128 _GLIBCXX_DEBUG_VERIFY_AT_F( \
129 __gnu_debug::__can_advance(_First2, __dist, -1), \
130 _M_message(__gnu_debug::__msg_iter_subscript_oob)\
131 ._M_iterator(_First2, #_First2) \
132 ._M_integer(-__dist.first), \
133 __FILE__,__LINE__,__PRETTY_FUNCTION__); \
134 } while(false)
135
136/** Verify that we can insert into *this with the iterator _Position.
137 * Insertion into a container at a specific position requires that
138 * the iterator be nonsingular, either dereferenceable or past-the-end,
139 * and that it reference the sequence we are inserting into. Note that
140 * this macro is only valid when the container is a_Safe_sequence and
141 * the iterator is a _Safe_iterator.
142*/
143#define __glibcxx_check_insert(_Position) \
144_GLIBCXX_DEBUG_VERIFY(!_Position._M_singular(), \
145 _M_message(__gnu_debug::__msg_insert_singular) \
146 ._M_sequence(*this, "this") \
147 ._M_iterator(_Position, #_Position)); \
148_GLIBCXX_DEBUG_VERIFY(_Position._M_attached_to(this), \
149 _M_message(__gnu_debug::__msg_insert_different) \
150 ._M_sequence(*this, "this") \
151 ._M_iterator(_Position, #_Position))
152
153/** Verify that we can insert into *this after the iterator _Position.
154 * Insertion into a container after a specific position requires that
155 * the iterator be nonsingular, either dereferenceable or before-begin,
156 * and that it reference the sequence we are inserting into. Note that
157 * this macro is only valid when the container is a_Safe_sequence and
158 * the iterator is a _Safe_iterator.
159*/
160#define __glibcxx_check_insert_after(_Position) \
161__glibcxx_check_insert(_Position); \
162_GLIBCXX_DEBUG_VERIFY(!_Position._M_is_end(), \
163 _M_message(__gnu_debug::__msg_insert_after_end) \
164 ._M_sequence(*this, "this") \
165 ._M_iterator(_Position, #_Position))
166
167/** Verify that we can insert the values in the iterator range
168 * [_First, _Last) into *this with the iterator _Position. Insertion
169 * into a container at a specific position requires that the iterator
170 * be nonsingular (i.e., either dereferenceable or past-the-end),
171 * that it reference the sequence we are inserting into, and that the
172 * iterator range [_First, _Last) is a valid (possibly empty)
173 * range which does not reference the sequence we are inserting into.
174 * Note that this macro is only valid when the container is a
175 * _Safe_sequence and the _Position iterator is a _Safe_iterator.
176*/
177#define __glibcxx_check_insert_range(_Position,_First,_Last,_Dist) \
178__glibcxx_check_valid_range2(_First,_Last,_Dist); \
179__glibcxx_check_insert(_Position); \
180_GLIBCXX_DEBUG_VERIFY(__gnu_debug::__foreign_iterator(_Position,_First,_Last),\
181 _M_message(__gnu_debug::__msg_insert_range_from_self)\
182 ._M_iterator(_First, #_First) \
183 ._M_iterator(_Last, #_Last) \
184 ._M_sequence(*this, "this"))
185
186/** Verify that we can insert the values in the iterator range
187 * [_First, _Last) into *this after the iterator _Position. Insertion
188 * into a container after a specific position requires that the iterator
189 * be nonsingular (i.e., either dereferenceable or past-the-end),
190 * that it reference the sequence we are inserting into, and that the
191 * iterator range [_First, _Last) is a valid (possibly empty)
192 * range which does not reference the sequence we are inserting into.
193 * Note that this macro is only valid when the container is a
194 * _Safe_sequence and the _Position iterator is a _Safe_iterator.
195*/
196#define __glibcxx_check_insert_range_after(_Position,_First,_Last,_Dist)\
197__glibcxx_check_valid_range2(_First,_Last,_Dist); \
198__glibcxx_check_insert_after(_Position); \
199_GLIBCXX_DEBUG_VERIFY(__gnu_debug::__foreign_iterator(_Position,_First,_Last),\
200 _M_message(__gnu_debug::__msg_insert_range_from_self)\
201 ._M_iterator(_First, #_First) \
202 ._M_iterator(_Last, #_Last) \
203 ._M_sequence(*this, "this"))
204
205/** Verify that we can erase the element referenced by the iterator
206 * _Position. We can erase the element if the _Position iterator is
207 * dereferenceable and references this sequence.
