1// Components for manipulating sequences of characters -*- C++ -*-
2
3// Copyright (C) 1997-2025 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 bits/basic_string.h
26 * This is an internal header file, included by other library headers.
27 * Do not attempt to use it directly. @headername{string}
28 */
29
30//
31// ISO C++ 14882: 21 Strings library
32//
33
34#ifndef _BASIC_STRING_H
35#define _BASIC_STRING_H 1
36
37#ifdef _GLIBCXX_SYSHDR
38#pragma GCC system_header
39#endif
40
41#include <ext/alloc_traits.h>
42#include <debug/debug.h>
43
44#if __cplusplus >= 201103L
45#include <initializer_list>
46#endif
47
48#include <bits/version.h>
49
50#ifdef __glibcxx_string_view // >= C++17
51# include <string_view>
52#endif
53
54#if __glibcxx_containers_ranges // C++ >= 23
55# include <bits/ranges_algobase.h> // ranges::copy
56# include <bits/ranges_util.h> // ranges::subrange
57#endif
58
59#if __cplusplus > 202302L
60# include <charconv>
61#endif
62
63
64#if ! _GLIBCXX_USE_CXX11_ABI
65# include "cow_string.h"
66#else
67
68namespace std _GLIBCXX_VISIBILITY(default)
69{
70_GLIBCXX_BEGIN_NAMESPACE_VERSION
71_GLIBCXX_BEGIN_NAMESPACE_CXX11
72
73 /**
74 * @class basic_string basic_string.h <string>
75 * @brief Managing sequences of characters and character-like objects.
76 *
77 * @ingroup strings
78 * @ingroup sequences
79 * @headerfile string
80 * @since C++98
81 *
82 * @tparam _CharT Type of character
83 * @tparam _Traits Traits for character type, defaults to
84 * char_traits<_CharT>.
85 * @tparam _Alloc Allocator type, defaults to allocator<_CharT>.
86 *
87 * Meets the requirements of a <a href="tables.html#65">container</a>, a
88 * <a href="tables.html#66">reversible container</a>, and a
89 * <a href="tables.html#67">sequence</a>. Of the
90 * <a href="tables.html#68">optional sequence requirements</a>, only
91 * @c push_back, @c at, and @c %array access are supported.
92 */
93 template<typename _CharT, typename _Traits, typename _Alloc>
94 class basic_string
95 {
96#if __cplusplus >= 202002L
97 static_assert(is_trivially_copyable_v<_CharT>
98 && is_trivially_default_constructible_v<_CharT>
99 && is_standard_layout_v<_CharT>);
100 static_assert(is_same_v<_CharT, typename _Traits::char_type>);
101 static_assert(is_same_v<_CharT, typename _Alloc::value_type>);
102 using _Char_alloc_type = _Alloc;
103#else
104 typedef typename __gnu_cxx::__alloc_traits<_Alloc>::template
105 rebind<_CharT>::other _Char_alloc_type;
106#endif
107
108 typedef __gnu_cxx::__alloc_traits<_Char_alloc_type> _Alloc_traits;
109
110 // Types:
111 public:
112 typedef _Traits traits_type;
113 typedef typename _Traits::char_type value_type;
114 typedef _Char_alloc_type allocator_type;
115 typedef typename _Alloc_traits::size_type size_type;
116 typedef typename _Alloc_traits::difference_type difference_type;
117 typedef typename _Alloc_traits::reference reference;
118 typedef typename _Alloc_traits::const_reference const_reference;
119 typedef typename _Alloc_traits::pointer pointer;
120 typedef typename _Alloc_traits::const_pointer const_pointer;
121 typedef __gnu_cxx::__normal_iterator<pointer, basic_string> iterator;
122 typedef __gnu_cxx::__normal_iterator<const_pointer, basic_string>
123 const_iterator;
124 typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
125 typedef std::reverse_iterator<iterator> reverse_iterator;
126
127 /// Value returned by various member functions when they fail.
128 static const size_type npos = static_cast<size_type>(-1);
129
130 protected:
131 // type used for positions in insert, erase etc.
132#if __cplusplus < 201103L
133 typedef iterator __const_iterator;
134#else
135 typedef const_iterator __const_iterator;
136#endif
137
138 private:
139 static _GLIBCXX20_CONSTEXPR pointer
140 _S_allocate(_Char_alloc_type& __a, size_type __n)
141 {
142 pointer __p = _Alloc_traits::allocate(__a, __n);
143#if __glibcxx_constexpr_string >= 201907L
144 // std::char_traits begins the lifetime of characters,
145 // but custom traits might not, so do it here.
146 if constexpr (!is_same_v<_Traits, char_traits<_CharT>>)
147 if (std::__is_constant_evaluated())
148 // Begin the lifetime of characters in allocated storage.
149 for (size_type __i = 0; __i < __n; ++__i)
150 std::construct_at(__builtin_addressof(__p[__i]));
151#endif
152 return __p;
153 }
154
155#ifdef __glibcxx_string_view // >= C++17
156 // A helper type for avoiding boiler-plate.
157 typedef basic_string_view<_CharT, _Traits> __sv_type;
158
159 template<typename _Tp, typename _Res>
160 using _If_sv = enable_if_t<
161 __and_<is_convertible<const _Tp&, __sv_type>,
162 __not_<is_convertible<const _Tp*, const basic_string*>>,
163 __not_<is_convertible<const _Tp&, const _CharT*>>>::value,
164 _Res>;
165
166 // Allows an implicit conversion to __sv_type.
167 _GLIBCXX20_CONSTEXPR
168 static __sv_type
169 _S_to_string_view(__sv_type __svt) noexcept
170 { return __svt; }
171
172 // Wraps a string_view by explicit conversion and thus
173 // allows to add an internal constructor that does not
174 // participate in overload resolution when a string_view
175 // is provided.
176 struct __sv_wrapper
177 {
178 _GLIBCXX20_CONSTEXPR explicit
179 __sv_wrapper(__sv_type __sv) noexcept : _M_sv(__sv) { }
180
181 __sv_type _M_sv;
182 };
183
184 /**
185 * @brief Only internally used: Construct string from a string view
186 * wrapper.
187 * @param __svw string view wrapper.
188 * @param __a Allocator to use.
189 */
190 _GLIBCXX20_CONSTEXPR
191 explicit
192 basic_string(__sv_wrapper __svw, const _Alloc& __a)
193 : basic_string(__svw._M_sv.data(), __svw._M_sv.size(), __a) { }
194#endif
195
196 // Use empty-base optimization: http://www.cantrip.org/emptyopt.html
197 struct _Alloc_hider : allocator_type // TODO check __is_final
198 {
199#if __cplusplus < 201103L
200 _Alloc_hider(pointer __dat, const _Alloc& __a = _Alloc())
201 : allocator_type(__a), _M_p(__dat) { }
202#else
203 _GLIBCXX20_CONSTEXPR
204 _Alloc_hider(pointer __dat, const _Alloc& __a)
205 : allocator_type(__a), _M_p(__dat) { }
206
207 _GLIBCXX20_CONSTEXPR
208 _Alloc_hider(pointer __dat, _Alloc&& __a = _Alloc())
209 : allocator_type(std::move(__a)), _M_p(__dat) { }
210#endif
211
212 pointer _M_p; // The actual data.
213 };
214
215 _Alloc_hider _M_dataplus;
216 size_type _M_string_length;
217
218 enum { _S_local_capacity = 15 / sizeof(_CharT) };
219
220 union
221 {
222 _CharT _M_local_buf[_S_local_capacity + 1];
223 size_type _M_allocated_capacity;
224 };
225
226 _GLIBCXX20_CONSTEXPR
227 void
228 _M_data(pointer __p)
229 { _M_dataplus._M_p = __p; }
230
231 _GLIBCXX20_CONSTEXPR
232 void
233 _M_length(size_type __length)
234 { _M_string_length = __length; }
235
236 _GLIBCXX20_CONSTEXPR
237 pointer
238 _M_data() const
239 { return _M_dataplus._M_p; }
240
241 _GLIBCXX20_CONSTEXPR
242 pointer
243 _M_local_data()
244 {
245#if __cplusplus >= 201103L
246 return std::pointer_traits<pointer>::pointer_to(*_M_local_buf);
247#else
248 return pointer(_M_local_buf);
249#endif
250 }
251
252 _GLIBCXX20_CONSTEXPR
253 const_pointer
254 _M_local_data() const
255 {
256#if __cplusplus >= 201103L
257 return std::pointer_traits<const_pointer>::pointer_to(*_M_local_buf);
258#else
259 return const_pointer(_M_local_buf);
260#endif
261 }
262
263 _GLIBCXX20_CONSTEXPR
264 void
265 _M_capacity(size_type __capacity)
266 { _M_allocated_capacity = __capacity; }
267
268 _GLIBCXX20_CONSTEXPR
269 void
270 _M_set_length(size_type __n)
271 {
272 _M_length(length: __n);
273 traits_type::assign(_M_data()[__n], _CharT());
274 }
275
276 _GLIBCXX20_CONSTEXPR
277 bool
278 _M_is_local() const
279 {
280 if (_M_data() == _M_local_data())
281 {
282 if (_M_string_length > _S_local_capacity)
283 __builtin_unreachable();
284 return true;
285 }
286 return false;
287 }
288
289 // Create & Destroy
290 _GLIBCXX20_CONSTEXPR
291 pointer
292 _M_create(size_type&, size_type);
293
294 _GLIBCXX20_CONSTEXPR
295 void
296 _M_dispose()
297 {
298 if (!_M_is_local())
299 _M_destroy(size: _M_allocated_capacity);
300 }
301
302 _GLIBCXX20_CONSTEXPR
303 void
304 _M_destroy(size_type __size) throw()
305 { _Alloc_traits::deallocate(_M_get_allocator(), _M_data(), __size + 1); }
306
307#if __cplusplus < 201103L || defined _GLIBCXX_DEFINING_STRING_INSTANTIATIONS
308 // _M_construct_aux is used to implement the 21.3.1 para 15 which
309 // requires special behaviour if _InIterator is an integral type
310 template<typename _InIterator>
311 void
312 _M_construct_aux(_InIterator __beg, _InIterator __end,
313 std::__false_type)
314 {
315 typedef typename iterator_traits<_InIterator>::iterator_category _Tag;
316 _M_construct(__beg, __end, _Tag());
317 }
318
319 // _GLIBCXX_RESOLVE_LIB_DEFECTS
320 // 438. Ambiguity in the "do the right thing" clause
321 template<typename _Integer>
322 void
323 _M_construct_aux(_Integer __beg, _Integer __end, std::__true_type)
324 { _M_construct_aux_2(static_cast<size_type>(__beg), __end); }
325
326 void
327 _M_construct_aux_2(size_type __req, _CharT __c)
328 { _M_construct(__req, __c); }
329#endif
330
331 // For Input Iterators, used in istreambuf_iterators, etc.
332 template<typename _InIterator>
333 _GLIBCXX20_CONSTEXPR
334 void
335 _M_construct(_InIterator __beg, _InIterator __end,
336 std::input_iterator_tag);
337
338 // For forward_iterators up to random_access_iterators, used for
339 // string::iterator, _CharT*, etc.
340 template<typename _FwdIterator>
341 _GLIBCXX20_CONSTEXPR
342 void
343 _M_construct(_FwdIterator __beg, _FwdIterator __end,
344 std::forward_iterator_tag);
345
346 _GLIBCXX20_CONSTEXPR
347 void
348 _M_construct(size_type __req, _CharT __c);
349
350 // Construct using block of memory of known size.
351 // If _Terminated is true assume that source is already 0 terminated.
352 template<bool _Terminated>
353 _GLIBCXX20_CONSTEXPR
354 void
355 _M_construct(const _CharT *__c, size_type __n);
356
357 _GLIBCXX20_CONSTEXPR
358 allocator_type&
359 _M_get_allocator()
360 { return _M_dataplus; }
361
362 _GLIBCXX20_CONSTEXPR
363 const allocator_type&
364 _M_get_allocator() const
365 { return _M_dataplus; }
366
367 // Ensure that _M_local_buf is the active member of the union.
368 __attribute__((__always_inline__))
369 _GLIBCXX14_CONSTEXPR
370 void
371 _M_init_local_buf() _GLIBCXX_NOEXCEPT
372 {
373#if __glibcxx_is_constant_evaluated
374 if (std::is_constant_evaluated())
375 for (size_type __i = 0; __i <= _S_local_capacity; ++__i)
376 _M_local_buf[__i] = _CharT();
377#endif
378 }
379
380 __attribute__((__always_inline__))
381 _GLIBCXX14_CONSTEXPR
382 pointer
383 _M_use_local_data() _GLIBCXX_NOEXCEPT
384 {
385#if __cpp_lib_is_constant_evaluated
386 _M_init_local_buf();
387#endif
388 return _M_local_data();
389 }
390
391 private:
392
393#ifdef _GLIBCXX_DISAMBIGUATE_REPLACE_INST
394 // The explicit instantiations in misc-inst.cc require this due to
395 // https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64063
396 template<typename _Tp, bool _Requires =
397 !__are_same<_Tp, _CharT*>::__value
398 && !__are_same<_Tp, const _CharT*>::__value
399 && !__are_same<_Tp, iterator>::__value
400 && !__are_same<_Tp, const_iterator>::__value>
401 struct __enable_if_not_native_iterator
402 { typedef basic_string& __type; };
403 template<typename _Tp>
404 struct __enable_if_not_native_iterator<_Tp, false> { };
405#endif
406
407 _GLIBCXX20_CONSTEXPR
408 size_type
409 _M_check(size_type __pos, const char* __s) const
410 {
411 if (__pos > this->size())
412 __throw_out_of_range_fmt(__N("%s: __pos (which is %zu) > "
413 "this->size() (which is %zu)"),
414 __s, __pos, this->size());
415 return __pos;
416 }
417
418 _GLIBCXX20_CONSTEXPR
419 void
420 _M_check_length(size_type __n1, size_type __n2, const char* __s) const
421 {
422 if (this->max_size() - (this->size() - __n1) < __n2)
423 __throw_length_error(__N(__s));
424 }
425
426
427 // NB: _M_limit doesn't check for a bad __pos value.
428 _GLIBCXX20_CONSTEXPR
429 size_type
430 _M_limit(size_type __pos, size_type __off) const _GLIBCXX_NOEXCEPT
431 {
432 const bool __testoff = __off < this->size() - __pos;
433 return __testoff ? __off : this->size() - __pos;
434 }
435
436 // True if _Rep and source do not overlap.
437 bool
438 _M_disjunct(const _CharT* __s) const _GLIBCXX_NOEXCEPT
439 {
440 return (less<const _CharT*>()(__s, _M_data())
441 || less<const _CharT*>()(_M_data() + this->size(), __s));
442 }
443
444 // When __n = 1 way faster than the general multichar
445 // traits_type::copy/move/assign.
446 _GLIBCXX20_CONSTEXPR
447 static void
448 _S_copy(_CharT* __d, const _CharT* __s, size_type __n)
449 {
450 if (__n == 1)
451 traits_type::assign(*__d, *__s);
452 else
453 traits_type::copy(__d, __s, __n);
454 }
455
456 _GLIBCXX20_CONSTEXPR
457 static void
458 _S_move(_CharT* __d, const _CharT* __s, size_type __n)
459 {
460 if (__n == 1)
461 traits_type::assign(*__d, *__s);
462 else
463 traits_type::move(__d, __s, __n);
464 }
465
466 _GLIBCXX20_CONSTEXPR
467 static void
468 _S_assign(_CharT* __d, size_type __n, _CharT __c)
469 {
470 if (__n == 1)
471 traits_type::assign(*__d, __c);
472 else
473 traits_type::assign(__d, __n, __c);
474 }
475
476#pragma GCC diagnostic push
477#pragma GCC diagnostic ignored "-Wc++17-extensions"
478 // _S_copy_chars is a separate template to permit specialization
479 // to optimize for the common case of pointers as iterators.
480 template<class _Iterator>
481 _GLIBCXX20_CONSTEXPR
482 static void
483 _S_copy_chars(_CharT* __p, _Iterator __k1, _Iterator __k2)
484 {
485#if __cplusplus >= 201103L
486 using _IterBase = decltype(std::__niter_base(__k1));
487 if constexpr (__or_<is_same<_IterBase, _CharT*>,
488 is_same<_IterBase, const _CharT*>>::value)
489 _S_copy(d: __p, s: std::__niter_base(__k1), n: __k2 - __k1);
490#if __cpp_lib_concepts
491 else if constexpr (requires {
492 requires contiguous_iterator<_Iterator>;
493 { std::to_address(__k1) }
494 -> convertible_to<const _CharT*>;
495 })
496 {
497 const auto __d = __k2 - __k1;
498 (void) (__k1 + __d); // See P3349R1
499 _S_copy(d: __p, s: std::to_address(__k1), n: static_cast<size_type>(__d));
500 }
501#endif
502 else
503#endif
504 for (; __k1 != __k2; ++__k1, (void)++__p)
505 traits_type::assign(*__p, static_cast<_CharT>(*__k1));
506 }
507#pragma GCC diagnostic pop
508
509#if __cplusplus < 201103L || defined _GLIBCXX_DEFINING_STRING_INSTANTIATIONS
510 static void
511 _S_copy_chars(_CharT* __p, iterator __k1, iterator __k2)
512 { _S_copy_chars(__p, __k1.base(), __k2.base()); }
513
514 static void
515 _S_copy_chars(_CharT* __p, const_iterator __k1, const_iterator __k2)
516 { _S_copy_chars(__p, __k1.base(), __k2.base()); }
517
518 static void
519 _S_copy_chars(_CharT* __p, _CharT* __k1, _CharT* __k2)
520 { _S_copy(__p, __k1, __k2 - __k1); }
521
522 static void
523 _S_copy_chars(_CharT* __p, const _CharT* __k1, const _CharT* __k2)
524 { _S_copy(__p, __k1, __k2 - __k1); }
525#endif
526
527#if __glibcxx_containers_ranges // C++ >= 23
528 // pre: __n == ranges::distance(__rg). __p+[0,__n) is a valid range.
529 template<typename _Rg>
530 static constexpr void
531 _S_copy_range(pointer __p, _Rg&& __rg, size_type __n)
532 {
533 if constexpr (requires {
534 requires ranges::contiguous_range<_Rg>;
535 { ranges::data(std::forward<_Rg>(__rg)) }
536 -> convertible_to<const _CharT*>;
537 })
538 _S_copy(__p, ranges::data(std::forward<_Rg>(__rg)), __n);
539 else
540 {
541 auto __first = ranges::begin(__rg);
542 const auto __last = ranges::end(__rg);
543 for (; __first != __last; ++__first)
544 traits_type::assign(*__p++, static_cast<_CharT>(*__first));
545 }
546 }
547#endif
548
549 _GLIBCXX20_CONSTEXPR
550 static int
551 _S_compare(size_type __n1, size_type __n2) _GLIBCXX_NOEXCEPT
552 {
553 const difference_type __d = difference_type(__n1 - __n2);
554
555 if (__d > __gnu_cxx::__numeric_traits<int>::__max)
556 return __gnu_cxx::__numeric_traits<int>::__max;
557 else if (__d < __gnu_cxx::__numeric_traits<int>::__min)
558 return __gnu_cxx::__numeric_traits<int>::__min;
559 else
560 return int(__d);
561 }
562
563 _GLIBCXX20_CONSTEXPR
564 void
565 _M_assign(const basic_string&);
566
567 _GLIBCXX20_CONSTEXPR
568 void
569 _M_mutate(size_type __pos, size_type __len1, const _CharT* __s,
570 size_type __len2);
571
572 _GLIBCXX20_CONSTEXPR
573 void
574 _M_erase(size_type __pos, size_type __n);
575
576 public:
577 // Construct/copy/destroy:
578 // NB: We overload ctors in some cases instead of using default
579 // arguments, per 17.4.4.4 para. 2 item 2.
580
581 /**
582 * @brief Default constructor creates an empty string.
583 */
584 _GLIBCXX20_CONSTEXPR
585 basic_string()
586 _GLIBCXX_NOEXCEPT_IF(is_nothrow_default_constructible<_Alloc>::value)
587#if __cpp_concepts && __glibcxx_type_trait_variable_templates
588 requires is_default_constructible_v<_Alloc>
589#endif
590 : _M_dataplus(_M_local_data())
591 {
592 _M_init_local_buf();
593 _M_set_length(n: 0);
594 }
595
596 /**
597 * @brief Construct an empty string using allocator @a a.
598 */
599 _GLIBCXX20_CONSTEXPR
600 explicit
601 basic_string(const _Alloc& __a) _GLIBCXX_NOEXCEPT
602 : _M_dataplus(_M_local_data(), __a)
603 {
604 _M_init_local_buf();
605 _M_set_length(n: 0);
606 }
607
608 /**
609 * @brief Construct string with copy of value of @a __str.