208*/
209#define __glibcxx_check_erase(_Position) \
210_GLIBCXX_DEBUG_VERIFY(_Position._M_dereferenceable(), \
211 _M_message(__gnu_debug::__msg_erase_bad) \
212 ._M_sequence(*this, "this") \
213 ._M_iterator(_Position, #_Position)); \
214_GLIBCXX_DEBUG_VERIFY(_Position._M_attached_to(this), \
215 _M_message(__gnu_debug::__msg_erase_different) \
216 ._M_sequence(*this, "this") \
217 ._M_iterator(_Position, #_Position))
218
219#if __cplusplus >= 201103L
220# define __glibcxx_check_erase2(_CPosition) \
221_GLIBCXX_DEBUG_VERIFY(_CPosition != _M_base().cend(), \
222 _M_message(__gnu_debug::__msg_erase_bad) \
223 ._M_sequence(*this, "this") \
224 ._M_iterator(_CPosition, #_CPosition));
225#endif
226
227/** Verify that we can erase the element after the iterator
228 * _Position. We can erase the element if the _Position iterator is
229 * before a dereferenceable one and references this sequence.
230*/
231#define __glibcxx_check_erase_after(_Position) \
232_GLIBCXX_DEBUG_VERIFY(_Position._M_before_dereferenceable(), \
233 _M_message(__gnu_debug::__msg_erase_after_bad) \
234 ._M_sequence(*this, "this") \
235 ._M_iterator(_Position, #_Position)); \
236_GLIBCXX_DEBUG_VERIFY(_Position._M_attached_to(this), \
237 _M_message(__gnu_debug::__msg_erase_different) \
238 ._M_sequence(*this, "this") \
239 ._M_iterator(_Position, #_Position))
240
241/** Verify that we can erase the elements in the iterator range
242 * [_First, _Last). We can erase the elements if [_First, _Last) is a
243 * valid iterator range within this sequence.
244*/
245#define __glibcxx_check_erase_range(_First,_Last) \
246__glibcxx_check_valid_range(_First,_Last); \
247_GLIBCXX_DEBUG_VERIFY(_First._M_attached_to(this), \
248 _M_message(__gnu_debug::__msg_erase_different) \
249 ._M_sequence(*this, "this") \
250 ._M_iterator(_First, #_First) \
251 ._M_iterator(_Last, #_Last))
252
253/** Verify that we can erase the elements in the iterator range
254 * (_First, _Last). We can erase the elements if (_First, _Last) is a
255 * valid iterator range within this sequence.
256*/
257#define __glibcxx_check_erase_range_after(_First,_Last) \
258_GLIBCXX_DEBUG_VERIFY(!_First._M_singular() && !_Last._M_singular(), \
259 _M_message(__gnu_debug::__msg_erase_different) \
260 ._M_sequence(*this, "this") \
261 ._M_iterator(_First, #_First) \
262 ._M_iterator(_Last, #_Last)); \
263_GLIBCXX_DEBUG_VERIFY(_First._M_can_compare(_Last), \
264 _M_message(__gnu_debug::__msg_erase_different) \
265 ._M_sequence(*this, "this") \
266 ._M_iterator(_First, #_First) \
267 ._M_iterator(_Last, #_Last)); \
268_GLIBCXX_DEBUG_VERIFY(_First._M_attached_to(this), \
269 _M_message(__gnu_debug::__msg_erase_different) \
270 ._M_sequence(*this, "this") \
271 ._M_iterator(_First, #_First)); \
272_GLIBCXX_DEBUG_VERIFY(_First != _Last, \
273 _M_message(__gnu_debug::__msg_valid_range2) \
274 ._M_sequence(*this, "this") \
275 ._M_iterator(_First, #_First) \
276 ._M_iterator(_Last, #_Last)); \
277_GLIBCXX_DEBUG_VERIFY(_First._M_incrementable(), \
278 _M_message(__gnu_debug::__msg_valid_range2) \
279 ._M_sequence(*this, "this") \
280 ._M_iterator(_First, #_First) \
281 ._M_iterator(_Last, #_Last)); \
282_GLIBCXX_DEBUG_VERIFY(!_Last._M_is_before_begin(), \
283 _M_message(__gnu_debug::__msg_valid_range2) \
284 ._M_sequence(*this, "this") \
285 ._M_iterator(_First, #_First) \
286 ._M_iterator(_Last, #_Last)) \
287
288// Verify that the subscript _N is less than the container's size.
289#define __glibcxx_check_subscript(_N) \
290_GLIBCXX_DEBUG_VERIFY(_N < this->size(), \
291 _M_message(__gnu_debug::__msg_subscript_oob) \
292 ._M_sequence(*this, "this") \
293 ._M_integer(_N, #_N) \
294 ._M_integer(this->size(), "size"))
295
296// Verify that the bucket _N is less than the container's buckets count.