610 * @param __str Source string.
611 */
612 _GLIBCXX20_CONSTEXPR
613 basic_string(const basic_string& __str)
614 : _M_dataplus(_M_local_data(),
615 _Alloc_traits::_S_select_on_copy(__str._M_get_allocator()))
616 {
617 _M_construct<true>(__str._M_data(), __str.length());
618 }
619
620 // _GLIBCXX_RESOLVE_LIB_DEFECTS
621 // 2583. no way to supply an allocator for basic_string(str, pos)
622 /**
623 * @brief Construct string as copy of a substring.
624 * @param __str Source string.
625 * @param __pos Index of first character to copy from.
626 * @param __a Allocator to use.
627 */
628 _GLIBCXX20_CONSTEXPR
629 basic_string(const basic_string& __str, size_type __pos,
630 const _Alloc& __a = _Alloc())
631 : _M_dataplus(_M_local_data(), __a)
632 {
633 const _CharT* __start = __str._M_data()
634 + __str._M_check(__pos, s: "basic_string::basic_string");
635 _M_construct(__start, __start + __str._M_limit(__pos, off: npos),
636 std::forward_iterator_tag());
637 }
638
639 /**
640 * @brief Construct string as copy of a substring.
641 * @param __str Source string.
642 * @param __pos Index of first character to copy from.
643 * @param __n Number of characters to copy.
644 */
645 _GLIBCXX20_CONSTEXPR
646 basic_string(const basic_string& __str, size_type __pos,
647 size_type __n)
648 : _M_dataplus(_M_local_data())
649 {
650 const _CharT* __start = __str._M_data()
651 + __str._M_check(__pos, s: "basic_string::basic_string");
652 _M_construct(__start, __start + __str._M_limit(__pos, off: __n),
653 std::forward_iterator_tag());
654 }
655
656 /**
657 * @brief Construct string as copy of a substring.
658 * @param __str Source string.
659 * @param __pos Index of first character to copy from.
660 * @param __n Number of characters to copy.
661 * @param __a Allocator to use.
662 */
663 _GLIBCXX20_CONSTEXPR
664 basic_string(const basic_string& __str, size_type __pos,
665 size_type __n, const _Alloc& __a)
666 : _M_dataplus(_M_local_data(), __a)
667 {
668 const _CharT* __start
669 = __str._M_data() + __str._M_check(__pos, s: "string::string");
670 _M_construct(__start, __start + __str._M_limit(__pos, off: __n),
671 std::forward_iterator_tag());
672 }
673
674 /**
675 * @brief Construct string initialized by a character %array.
676 * @param __s Source character %array.
677 * @param __n Number of characters to copy.
678 * @param __a Allocator to use (default is default allocator).
679 *
680 * NB: @a __s must have at least @a __n characters, &apos;\\0&apos;
681 * has no special meaning.
682 */
683 _GLIBCXX20_CONSTEXPR
684 basic_string(const _CharT* __s, size_type __n,
685 const _Alloc& __a = _Alloc())
686 : _M_dataplus(_M_local_data(), __a)
687 {
688 // NB: Not required, but considered best practice.
689 if (__s == 0 && __n > 0)
690 std::__throw_logic_error(__N("basic_string: "
691 "construction from null is not valid"));
692 _M_construct(__s, __s + __n, std::forward_iterator_tag());
693 }
694
695 /**
696 * @brief Construct string as copy of a C string.
697 * @param __s Source C string.
698 * @param __a Allocator to use (default is default allocator).
699 */
700#if __cpp_deduction_guides && ! defined _GLIBCXX_DEFINING_STRING_INSTANTIATIONS
701 // _GLIBCXX_RESOLVE_LIB_DEFECTS
702 // 3076. basic_string CTAD ambiguity
703 template<typename = _RequireAllocator<_Alloc>>
704#endif
705 _GLIBCXX20_CONSTEXPR
706 basic_string(const _CharT* __s, const _Alloc& __a = _Alloc())
707 : _M_dataplus(_M_local_data(), __a)
708 {
709 // NB: Not required, but considered best practice.
710 if (__s == 0)
711 std::__throw_logic_error(__N("basic_string: "
712 "construction from null is not valid"));
713 const _CharT* __end = __s + traits_type::length(__s);
714 _M_construct(__s, __end, forward_iterator_tag());
715 }
716
717 /**
718 * @brief Construct string as multiple characters.
719 * @param __n Number of characters.
720 * @param __c Character to use.
721 * @param __a Allocator to use (default is default allocator).
722 */
723#if __cpp_deduction_guides && ! defined _GLIBCXX_DEFINING_STRING_INSTANTIATIONS
724 // _GLIBCXX_RESOLVE_LIB_DEFECTS
725 // 3076. basic_string CTAD ambiguity
726 template<typename = _RequireAllocator<_Alloc>>
727#endif
728 _GLIBCXX20_CONSTEXPR
729 basic_string(size_type __n, _CharT __c, const _Alloc& __a = _Alloc())
730 : _M_dataplus(_M_local_data(), __a)
731 { _M_construct(__n, __c); }
732
733#if __cplusplus >= 201103L
734 /**
735 * @brief Move construct string.
736 * @param __str Source string.
737 *
738 * The newly-created string contains the exact contents of @a __str.
739 * @a __str is a valid, but unspecified string.
740 */
741 _GLIBCXX20_CONSTEXPR
742 basic_string(basic_string&& __str) noexcept
743 : _M_dataplus(_M_local_data(), std::move(__str._M_get_allocator()))
744 {
745 if (__str._M_is_local())
746 {
747 _M_init_local_buf();
748 traits_type::copy(_M_local_buf, __str._M_local_buf,
749 __str.length() + 1);
750 }
751 else
752 {
753 _M_data(__str._M_data());
754 _M_capacity(capacity: __str._M_allocated_capacity);
755 }
756
757 // Must use _M_length() here not _M_set_length() because
758 // basic_stringbuf relies on writing into unallocated capacity so
759 // we mess up the contents if we put a '\0' in the string.
760 _M_length(length: __str.length());
761 __str._M_data(__str._M_use_local_data());
762 __str._M_set_length(n: 0);
763 }
764
765#if __glibcxx_containers_ranges // C++ >= 23
766 /**
767 * @brief Construct a string from a range.
768 * @since C++23
769 */
770 template<__detail::__container_compatible_range<_CharT> _Rg>
771 constexpr
772 basic_string(from_range_t, _Rg&& __rg, const _Alloc& __a = _Alloc())
773 : basic_string(__a)
774 {
775 if constexpr (ranges::forward_range<_Rg> || ranges::sized_range<_Rg>)
776 {
777 const auto __n = static_cast<size_type>(ranges::distance(__rg));
778 reserve(__n);
779 _S_copy_range(_M_data(), std::forward<_Rg>(__rg), __n);
780 _M_set_length(__n);
781 }
782 else
783 {
784 auto __first = ranges::begin(__rg);
785 const auto __last = ranges::end(__rg);
786 for (; __first != __last; ++__first)
787 push_back(*__first);
788 }
789 }
790#endif
791
792 /**
793 * @brief Construct string from an initializer %list.
794 * @param __l std::initializer_list of characters.
795 * @param __a Allocator to use (default is default allocator).
796 */
797 _GLIBCXX20_CONSTEXPR
798 basic_string(initializer_list<_CharT> __l, const _Alloc& __a = _Alloc())
799 : _M_dataplus(_M_local_data(), __a)
800 { _M_construct(__l.begin(), __l.end(), std::forward_iterator_tag()); }
801
802 _GLIBCXX20_CONSTEXPR
803 basic_string(const basic_string& __str, const _Alloc& __a)
804 : _M_dataplus(_M_local_data(), __a)
805 { _M_construct(__str.begin(), __str.end(), std::forward_iterator_tag()); }
806
807 _GLIBCXX20_CONSTEXPR
808 basic_string(basic_string&& __str, const _Alloc& __a)
809 noexcept(_Alloc_traits::_S_always_equal())
810 : _M_dataplus(_M_local_data(), __a)
811 {
812 if (__str._M_is_local())
813 {
814 _M_init_local_buf();
815 traits_type::copy(_M_local_buf, __str._M_local_buf,
816 __str.length() + 1);
817 _M_length(length: __str.length());
818 __str._M_set_length(n: 0);
819 }
820 else if (_Alloc_traits::_S_always_equal()
821 || __str.get_allocator() == __a)
822 {
823 _M_data(__str._M_data());
824 _M_length(length: __str.length());
825 _M_capacity(capacity: __str._M_allocated_capacity);
826 __str._M_data(__str._M_use_local_data());
827 __str._M_set_length(n: 0);
828 }
829 else
830 _M_construct(__str.begin(), __str.end(), std::forward_iterator_tag());
831 }
832#endif // C++11
833
834#if __cplusplus >= 202100L
835 basic_string(nullptr_t) = delete;
836 basic_string& operator=(nullptr_t) = delete;
837#endif // C++23
838
839 /**
840 * @brief Construct string as copy of a range.
841 * @param __beg Start of range.
842 * @param __end End of range.
843 * @param __a Allocator to use (default is default allocator).
844 */
845#if __cplusplus >= 201103L
846 template<typename _InputIterator,
847 typename = std::_RequireInputIter<_InputIterator>>
848#else
849 template<typename _InputIterator>
850#endif
851 _GLIBCXX20_CONSTEXPR
852 basic_string(_InputIterator __beg, _InputIterator __end,
853 const _Alloc& __a = _Alloc())
854 : _M_dataplus(_M_local_data(), __a), _M_string_length(0)
855 {
856#if __cplusplus >= 201103L
857 _M_construct(__beg, __end, std::__iterator_category(__beg));
858#else
859 typedef typename std::__is_integer<_InputIterator>::__type _Integral;
860 _M_construct_aux(__beg, __end, _Integral());
861#endif
862 }
863
864#ifdef __glibcxx_string_view // >= C++17
865 /**
866 * @brief Construct string from a substring of a string_view.
867 * @param __t Source object convertible to string view.
868 * @param __pos The index of the first character to copy from __t.
869 * @param __n The number of characters to copy from __t.
870 * @param __a Allocator to use.
871 */
872 template<typename _Tp,
873 typename = enable_if_t<is_convertible_v<const _Tp&, __sv_type>>>
874 _GLIBCXX20_CONSTEXPR
875 basic_string(const _Tp& __t, size_type __pos, size_type __n,
876 const _Alloc& __a = _Alloc())
877 : basic_string(_S_to_string_view(svt: __t).substr(__pos, __n), __a) { }
878
879 /**
880 * @brief Construct string from a string_view.
881 * @param __t Source object convertible to string view.
882 * @param __a Allocator to use (default is default allocator).
883 */
884 template<typename _Tp, typename = _If_sv<_Tp, void>>
885 _GLIBCXX20_CONSTEXPR
886 explicit
887 basic_string(const _Tp& __t, const _Alloc& __a = _Alloc())
888 : basic_string(__sv_wrapper(_S_to_string_view(svt: __t)), __a) { }
889#endif // C++17
890
891 /**
892 * @brief Destroy the string instance.
893 */
894 _GLIBCXX20_CONSTEXPR
895 ~basic_string()
896 { _M_dispose(); }
897
898 /**
899 * @brief Assign the value of @a str to this string.
900 * @param __str Source string.
901 */
902 _GLIBCXX20_CONSTEXPR
903 basic_string&
904 operator=(const basic_string& __str)
905 {
906 return this->assign(__str);
907 }
908
909 /**
910 * @brief Copy contents of @a s into this string.
911 * @param __s Source null-terminated string.
912 */
913 _GLIBCXX20_CONSTEXPR
914 basic_string&
915 operator=(const _CharT* __s)
916 { return this->assign(__s); }
917
918 /**
919 * @brief Set value to string of length 1.
920 * @param __c Source character.
921 *
922 * Assigning to a character makes this string length 1 and
923 * (*this)[0] == @a c.
924 */
925 _GLIBCXX20_CONSTEXPR
926 basic_string&
927 operator=(_CharT __c)
928 {
929 this->assign(1, __c);
930 return *this;
931 }
932
933#if __cplusplus >= 201103L
934 /**
935 * @brief Move assign the value of @a str to this string.
936 * @param __str Source string.
937 *
938 * The contents of @a str are moved into this string (without copying).
939 * @a str is a valid, but unspecified string.
940 */
941 // _GLIBCXX_RESOLVE_LIB_DEFECTS
942 // 2063. Contradictory requirements for string move assignment
943 _GLIBCXX20_CONSTEXPR
944 basic_string&
945 operator=(basic_string&& __str)
946 noexcept(_Alloc_traits::_S_nothrow_move())
947 {
948 const bool __equal_allocs = _Alloc_traits::_S_always_equal()
949 || _M_get_allocator() == __str._M_get_allocator();
950 if (!_M_is_local() && _Alloc_traits::_S_propagate_on_move_assign()
951 && !__equal_allocs)
952 {
953 // Destroy existing storage before replacing allocator.
954 _M_destroy(size: _M_allocated_capacity);
955 _M_data(_M_local_data());
956 _M_set_length(n: 0);
957 }
958 // Replace allocator if POCMA is true.
959 std::__alloc_on_move(_M_get_allocator(), __str._M_get_allocator());
960
961 if (__str._M_is_local())
962 {
963 // We've always got room for a short string, just copy it
964 // (unless this is a self-move, because that would violate the
965 // char_traits::copy precondition that the ranges don't overlap).
966 if (__builtin_expect(std::__addressof(__str) != this, true))
967 {
968 if (__str.size())
969 this->_S_copy(d: _M_data(), s: __str._M_data(), n: __str.size());
970 _M_set_length(n: __str.size());
971 }
972 }
973 else if (_Alloc_traits::_S_propagate_on_move_assign() || __equal_allocs)
974 {
975 // Just move the allocated pointer, our allocator can free it.
976 pointer __data = nullptr;
977 size_type __capacity;
978 if (!_M_is_local())
979 {
980 if (__equal_allocs)
981 {
982 // __str can reuse our existing storage.
983 __data = _M_data();
984 __capacity = _M_allocated_capacity;
985 }
986 else // __str can't use it, so free it.
987 _M_destroy(size: _M_allocated_capacity);
988 }
989
990 _M_data(__str._M_data());
991 _M_length(length: __str.length());
992 _M_capacity(capacity: __str._M_allocated_capacity);
993 if (__data)
994 {
995 __str._M_data(__data);
996 __str._M_capacity(__capacity);
997 }
998 else
999 __str._M_data(__str._M_use_local_data());
1000 }
1001 else // Need to do a deep copy
1002 _M_assign(__str);
1003 __str.clear();
1004 return *this;
1005 }
1006
1007 /**
1008 * @brief Set value to string constructed from initializer %list.
1009 * @param __l std::initializer_list.
1010 */
1011 _GLIBCXX20_CONSTEXPR
1012 basic_string&
1013 operator=(initializer_list<_CharT> __l)
1014 {
1015 this->assign(__l.begin(), __l.size());
1016 return *this;
1017 }
1018#endif // C++11
1019
1020#ifdef __glibcxx_string_view // >= C++17
1021 /**
1022 * @brief Set value to string constructed from a string_view.
1023 * @param __svt An object convertible to string_view.
1024 */
1025 template<typename _Tp>
1026 _GLIBCXX20_CONSTEXPR
1027 _If_sv<_Tp, basic_string&>
1028 operator=(const _Tp& __svt)
1029 { return this->assign(__svt); }
1030
1031 /**
1032 * @brief Convert to a string_view.
1033 * @return A string_view.
1034 */
1035 _GLIBCXX20_CONSTEXPR
1036 operator __sv_type() const noexcept
1037 { return __sv_type(data(), size()); }
1038#endif // C++17
1039
1040 // Iterators:
1041 /**
1042 * Returns a read/write iterator that points to the first character in
1043 * the %string.
1044 */
1045 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1046 iterator
1047 begin() _GLIBCXX_NOEXCEPT
1048 { return iterator(_M_data()); }
1049
1050 /**
1051 * Returns a read-only (constant) iterator that points to the first
1052 * character in the %string.
1053 */
1054 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1055 const_iterator
1056 begin() const _GLIBCXX_NOEXCEPT
1057 { return const_iterator(_M_data()); }
1058
1059 /**
1060 * Returns a read/write iterator that points one past the last
1061 * character in the %string.
1062 */
1063 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1064 iterator
1065 end() _GLIBCXX_NOEXCEPT
1066 { return iterator(_M_data() + this->size()); }
1067
1068 /**
1069 * Returns a read-only (constant) iterator that points one past the
1070 * last character in the %string.
1071 */
1072 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1073 const_iterator
1074 end() const _GLIBCXX_NOEXCEPT
1075 { return const_iterator(_M_data() + this->size()); }
1076
1077 /**
1078 * Returns a read/write reverse iterator that points to the last
1079 * character in the %string. Iteration is done in reverse element
1080 * order.
1081 */
1082 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1083 reverse_iterator
1084 rbegin() _GLIBCXX_NOEXCEPT
1085 { return reverse_iterator(this->end()); }
1086
1087 /**
1088 * Returns a read-only (constant) reverse iterator that points
1089 * to the last character in the %string. Iteration is done in
1090 * reverse element order.
1091 */
1092 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1093 const_reverse_iterator
1094 rbegin() const _GLIBCXX_NOEXCEPT
1095 { return const_reverse_iterator(this->end()); }
1096
1097 /**
1098 * Returns a read/write reverse iterator that points to one before the
1099 * first character in the %string. Iteration is done in reverse
1100 * element order.
1101 */
1102 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1103 reverse_iterator
1104 rend() _GLIBCXX_NOEXCEPT
1105 { return reverse_iterator(this->begin()); }
1106
1107 /**
1108 * Returns a read-only (constant) reverse iterator that points
1109 * to one before the first character in the %string. Iteration
1110 * is done in reverse element order.
1111 */
1112 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1113 const_reverse_iterator
1114 rend() const _GLIBCXX_NOEXCEPT
1115 { return const_reverse_iterator(this->begin()); }
1116
1117#if __cplusplus >= 201103L
1118 /**
1119 * Returns a read-only (constant) iterator that points to the first
1120 * character in the %string.
1121 */
1122 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1123 const_iterator
1124 cbegin() const noexcept
1125 { return const_iterator(this->_M_data()); }
1126
1127 /**
1128 * Returns a read-only (constant) iterator that points one past the
1129 * last character in the %string.
1130 */
1131 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1132 const_iterator
1133 cend() const noexcept
1134 { return const_iterator(this->_M_data() + this->size()); }
1135
1136 /**
1137 * Returns a read-only (constant) reverse iterator that points
1138 * to the last character in the %string. Iteration is done in
1139 * reverse element order.
1140 */
1141 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1142 const_reverse_iterator
1143 crbegin() const noexcept
1144 { return const_reverse_iterator(this->end()); }
1145
1146 /**
1147 * Returns a read-only (constant) reverse iterator that points
1148 * to one before the first character in the %string. Iteration
1149 * is done in reverse element order.
1150 */
1151 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1152 const_reverse_iterator
1153 crend() const noexcept
1154 { return const_reverse_iterator(this->begin()); }
1155#endif
1156
1157 public:
1158 // Capacity:
1159 /// Returns the number of characters in the string, not including any
1160 /// null-termination.
1161 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1162 size_type
1163 size() const _GLIBCXX_NOEXCEPT
1164 {
1165 size_type __sz = _M_string_length;
1166 if (__sz > max_size ())
1167 __builtin_unreachable ();
1168 return __sz;
1169 }
1170
1171 /// Returns the number of characters in the string, not including any
1172 /// null-termination.
1173 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1174 size_type
1175 length() const _GLIBCXX_NOEXCEPT
1176 { return size(); }
1177
1178 /// Returns the size() of the largest possible %string.
1179 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1180 size_type
1181 max_size() const _GLIBCXX_NOEXCEPT
1182 {
1183 const size_t __diffmax
1184 = __gnu_cxx::__numeric_traits<ptrdiff_t>::__max / sizeof(_CharT);
1185 const size_t __allocmax = _Alloc_traits::max_size(_M_get_allocator());
1186 return (std::min)(a: __diffmax, b: __allocmax) - 1;
1187 }
1188
1189 /**
1190 * @brief Resizes the %string to the specified number of characters.
1191 * @param __n Number of characters the %string should contain.
1192 * @param __c Character to fill any new elements.
1193 *
1194 * This function will %resize the %string to the specified
1195 * number of characters. If the number is smaller than the
1196 * %string's current size the %string is truncated, otherwise
1197 * the %string is extended and new elements are %set to @a __c.
1198 */
1199 _GLIBCXX20_CONSTEXPR
1200 void
1201 resize(size_type __n, _CharT __c);
1202
1203 /**
1204 * @brief Resizes the %string to the specified number of characters.
1205 * @param __n Number of characters the %string should contain.
1206 *
1207 * This function will resize the %string to the specified length. If
1208 * the new size is smaller than the %string's current size the %string
1209 * is truncated, otherwise the %string is extended and new characters
1210 * are default-constructed. For basic types such as char, this means
1211 * setting them to 0.
1212 */
1213 _GLIBCXX20_CONSTEXPR
1214 void
1215 resize(size_type __n)
1216 { this->resize(__n, _CharT()); }
1217
1218#if __cplusplus >= 201103L
1219#pragma GCC diagnostic push
1220#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
1221 /// A non-binding request to reduce capacity() to size().
1222 _GLIBCXX20_CONSTEXPR
1223 void
1224 shrink_to_fit() noexcept
1225 { reserve(); }
1226#pragma GCC diagnostic pop
1227#endif
1228
1229#ifdef __glibcxx_string_resize_and_overwrite // C++ >= 23
1230 /** Resize the string and call a function to fill it.
1231 *
1232 * @param __n The maximum size requested.
1233 * @param __op A callable object that writes characters to the string.
1234 *
1235 * This is a low-level function that is easy to misuse, be careful.
1236 *
1237 * Calling `str.resize_and_overwrite(n, op)` will reserve at least `n`
1238 * characters in `str`, evaluate `n2 = std::move(op)(str.data(), n)`,
1239 * and finally set the string length to `n2` (adding a null terminator
1240 * at the end). The function object `op` is allowed to write to the
1241 * extra capacity added by the initial reserve operation, which is not
1242 * allowed if you just call `str.reserve(n)` yourself.
1243 *
1244 * This can be used to efficiently fill a `string` buffer without the
1245 * overhead of zero-initializing characters that will be overwritten
1246 * anyway.
1247 *
1248 * The callable `op` must not access the string directly (only through
1249 * the pointer passed as its first argument), must not write more than
1250 * `n` characters to the string, must return a value no greater than `n`,
1251 * and must ensure that all characters up to the returned length are
1252 * valid after it returns (i.e. there must be no uninitialized values
1253 * left in the string after the call, because accessing them would
1254 * have undefined behaviour). If `op` exits by throwing an exception
1255 * the behaviour is undefined.
1256 *
1257 * @since C++23
1258 */
1259 template<typename _Operation>
1260 constexpr void
1261 resize_and_overwrite(size_type __n, _Operation __op);
1262#endif
1263
1264#if __cplusplus >= 201103L
1265 /// Non-standard version of resize_and_overwrite for C++11 and above.
1266 template<typename _Operation>
1267 _GLIBCXX20_CONSTEXPR void
1268 __resize_and_overwrite(size_type __n, _Operation __op);
1269#endif
1270
1271 /**
1272 * Returns the total number of characters that the %string can hold
1273 * before needing to allocate more memory.
1274 */
1275 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1276 size_type
1277 capacity() const _GLIBCXX_NOEXCEPT
1278 {
1279 size_t __sz = _M_is_local() ? size_type(_S_local_capacity)
1280 : _M_allocated_capacity;
1281 if (__sz < _S_local_capacity || __sz > max_size ())
1282 __builtin_unreachable ();
1283 return __sz;
1284 }
1285
1286 /**
1287 * @brief Attempt to preallocate enough memory for specified number of
1288 * characters.
1289 * @param __res_arg Number of characters required.
1290 * @throw std::length_error If @a __res_arg exceeds @c max_size().
1291 *
1292 * This function attempts to reserve enough memory for the
1293 * %string to hold the specified number of characters. If the
1294 * number requested is more than max_size(), length_error is
1295 * thrown.
1296 *
1297 * The advantage of this function is that if optimal code is a
1298 * necessity and the user can determine the string length that will be
1299 * required, the user can reserve the memory in %advance, and thus
1300 * prevent a possible reallocation of memory and copying of %string
1301 * data.
1302 */
1303 _GLIBCXX20_CONSTEXPR
1304 void
1305 reserve(size_type __res_arg);
1306
1307 /**
1308 * Equivalent to shrink_to_fit().
1309 */
1310#if __cplusplus > 201703L
1311 [[deprecated("use shrink_to_fit() instead")]]
1312#endif
1313 _GLIBCXX20_CONSTEXPR
1314 void
1315 reserve();
1316
1317 /**
1318 * Erases the string, making it empty.
1319 */
1320 _GLIBCXX20_CONSTEXPR
1321 void
1322 clear() _GLIBCXX_NOEXCEPT
1323 { _M_set_length(n: 0); }
1324
1325 /**
1326 * Returns true if the %string is empty. Equivalent to
1327 * <code>*this == ""</code>.
1328 */
1329 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1330 bool
1331 empty() const _GLIBCXX_NOEXCEPT
1332 { return _M_string_length == 0; }
1333
1334 // Element access:
1335 /**
1336 * @brief Subscript access to the data contained in the %string.
1337 * @param __pos The index of the character to access.
1338 * @return Read-only (constant) reference to the character.
1339 *
1340 * This operator allows for easy, array-style, data access.
1341 * Note that data access with this operator is unchecked and
1342 * out_of_range lookups are not defined. (For checked lookups
1343 * see at().)
1344 */
1345 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1346 const_reference
1347 operator[] (size_type __pos) const _GLIBCXX_NOEXCEPT
1348 {
1349 __glibcxx_assert(__pos <= size());
1350 return _M_data()[__pos];
1351 }
1352
1353 /**
1354 * @brief Subscript access to the data contained in the %string.
1355 * @param __pos The index of the character to access.
1356 * @return Read/write reference to the character.
1357 *
1358 * This operator allows for easy, array-style, data access.
1359 * Note that data access with this operator is unchecked and
1360 * out_of_range lookups are not defined. (For checked lookups
1361 * see at().)
1362 */
1363 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1364 reference
1365 operator[](size_type __pos)
1366 {
1367 // Allow pos == size() both in C++98 mode, as v3 extension,
1368 // and in C++11 mode.
1369 __glibcxx_assert(__pos <= size());
1370 // In pedantic mode be strict in C++98 mode.
1371 _GLIBCXX_DEBUG_PEDASSERT(__cplusplus >= 201103L || __pos < size());
1372 return _M_data()[__pos];
1373 }
1374
1375 /**
1376 * @brief Provides access to the data contained in the %string.
1377 * @param __n The index of the character to access.
1378 * @return Read-only (const) reference to the character.
1379 * @throw std::out_of_range If @a n is an invalid index.
1380 *
1381 * This function provides for safer data access. The parameter is
1382 * first checked that it is in the range of the string. The function
1383 * throws out_of_range if the check fails.
1384 */
1385 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1386 const_reference
1387 at(size_type __n) const
1388 {
1389 if (__n >= this->size())
1390 __throw_out_of_range_fmt(__N("basic_string::at: __n "
1391 "(which is %zu) >= this->size() "
1392 "(which is %zu)"),
1393 __n, this->size());
1394 return _M_data()[__n];
1395 }
1396
1397 /**
1398 * @brief Provides access to the data contained in the %string.
1399 * @param __n The index of the character to access.
1400 * @return Read/write reference to the character.
1401 * @throw std::out_of_range If @a n is an invalid index.
1402 *
1403 * This function provides for safer data access. The parameter is
1404 * first checked that it is in the range of the string. The function
1405 * throws out_of_range if the check fails.
1406 */
1407 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1408 reference
1409 at(size_type __n)
1410 {
1411 if (__n >= size())
1412 __throw_out_of_range_fmt(__N("basic_string::at: __n "
1413 "(which is %zu) >= this->size() "
1414 "(which is %zu)"),
1415 __n, this->size());
1416 return _M_data()[__n];
1417 }
1418
1419#if __cplusplus >= 201103L
1420 /**
1421 * Returns a read/write reference to the data at the first
1422 * element of the %string.
1423 */
1424 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1425 reference
1426 front() noexcept
1427 {
1428 __glibcxx_assert(!empty());
1429 return operator[](0);
1430 }
1431
1432 /**
1433 * Returns a read-only (constant) reference to the data at the first
1434 * element of the %string.
1435 */
1436 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1437 const_reference
1438 front() const noexcept
1439 {
1440 __glibcxx_assert(!empty());
1441 return operator[](0);
1442 }
1443
1444 /**
1445 * Returns a read/write reference to the data at the last
1446 * element of the %string.
1447 */
1448 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1449 reference
1450 back() noexcept
1451 {
1452 __glibcxx_assert(!empty());
1453 return operator[](this->size() - 1);
1454 }
1455
1456 /**
1457 * Returns a read-only (constant) reference to the data at the
1458 * last element of the %string.
1459 */
1460 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
1461 const_reference
1462 back() const noexcept
1463 {
1464 __glibcxx_assert(!empty());
1465 return operator[](this->size() - 1);
1466 }
1467#endif
1468
1469 // Modifiers:
1470 /**
1471 * @brief Append a string to this string.
1472 * @param __str The string to append.
1473 * @return Reference to this string.
1474 */
1475 _GLIBCXX20_CONSTEXPR
1476 basic_string&
1477 operator+=(const basic_string& __str)
1478 { return this->append(__str); }
1479
1480 /**
1481 * @brief Append a C string.
1482 * @param __s The C string to append.
1483 * @return Reference to this string.
1484 */
1485 _GLIBCXX20_CONSTEXPR
1486 basic_string&
1487 operator+=(const _CharT* __s)
1488 { return this->append(__s); }
1489
1490 /**
1491 * @brief Append a character.
1492 * @param __c The character to append.
1493 * @return Reference to this string.
1494 */
1495 _GLIBCXX20_CONSTEXPR
1496 basic_string&
1497 operator+=(_CharT __c)
1498 {
1499 this->push_back(__c);
1500 return *this;
1501 }
1502
1503#if __cplusplus >= 201103L
1504 /**
1505 * @brief Append an initializer_list of characters.
1506 * @param __l The initializer_list of characters to be appended.
1507 * @return Reference to this string.
1508 */
1509 _GLIBCXX20_CONSTEXPR
1510 basic_string&
1511 operator+=(initializer_list<_CharT> __l)
1512 { return this->append(__l.begin(), __l.size()); }
1513#endif // C++11
1514
1515#ifdef __glibcxx_string_view // >= C++17
1516 /**
1517 * @brief Append a string_view.
1518 * @param __svt An object convertible to string_view to be appended.
1519 * @return Reference to this string.
1520 */
1521 template<typename _Tp>
1522 _GLIBCXX20_CONSTEXPR
1523 _If_sv<_Tp, basic_string&>
1524 operator+=(const _Tp& __svt)
1525 { return this->append(__svt); }
1526#endif // C++17
1527
1528 /**
1529 * @brief Append a string to this string.
1530 * @param __str The string to append.
1531 * @return Reference to this string.
1532 */
1533 _GLIBCXX20_CONSTEXPR
1534 basic_string&
1535 append(const basic_string& __str)
1536 { return this->append(__str._M_data(), __str.size()); }
1537
1538 /**
1539 * @brief Append a substring.
1540 * @param __str The string to append.
1541 * @param __pos Index of the first character of str to append.
1542 * @param __n The number of characters to append.
1543 * @return Reference to this string.
1544 * @throw std::out_of_range if @a __pos is not a valid index.
1545 *
1546 * This function appends @a __n characters from @a __str
1547 * starting at @a __pos to this string. If @a __n is is larger
1548 * than the number of available characters in @a __str, the
1549 * remainder of @a __str is appended.
1550 */
1551 _GLIBCXX20_CONSTEXPR
1552 basic_string&
1553 append(const basic_string& __str, size_type __pos, size_type __n = npos)
1554 { return this->append(__str._M_data()
1555 + __str._M_check(__pos, s: "basic_string::append"),
1556 __str._M_limit(__pos, off: __n)); }
1557
1558 /**
1559 * @brief Append a C substring.
1560 * @param __s The C string to append.
1561 * @param __n The number of characters to append.
1562 * @return Reference to this string.
1563 */
1564 _GLIBCXX20_CONSTEXPR
1565 basic_string&
1566 append(const _CharT* __s, size_type __n)
1567 {
1568 __glibcxx_requires_string_len(__s, __n);
1569 _M_check_length(n1: size_type(0), n2: __n, s: "basic_string::append");
1570 return _M_append(__s, __n);
1571 }
1572
1573 /**
1574 * @brief Append a C string.
1575 * @param __s The C string to append.
1576 * @return Reference to this string.
1577 */
1578 _GLIBCXX20_CONSTEXPR
1579 basic_string&
1580 append(const _CharT* __s)
1581 {
1582 __glibcxx_requires_string(__s);
1583 const size_type __n = traits_type::length(__s);
1584 _M_check_length(n1: size_type(0), n2: __n, s: "basic_string::append");
1585 return _M_append(__s, __n);
1586 }
1587
1588 /**
1589 * @brief Append multiple characters.
1590 * @param __n The number of characters to append.
1591 * @param __c The character to use.
1592 * @return Reference to this string.
1593 *
1594 * Appends __n copies of __c to this string.
1595 */
1596 _GLIBCXX20_CONSTEXPR
1597 basic_string&
1598 append(size_type __n, _CharT __c)
1599 { return _M_replace_aux(pos1: this->size(), n1: size_type(0), n2: __n, __c); }
1600
1601#if __glibcxx_containers_ranges // C++ >= 23
1602 /**
1603 * @brief Append a range to the string.
1604 * @param __rg A range of values that are convertible to `value_type`.
1605 * @since C++23
1606 *
1607 * The range `__rg` is allowed to overlap with `*this`.
1608 */
1609 template<__detail::__container_compatible_range<_CharT> _Rg>
1610 constexpr basic_string&
1611 append_range(_Rg&& __rg)
1612 {
1613 // N.B. __rg may overlap with *this, so we must copy from __rg before
1614 // existing elements or iterators referring to *this are invalidated.
1615 // e.g. in s.append_range(views::concat(s, str)), rg overlaps s.
1616 if constexpr (ranges::forward_range<_Rg> || ranges::sized_range<_Rg>)
1617 {
1618 const auto __len = size_type(ranges::distance(__rg));
1619
1620 // Don't care if this addition wraps around, we check it below:
1621 const size_type __newlen = size() + __len;
1622
1623 if ((capacity() - size()) >= __len)
1624 _S_copy_range(_M_data() + size(), std::forward<_Rg>(__rg),
1625 __len);
1626 else
1627 {
1628 _M_check_length(0, __len, "basic_string::append_range");
1629 basic_string __s(_M_get_allocator());
1630 __s.reserve(__newlen);
1631 _S_copy_range(__s._M_data() + size(), std::forward<_Rg>(__rg),
1632 __len);
1633 _S_copy(__s._M_data(), _M_data(), size());
1634 if (!_M_is_local())
1635 _M_destroy(_M_allocated_capacity);
1636 _M_data(__s._M_data());
1637 _M_capacity(__s._M_allocated_capacity);
1638 __s._M_data(__s._M_local_data());
1639 __s._M_length(0);
1640 }
1641 _M_set_length(__newlen); // adds null-terminator
1642 }
1643 else
1644 {
1645 basic_string __s(from_range, std::forward<_Rg>(__rg),
1646 _M_get_allocator());
1647 append(__s);
1648 }
1649 return *this;
1650 }
1651#endif
1652
1653#if __cplusplus >= 201103L
1654 /**
1655 * @brief Append an initializer_list of characters.
1656 * @param __l The initializer_list of characters to append.
1657 * @return Reference to this string.
1658 */
1659 _GLIBCXX20_CONSTEXPR
1660 basic_string&
1661 append(initializer_list<_CharT> __l)
1662 { return this->append(__l.begin(), __l.size()); }
1663#endif // C++11
1664
1665 /**
1666 * @brief Append a range of characters.
1667 * @param __first Iterator referencing the first character to append.
1668 * @param __last Iterator marking the end of the range.
1669 * @return Reference to this string.
1670 *
1671 * Appends characters in the range [__first,__last) to this string.
1672 */
1673#if __cplusplus >= 201103L
1674 template<class _InputIterator,
1675 typename = std::_RequireInputIter<_InputIterator>>
1676 _GLIBCXX20_CONSTEXPR
1677#else
1678 template<class _InputIterator>
1679#endif
1680 basic_string&
1681 append(_InputIterator __first, _InputIterator __last)
1682 { return this->replace(end(), end(), __first, __last); }
1683
1684#ifdef __glibcxx_string_view
1685 /**
1686 * @brief Append a string_view.
1687 * @param __svt An object convertible to string_view to be appended.
1688 * @return Reference to this string.
1689 */
1690 template<typename _Tp>
1691 _GLIBCXX20_CONSTEXPR
1692 _If_sv<_Tp, basic_string&>
1693 append(const _Tp& __svt)
1694 {
1695 __sv_type __sv = __svt;
1696 return this->append(__sv.data(), __sv.size());
1697 }
1698
1699 /**
1700 * @brief Append a range of characters from a string_view.
1701 * @param __svt An object convertible to string_view to be appended from.
1702 * @param __pos The position in the string_view to append from.
1703 * @param __n The number of characters to append from the string_view.
1704 * @return Reference to this string.
1705 */
1706 template<typename _Tp>
1707 _GLIBCXX20_CONSTEXPR
1708 _If_sv<_Tp, basic_string&>
1709 append(const _Tp& __svt, size_type __pos, size_type __n = npos)
1710 {
1711 __sv_type __sv = __svt;
1712 return _M_append(s: __sv.data()
1713 + std::__sv_check(size: __sv.size(), __pos, s: "basic_string::append"),
1714 n: std::__sv_limit(size: __sv.size(), __pos, off: __n));
1715 }
1716#endif // C++17
1717
1718 /**
1719 * @brief Append a single character.
1720 * @param __c Character to append.
1721 */
1722 _GLIBCXX20_CONSTEXPR
1723 void
1724 push_back(_CharT __c)
1725 {
1726 const size_type __size = this->size();
1727 if (__size + 1 > this->capacity())
1728 this->_M_mutate(pos: __size, len1: size_type(0), s: 0, len2: size_type(1));
1729 traits_type::assign(this->_M_data()[__size], __c);
1730 this->_M_set_length(n: __size + 1);
1731 }
1732
1733 /**
1734 * @brief Set value to contents of another string.
1735 * @param __str Source string to use.
1736 * @return Reference to this string.
1737 */
1738 _GLIBCXX20_CONSTEXPR
1739 basic_string&
1740 assign(const basic_string& __str)
1741 {
1742#if __cplusplus >= 201103L
1743 if (_Alloc_traits::_S_propagate_on_copy_assign())
1744 {
1745 if (!_Alloc_traits::_S_always_equal() && !_M_is_local()
1746 && _M_get_allocator() != __str._M_get_allocator())
1747 {
1748 // Propagating allocator cannot free existing storage so must
1749 // deallocate it before replacing current allocator.
1750 if (__str.size() <= _S_local_capacity)
1751 {
1752 _M_destroy(size: _M_allocated_capacity);
1753 _M_data(_M_use_local_data());
1754 _M_set_length(n: 0);
1755 }
1756 else
1757 {
1758 const auto __len = __str.size();
1759 auto __alloc = __str._M_get_allocator();
1760 // If this allocation throws there are no effects:
1761 auto __ptr = _S_allocate(a&: __alloc, n: __len + 1);
1762 _M_destroy(size: _M_allocated_capacity);
1763 _M_data(__ptr);
1764 _M_capacity(capacity: __len);
1765 _M_set_length(n: __len);
1766 }
1767 }
1768 std::__alloc_on_copy(_M_get_allocator(), __str._M_get_allocator());
1769 }
1770#endif
1771 this->_M_assign(__str);
1772 return *this;
1773 }
1774
1775#if __cplusplus >= 201103L
1776 /**
1777 * @brief Set value to contents of another string.
1778 * @param __str Source string to use.
1779 * @return Reference to this string.
1780 *
1781 * This function sets this string to the exact contents of @a __str.
1782 * @a __str is a valid, but unspecified string.
1783 */
1784 _GLIBCXX20_CONSTEXPR
1785 basic_string&
1786 assign(basic_string&& __str)
1787 noexcept(_Alloc_traits::_S_nothrow_move())
1788 {
1789 // _GLIBCXX_RESOLVE_LIB_DEFECTS
1790 // 2063. Contradictory requirements for string move assignment
1791 return *this = std::move(__str);
1792 }
1793#endif // C++11
1794
1795 /**
1796 * @brief Set value to a substring of a string.
1797 * @param __str The string to use.
1798 * @param __pos Index of the first character of str.
1799 * @param __n Number of characters to use.
1800 * @return Reference to this string.