297#define __glibcxx_check_bucket_index(_N) \
298_GLIBCXX_DEBUG_VERIFY(_N < this->bucket_count(), \
299 _M_message(__gnu_debug::__msg_bucket_index_oob) \
300 ._M_sequence(*this, "this") \
301 ._M_integer(_N, #_N) \
302 ._M_integer(this->bucket_count(), "size"))
303
304// Verify that the container is nonempty
305#define __glibcxx_check_nonempty() \
306_GLIBCXX_DEBUG_VERIFY(! this->empty(), \
307 _M_message(__gnu_debug::__msg_empty) \
308 ._M_sequence(*this, "this"))
309
310// Verify that a predicate is irreflexive
311#define __glibcxx_check_irreflexive(_First,_Last) \
312 _GLIBCXX_DEBUG_VERIFY(_First == _Last || !(*_First < *_First), \
313 _M_message(__gnu_debug::__msg_irreflexive_ordering) \
314 ._M_iterator_value_type(_First, "< operator type"))
315
316#if __cplusplus >= 201103L
317# define __glibcxx_check_irreflexive2(_First,_Last) \
318 _GLIBCXX_DEBUG_VERIFY(_First == _Last \
319 || __gnu_debug::__is_irreflexive(_First), \
320 _M_message(__gnu_debug::__msg_irreflexive_ordering) \
321 ._M_iterator_value_type(_First, "< operator type"))
322#else
323# define __glibcxx_check_irreflexive2(_First,_Last)
324#endif
325
326#define __glibcxx_check_irreflexive_pred(_First,_Last,_Pred) \
327 _GLIBCXX_DEBUG_VERIFY(_First == _Last || !_Pred(*_First, *_First), \
328 _M_message(__gnu_debug::__msg_irreflexive_ordering) \
329 ._M_instance(_Pred, "functor") \
330 ._M_iterator_value_type(_First, "ordered type"))
331
332#if __cplusplus >= 201103L
333# define __glibcxx_check_irreflexive_pred2(_First,_Last,_Pred) \
334 _GLIBCXX_DEBUG_VERIFY(_First == _Last \
335 ||__gnu_debug::__is_irreflexive_pred(_First, _Pred), \
336 _M_message(__gnu_debug::__msg_irreflexive_ordering) \
337 ._M_instance(_Pred, "functor") \
338 ._M_iterator_value_type(_First, "ordered type"))
339#else
340# define __glibcxx_check_irreflexive_pred2(_First,_Last,_Pred)
341#endif
342
343// Verify that the iterator range [_First, _Last) is sorted
344#define __glibcxx_check_sorted(_First,_Last) \
345__glibcxx_check_valid_range(_First,_Last); \
346__glibcxx_check_irreflexive(_First,_Last); \
347 _GLIBCXX_DEBUG_VERIFY(__gnu_debug::__check_sorted( \
348 __gnu_debug::__base(_First), \
349 __gnu_debug::__base(_Last)), \
350 _M_message(__gnu_debug::__msg_unsorted) \
351 ._M_iterator(_First, #_First) \
352 ._M_iterator(_Last, #_Last))
353
354/** Verify that the iterator range [_First, _Last) is sorted by the
355 predicate _Pred. */
356#define __glibcxx_check_sorted_pred(_First,_Last,_Pred) \
357__glibcxx_check_valid_range(_First,_Last); \
358__glibcxx_check_irreflexive_pred(_First,_Last,_Pred); \
359_GLIBCXX_DEBUG_VERIFY(__gnu_debug::__check_sorted( \
360 __gnu_debug::__base(_First), \
361 __gnu_debug::__base(_Last), _Pred), \
362 _M_message(__gnu_debug::__msg_unsorted_pred) \
363 ._M_iterator(_First, #_First) \
364 ._M_iterator(_Last, #_Last) \
365 ._M_string(#_Pred))
366
367// Special variant for std::merge, std::includes, std::set_*
368#define __glibcxx_check_sorted_set(_First1,_Last1,_First2) \
369__glibcxx_check_valid_range(_First1,_Last1); \
370_GLIBCXX_DEBUG_VERIFY( \
371 __gnu_debug::__check_sorted_set(__gnu_debug::__base(_First1), \
372 __gnu_debug::__base(_Last1), _First2),\
373 _M_message(__gnu_debug::__msg_unsorted) \
374 ._M_iterator(_First1, #_First1) \
375 ._M_iterator(_Last1, #_Last1))
376
377// Likewise with a _Pred.