1801 * @throw std::out_of_range if @a pos is not a valid index.
1802 *
1803 * This function sets this string to the substring of @a __str
1804 * consisting of @a __n characters at @a __pos. If @a __n is
1805 * is larger than the number of available characters in @a
1806 * __str, the remainder of @a __str is used.
1807 */
1808 _GLIBCXX20_CONSTEXPR
1809 basic_string&
1810 assign(const basic_string& __str, size_type __pos, size_type __n = npos)
1811 { return _M_replace(pos: size_type(0), len1: this->size(), s: __str._M_data()
1812 + __str._M_check(__pos, s: "basic_string::assign"),
1813 len2: __str._M_limit(__pos, off: __n)); }
1814
1815 /**
1816 * @brief Set value to a C substring.
1817 * @param __s The C string to use.
1818 * @param __n Number of characters to use.
1819 * @return Reference to this string.
1820 *
1821 * This function sets the value of this string to the first @a __n
1822 * characters of @a __s. If @a __n is is larger than the number of
1823 * available characters in @a __s, the remainder of @a __s is used.
1824 */
1825 _GLIBCXX20_CONSTEXPR
1826 basic_string&
1827 assign(const _CharT* __s, size_type __n)
1828 {
1829 __glibcxx_requires_string_len(__s, __n);
1830 return _M_replace(pos: size_type(0), len1: this->size(), __s, len2: __n);
1831 }
1832
1833 /**
1834 * @brief Set value to contents of a C string.
1835 * @param __s The C string to use.
1836 * @return Reference to this string.
1837 *
1838 * This function sets the value of this string to the value of @a __s.
1839 * The data is copied, so there is no dependence on @a __s once the
1840 * function returns.
1841 */
1842 _GLIBCXX20_CONSTEXPR
1843 basic_string&
1844 assign(const _CharT* __s)
1845 {
1846 __glibcxx_requires_string(__s);
1847 return _M_replace(pos: size_type(0), len1: this->size(), __s,
1848 len2: traits_type::length(__s));
1849 }
1850
1851 /**
1852 * @brief Set value to multiple characters.
1853 * @param __n Length of the resulting string.
1854 * @param __c The character to use.
1855 * @return Reference to this string.
1856 *
1857 * This function sets the value of this string to @a __n copies of
1858 * character @a __c.
1859 */
1860 _GLIBCXX20_CONSTEXPR
1861 basic_string&
1862 assign(size_type __n, _CharT __c)
1863 { return _M_replace_aux(pos1: size_type(0), n1: this->size(), n2: __n, __c); }
1864
1865 /**
1866 * @brief Set value to a range of characters.
1867 * @param __first Iterator referencing the first character to append.
1868 * @param __last Iterator marking the end of the range.
1869 * @return Reference to this string.
1870 *
1871 * Sets value of string to characters in the range [__first,__last).
1872 */
1873#if __cplusplus >= 201103L
1874#pragma GCC diagnostic push
1875#pragma GCC diagnostic ignored "-Wc++17-extensions"
1876 template<class _InputIterator,
1877 typename = std::_RequireInputIter<_InputIterator>>
1878 _GLIBCXX20_CONSTEXPR
1879 basic_string&
1880 assign(_InputIterator __first, _InputIterator __last)
1881 {
1882 using _IterTraits = iterator_traits<_InputIterator>;
1883 if constexpr (is_pointer<decltype(std::__niter_base(__first))>::value
1884 && is_same<typename _IterTraits::value_type,
1885 _CharT>::value)
1886 {
1887 __glibcxx_requires_valid_range(__first, __last);
1888 return _M_replace(pos: size_type(0), len1: size(),
1889 s: std::__niter_base(__first), len2: __last - __first);
1890 }
1891#if __cplusplus >= 202002L
1892 else if constexpr (contiguous_iterator<_InputIterator>
1893 && is_same_v<iter_value_t<_InputIterator>,
1894 _CharT>)
1895 {
1896 __glibcxx_requires_valid_range(__first, __last);
1897 return _M_replace(pos: size_type(0), len1: size(),
1898 s: std::to_address(__first), len2: __last - __first);
1899 }
1900#endif
1901 else
1902 return *this = basic_string(__first, __last, get_allocator());
1903 }
1904#pragma GCC diagnostic pop
1905#else
1906 template<class _InputIterator>
1907 basic_string&
1908 assign(_InputIterator __first, _InputIterator __last)
1909 { return this->replace(begin(), end(), __first, __last); }
1910#endif
1911
1912#if __glibcxx_containers_ranges // C++ >= 23
1913 /**
1914 * @brief Assign a range to the string.
1915 * @param __rg A range of values that are convertible to `value_type`.
1916 * @since C++23
1917 *
1918 * The range `__rg` is allowed to overlap with `*this`.
1919 */
1920 template<__detail::__container_compatible_range<_CharT> _Rg>
1921 constexpr basic_string&
1922 assign_range(_Rg&& __rg)
1923 {
1924 basic_string __s(from_range, std::forward<_Rg>(__rg),
1925 _M_get_allocator());
1926 assign(std::move(__s));
1927 return *this;
1928 }
1929#endif
1930
1931#if __cplusplus >= 201103L
1932 /**
1933 * @brief Set value to an initializer_list of characters.
1934 * @param __l The initializer_list of characters to assign.
1935 * @return Reference to this string.
1936 */
1937 _GLIBCXX20_CONSTEXPR
1938 basic_string&
1939 assign(initializer_list<_CharT> __l)
1940 {
1941 // The initializer_list array cannot alias the characters in *this
1942 // so we don't need to use replace to that case.
1943 const size_type __n = __l.size();
1944 if (__n > capacity())
1945 *this = basic_string(__l.begin(), __l.end(), get_allocator());
1946 else
1947 {
1948 if (__n)
1949 _S_copy(d: _M_data(), s: __l.begin(), __n);
1950 _M_set_length(__n);
1951 }
1952 return *this;
1953 }
1954#endif // C++11
1955
1956#ifdef __glibcxx_string_view // >= C++17
1957 /**
1958 * @brief Set value from a string_view.
1959 * @param __svt The source object convertible to string_view.
1960 * @return Reference to this string.
1961 */
1962 template<typename _Tp>
1963 _GLIBCXX20_CONSTEXPR
1964 _If_sv<_Tp, basic_string&>
1965 assign(const _Tp& __svt)
1966 {
1967 __sv_type __sv = __svt;
1968 return this->assign(__sv.data(), __sv.size());
1969 }
1970
1971 /**
1972 * @brief Set value from a range of characters in a string_view.
1973 * @param __svt The source object convertible to string_view.
1974 * @param __pos The position in the string_view to assign from.
1975 * @param __n The number of characters to assign.
1976 * @return Reference to this string.
1977 */
1978 template<typename _Tp>
1979 _GLIBCXX20_CONSTEXPR
1980 _If_sv<_Tp, basic_string&>
1981 assign(const _Tp& __svt, size_type __pos, size_type __n = npos)
1982 {
1983 __sv_type __sv = __svt;
1984 return _M_replace(pos: size_type(0), len1: this->size(),
1985 s: __sv.data()
1986 + std::__sv_check(size: __sv.size(), __pos, s: "basic_string::assign"),
1987 len2: std::__sv_limit(size: __sv.size(), __pos, off: __n));
1988 }
1989#endif // C++17
1990
1991#if __cplusplus >= 201103L
1992 /**
1993 * @brief Insert multiple characters.
1994 * @param __p Const_iterator referencing location in string to
1995 * insert at.
1996 * @param __n Number of characters to insert
1997 * @param __c The character to insert.
1998 * @return Iterator referencing the first inserted char.
1999 * @throw std::length_error If new length exceeds @c max_size().
2000 *
2001 * Inserts @a __n copies of character @a __c starting at the
2002 * position referenced by iterator @a __p. If adding
2003 * characters causes the length to exceed max_size(),
2004 * length_error is thrown. The value of the string doesn't
2005 * change if an error is thrown.
2006 */
2007 _GLIBCXX20_CONSTEXPR
2008 iterator
2009 insert(const_iterator __p, size_type __n, _CharT __c)
2010 {
2011 _GLIBCXX_DEBUG_PEDASSERT(__p >= begin() && __p <= end());
2012 const size_type __pos = __p - begin();
2013 this->replace(__p, __p, __n, __c);
2014 return iterator(this->_M_data() + __pos);
2015 }
2016#else
2017 /**
2018 * @brief Insert multiple characters.
2019 * @param __p Iterator referencing location in string to insert at.
2020 * @param __n Number of characters to insert
2021 * @param __c The character to insert.
2022 * @throw std::length_error If new length exceeds @c max_size().
2023 *
2024 * Inserts @a __n copies of character @a __c starting at the
2025 * position referenced by iterator @a __p. If adding
2026 * characters causes the length to exceed max_size(),
2027 * length_error is thrown. The value of the string doesn't
2028 * change if an error is thrown.
2029 */
2030 void
2031 insert(iterator __p, size_type __n, _CharT __c)
2032 { this->replace(__p, __p, __n, __c); }
2033#endif
2034
2035#if __cplusplus >= 201103L
2036 /**
2037 * @brief Insert a range of characters.
2038 * @param __p Const_iterator referencing location in string to
2039 * insert at.
2040 * @param __beg Start of range.
2041 * @param __end End of range.
2042 * @return Iterator referencing the first inserted char.
2043 * @throw std::length_error If new length exceeds @c max_size().
2044 *
2045 * Inserts characters in range [beg,end). If adding characters
2046 * causes the length to exceed max_size(), length_error is
2047 * thrown. The value of the string doesn't change if an error
2048 * is thrown.
2049 */
2050 template<class _InputIterator,
2051 typename = std::_RequireInputIter<_InputIterator>>
2052 _GLIBCXX20_CONSTEXPR
2053 iterator
2054 insert(const_iterator __p, _InputIterator __beg, _InputIterator __end)
2055 {
2056 _GLIBCXX_DEBUG_PEDASSERT(__p >= begin() && __p <= end());
2057 const size_type __pos = __p - begin();
2058 this->replace(__p, __p, __beg, __end);
2059 return iterator(this->_M_data() + __pos);
2060 }
2061#else
2062 /**
2063 * @brief Insert a range of characters.
2064 * @param __p Iterator referencing location in string to insert at.
2065 * @param __beg Start of range.
2066 * @param __end End of range.
2067 * @throw std::length_error If new length exceeds @c max_size().
2068 *
2069 * Inserts characters in range [__beg,__end). If adding
2070 * characters causes the length to exceed max_size(),
2071 * length_error is thrown. The value of the string doesn't
2072 * change if an error is thrown.
2073 */
2074 template<class _InputIterator>
2075 void
2076 insert(iterator __p, _InputIterator __beg, _InputIterator __end)
2077 { this->replace(__p, __p, __beg, __end); }
2078#endif
2079
2080#if __glibcxx_containers_ranges // C++ >= 23
2081 /**
2082 * @brief Insert a range into the string.
2083 * @param __rg A range of values that are convertible to `value_type`.
2084 * @since C++23
2085 *
2086 * The range `__rg` is allowed to overlap with `*this`.
2087 */
2088 template<__detail::__container_compatible_range<_CharT> _Rg>
2089 constexpr iterator
2090 insert_range(const_iterator __p, _Rg&& __rg)
2091 {
2092 auto __pos = __p - cbegin();
2093
2094 if constexpr (ranges::forward_range<_Rg>)
2095 if (ranges::empty(__rg))
2096 return begin() + __pos;
2097
2098
2099 if (__p == cend())
2100 append_range(std::forward<_Rg>(__rg));
2101 else
2102 {
2103 basic_string __s(from_range, std::forward<_Rg>(__rg),
2104 _M_get_allocator());
2105 insert(__pos, __s);
2106 }
2107 return begin() + __pos;
2108 }
2109#endif
2110
2111#if __cplusplus >= 201103L
2112 /**
2113 * @brief Insert an initializer_list of characters.
2114 * @param __p Iterator referencing location in string to insert at.
2115 * @param __l The initializer_list of characters to insert.
2116 * @throw std::length_error If new length exceeds @c max_size().
2117 */
2118 _GLIBCXX20_CONSTEXPR
2119 iterator
2120 insert(const_iterator __p, initializer_list<_CharT> __l)
2121 { return this->insert(__p, __l.begin(), __l.end()); }
2122
2123#ifdef _GLIBCXX_DEFINING_STRING_INSTANTIATIONS
2124 // See PR libstdc++/83328
2125 void
2126 insert(iterator __p, initializer_list<_CharT> __l)
2127 {
2128 _GLIBCXX_DEBUG_PEDASSERT(__p >= begin() && __p <= end());
2129 this->insert(__p - begin(), __l.begin(), __l.size());
2130 }
2131#endif
2132#endif // C++11
2133
2134 /**
2135 * @brief Insert value of a string.
2136 * @param __pos1 Position in string to insert at.
2137 * @param __str The string to insert.
2138 * @return Reference to this string.
2139 * @throw std::length_error If new length exceeds @c max_size().
2140 *
2141 * Inserts value of @a __str starting at @a __pos1. If adding
2142 * characters causes the length to exceed max_size(),
2143 * length_error is thrown. The value of the string doesn't
2144 * change if an error is thrown.
2145 */
2146 _GLIBCXX20_CONSTEXPR
2147 basic_string&
2148 insert(size_type __pos1, const basic_string& __str)
2149 { return this->replace(__pos1, size_type(0),
2150 __str._M_data(), __str.size()); }
2151
2152 /**
2153 * @brief Insert a substring.
2154 * @param __pos1 Position in string to insert at.
2155 * @param __str The string to insert.
2156 * @param __pos2 Start of characters in str to insert.
2157 * @param __n Number of characters to insert.
2158 * @return Reference to this string.
2159 * @throw std::length_error If new length exceeds @c max_size().
2160 * @throw std::out_of_range If @a pos1 > size() or
2161 * @a __pos2 > @a str.size().
2162 *
2163 * Starting at @a pos1, insert @a __n character of @a __str
2164 * beginning with @a __pos2. If adding characters causes the
2165 * length to exceed max_size(), length_error is thrown. If @a
2166 * __pos1 is beyond the end of this string or @a __pos2 is
2167 * beyond the end of @a __str, out_of_range is thrown. The
2168 * value of the string doesn't change if an error is thrown.
2169 */
2170 _GLIBCXX20_CONSTEXPR
2171 basic_string&
2172 insert(size_type __pos1, const basic_string& __str,
2173 size_type __pos2, size_type __n = npos)
2174 { return this->replace(__pos1, size_type(0), __str._M_data()
2175 + __str._M_check(pos: __pos2, s: "basic_string::insert"),
2176 __str._M_limit(pos: __pos2, off: __n)); }
2177
2178 /**
2179 * @brief Insert a C substring.
2180 * @param __pos Position in string to insert at.
2181 * @param __s The C string to insert.
2182 * @param __n The number of characters to insert.
2183 * @return Reference to this string.
2184 * @throw std::length_error If new length exceeds @c max_size().
2185 * @throw std::out_of_range If @a __pos is beyond the end of this
2186 * string.
2187 *
2188 * Inserts the first @a __n characters of @a __s starting at @a
2189 * __pos. If adding characters causes the length to exceed
2190 * max_size(), length_error is thrown. If @a __pos is beyond
2191 * end(), out_of_range is thrown. The value of the string
2192 * doesn't change if an error is thrown.
2193 */
2194 _GLIBCXX20_CONSTEXPR
2195 basic_string&
2196 insert(size_type __pos, const _CharT* __s, size_type __n)
2197 { return this->replace(__pos, size_type(0), __s, __n); }
2198
2199 /**
2200 * @brief Insert a C string.
2201 * @param __pos Position in string to insert at.
2202 * @param __s The C string to insert.
2203 * @return Reference to this string.
2204 * @throw std::length_error If new length exceeds @c max_size().
2205 * @throw std::out_of_range If @a pos is beyond the end of this
2206 * string.
2207 *
2208 * Inserts the first @a n characters of @a __s starting at @a __pos. If
2209 * adding characters causes the length to exceed max_size(),
2210 * length_error is thrown. If @a __pos is beyond end(), out_of_range is
2211 * thrown. The value of the string doesn't change if an error is
2212 * thrown.
2213 */
2214 _GLIBCXX20_CONSTEXPR
2215 basic_string&
2216 insert(size_type __pos, const _CharT* __s)
2217 {
2218 __glibcxx_requires_string(__s);
2219 return this->replace(__pos, size_type(0), __s,
2220 traits_type::length(__s));
2221 }
2222
2223 /**
2224 * @brief Insert multiple characters.
2225 * @param __pos Index in string to insert at.
2226 * @param __n Number of characters to insert
2227 * @param __c The character to insert.
2228 * @return Reference to this string.
2229 * @throw std::length_error If new length exceeds @c max_size().
2230 * @throw std::out_of_range If @a __pos is beyond the end of this
2231 * string.
2232 *
2233 * Inserts @a __n copies of character @a __c starting at index
2234 * @a __pos. If adding characters causes the length to exceed
2235 * max_size(), length_error is thrown. If @a __pos > length(),
2236 * out_of_range is thrown. The value of the string doesn't
2237 * change if an error is thrown.
2238 */
2239 _GLIBCXX20_CONSTEXPR
2240 basic_string&
2241 insert(size_type __pos, size_type __n, _CharT __c)
2242 { return _M_replace_aux(pos1: _M_check(__pos, s: "basic_string::insert"),
2243 n1: size_type(0), n2: __n, __c); }
2244
2245 /**
2246 * @brief Insert one character.
2247 * @param __p Iterator referencing position in string to insert at.
2248 * @param __c The character to insert.
2249 * @return Iterator referencing newly inserted char.
2250 * @throw std::length_error If new length exceeds @c max_size().
2251 *
2252 * Inserts character @a __c at position referenced by @a __p.
2253 * If adding character causes the length to exceed max_size(),
2254 * length_error is thrown. If @a __p is beyond end of string,
2255 * out_of_range is thrown. The value of the string doesn't
2256 * change if an error is thrown.
2257 */
2258 _GLIBCXX20_CONSTEXPR
2259 iterator
2260 insert(__const_iterator __p, _CharT __c)
2261 {
2262 _GLIBCXX_DEBUG_PEDASSERT(__p >= begin() && __p <= end());
2263 const size_type __pos = __p - begin();
2264 _M_replace_aux(pos1: __pos, n1: size_type(0), n2: size_type(1), __c);
2265 return iterator(_M_data() + __pos);
2266 }
2267
2268#ifdef __glibcxx_string_view // >= C++17
2269 /**
2270 * @brief Insert a string_view.
2271 * @param __pos Position in string to insert at.
2272 * @param __svt The object convertible to string_view to insert.
2273 * @return Reference to this string.
2274 */
2275 template<typename _Tp>
2276 _GLIBCXX20_CONSTEXPR
2277 _If_sv<_Tp, basic_string&>
2278 insert(size_type __pos, const _Tp& __svt)
2279 {
2280 __sv_type __sv = __svt;
2281 return this->insert(__pos, __sv.data(), __sv.size());
2282 }
2283
2284 /**
2285 * @brief Insert a string_view.
2286 * @param __pos1 Position in string to insert at.
2287 * @param __svt The object convertible to string_view to insert from.
2288 * @param __pos2 Start of characters in str to insert.
2289 * @param __n The number of characters to insert.
2290 * @return Reference to this string.
2291 */
2292 template<typename _Tp>
2293 _GLIBCXX20_CONSTEXPR
2294 _If_sv<_Tp, basic_string&>
2295 insert(size_type __pos1, const _Tp& __svt,
2296 size_type __pos2, size_type __n = npos)
2297 {
2298 __sv_type __sv = __svt;
2299 return this->replace(__pos1, size_type(0),
2300 __sv.data()
2301 + std::__sv_check(size: __sv.size(), pos: __pos2, s: "basic_string::insert"),
2302 std::__sv_limit(size: __sv.size(), pos: __pos2, off: __n));
2303 }
2304#endif // C++17
2305
2306 /**
2307 * @brief Remove characters.
2308 * @param __pos Index of first character to remove (default 0).
2309 * @param __n Number of characters to remove (default remainder).
2310 * @return Reference to this string.
2311 * @throw std::out_of_range If @a pos is beyond the end of this
2312 * string.
2313 *
2314 * Removes @a __n characters from this string starting at @a
2315 * __pos. The length of the string is reduced by @a __n. If
2316 * there are < @a __n characters to remove, the remainder of
2317 * the string is truncated. If @a __p is beyond end of string,
2318 * out_of_range is thrown. The value of the string doesn't
2319 * change if an error is thrown.
2320 */
2321 _GLIBCXX20_CONSTEXPR
2322 basic_string&
2323 erase(size_type __pos = 0, size_type __n = npos)
2324 {
2325 _M_check(__pos, s: "basic_string::erase");
2326 if (__n == npos)
2327 this->_M_set_length(n: __pos);
2328 else if (__n != 0)
2329 this->_M_erase(__pos, n: _M_limit(__pos, off: __n));
2330 return *this;
2331 }
2332
2333 /**
2334 * @brief Remove one character.
2335 * @param __position Iterator referencing the character to remove.
2336 * @return iterator referencing same location after removal.
2337 *
2338 * Removes the character at @a __position from this string. The value
2339 * of the string doesn't change if an error is thrown.
2340 */
2341 _GLIBCXX20_CONSTEXPR
2342 iterator
2343 erase(__const_iterator __position)
2344 {
2345 _GLIBCXX_DEBUG_PEDASSERT(__position >= begin()
2346 && __position < end());
2347 const size_type __pos = __position - begin();
2348 this->_M_erase(__pos, n: size_type(1));
2349 return iterator(_M_data() + __pos);
2350 }
2351
2352 /**
2353 * @brief Remove a range of characters.
2354 * @param __first Iterator referencing the first character to remove.
2355 * @param __last Iterator referencing the end of the range.
2356 * @return Iterator referencing location of first after removal.
2357 *
2358 * Removes the characters in the range [first,last) from this string.
2359 * The value of the string doesn't change if an error is thrown.
2360 */
2361 _GLIBCXX20_CONSTEXPR
2362 iterator
2363 erase(__const_iterator __first, __const_iterator __last)
2364 {
2365 _GLIBCXX_DEBUG_PEDASSERT(__first >= begin() && __first <= __last
2366 && __last <= end());
2367 const size_type __pos = __first - begin();
2368 if (__last == end())
2369 this->_M_set_length(n: __pos);
2370 else
2371 this->_M_erase(__pos, n: __last - __first);
2372 return iterator(this->_M_data() + __pos);
2373 }
2374
2375#if __cplusplus >= 201103L
2376 /**
2377 * @brief Remove the last character.
2378 *
2379 * The string must be non-empty.
2380 */
2381 _GLIBCXX20_CONSTEXPR
2382 void
2383 pop_back() noexcept
2384 {
2385 __glibcxx_assert(!empty());
2386 _M_erase(pos: size() - 1, n: 1);
2387 }
2388#endif // C++11
2389
2390 /**
2391 * @brief Replace characters with value from another string.
2392 * @param __pos Index of first character to replace.
2393 * @param __n Number of characters to be replaced.
2394 * @param __str String to insert.
2395 * @return Reference to this string.
2396 * @throw std::out_of_range If @a pos is beyond the end of this
2397 * string.
2398 * @throw std::length_error If new length exceeds @c max_size().
2399 *
2400 * Removes the characters in the range [__pos,__pos+__n) from
2401 * this string. In place, the value of @a __str is inserted.
2402 * If @a __pos is beyond end of string, out_of_range is thrown.
2403 * If the length of the result exceeds max_size(), length_error
2404 * is thrown. The value of the string doesn't change if an
2405 * error is thrown.
2406 */
2407 _GLIBCXX20_CONSTEXPR
2408 basic_string&
2409 replace(size_type __pos, size_type __n, const basic_string& __str)
2410 { return this->replace(__pos, __n, __str._M_data(), __str.size()); }
2411
2412 /**
2413 * @brief Replace characters with value from another string.
2414 * @param __pos1 Index of first character to replace.
2415 * @param __n1 Number of characters to be replaced.
2416 * @param __str String to insert.
2417 * @param __pos2 Index of first character of str to use.
2418 * @param __n2 Number of characters from str to use.
2419 * @return Reference to this string.
2420 * @throw std::out_of_range If @a __pos1 > size() or @a __pos2 >
2421 * __str.size().
2422 * @throw std::length_error If new length exceeds @c max_size().
2423 *
2424 * Removes the characters in the range [__pos1,__pos1 + n) from this
2425 * string. In place, the value of @a __str is inserted. If @a __pos is
2426 * beyond end of string, out_of_range is thrown. If the length of the
2427 * result exceeds max_size(), length_error is thrown. The value of the
2428 * string doesn't change if an error is thrown.
2429 */
2430 _GLIBCXX20_CONSTEXPR
2431 basic_string&
2432 replace(size_type __pos1, size_type __n1, const basic_string& __str,
2433 size_type __pos2, size_type __n2 = npos)
2434 { return this->replace(__pos1, __n1, __str._M_data()
2435 + __str._M_check(pos: __pos2, s: "basic_string::replace"),
2436 __str._M_limit(pos: __pos2, off: __n2)); }
2437
2438 /**
2439 * @brief Replace characters with value of a C substring.
2440 * @param __pos Index of first character to replace.
2441 * @param __n1 Number of characters to be replaced.
2442 * @param __s C string to insert.
2443 * @param __n2 Number of characters from @a s to use.
2444 * @return Reference to this string.
2445 * @throw std::out_of_range If @a pos1 > size().
2446 * @throw std::length_error If new length exceeds @c max_size().
2447 *
2448 * Removes the characters in the range [__pos,__pos + __n1)
2449 * from this string. In place, the first @a __n2 characters of
2450 * @a __s are inserted, or all of @a __s if @a __n2 is too large. If
2451 * @a __pos is beyond end of string, out_of_range is thrown. If
2452 * the length of result exceeds max_size(), length_error is
2453 * thrown. The value of the string doesn't change if an error
2454 * is thrown.
2455 */
2456 _GLIBCXX20_CONSTEXPR
2457 basic_string&
2458 replace(size_type __pos, size_type __n1, const _CharT* __s,
2459 size_type __n2)
2460 {
2461 __glibcxx_requires_string_len(__s, __n2);
2462 return _M_replace(pos: _M_check(__pos, s: "basic_string::replace"),
2463 len1: _M_limit(__pos, off: __n1), __s, len2: __n2);
2464 }
2465
2466 /**
2467 * @brief Replace characters with value of a C string.
2468 * @param __pos Index of first character to replace.
2469 * @param __n1 Number of characters to be replaced.
2470 * @param __s C string to insert.
2471 * @return Reference to this string.
2472 * @throw std::out_of_range If @a pos > size().
2473 * @throw std::length_error If new length exceeds @c max_size().
2474 *
2475 * Removes the characters in the range [__pos,__pos + __n1)
2476 * from this string. In place, the characters of @a __s are
2477 * inserted. If @a __pos is beyond end of string, out_of_range
2478 * is thrown. If the length of result exceeds max_size(),
2479 * length_error is thrown. The value of the string doesn't
2480 * change if an error is thrown.
2481 */
2482 _GLIBCXX20_CONSTEXPR
2483 basic_string&
2484 replace(size_type __pos, size_type __n1, const _CharT* __s)
2485 {
2486 __glibcxx_requires_string(__s);
2487 return this->replace(__pos, __n1, __s, traits_type::length(__s));
2488 }
2489
2490 /**
2491 * @brief Replace characters with multiple characters.
2492 * @param __pos Index of first character to replace.
2493 * @param __n1 Number of characters to be replaced.
2494 * @param __n2 Number of characters to insert.
2495 * @param __c Character to insert.
2496 * @return Reference to this string.
2497 * @throw std::out_of_range If @a __pos > size().
2498 * @throw std::length_error If new length exceeds @c max_size().
2499 *
2500 * Removes the characters in the range [pos,pos + n1) from this
2501 * string. In place, @a __n2 copies of @a __c are inserted.
2502 * If @a __pos is beyond end of string, out_of_range is thrown.
2503 * If the length of result exceeds max_size(), length_error is
2504 * thrown. The value of the string doesn't change if an error
2505 * is thrown.
2506 */
2507 _GLIBCXX20_CONSTEXPR
2508 basic_string&
2509 replace(size_type __pos, size_type __n1, size_type __n2, _CharT __c)
2510 { return _M_replace_aux(pos1: _M_check(__pos, s: "basic_string::replace"),
2511 n1: _M_limit(__pos, off: __n1), __n2, __c); }
2512
2513 /**
2514 * @brief Replace range of characters with string.
2515 * @param __i1 Iterator referencing start of range to replace.
2516 * @param __i2 Iterator referencing end of range to replace.
2517 * @param __str String value to insert.
2518 * @return Reference to this string.
2519 * @throw std::length_error If new length exceeds @c max_size().
2520 *
2521 * Removes the characters in the range [__i1,__i2). In place,
2522 * the value of @a __str is inserted. If the length of result
2523 * exceeds max_size(), length_error is thrown. The value of
2524 * the string doesn't change if an error is thrown.
2525 */
2526 _GLIBCXX20_CONSTEXPR
2527 basic_string&
2528 replace(__const_iterator __i1, __const_iterator __i2,
2529 const basic_string& __str)
2530 { return this->replace(__i1, __i2, __str._M_data(), __str.size()); }
2531
2532 /**
2533 * @brief Replace range of characters with C substring.
2534 * @param __i1 Iterator referencing start of range to replace.
2535 * @param __i2 Iterator referencing end of range to replace.
2536 * @param __s C string value to insert.
2537 * @param __n Number of characters from s to insert.
2538 * @return Reference to this string.
2539 * @throw std::length_error If new length exceeds @c max_size().
2540 *
2541 * Removes the characters in the range [__i1,__i2). In place,
2542 * the first @a __n characters of @a __s are inserted. If the
2543 * length of result exceeds max_size(), length_error is thrown.
2544 * The value of the string doesn't change if an error is
2545 * thrown.
2546 */
2547 _GLIBCXX20_CONSTEXPR
2548 basic_string&
2549 replace(__const_iterator __i1, __const_iterator __i2,
2550 const _CharT* __s, size_type __n)
2551 {
2552 _GLIBCXX_DEBUG_PEDASSERT(begin() <= __i1 && __i1 <= __i2
2553 && __i2 <= end());
2554 return this->replace(__i1 - begin(), __i2 - __i1, __s, __n);
2555 }
2556
2557 /**
2558 * @brief Replace range of characters with C string.
2559 * @param __i1 Iterator referencing start of range to replace.
2560 * @param __i2 Iterator referencing end of range to replace.
2561 * @param __s C string value to insert.
2562 * @return Reference to this string.
2563 * @throw std::length_error If new length exceeds @c max_size().
2564 *
2565 * Removes the characters in the range [__i1,__i2). In place,
2566 * the characters of @a __s are inserted. If the length of
2567 * result exceeds max_size(), length_error is thrown. The
2568 * value of the string doesn't change if an error is thrown.
2569 */
2570 _GLIBCXX20_CONSTEXPR
2571 basic_string&
2572 replace(__const_iterator __i1, __const_iterator __i2, const _CharT* __s)
2573 {
2574 __glibcxx_requires_string(__s);
2575 return this->replace(__i1, __i2, __s, traits_type::length(__s));
2576 }
2577
2578 /**
2579 * @brief Replace range of characters with multiple characters
2580 * @param __i1 Iterator referencing start of range to replace.
2581 * @param __i2 Iterator referencing end of range to replace.
2582 * @param __n Number of characters to insert.
2583 * @param __c Character to insert.
2584 * @return Reference to this string.
2585 * @throw std::length_error If new length exceeds @c max_size().
2586 *
2587 * Removes the characters in the range [__i1,__i2). In place,
2588 * @a __n copies of @a __c are inserted. If the length of
2589 * result exceeds max_size(), length_error is thrown. The
2590 * value of the string doesn't change if an error is thrown.
2591 */
2592 _GLIBCXX20_CONSTEXPR
2593 basic_string&
2594 replace(__const_iterator __i1, __const_iterator __i2, size_type __n,
2595 _CharT __c)
2596 {
2597 _GLIBCXX_DEBUG_PEDASSERT(begin() <= __i1 && __i1 <= __i2
2598 && __i2 <= end());
2599 return _M_replace_aux(pos1: __i1 - begin(), n1: __i2 - __i1, n2: __n, __c);
2600 }
2601
2602 /**
2603 * @brief Replace range of characters with range.
2604 * @param __i1 Iterator referencing start of range to replace.
2605 * @param __i2 Iterator referencing end of range to replace.
2606 * @param __k1 Iterator referencing start of range to insert.
2607 * @param __k2 Iterator referencing end of range to insert.
2608 * @return Reference to this string.
2609 * @throw std::length_error If new length exceeds @c max_size().
2610 *
2611 * Removes the characters in the range [__i1,__i2). In place,
2612 * characters in the range [__k1,__k2) are inserted. If the
2613 * length of result exceeds max_size(), length_error is thrown.
2614 * The value of the string doesn't change if an error is
2615 * thrown.
2616 */
2617#if __cplusplus >= 201103L
2618 template<class _InputIterator,
2619 typename = std::_RequireInputIter<_InputIterator>>
2620 _GLIBCXX20_CONSTEXPR
2621 basic_string&
2622 replace(const_iterator __i1, const_iterator __i2,
2623 _InputIterator __k1, _InputIterator __k2)
2624 {
2625 _GLIBCXX_DEBUG_PEDASSERT(begin() <= __i1 && __i1 <= __i2
2626 && __i2 <= end());
2627 __glibcxx_requires_valid_range(__k1, __k2);
2628 return this->_M_replace_dispatch(__i1, __i2, __k1, __k2,
2629 std::__false_type());
2630 }
2631#else
2632 template<class _InputIterator>
2633#ifdef _GLIBCXX_DISAMBIGUATE_REPLACE_INST
2634 typename __enable_if_not_native_iterator<_InputIterator>::__type
2635#else
2636 basic_string&
2637#endif
2638 replace(iterator __i1, iterator __i2,
2639 _InputIterator __k1, _InputIterator __k2)
2640 {
2641 _GLIBCXX_DEBUG_PEDASSERT(begin() <= __i1 && __i1 <= __i2
2642 && __i2 <= end());
2643 __glibcxx_requires_valid_range(__k1, __k2);
2644 typedef typename std::__is_integer<_InputIterator>::__type _Integral;
2645 return _M_replace_dispatch(__i1, __i2, __k1, __k2, _Integral());
2646 }
2647#endif
2648
2649 // Specializations for the common case of pointer and iterator:
2650 // useful to avoid the overhead of temporary buffering in _M_replace.
2651 _GLIBCXX20_CONSTEXPR
2652 basic_string&
2653 replace(__const_iterator __i1, __const_iterator __i2,
2654 _CharT* __k1, _CharT* __k2)
2655 {
2656 _GLIBCXX_DEBUG_PEDASSERT(begin() <= __i1 && __i1 <= __i2
2657 && __i2 <= end());
2658 __glibcxx_requires_valid_range(__k1, __k2);
2659 return this->replace(__i1 - begin(), __i2 - __i1,
2660 __k1, __k2 - __k1);
2661 }
2662
2663 _GLIBCXX20_CONSTEXPR
2664 basic_string&
2665 replace(__const_iterator __i1, __const_iterator __i2,
2666 const _CharT* __k1, const _CharT* __k2)
2667 {
2668 _GLIBCXX_DEBUG_PEDASSERT(begin() <= __i1 && __i1 <= __i2
2669 && __i2 <= end());
2670 __glibcxx_requires_valid_range(__k1, __k2);
2671 return this->replace(__i1 - begin(), __i2 - __i1,
2672 __k1, __k2 - __k1);
2673 }
2674
2675 _GLIBCXX20_CONSTEXPR
2676 basic_string&
2677 replace(__const_iterator __i1, __const_iterator __i2,
2678 iterator __k1, iterator __k2)
2679 {
2680 _GLIBCXX_DEBUG_PEDASSERT(begin() <= __i1 && __i1 <= __i2
2681 && __i2 <= end());
2682 __glibcxx_requires_valid_range(__k1, __k2);
2683 return this->replace(__i1 - begin(), __i2 - __i1,
2684 __k1.base(), __k2 - __k1);
2685 }
2686
2687 _GLIBCXX20_CONSTEXPR
2688 basic_string&
2689 replace(__const_iterator __i1, __const_iterator __i2,
2690 const_iterator __k1, const_iterator __k2)
2691 {
2692 _GLIBCXX_DEBUG_PEDASSERT(begin() <= __i1 && __i1 <= __i2
2693 && __i2 <= end());
2694 __glibcxx_requires_valid_range(__k1, __k2);
2695 return this->replace(__i1 - begin(), __i2 - __i1,
2696 __k1.base(), __k2 - __k1);
2697 }
2698
2699#if __glibcxx_containers_ranges // C++ >= 23
2700 /**
2701 * @brief Replace part of the string with a range.
2702 * @param __rg A range of values that are convertible to `value_type`.
2703 * @since C++23
2704 *
2705 * The range `__rg` is allowed to overlap with `*this`.
2706 */
2707 template<__detail::__container_compatible_range<_CharT> _Rg>
2708 constexpr basic_string&
2709 replace_with_range(const_iterator __i1, const_iterator __i2, _Rg&& __rg)
2710 {
2711 if (__i1 == cend())
2712 append_range(std::forward<_Rg>(__rg));
2713 else
2714 {
2715 basic_string __s(from_range, std::forward<_Rg>(__rg),
2716 _M_get_allocator());
2717 replace(__i1, __i2, __s);
2718 }
2719 return *this;
2720 }
2721#endif
2722
2723#if __cplusplus >= 201103L
2724 /**
2725 * @brief Replace range of characters with initializer_list.
2726 * @param __i1 Iterator referencing start of range to replace.
2727 * @param __i2 Iterator referencing end of range to replace.
2728 * @param __l The initializer_list of characters to insert.
2729 * @return Reference to this string.
2730 * @throw std::length_error If new length exceeds @c max_size().
2731 *
2732 * Removes the characters in the range [__i1,__i2). In place,
2733 * characters in the range [__k1,__k2) are inserted. If the
2734 * length of result exceeds max_size(), length_error is thrown.
2735 * The value of the string doesn't change if an error is
2736 * thrown.
2737 */
2738 _GLIBCXX20_CONSTEXPR
2739 basic_string& replace(const_iterator __i1, const_iterator __i2,
2740 initializer_list<_CharT> __l)
2741 { return this->replace(__i1, __i2, __l.begin(), __l.size()); }
2742#endif // C++11
2743
2744#ifdef __glibcxx_string_view // >= C++17
2745 /**
2746 * @brief Replace range of characters with string_view.
2747 * @param __pos The position to replace at.
2748 * @param __n The number of characters to replace.
2749 * @param __svt The object convertible to string_view to insert.
2750 * @return Reference to this string.
2751 */
2752 template<typename _Tp>
2753 _GLIBCXX20_CONSTEXPR
2754 _If_sv<_Tp, basic_string&>
2755 replace(size_type __pos, size_type __n, const _Tp& __svt)
2756 {
2757 __sv_type __sv = __svt;
2758 return this->replace(__pos, __n, __sv.data(), __sv.size());
2759 }
2760
2761 /**
2762 * @brief Replace range of characters with string_view.
2763 * @param __pos1 The position to replace at.
2764 * @param __n1 The number of characters to replace.
2765 * @param __svt The object convertible to string_view to insert from.
2766 * @param __pos2 The position in the string_view to insert from.
2767 * @param __n2 The number of characters to insert.
2768 * @return Reference to this string.
2769 */
2770 template<typename _Tp>
2771 _GLIBCXX20_CONSTEXPR
2772 _If_sv<_Tp, basic_string&>
2773 replace(size_type __pos1, size_type __n1, const _Tp& __svt,
2774 size_type __pos2, size_type __n2 = npos)
2775 {
2776 __sv_type __sv = __svt;
2777 return this->replace(__pos1, __n1,
2778 __sv.data()
2779 + std::__sv_check(size: __sv.size(), pos: __pos2, s: "basic_string::replace"),
2780 std::__sv_limit(size: __sv.size(), pos: __pos2, off: __n2));
2781 }
2782
2783 /**
2784 * @brief Replace range of characters with string_view.
2785 * @param __i1 An iterator referencing the start position
2786 to replace at.
2787 * @param __i2 An iterator referencing the end position
2788 for the replace.
2789 * @param __svt The object convertible to string_view to insert from.
2790 * @return Reference to this string.