378#define __glibcxx_check_sorted_set_pred(_First1,_Last1,_First2,_Pred) \
379__glibcxx_check_valid_range(_First1,_Last1); \
380_GLIBCXX_DEBUG_VERIFY( \
381 __gnu_debug::__check_sorted_set(__gnu_debug::__base(_First1), \
382 __gnu_debug::__base(_Last1), \
383 _First2, _Pred), \
384 _M_message(__gnu_debug::__msg_unsorted_pred) \
385 ._M_iterator(_First1, #_First1) \
386 ._M_iterator(_Last1, #_Last1) \
387 ._M_string(#_Pred))
388
389/** Verify that the iterator range [_First, _Last) is partitioned
390 w.r.t. the value _Value. */
391#define __glibcxx_check_partitioned_lower(_First,_Last,_Value) \
392__glibcxx_check_valid_range(_First,_Last); \
393_GLIBCXX_DEBUG_VERIFY(__gnu_debug::__check_partitioned_lower( \
394 __gnu_debug::__base(_First), \
395 __gnu_debug::__base(_Last), _Value), \
396 _M_message(__gnu_debug::__msg_unpartitioned) \
397 ._M_iterator(_First, #_First) \
398 ._M_iterator(_Last, #_Last) \
399 ._M_string(#_Value))
400
401#define __glibcxx_check_partitioned_upper(_First,_Last,_Value) \
402__glibcxx_check_valid_range(_First,_Last); \
403_GLIBCXX_DEBUG_VERIFY(__gnu_debug::__check_partitioned_upper( \
404 __gnu_debug::__base(_First), \
405 __gnu_debug::__base(_Last), _Value), \
406 _M_message(__gnu_debug::__msg_unpartitioned) \
407 ._M_iterator(_First, #_First) \
408 ._M_iterator(_Last, #_Last) \
409 ._M_string(#_Value))
410
411/** Verify that the iterator range [_First, _Last) is partitioned
412 w.r.t. the value _Value and predicate _Pred. */
413#define __glibcxx_check_partitioned_lower_pred(_First,_Last,_Value,_Pred) \
414__glibcxx_check_valid_range(_First,_Last); \
415_GLIBCXX_DEBUG_VERIFY(__gnu_debug::__check_partitioned_lower( \
416 __gnu_debug::__base(_First), \
417 __gnu_debug::__base(_Last), _Value, _Pred), \
418 _M_message(__gnu_debug::__msg_unpartitioned_pred) \
419 ._M_iterator(_First, #_First) \
420 ._M_iterator(_Last, #_Last) \
421 ._M_string(#_Pred) \
422 ._M_string(#_Value))
423
424/** Verify that the iterator range [_First, _Last) is partitioned
425 w.r.t. the value _Value and predicate _Pred. */
426#define __glibcxx_check_partitioned_upper_pred(_First,_Last,_Value,_Pred) \
427__glibcxx_check_valid_range(_First,_Last); \
428_GLIBCXX_DEBUG_VERIFY(__gnu_debug::__check_partitioned_upper( \
429 __gnu_debug::__base(_First), \
430 __gnu_debug::__base(_Last), _Value, _Pred), \
431 _M_message(__gnu_debug::__msg_unpartitioned_pred) \
432 ._M_iterator(_First, #_First) \
433 ._M_iterator(_Last, #_Last) \
434 ._M_string(#_Pred) \
435 ._M_string(#_Value))
436
437// Verify that the iterator range [_First, _Last) is a heap
438#define __glibcxx_check_heap(_First,_Last) \
439 _GLIBCXX_DEBUG_VERIFY(std::__is_heap(__gnu_debug::__base(_First), \
440 __gnu_debug::__base(_Last)), \
441 _M_message(__gnu_debug::__msg_not_heap) \
442 ._M_iterator(_First, #_First) \
443 ._M_iterator(_Last, #_Last))
444
445/** Verify that the iterator range [_First, _Last) is a heap
446 w.r.t. the predicate _Pred. */
447#define __glibcxx_check_heap_pred(_First,_Last,_Pred) \
448 _GLIBCXX_DEBUG_VERIFY(std::__is_heap(__gnu_debug::__base(_First), \
449 __gnu_debug::__base(_Last), \
450 _Pred), \
451 _M_message(__gnu_debug::__msg_not_heap_pred) \
452 ._M_iterator(_First, #_First) \
453 ._M_iterator(_Last, #_Last) \
454 ._M_string(#_Pred))
455
456// Verify that load factor is positive
457#define __glibcxx_check_max_load_factor(_F) \
458_GLIBCXX_DEBUG_VERIFY(_F > 0.0f, \
459 _M_message(__gnu_debug::__msg_valid_load_factor) \
460 ._M_sequence(*this, "this"))
461
462#define __glibcxx_check_equal_allocs(_This, _Other) \
463_GLIBCXX_DEBUG_VERIFY(_This.get_allocator() == _Other.get_allocator(), \
464 _M_message(__gnu_debug::__msg_equal_allocs) \
465 ._M_sequence(_This, "this"))
466
467#endif
468