2791 */
2792 template<typename _Tp>
2793 _GLIBCXX20_CONSTEXPR
2794 _If_sv<_Tp, basic_string&>
2795 replace(const_iterator __i1, const_iterator __i2, const _Tp& __svt)
2796 {
2797 __sv_type __sv = __svt;
2798 return this->replace(__i1 - begin(), __i2 - __i1, __sv);
2799 }
2800#endif // C++17
2801
2802 private:
2803 template<class _Integer>
2804 _GLIBCXX20_CONSTEXPR
2805 basic_string&
2806 _M_replace_dispatch(const_iterator __i1, const_iterator __i2,
2807 _Integer __n, _Integer __val, __true_type)
2808 { return _M_replace_aux(pos1: __i1 - begin(), n1: __i2 - __i1, n2: __n, c: __val); }
2809
2810 template<class _InputIterator>
2811 _GLIBCXX20_CONSTEXPR
2812 basic_string&
2813 _M_replace_dispatch(const_iterator __i1, const_iterator __i2,
2814 _InputIterator __k1, _InputIterator __k2,
2815 __false_type);
2816
2817 _GLIBCXX20_CONSTEXPR
2818 basic_string&
2819 _M_replace_aux(size_type __pos1, size_type __n1, size_type __n2,
2820 _CharT __c);
2821
2822 __attribute__((__noinline__, __noclone__, __cold__)) void
2823 _M_replace_cold(pointer __p, size_type __len1, const _CharT* __s,
2824 const size_type __len2, const size_type __how_much);
2825
2826 _GLIBCXX20_CONSTEXPR
2827 basic_string&
2828 _M_replace(size_type __pos, size_type __len1, const _CharT* __s,
2829 const size_type __len2);
2830
2831 _GLIBCXX20_CONSTEXPR
2832 basic_string&
2833 _M_append(const _CharT* __s, size_type __n);
2834
2835 public:
2836
2837 /**
2838 * @brief Copy substring into C string.
2839 * @param __s C string to copy value into.
2840 * @param __n Number of characters to copy.
2841 * @param __pos Index of first character to copy.
2842 * @return Number of characters actually copied
2843 * @throw std::out_of_range If __pos > size().
2844 *
2845 * Copies up to @a __n characters starting at @a __pos into the
2846 * C string @a __s. If @a __pos is %greater than size(),
2847 * out_of_range is thrown.
2848 */
2849 _GLIBCXX20_CONSTEXPR
2850 size_type
2851 copy(_CharT* __s, size_type __n, size_type __pos = 0) const;
2852
2853 /**
2854 * @brief Swap contents with another string.
2855 * @param __s String to swap with.
2856 *
2857 * Exchanges the contents of this string with that of @a __s in constant
2858 * time.
2859 */
2860 _GLIBCXX20_CONSTEXPR
2861 void
2862 swap(basic_string& __s) _GLIBCXX_NOEXCEPT;
2863
2864 // String operations:
2865 /**
2866 * @brief Return const pointer to null-terminated contents.
2867 *
2868 * This is a handle to internal data. Do not modify or dire things may
2869 * happen.
2870 */
2871 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
2872 const _CharT*
2873 c_str() const _GLIBCXX_NOEXCEPT
2874 { return _M_data(); }
2875
2876 /**
2877 * @brief Return const pointer to contents.
2878 *
2879 * This is a pointer to internal data. It is undefined to modify
2880 * the contents through the returned pointer. To get a pointer that
2881 * allows modifying the contents use @c &str[0] instead,
2882 * (or in C++17 the non-const @c str.data() overload).
2883 */
2884 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
2885 const _CharT*
2886 data() const _GLIBCXX_NOEXCEPT
2887 { return _M_data(); }
2888
2889#if __cplusplus >= 201703L
2890 /**
2891 * @brief Return non-const pointer to contents.
2892 *
2893 * This is a pointer to the character sequence held by the string.
2894 * Modifying the characters in the sequence is allowed.
2895 */
2896 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
2897 _CharT*
2898 data() noexcept
2899 { return _M_data(); }
2900#endif
2901
2902 /**
2903 * @brief Return copy of allocator used to construct this string.
2904 */
2905 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
2906 allocator_type
2907 get_allocator() const _GLIBCXX_NOEXCEPT
2908 { return _M_get_allocator(); }
2909
2910 /**
2911 * @brief Find position of a C substring.
2912 * @param __s C string to locate.
2913 * @param __pos Index of character to search from.
2914 * @param __n Number of characters from @a s to search for.
2915 * @return Index of start of first occurrence.
2916 *
2917 * Starting from @a __pos, searches forward for the first @a
2918 * __n characters in @a __s within this string. If found,
2919 * returns the index where it begins. If not found, returns
2920 * npos.
2921 */
2922 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
2923 size_type
2924 find(const _CharT* __s, size_type __pos, size_type __n) const
2925 _GLIBCXX_NOEXCEPT;
2926
2927 /**
2928 * @brief Find position of a string.
2929 * @param __str String to locate.
2930 * @param __pos Index of character to search from (default 0).
2931 * @return Index of start of first occurrence.
2932 *
2933 * Starting from @a __pos, searches forward for value of @a __str within
2934 * this string. If found, returns the index where it begins. If not
2935 * found, returns npos.
2936 */
2937 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
2938 size_type
2939 find(const basic_string& __str, size_type __pos = 0) const
2940 _GLIBCXX_NOEXCEPT
2941 { return this->find(__str.data(), __pos, __str.size()); }
2942
2943#ifdef __glibcxx_string_view // >= C++17
2944 /**
2945 * @brief Find position of a string_view.
2946 * @param __svt The object convertible to string_view to locate.
2947 * @param __pos Index of character to search from (default 0).
2948 * @return Index of start of first occurrence.
2949 */
2950 template<typename _Tp>
2951 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
2952 _If_sv<_Tp, size_type>
2953 find(const _Tp& __svt, size_type __pos = 0) const
2954 noexcept(is_same<_Tp, __sv_type>::value)
2955 {
2956 __sv_type __sv = __svt;
2957 return this->find(__sv.data(), __pos, __sv.size());
2958 }
2959#endif // C++17
2960
2961 /**
2962 * @brief Find position of a C string.
2963 * @param __s C string to locate.
2964 * @param __pos Index of character to search from (default 0).
2965 * @return Index of start of first occurrence.
2966 *
2967 * Starting from @a __pos, searches forward for the value of @a
2968 * __s within this string. If found, returns the index where
2969 * it begins. If not found, returns npos.
2970 */
2971 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
2972 size_type
2973 find(const _CharT* __s, size_type __pos = 0) const _GLIBCXX_NOEXCEPT
2974 {
2975 __glibcxx_requires_string(__s);
2976 return this->find(__s, __pos, traits_type::length(__s));
2977 }
2978
2979 /**
2980 * @brief Find position of a character.
2981 * @param __c Character to locate.
2982 * @param __pos Index of character to search from (default 0).
2983 * @return Index of first occurrence.
2984 *
2985 * Starting from @a __pos, searches forward for @a __c within
2986 * this string. If found, returns the index where it was
2987 * found. If not found, returns npos.
2988 */
2989 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
2990 size_type
2991 find(_CharT __c, size_type __pos = 0) const _GLIBCXX_NOEXCEPT;
2992
2993 /**
2994 * @brief Find last position of a string.
2995 * @param __str String to locate.
2996 * @param __pos Index of character to search back from (default end).
2997 * @return Index of start of last occurrence.
2998 *
2999 * Starting from @a __pos, searches backward for value of @a
3000 * __str within this string. If found, returns the index where
3001 * it begins. If not found, returns npos.
3002 */
3003 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
3004 size_type
3005 rfind(const basic_string& __str, size_type __pos = npos) const
3006 _GLIBCXX_NOEXCEPT
3007 { return this->rfind(__str.data(), __pos, __str.size()); }
3008
3009#ifdef __glibcxx_string_view // >= C++17
3010 /**
3011 * @brief Find last position of a string_view.
3012 * @param __svt The object convertible to string_view to locate.
3013 * @param __pos Index of character to search back from (default end).
3014 * @return Index of start of last occurrence.
3015 */
3016 template<typename _Tp>
3017 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
3018 _If_sv<_Tp, size_type>
3019 rfind(const _Tp& __svt, size_type __pos = npos) const
3020 noexcept(is_same<_Tp, __sv_type>::value)
3021 {
3022 __sv_type __sv = __svt;
3023 return this->rfind(__sv.data(), __pos, __sv.size());
3024 }
3025#endif // C++17
3026
3027 /**
3028 * @brief Find last position of a C substring.
3029 * @param __s C string to locate.
3030 * @param __pos Index of character to search back from.
3031 * @param __n Number of characters from s to search for.
3032 * @return Index of start of last occurrence.
3033 *
3034 * Starting from @a __pos, searches backward for the first @a
3035 * __n characters in @a __s within this string. If found,
3036 * returns the index where it begins. If not found, returns
3037 * npos.
3038 */
3039 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
3040 size_type
3041 rfind(const _CharT* __s, size_type __pos, size_type __n) const
3042 _GLIBCXX_NOEXCEPT;
3043
3044 /**
3045 * @brief Find last position of a C string.
3046 * @param __s C string to locate.
3047 * @param __pos Index of character to start search at (default end).
3048 * @return Index of start of last occurrence.
3049 *
3050 * Starting from @a __pos, searches backward for the value of
3051 * @a __s within this string. If found, returns the index
3052 * where it begins. If not found, returns npos.
3053 */
3054 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
3055 size_type
3056 rfind(const _CharT* __s, size_type __pos = npos) const
3057 {
3058 __glibcxx_requires_string(__s);
3059 return this->rfind(__s, __pos, traits_type::length(__s));
3060 }
3061
3062 /**
3063 * @brief Find last position of a character.
3064 * @param __c Character to locate.
3065 * @param __pos Index of character to search back from (default end).
3066 * @return Index of last occurrence.
3067 *
3068 * Starting from @a __pos, searches backward for @a __c within
3069 * this string. If found, returns the index where it was
3070 * found. If not found, returns npos.
3071 */
3072 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
3073 size_type
3074 rfind(_CharT __c, size_type __pos = npos) const _GLIBCXX_NOEXCEPT;
3075
3076 /**
3077 * @brief Find position of a character of string.
3078 * @param __str String containing characters to locate.
3079 * @param __pos Index of character to search from (default 0).
3080 * @return Index of first occurrence.
3081 *
3082 * Starting from @a __pos, searches forward for one of the
3083 * characters of @a __str within this string. If found,
3084 * returns the index where it was found. If not found, returns
3085 * npos.
3086 */
3087 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
3088 size_type
3089 find_first_of(const basic_string& __str, size_type __pos = 0) const
3090 _GLIBCXX_NOEXCEPT
3091 { return this->find_first_of(__str.data(), __pos, __str.size()); }
3092
3093#ifdef __glibcxx_string_view // >= C++17
3094 /**
3095 * @brief Find position of a character of a string_view.
3096 * @param __svt An object convertible to string_view containing
3097 * characters to locate.
3098 * @param __pos Index of character to search from (default 0).
3099 * @return Index of first occurrence.
3100 */
3101 template<typename _Tp>
3102 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
3103 _If_sv<_Tp, size_type>
3104 find_first_of(const _Tp& __svt, size_type __pos = 0) const
3105 noexcept(is_same<_Tp, __sv_type>::value)
3106 {
3107 __sv_type __sv = __svt;
3108 return this->find_first_of(__sv.data(), __pos, __sv.size());
3109 }
3110#endif // C++17
3111
3112 /**
3113 * @brief Find position of a character of C substring.
3114 * @param __s String containing characters to locate.
3115 * @param __pos Index of character to search from.
3116 * @param __n Number of characters from s to search for.
3117 * @return Index of first occurrence.
3118 *
3119 * Starting from @a __pos, searches forward for one of the
3120 * first @a __n characters of @a __s within this string. If
3121 * found, returns the index where it was found. If not found,
3122 * returns npos.
3123 */
3124 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
3125 size_type
3126 find_first_of(const _CharT* __s, size_type __pos, size_type __n) const
3127 _GLIBCXX_NOEXCEPT;
3128
3129 /**
3130 * @brief Find position of a character of C string.
3131 * @param __s String containing characters to locate.
3132 * @param __pos Index of character to search from (default 0).
3133 * @return Index of first occurrence.
3134 *
3135 * Starting from @a __pos, searches forward for one of the
3136 * characters of @a __s within this string. If found, returns
3137 * the index where it was found. If not found, returns npos.
3138 */
3139 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
3140 size_type
3141 find_first_of(const _CharT* __s, size_type __pos = 0) const
3142 _GLIBCXX_NOEXCEPT
3143 {
3144 __glibcxx_requires_string(__s);
3145 return this->find_first_of(__s, __pos, traits_type::length(__s));
3146 }
3147
3148 /**
3149 * @brief Find position of a character.
3150 * @param __c Character to locate.
3151 * @param __pos Index of character to search from (default 0).
3152 * @return Index of first occurrence.
3153 *
3154 * Starting from @a __pos, searches forward for the character
3155 * @a __c within this string. If found, returns the index
3156 * where it was found. If not found, returns npos.
3157 *
3158 * Note: equivalent to find(__c, __pos).
3159 */
3160 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
3161 size_type
3162 find_first_of(_CharT __c, size_type __pos = 0) const _GLIBCXX_NOEXCEPT
3163 { return this->find(__c, __pos); }
3164
3165 /**
3166 * @brief Find last position of a character of string.
3167 * @param __str String containing characters to locate.
3168 * @param __pos Index of character to search back from (default end).
3169 * @return Index of last occurrence.
3170 *
3171 * Starting from @a __pos, searches backward for one of the
3172 * characters of @a __str within this string. If found,
3173 * returns the index where it was found. If not found, returns
3174 * npos.
3175 */
3176 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
3177 size_type
3178 find_last_of(const basic_string& __str, size_type __pos = npos) const
3179 _GLIBCXX_NOEXCEPT
3180 { return this->find_last_of(__str.data(), __pos, __str.size()); }
3181
3182#ifdef __glibcxx_string_view // >= C++17
3183 /**
3184 * @brief Find last position of a character of string.
3185 * @param __svt An object convertible to string_view containing
3186 * characters to locate.
3187 * @param __pos Index of character to search back from (default end).
3188 * @return Index of last occurrence.
3189 */
3190 template<typename _Tp>
3191 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
3192 _If_sv<_Tp, size_type>
3193 find_last_of(const _Tp& __svt, size_type __pos = npos) const
3194 noexcept(is_same<_Tp, __sv_type>::value)
3195 {
3196 __sv_type __sv = __svt;
3197 return this->find_last_of(__sv.data(), __pos, __sv.size());
3198 }
3199#endif // C++17
3200
3201 /**
3202 * @brief Find last position of a character of C substring.
3203 * @param __s C string containing characters to locate.
3204 * @param __pos Index of character to search back from.
3205 * @param __n Number of characters from s to search for.
3206 * @return Index of last occurrence.
3207 *
3208 * Starting from @a __pos, searches backward for one of the
3209 * first @a __n characters of @a __s within this string. If
3210 * found, returns the index where it was found. If not found,
3211 * returns npos.
3212 */
3213 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
3214 size_type
3215 find_last_of(const _CharT* __s, size_type __pos, size_type __n) const
3216 _GLIBCXX_NOEXCEPT;
3217
3218 /**
3219 * @brief Find last position of a character of C string.
3220 * @param __s C string containing characters to locate.
3221 * @param __pos Index of character to search back from (default end).
3222 * @return Index of last occurrence.
3223 *
3224 * Starting from @a __pos, searches backward for one of the
3225 * characters of @a __s within this string. If found, returns
3226 * the index where it was found. If not found, returns npos.
3227 */
3228 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
3229 size_type
3230 find_last_of(const _CharT* __s, size_type __pos = npos) const
3231 _GLIBCXX_NOEXCEPT
3232 {
3233 __glibcxx_requires_string(__s);
3234 return this->find_last_of(__s, __pos, traits_type::length(__s));
3235 }
3236
3237 /**
3238 * @brief Find last position of a character.
3239 * @param __c Character to locate.
3240 * @param __pos Index of character to search back from (default end).
3241 * @return Index of last occurrence.
3242 *
3243 * Starting from @a __pos, searches backward for @a __c within
3244 * this string. If found, returns the index where it was
3245 * found. If not found, returns npos.
3246 *
3247 * Note: equivalent to rfind(__c, __pos).
3248 */
3249 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
3250 size_type
3251 find_last_of(_CharT __c, size_type __pos = npos) const _GLIBCXX_NOEXCEPT
3252 { return this->rfind(__c, __pos); }
3253
3254 /**
3255 * @brief Find position of a character not in string.
3256 * @param __str String containing characters to avoid.
3257 * @param __pos Index of character to search from (default 0).
3258 * @return Index of first occurrence.
3259 *
3260 * Starting from @a __pos, searches forward for a character not contained
3261 * in @a __str within this string. If found, returns the index where it
3262 * was found. If not found, returns npos.
3263 */
3264 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
3265 size_type
3266 find_first_not_of(const basic_string& __str, size_type __pos = 0) const
3267 _GLIBCXX_NOEXCEPT
3268 { return this->find_first_not_of(__str.data(), __pos, __str.size()); }
3269
3270#ifdef __glibcxx_string_view // >= C++17
3271 /**
3272 * @brief Find position of a character not in a string_view.
3273 * @param __svt A object convertible to string_view containing
3274 * characters to avoid.
3275 * @param __pos Index of character to search from (default 0).
3276 * @return Index of first occurrence.
3277 */
3278 template<typename _Tp>
3279 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
3280 _If_sv<_Tp, size_type>
3281 find_first_not_of(const _Tp& __svt, size_type __pos = 0) const
3282 noexcept(is_same<_Tp, __sv_type>::value)
3283 {
3284 __sv_type __sv = __svt;
3285 return this->find_first_not_of(__sv.data(), __pos, __sv.size());
3286 }
3287#endif // C++17
3288
3289 /**
3290 * @brief Find position of a character not in C substring.
3291 * @param __s C string containing characters to avoid.
3292 * @param __pos Index of character to search from.
3293 * @param __n Number of characters from __s to consider.
3294 * @return Index of first occurrence.
3295 *
3296 * Starting from @a __pos, searches forward for a character not
3297 * contained in the first @a __n characters of @a __s within
3298 * this string. If found, returns the index where it was
3299 * found. If not found, returns npos.
3300 */
3301 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
3302 size_type
3303 find_first_not_of(const _CharT* __s, size_type __pos,
3304 size_type __n) const _GLIBCXX_NOEXCEPT;
3305
3306 /**
3307 * @brief Find position of a character not in C string.
3308 * @param __s C string containing characters to avoid.
3309 * @param __pos Index of character to search from (default 0).
3310 * @return Index of first occurrence.
3311 *
3312 * Starting from @a __pos, searches forward for a character not
3313 * contained in @a __s within this string. If found, returns
3314 * the index where it was found. If not found, returns npos.
3315 */
3316 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
3317 size_type
3318 find_first_not_of(const _CharT* __s, size_type __pos = 0) const
3319 _GLIBCXX_NOEXCEPT
3320 {
3321 __glibcxx_requires_string(__s);
3322 return this->find_first_not_of(__s, __pos, traits_type::length(__s));
3323 }
3324
3325 /**
3326 * @brief Find position of a different character.
3327 * @param __c Character to avoid.
3328 * @param __pos Index of character to search from (default 0).
3329 * @return Index of first occurrence.
3330 *
3331 * Starting from @a __pos, searches forward for a character
3332 * other than @a __c within this string. If found, returns the
3333 * index where it was found. If not found, returns npos.
3334 */
3335 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
3336 size_type
3337 find_first_not_of(_CharT __c, size_type __pos = 0) const
3338 _GLIBCXX_NOEXCEPT;
3339
3340 /**
3341 * @brief Find last position of a character not in string.
3342 * @param __str String containing characters to avoid.
3343 * @param __pos Index of character to search back from (default end).
3344 * @return Index of last occurrence.
3345 *
3346 * Starting from @a __pos, searches backward for a character
3347 * not contained in @a __str within this string. If found,
3348 * returns the index where it was found. If not found, returns
3349 * npos.
3350 */
3351 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
3352 size_type
3353 find_last_not_of(const basic_string& __str, size_type __pos = npos) const
3354 _GLIBCXX_NOEXCEPT
3355 { return this->find_last_not_of(__str.data(), __pos, __str.size()); }
3356
3357#ifdef __glibcxx_string_view // >= C++17
3358 /**
3359 * @brief Find last position of a character not in a string_view.
3360 * @param __svt An object convertible to string_view containing
3361 * characters to avoid.
3362 * @param __pos Index of character to search back from (default end).
3363 * @return Index of last occurrence.
3364 */
3365 template<typename _Tp>
3366 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
3367 _If_sv<_Tp, size_type>
3368 find_last_not_of(const _Tp& __svt, size_type __pos = npos) const
3369 noexcept(is_same<_Tp, __sv_type>::value)
3370 {
3371 __sv_type __sv = __svt;
3372 return this->find_last_not_of(__sv.data(), __pos, __sv.size());
3373 }
3374#endif // C++17
3375
3376 /**
3377 * @brief Find last position of a character not in C substring.
3378 * @param __s C string containing characters to avoid.
3379 * @param __pos Index of character to search back from.
3380 * @param __n Number of characters from s to consider.
3381 * @return Index of last occurrence.
3382 *
3383 * Starting from @a __pos, searches backward for a character not
3384 * contained in the first @a __n characters of @a __s within this string.
3385 * If found, returns the index where it was found. If not found,
3386 * returns npos.
3387 */
3388 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
3389 size_type
3390 find_last_not_of(const _CharT* __s, size_type __pos,
3391 size_type __n) const _GLIBCXX_NOEXCEPT;
3392 /**
3393 * @brief Find last position of a character not in C string.
3394 * @param __s C string containing characters to avoid.
3395 * @param __pos Index of character to search back from (default end).
3396 * @return Index of last occurrence.
3397 *
3398 * Starting from @a __pos, searches backward for a character
3399 * not contained in @a __s within this string. If found,
3400 * returns the index where it was found. If not found, returns
3401 * npos.
3402 */
3403 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
3404 size_type
3405 find_last_not_of(const _CharT* __s, size_type __pos = npos) const
3406 _GLIBCXX_NOEXCEPT
3407 {
3408 __glibcxx_requires_string(__s);
3409 return this->find_last_not_of(__s, __pos, traits_type::length(__s));
3410 }
3411
3412 /**
3413 * @brief Find last position of a different character.
3414 * @param __c Character to avoid.
3415 * @param __pos Index of character to search back from (default end).
3416 * @return Index of last occurrence.
3417 *
3418 * Starting from @a __pos, searches backward for a character other than
3419 * @a __c within this string. If found, returns the index where it was
3420 * found. If not found, returns npos.
3421 */
3422 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
3423 size_type
3424 find_last_not_of(_CharT __c, size_type __pos = npos) const
3425 _GLIBCXX_NOEXCEPT;
3426
3427 /**
3428 * @brief Get a substring.
3429 * @param __pos Index of first character (default 0).
3430 * @param __n Number of characters in substring (default remainder).
3431 * @return The new string.
3432 * @throw std::out_of_range If __pos > size().
3433 *
3434 * Construct and return a new string using the @a __n
3435 * characters starting at @a __pos. If the string is too
3436 * short, use the remainder of the characters. If @a __pos is
3437 * beyond the end of the string, out_of_range is thrown.
3438 */
3439 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
3440 basic_string
3441 substr(size_type __pos = 0, size_type __n = npos) const
3442 { return basic_string(*this,
3443 _M_check(__pos, s: "basic_string::substr"), __n); }
3444
3445 /**
3446 * @brief Compare to a string.
3447 * @param __str String to compare against.
3448 * @return Integer < 0, 0, or > 0.
3449 *
3450 * Returns an integer < 0 if this string is ordered before @a
3451 * __str, 0 if their values are equivalent, or > 0 if this
3452 * string is ordered after @a __str. Determines the effective
3453 * length rlen of the strings to compare as the smallest of
3454 * size() and str.size(). The function then compares the two
3455 * strings by calling traits::compare(data(), str.data(),rlen).
3456 * If the result of the comparison is nonzero returns it,
3457 * otherwise the shorter one is ordered first.
3458 */
3459 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
3460 int
3461 compare(const basic_string& __str) const
3462 {
3463 const size_type __size = this->size();
3464 const size_type __osize = __str.size();
3465 const size_type __len = std::min(__size, __osize);
3466
3467 int __r = traits_type::compare(_M_data(), __str.data(), __len);
3468 if (!__r)
3469 __r = _S_compare(n1: __size, n2: __osize);
3470 return __r;
3471 }
3472
3473#ifdef __glibcxx_string_view // >= C++17
3474 /**
3475 * @brief Compare to a string_view.
3476 * @param __svt An object convertible to string_view to compare against.
3477 * @return Integer < 0, 0, or > 0.
3478 */
3479 template<typename _Tp>
3480 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
3481 _If_sv<_Tp, int>
3482 compare(const _Tp& __svt) const
3483 noexcept(is_same<_Tp, __sv_type>::value)
3484 {
3485 __sv_type __sv = __svt;
3486 const size_type __size = this->size();
3487 const size_type __osize = __sv.size();
3488 const size_type __len = std::min(__size, __osize);
3489
3490 int __r = traits_type::compare(_M_data(), __sv.data(), __len);
3491 if (!__r)
3492 __r = _S_compare(n1: __size, n2: __osize);
3493 return __r;
3494 }
3495
3496 /**
3497 * @brief Compare to a string_view.
3498 * @param __pos A position in the string to start comparing from.
3499 * @param __n The number of characters to compare.
3500 * @param __svt An object convertible to string_view to compare
3501 * against.
3502 * @return Integer < 0, 0, or > 0.
3503 */
3504 template<typename _Tp>
3505 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
3506 _If_sv<_Tp, int>
3507 compare(size_type __pos, size_type __n, const _Tp& __svt) const
3508 noexcept(is_same<_Tp, __sv_type>::value)
3509 {
3510 __sv_type __sv = __svt;
3511 return __sv_type(*this).substr(__pos, __n).compare(__sv);
3512 }
3513
3514 /**
3515 * @brief Compare to a string_view.
3516 * @param __pos1 A position in the string to start comparing from.
3517 * @param __n1 The number of characters to compare.
3518 * @param __svt An object convertible to string_view to compare
3519 * against.
3520 * @param __pos2 A position in the string_view to start comparing from.
3521 * @param __n2 The number of characters to compare.
3522 * @return Integer < 0, 0, or > 0.
3523 */
3524 template<typename _Tp>
3525 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
3526 _If_sv<_Tp, int>
3527 compare(size_type __pos1, size_type __n1, const _Tp& __svt,
3528 size_type __pos2, size_type __n2 = npos) const
3529 noexcept(is_same<_Tp, __sv_type>::value)
3530 {
3531 __sv_type __sv = __svt;
3532 return __sv_type(*this)
3533 .substr(__pos1, __n1).compare(__sv.substr(__pos2, __n2));
3534 }
3535#endif // C++17
3536
3537 /**
3538 * @brief Compare substring to a string.
3539 * @param __pos Index of first character of substring.
3540 * @param __n Number of characters in substring.
3541 * @param __str String to compare against.
3542 * @return Integer < 0, 0, or > 0.
3543 *
3544 * Form the substring of this string from the @a __n characters
3545 * starting at @a __pos. Returns an integer < 0 if the
3546 * substring is ordered before @a __str, 0 if their values are
3547 * equivalent, or > 0 if the substring is ordered after @a
3548 * __str. Determines the effective length rlen of the strings
3549 * to compare as the smallest of the length of the substring
3550 * and @a __str.size(). The function then compares the two
3551 * strings by calling
3552 * traits::compare(substring.data(),str.data(),rlen). If the
3553 * result of the comparison is nonzero returns it, otherwise
3554 * the shorter one is ordered first.
3555 */
3556 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
3557 int
3558 compare(size_type __pos, size_type __n, const basic_string& __str) const
3559 {
3560 _M_check(__pos, s: "basic_string::compare");
3561 __n = _M_limit(__pos, off: __n);
3562 const size_type __osize = __str.size();
3563 const size_type __len = std::min(__n, __osize);
3564 int __r = traits_type::compare(_M_data() + __pos, __str.data(), __len);
3565 if (!__r)
3566 __r = _S_compare(n1: __n, n2: __osize);
3567 return __r;
3568 }
3569
3570 /**
3571 * @brief Compare substring to a substring.
3572 * @param __pos1 Index of first character of substring.
3573 * @param __n1 Number of characters in substring.
3574 * @param __str String to compare against.
3575 * @param __pos2 Index of first character of substring of str.
3576 * @param __n2 Number of characters in substring of str.
3577 * @return Integer < 0, 0, or > 0.
3578 *
3579 * Form the substring of this string from the @a __n1
3580 * characters starting at @a __pos1. Form the substring of @a
3581 * __str from the @a __n2 characters starting at @a __pos2.
3582 * Returns an integer < 0 if this substring is ordered before
3583 * the substring of @a __str, 0 if their values are equivalent,
3584 * or > 0 if this substring is ordered after the substring of
3585 * @a __str. Determines the effective length rlen of the
3586 * strings to compare as the smallest of the lengths of the
3587 * substrings. The function then compares the two strings by
3588 * calling
3589 * traits::compare(substring.data(),str.substr(pos2,n2).data(),rlen).
3590 * If the result of the comparison is nonzero returns it,
3591 * otherwise the shorter one is ordered first.
3592 */
3593 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
3594 int
3595 compare(size_type __pos1, size_type __n1, const basic_string& __str,
3596 size_type __pos2, size_type __n2 = npos) const
3597 {
3598 _M_check(pos: __pos1, s: "basic_string::compare");
3599 __str._M_check(pos: __pos2, s: "basic_string::compare");
3600 __n1 = _M_limit(pos: __pos1, off: __n1);
3601 __n2 = __str._M_limit(pos: __pos2, off: __n2);
3602 const size_type __len = std::min(__n1, __n2);
3603 int __r = traits_type::compare(_M_data() + __pos1,
3604 __str.data() + __pos2, __len);
3605 if (!__r)
3606 __r = _S_compare(__n1, __n2);
3607 return __r;
3608 }
3609
3610 /**
3611 * @brief Compare to a C string.
3612 * @param __s C string to compare against.
3613 * @return Integer < 0, 0, or > 0.
3614 *
3615 * Returns an integer < 0 if this string is ordered before @a __s, 0 if
3616 * their values are equivalent, or > 0 if this string is ordered after
3617 * @a __s. Determines the effective length rlen of the strings to
3618 * compare as the smallest of size() and the length of a string
3619 * constructed from @a __s. The function then compares the two strings
3620 * by calling traits::compare(data(),s,rlen). If the result of the
3621 * comparison is nonzero returns it, otherwise the shorter one is
3622 * ordered first.
3623 */
3624 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
3625 int
3626 compare(const _CharT* __s) const _GLIBCXX_NOEXCEPT
3627 {
3628 __glibcxx_requires_string(__s);
3629 const size_type __size = this->size();
3630 const size_type __osize = traits_type::length(__s);
3631 const size_type __len = std::min(__size, __osize);
3632 int __r = traits_type::compare(_M_data(), __s, __len);
3633 if (!__r)
3634 __r = _S_compare(n1: __size, n2: __osize);
3635 return __r;
3636 }
3637
3638 // _GLIBCXX_RESOLVE_LIB_DEFECTS
3639 // 5 String::compare specification questionable
3640 /**
3641 * @brief Compare substring to a C string.
3642 * @param __pos Index of first character of substring.
3643 * @param __n1 Number of characters in substring.
3644 * @param __s C string to compare against.
3645 * @return Integer < 0, 0, or > 0.
3646 *
3647 * Form the substring of this string from the @a __n1
3648 * characters starting at @a pos. Returns an integer < 0 if
3649 * the substring is ordered before @a __s, 0 if their values
3650 * are equivalent, or > 0 if the substring is ordered after @a
3651 * __s. Determines the effective length rlen of the strings to
3652 * compare as the smallest of the length of the substring and
3653 * the length of a string constructed from @a __s. The
3654 * function then compares the two string by calling
3655 * traits::compare(substring.data(),__s,rlen). If the result of
3656 * the comparison is nonzero returns it, otherwise the shorter
3657 * one is ordered first.
3658 */
3659 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
3660 int
3661 compare(size_type __pos, size_type __n1, const _CharT* __s) const
3662 {
3663 __glibcxx_requires_string(__s);
3664 _M_check(__pos, s: "basic_string::compare");
3665 __n1 = _M_limit(__pos, off: __n1);
3666 const size_type __osize = traits_type::length(__s);
3667 const size_type __len = std::min(__n1, __osize);
3668 int __r = traits_type::compare(_M_data() + __pos, __s, __len);
3669 if (!__r)
3670 __r = _S_compare(__n1, n2: __osize);
3671 return __r;
3672 }
3673
3674 /**
3675 * @brief Compare substring against a character %array.
3676 * @param __pos Index of first character of substring.
3677 * @param __n1 Number of characters in substring.
3678 * @param __s character %array to compare against.
3679 * @param __n2 Number of characters of s.
3680 * @return Integer < 0, 0, or > 0.
3681 *
3682 * Form the substring of this string from the @a __n1
3683 * characters starting at @a __pos. Form a string from the
3684 * first @a __n2 characters of @a __s. Returns an integer < 0
3685 * if this substring is ordered before the string from @a __s,
3686 * 0 if their values are equivalent, or > 0 if this substring
3687 * is ordered after the string from @a __s. Determines the
3688 * effective length rlen of the strings to compare as the
3689 * smallest of the length of the substring and @a __n2. The
3690 * function then compares the two strings by calling
3691 * traits::compare(substring.data(),s,rlen). If the result of
3692 * the comparison is nonzero returns it, otherwise the shorter
3693 * one is ordered first.
3694 *
3695 * NB: s must have at least n2 characters, &apos;\\0&apos; has
3696 * no special meaning.
3697 */
3698 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
3699 int
3700 compare(size_type __pos, size_type __n1, const _CharT* __s,
3701 size_type __n2) const
3702 {
3703 __glibcxx_requires_string_len(__s, __n2);
3704 _M_check(__pos, s: "basic_string::compare");
3705 __n1 = _M_limit(__pos, off: __n1);
3706 const size_type __len = std::min(__n1, __n2);
3707 int __r = traits_type::compare(_M_data() + __pos, __s, __len);
3708 if (!__r)
3709 __r = _S_compare(__n1, __n2);
3710 return __r;
3711 }
3712
3713#if __cplusplus >= 202002L
3714 [[nodiscard]]
3715 constexpr bool
3716 starts_with(basic_string_view<_CharT, _Traits> __x) const noexcept
3717 { return __sv_type(this->data(), this->size()).starts_with(__x); }
3718
3719 [[nodiscard]]
3720 constexpr bool
3721 starts_with(_CharT __x) const noexcept
3722 { return __sv_type(this->data(), this->size()).starts_with(__x); }
3723
3724 [[nodiscard, __gnu__::__nonnull__]]
3725 constexpr bool
3726 starts_with(const _CharT* __x) const noexcept
3727 { return __sv_type(this->data(), this->size()).starts_with(__x); }
3728
3729 [[nodiscard]]
3730 constexpr bool
3731 ends_with(basic_string_view<_CharT, _Traits> __x) const noexcept
3732 { return __sv_type(this->data(), this->size()).ends_with(__x); }
3733
3734 [[nodiscard]]
3735 constexpr bool
3736 ends_with(_CharT __x) const noexcept
3737 { return __sv_type(this->data(), this->size()).ends_with(__x); }
3738
3739 [[nodiscard, __gnu__::__nonnull__]]
3740 constexpr bool
3741 ends_with(const _CharT* __x) const noexcept
3742 { return __sv_type(this->data(), this->size()).ends_with(__x); }
3743#endif // C++20
3744
3745#if __cplusplus > 202002L
3746 [[nodiscard]]
3747 constexpr bool
3748 contains(basic_string_view<_CharT, _Traits> __x) const noexcept
3749 { return __sv_type(this->data(), this->size()).contains(__x); }
3750
3751 [[nodiscard]]
3752 constexpr bool
3753 contains(_CharT __x) const noexcept
3754 { return __sv_type(this->data(), this->size()).contains(__x); }
3755
3756 [[nodiscard, __gnu__::__nonnull__]]
3757 constexpr bool
3758 contains(const _CharT* __x) const noexcept
3759 { return __sv_type(this->data(), this->size()).contains(__x); }
3760#endif // C++23
3761
3762 // Allow basic_stringbuf::__xfer_bufptrs to call _M_length:
3763 template<typename, typename, typename> friend class basic_stringbuf;
3764 };
3765_GLIBCXX_END_NAMESPACE_CXX11
3766_GLIBCXX_END_NAMESPACE_VERSION
3767} // namespace std
3768#endif // _GLIBCXX_USE_CXX11_ABI
3769
3770namespace std _GLIBCXX_VISIBILITY(default)
3771{
3772_GLIBCXX_BEGIN_NAMESPACE_VERSION
3773
3774#if __cpp_deduction_guides >= 201606
3775_GLIBCXX_BEGIN_NAMESPACE_CXX11
3776 template<typename _InputIterator, typename _CharT
3777 = typename iterator_traits<_InputIterator>::value_type,
3778 typename _Allocator = allocator<_CharT>,
3779 typename = _RequireInputIter<_InputIterator>,
3780 typename = _RequireAllocator<_Allocator>>
3781 basic_string(_InputIterator, _InputIterator, _Allocator = _Allocator())
3782 -> basic_string<_CharT, char_traits<_CharT>, _Allocator>;
3783
3784 // _GLIBCXX_RESOLVE_LIB_DEFECTS
3785 // 3075. basic_string needs deduction guides from basic_string_view
3786 template<typename _CharT, typename _Traits,
3787 typename _Allocator = allocator<_CharT>,
3788 typename = _RequireAllocator<_Allocator>>
3789 basic_string(basic_string_view<_CharT, _Traits>, const _Allocator& = _Allocator())
3790 -> basic_string<_CharT, _Traits, _Allocator>;
3791
3792 template<typename _CharT, typename _Traits,
3793 typename _Allocator = allocator<_CharT>,
3794 typename = _RequireAllocator<_Allocator>>
3795 basic_string(basic_string_view<_CharT, _Traits>,
3796 typename basic_string<_CharT, _Traits, _Allocator>::size_type,
3797 typename basic_string<_CharT, _Traits, _Allocator>::size_type,
3798 const _Allocator& = _Allocator())
3799 -> basic_string<_CharT, _Traits, _Allocator>;
3800
3801#if __glibcxx_containers_ranges // C++ >= 23
3802 template<ranges::input_range _Rg,
3803 typename _Allocator = allocator<ranges::range_value_t<_Rg>>>
3804 basic_string(from_range_t, _Rg&&, _Allocator = _Allocator())
3805 -> basic_string<ranges::range_value_t<_Rg>,
3806 char_traits<ranges::range_value_t<_Rg>>,
3807 _Allocator>;
3808#endif
3809_GLIBCXX_END_NAMESPACE_CXX11
3810#endif
3811
3812 template<typename _Str>
3813 _GLIBCXX20_CONSTEXPR
3814 inline _Str
3815 __str_concat(typename _Str::value_type const* __lhs,
3816 typename _Str::size_type __lhs_len,
3817 typename _Str::value_type const* __rhs,
3818 typename _Str::size_type __rhs_len,
3819 typename _Str::allocator_type const& __a)
3820 {
3821 typedef typename _Str::allocator_type allocator_type;
3822 typedef __gnu_cxx::__alloc_traits<allocator_type> _Alloc_traits;
3823 _Str __str(_Alloc_traits::_S_select_on_copy(__a));
3824 __str.reserve(__lhs_len + __rhs_len);
3825 __str.append(__lhs, __lhs_len);
3826 __str.append(__rhs, __rhs_len);
3827 return __str;
3828 }
3829
3830 // operator+
3831 /**
3832 * @brief Concatenate two strings.
3833 * @param __lhs First string.
3834 * @param __rhs Last string.
3835 * @return New string with value of @a __lhs followed by @a __rhs.
3836 */
3837 template<typename _CharT, typename _Traits, typename _Alloc>
3838 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
3839 inline basic_string<_CharT, _Traits, _Alloc>
3840 operator+(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
3841 const basic_string<_CharT, _Traits, _Alloc>& __rhs)
3842 {
3843 typedef basic_string<_CharT, _Traits, _Alloc> _Str;
3844 return std::__str_concat<_Str>(__lhs.c_str(), __lhs.size(),
3845 __rhs.c_str(), __rhs.size(),
3846 __lhs.get_allocator());
3847 }
3848
3849 /**
3850 * @brief Concatenate C string and string.
3851 * @param __lhs First string.
3852 * @param __rhs Last string.
3853 * @return New string with value of @a __lhs followed by @a __rhs.
3854 */
3855 template<typename _CharT, typename _Traits, typename _Alloc>
3856 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
3857 inline basic_string<_CharT,_Traits,_Alloc>
3858 operator+(const _CharT* __lhs,
3859 const basic_string<_CharT,_Traits,_Alloc>& __rhs)
3860 {
3861 __glibcxx_requires_string(__lhs);
3862 typedef basic_string<_CharT, _Traits, _Alloc> _Str;
3863 return std::__str_concat<_Str>(__lhs, _Traits::length(__lhs),
3864 __rhs.c_str(), __rhs.size(),
3865 __rhs.get_allocator());
3866 }
3867
3868 /**
3869 * @brief Concatenate character and string.
3870 * @param __lhs First string.
3871 * @param __rhs Last string.
3872 * @return New string with @a __lhs followed by @a __rhs.
3873 */
3874 template<typename _CharT, typename _Traits, typename _Alloc>
3875 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
3876 inline basic_string<_CharT,_Traits,_Alloc>
3877 operator+(_CharT __lhs, const basic_string<_CharT,_Traits,_Alloc>& __rhs)
3878 {
3879 typedef basic_string<_CharT, _Traits, _Alloc> _Str;
3880 return std::__str_concat<_Str>(__builtin_addressof(__lhs), 1,
3881 __rhs.c_str(), __rhs.size(),
3882 __rhs.get_allocator());
3883 }
3884
3885 /**
3886 * @brief Concatenate string and C string.
3887 * @param __lhs First string.
3888 * @param __rhs Last string.
3889 * @return New string with @a __lhs followed by @a __rhs.
3890 */
3891 template<typename _CharT, typename _Traits, typename _Alloc>
3892 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
3893 inline basic_string<_CharT, _Traits, _Alloc>
3894 operator+(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
3895 const _CharT* __rhs)
3896 {
3897 __glibcxx_requires_string(__rhs);
3898 typedef basic_string<_CharT, _Traits, _Alloc> _Str;
3899 return std::__str_concat<_Str>(__lhs.c_str(), __lhs.size(),
3900 __rhs, _Traits::length(__rhs),
3901 __lhs.get_allocator());
3902 }
3903 /**
3904 * @brief Concatenate string and character.
3905 * @param __lhs First string.
3906 * @param __rhs Last string.
3907 * @return New string with @a __lhs followed by @a __rhs.
3908 */
3909 template<typename _CharT, typename _Traits, typename _Alloc>
3910 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
3911 inline basic_string<_CharT, _Traits, _Alloc>
3912 operator+(const basic_string<_CharT, _Traits, _Alloc>& __lhs, _CharT __rhs)
3913 {
3914 typedef basic_string<_CharT, _Traits, _Alloc> _Str;
3915 return std::__str_concat<_Str>(__lhs.c_str(), __lhs.size(),
3916 __builtin_addressof(__rhs), 1,
3917 __lhs.get_allocator());
3918 }
3919
3920#if __cplusplus >= 201103L
3921 template<typename _CharT, typename _Traits, typename _Alloc>
3922 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
3923 inline basic_string<_CharT, _Traits, _Alloc>
3924 operator+(basic_string<_CharT, _Traits, _Alloc>&& __lhs,
3925 const basic_string<_CharT, _Traits, _Alloc>& __rhs)
3926 { return std::move(__lhs.append(__rhs)); }
3927
3928 template<typename _CharT, typename _Traits, typename _Alloc>
3929 _GLIBCXX20_CONSTEXPR
3930 inline basic_string<_CharT, _Traits, _Alloc>
3931 operator+(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
3932 basic_string<_CharT, _Traits, _Alloc>&& __rhs)
3933 { return std::move(__rhs.insert(0, __lhs)); }
3934
3935 template<typename _CharT, typename _Traits, typename _Alloc>
3936 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
3937 inline basic_string<_CharT, _Traits, _Alloc>
3938 operator+(basic_string<_CharT, _Traits, _Alloc>&& __lhs,
3939 basic_string<_CharT, _Traits, _Alloc>&& __rhs)
3940 {
3941#if _GLIBCXX_USE_CXX11_ABI
3942 using _Alloc_traits = allocator_traits<_Alloc>;
3943 bool __use_rhs = false;
3944 if _GLIBCXX17_CONSTEXPR (typename _Alloc_traits::is_always_equal{})
3945 __use_rhs = true;
3946 else if (__lhs.get_allocator() == __rhs.get_allocator())
3947 __use_rhs = true;
3948 if (__use_rhs)
3949#endif
3950 {
3951 const auto __size = __lhs.size() + __rhs.size();
3952 if (__size > __lhs.capacity() && __size <= __rhs.capacity())
3953 return std::move(__rhs.insert(0, __lhs));
3954 }
3955 return std::move(__lhs.append(__rhs));
3956 }
3957
3958 template<typename _CharT, typename _Traits, typename _Alloc>
3959 _GLIBCXX_NODISCARD _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
3960 inline basic_string<_CharT, _Traits, _Alloc>
3961 operator+(const _CharT* __lhs,
3962 basic_string<_CharT, _Traits, _Alloc>&& __rhs)
3963 { return std::move(__rhs.insert(0, __lhs)); }
3964
3965 template<typename _CharT, typename _Traits, typename _Alloc>
3966 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
3967 inline basic_string<_CharT, _Traits, _Alloc>
3968 operator+(_CharT __lhs,
3969 basic_string<_CharT, _Traits, _Alloc>&& __rhs)
3970 { return std::move(__rhs.insert(0, 1, __lhs)); }
3971
3972 template<typename _CharT, typename _Traits, typename _Alloc>
3973 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
3974 inline basic_string<_CharT, _Traits, _Alloc>
3975 operator+(basic_string<_CharT, _Traits, _Alloc>&& __lhs,
3976 const _CharT* __rhs)
3977 { return std::move(__lhs.append(__rhs)); }
3978
3979 template<typename _CharT, typename _Traits, typename _Alloc>
3980 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
3981 inline basic_string<_CharT, _Traits, _Alloc>
3982 operator+(basic_string<_CharT, _Traits, _Alloc>&& __lhs,
3983 _CharT __rhs)
3984 { return std::move(__lhs.append(1, __rhs)); }
3985#endif
3986
3987#if __glibcxx_string_view >= 202403L
3988 // const string & + string_view
3989 template<typename _CharT, typename _Traits, typename _Alloc>
3990 [[nodiscard]]
3991 constexpr basic_string<_CharT, _Traits, _Alloc>
3992 operator+(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
3993 type_identity_t<basic_string_view<_CharT, _Traits>> __rhs)
3994 {
3995 using _Str = basic_string<_CharT, _Traits, _Alloc>;
3996 return std::__str_concat<_Str>(__lhs.data(), __lhs.size(),
3997 __rhs.data(), __rhs.size(),
3998 __lhs.get_allocator());
3999 }
4000
4001 // string && + string_view
4002 template<typename _CharT, typename _Traits, typename _Alloc>
4003 [[nodiscard]]
4004 constexpr basic_string<_CharT, _Traits, _Alloc>
4005 operator+(basic_string<_CharT, _Traits, _Alloc>&& __lhs,
4006 type_identity_t<basic_string_view<_CharT, _Traits>> __rhs)
4007 {
4008 return std::move(__lhs.append(__rhs));
4009 }
4010
4011 // string_view + const string &
4012 template<typename _CharT, typename _Traits, typename _Alloc>
4013 [[nodiscard]]
4014 constexpr basic_string<_CharT, _Traits, _Alloc>
4015 operator+(type_identity_t<basic_string_view<_CharT, _Traits>> __lhs,
4016 const basic_string<_CharT, _Traits, _Alloc>& __rhs)
4017 {
4018 using _Str = basic_string<_CharT, _Traits, _Alloc>;
4019 return std::__str_concat<_Str>(__lhs.data(), __lhs.size(),
4020 __rhs.data(), __rhs.size(),
4021 __rhs.get_allocator());
4022 }
4023
4024 // string_view + string &&
4025 template<typename _CharT, typename _Traits, typename _Alloc>
4026 [[nodiscard]]
4027 constexpr basic_string<_CharT, _Traits, _Alloc>
4028 operator+(type_identity_t<basic_string_view<_CharT, _Traits>> __lhs,
4029 basic_string<_CharT, _Traits, _Alloc>&& __rhs)
4030 {
4031 return std::move(__rhs.insert(0, __lhs));
4032 }
4033#endif
4034
4035 // operator ==
4036 /**
4037 * @brief Test equivalence of two strings.
4038 * @param __lhs First string.
4039 * @param __rhs Second string.
4040 * @return True if @a __lhs.compare(@a __rhs) == 0. False otherwise.
4041 */
4042 template<typename _CharT, typename _Traits, typename _Alloc>
4043 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
4044 inline bool
4045 operator==(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
4046 const basic_string<_CharT, _Traits, _Alloc>& __rhs)
4047 _GLIBCXX_NOEXCEPT
4048 {
4049 return __lhs.size() == __rhs.size()
4050 && !_Traits::compare(__lhs.data(), __rhs.data(), __lhs.size());
4051 }
4052
4053 /**
4054 * @brief Test equivalence of string and C string.
4055 * @param __lhs String.
4056 * @param __rhs C string.
4057 * @return True if @a __lhs.compare(@a __rhs) == 0. False otherwise.
4058 */
4059 template<typename _CharT, typename _Traits, typename _Alloc>
4060 _GLIBCXX_NODISCARD _GLIBCXX20_CONSTEXPR
4061 inline bool
4062 operator==(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
4063 const _CharT* __rhs)
4064 {
4065 return __lhs.size() == _Traits::length(__rhs)
4066 && !_Traits::compare(__lhs.data(), __rhs, __lhs.size());
4067 }
4068
4069#if __cpp_lib_three_way_comparison
4070 /**
4071 * @brief Three-way comparison of a string and a C string.
4072 * @param __lhs A string.
4073 * @param __rhs A null-terminated string.
4074 * @return A value indicating whether `__lhs` is less than, equal to,
4075 * greater than, or incomparable with `__rhs`.
4076 */
4077 template<typename _CharT, typename _Traits, typename _Alloc>
4078 [[nodiscard]]
4079 constexpr auto
4080 operator<=>(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
4081 const basic_string<_CharT, _Traits, _Alloc>& __rhs) noexcept
4082 -> decltype(__detail::__char_traits_cmp_cat<_Traits>(0))
4083 { return __detail::__char_traits_cmp_cat<_Traits>(__lhs.compare(__rhs)); }
4084
4085 /**
4086 * @brief Three-way comparison of a string and a C string.
4087 * @param __lhs A string.
4088 * @param __rhs A null-terminated string.
4089 * @return A value indicating whether `__lhs` is less than, equal to,
4090 * greater than, or incomparable with `__rhs`.
4091 */
4092 template<typename _CharT, typename _Traits, typename _Alloc>
4093 [[nodiscard]]
4094 constexpr auto
4095 operator<=>(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
4096 const _CharT* __rhs) noexcept
4097 -> decltype(__detail::__char_traits_cmp_cat<_Traits>(0))
4098 { return __detail::__char_traits_cmp_cat<_Traits>(__lhs.compare(__rhs)); }
4099#else
4100 /**
4101 * @brief Test equivalence of C string and string.
4102 * @param __lhs C string.
4103 * @param __rhs String.
4104 * @return True if @a __rhs.compare(@a __lhs) == 0. False otherwise.
4105 */
4106 template<typename _CharT, typename _Traits, typename _Alloc>
4107 _GLIBCXX_NODISCARD
4108 inline bool
4109 operator==(const _CharT* __lhs,
4110 const basic_string<_CharT, _Traits, _Alloc>& __rhs)
4111 { return __rhs == __lhs; }
4112
4113 // operator !=
4114 /**
4115 * @brief Test difference of two strings.
4116 * @param __lhs First string.
4117 * @param __rhs Second string.
4118 * @return True if @a __lhs.compare(@a __rhs) != 0. False otherwise.
4119 */
4120 template<typename _CharT, typename _Traits, typename _Alloc>
4121 _GLIBCXX_NODISCARD
4122 inline bool
4123 operator!=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
4124 const basic_string<_CharT, _Traits, _Alloc>& __rhs)
4125 _GLIBCXX_NOEXCEPT
4126 { return !(__lhs == __rhs); }
4127
4128 /**
4129 * @brief Test difference of C string and string.
4130 * @param __lhs C string.
4131 * @param __rhs String.
4132 * @return True if @a __rhs.compare(@a __lhs) != 0. False otherwise.
4133 */
4134 template<typename _CharT, typename _Traits, typename _Alloc>
4135 _GLIBCXX_NODISCARD
4136 inline bool
4137 operator!=(const _CharT* __lhs,
4138 const basic_string<_CharT, _Traits, _Alloc>& __rhs)
4139 { return !(__rhs == __lhs); }
4140
4141 /**
4142 * @brief Test difference of string and C string.
4143 * @param __lhs String.
4144 * @param __rhs C string.
4145 * @return True if @a __lhs.compare(@a __rhs) != 0. False otherwise.
4146 */
4147 template<typename _CharT, typename _Traits, typename _Alloc>
4148 _GLIBCXX_NODISCARD
4149 inline bool
4150 operator!=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
4151 const _CharT* __rhs)
4152 { return !(__lhs == __rhs); }
4153
4154 // operator <
4155 /**
4156 * @brief Test if string precedes string.
4157 * @param __lhs First string.
4158 * @param __rhs Second string.
4159 * @return True if @a __lhs precedes @a __rhs. False otherwise.
4160 */
4161 template<typename _CharT, typename _Traits, typename _Alloc>
4162 _GLIBCXX_NODISCARD
4163 inline bool
4164 operator<(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
4165 const basic_string<_CharT, _Traits, _Alloc>& __rhs)
4166 _GLIBCXX_NOEXCEPT
4167 { return __lhs.compare(__rhs) < 0; }
4168
4169 /**
4170 * @brief Test if string precedes C string.
4171 * @param __lhs String.
4172 * @param __rhs C string.
4173 * @return True if @a __lhs precedes @a __rhs. False otherwise.
4174 */
4175 template<typename _CharT, typename _Traits, typename _Alloc>
4176 _GLIBCXX_NODISCARD
4177 inline bool
4178 operator<(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
4179 const _CharT* __rhs)
4180 { return __lhs.compare(__rhs) < 0; }
4181
4182 /**
4183 * @brief Test if C string precedes string.
4184 * @param __lhs C string.
4185 * @param __rhs String.
4186 * @return True if @a __lhs precedes @a __rhs. False otherwise.
4187 */
4188 template<typename _CharT, typename _Traits, typename _Alloc>
4189 _GLIBCXX_NODISCARD
4190 inline bool
4191 operator<(const _CharT* __lhs,
4192 const basic_string<_CharT, _Traits, _Alloc>& __rhs)
4193 { return __rhs.compare(__lhs) > 0; }
4194
4195 // operator >
4196 /**
4197 * @brief Test if string follows string.
4198 * @param __lhs First string.
4199 * @param __rhs Second string.
4200 * @return True if @a __lhs follows @a __rhs. False otherwise.
4201 */
4202 template<typename _CharT, typename _Traits, typename _Alloc>
4203 _GLIBCXX_NODISCARD
4204 inline bool
4205 operator>(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
4206 const basic_string<_CharT, _Traits, _Alloc>& __rhs)
4207 _GLIBCXX_NOEXCEPT
4208 { return __lhs.compare(__rhs) > 0; }
4209
4210 /**
4211 * @brief Test if string follows C string.
4212 * @param __lhs String.
4213 * @param __rhs C string.
4214 * @return True if @a __lhs follows @a __rhs. False otherwise.
4215 */
4216 template<typename _CharT, typename _Traits, typename _Alloc>
4217 _GLIBCXX_NODISCARD
4218 inline bool
4219 operator>(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
4220 const _CharT* __rhs)
4221 { return __lhs.compare(__rhs) > 0; }
4222
4223 /**
4224 * @brief Test if C string follows string.
4225 * @param __lhs C string.
4226 * @param __rhs String.
4227 * @return True if @a __lhs follows @a __rhs. False otherwise.
4228 */
4229 template<typename _CharT, typename _Traits, typename _Alloc>
4230 _GLIBCXX_NODISCARD
4231 inline bool
4232 operator>(const _CharT* __lhs,
4233 const basic_string<_CharT, _Traits, _Alloc>& __rhs)
4234 { return __rhs.compare(__lhs) < 0; }
4235
4236 // operator <=
4237 /**
4238 * @brief Test if string doesn't follow string.
4239 * @param __lhs First string.
4240 * @param __rhs Second string.
4241 * @return True if @a __lhs doesn't follow @a __rhs. False otherwise.
4242 */
4243 template<typename _CharT, typename _Traits, typename _Alloc>
4244 _GLIBCXX_NODISCARD
4245 inline bool
4246 operator<=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
4247 const basic_string<_CharT, _Traits, _Alloc>& __rhs)
4248 _GLIBCXX_NOEXCEPT
4249 { return __lhs.compare(__rhs) <= 0; }
4250
4251 /**
4252 * @brief Test if string doesn't follow C string.
4253 * @param __lhs String.
4254 * @param __rhs C string.
4255 * @return True if @a __lhs doesn't follow @a __rhs. False otherwise.
4256 */
4257 template<typename _CharT, typename _Traits, typename _Alloc>
4258 _GLIBCXX_NODISCARD
4259 inline bool
4260 operator<=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
4261 const _CharT* __rhs)
4262 { return __lhs.compare(__rhs) <= 0; }
4263
4264 /**
4265 * @brief Test if C string doesn't follow string.
4266 * @param __lhs C string.
4267 * @param __rhs String.
4268 * @return True if @a __lhs doesn't follow @a __rhs. False otherwise.
4269 */
4270 template<typename _CharT, typename _Traits, typename _Alloc>
4271 _GLIBCXX_NODISCARD
4272 inline bool
4273 operator<=(const _CharT* __lhs,
4274 const basic_string<_CharT, _Traits, _Alloc>& __rhs)
4275 { return __rhs.compare(__lhs) >= 0; }
4276
4277 // operator >=
4278 /**
4279 * @brief Test if string doesn't precede string.
4280 * @param __lhs First string.
4281 * @param __rhs Second string.
4282 * @return True if @a __lhs doesn't precede @a __rhs. False otherwise.
4283 */
4284 template<typename _CharT, typename _Traits, typename _Alloc>
4285 _GLIBCXX_NODISCARD
4286 inline bool
4287 operator>=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
4288 const basic_string<_CharT, _Traits, _Alloc>& __rhs)
4289 _GLIBCXX_NOEXCEPT
4290 { return __lhs.compare(__rhs) >= 0; }
4291
4292 /**
4293 * @brief Test if string doesn't precede C string.
4294 * @param __lhs String.
4295 * @param __rhs C string.
4296 * @return True if @a __lhs doesn't precede @a __rhs. False otherwise.
4297 */
4298 template<typename _CharT, typename _Traits, typename _Alloc>
4299 _GLIBCXX_NODISCARD
4300 inline bool
4301 operator>=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
4302 const _CharT* __rhs)
4303 { return __lhs.compare(__rhs) >= 0; }
4304
4305 /**
4306 * @brief Test if C string doesn't precede string.
4307 * @param __lhs C string.
4308 * @param __rhs String.
4309 * @return True if @a __lhs doesn't precede @a __rhs. False otherwise.
4310 */
4311 template<typename _CharT, typename _Traits, typename _Alloc>
4312 _GLIBCXX_NODISCARD
4313 inline bool
4314 operator>=(const _CharT* __lhs,
4315 const basic_string<_CharT, _Traits, _Alloc>& __rhs)
4316 { return __rhs.compare(__lhs) <= 0; }
4317#endif // three-way comparison
4318
4319 /**
4320 * @brief Swap contents of two strings.
4321 * @param __lhs First string.
4322 * @param __rhs Second string.
4323 *
4324 * Exchanges the contents of @a __lhs and @a __rhs in constant time.
4325 */
4326 template<typename _CharT, typename _Traits, typename _Alloc>
4327 _GLIBCXX20_CONSTEXPR
4328 inline void
4329 swap(basic_string<_CharT, _Traits, _Alloc>& __lhs,
4330 basic_string<_CharT, _Traits, _Alloc>& __rhs)
4331 _GLIBCXX_NOEXCEPT_IF(noexcept(__lhs.swap(__rhs)))
4332 { __lhs.swap(__rhs); }
4333
4334
4335 /**
4336 * @brief Read stream into a string.
4337 * @param __is Input stream.
4338 * @param __str Buffer to store into.
4339 * @return Reference to the input stream.
4340 *
4341 * Stores characters from @a __is into @a __str until whitespace is
4342 * found, the end of the stream is encountered, or str.max_size()
4343 * is reached. If is.width() is non-zero, that is the limit on the
4344 * number of characters stored into @a __str. Any previous
4345 * contents of @a __str are erased.
4346 */
4347 template<typename _CharT, typename _Traits, typename _Alloc>
4348 basic_istream<_CharT, _Traits>&
4349 operator>>(basic_istream<_CharT, _Traits>& __is,
4350 basic_string<_CharT, _Traits, _Alloc>& __str);
4351
4352 template<>
4353 basic_istream<char>&
4354 operator>>(basic_istream<char>& __is, basic_string<char>& __str);
4355
4356 /**
4357 * @brief Write string to a stream.
4358 * @param __os Output stream.
4359 * @param __str String to write out.
4360 * @return Reference to the output stream.
4361 *
4362 * Output characters of @a __str into os following the same rules as for
4363 * writing a C string.
4364 */
4365 template<typename _CharT, typename _Traits, typename _Alloc>
4366 inline basic_ostream<_CharT, _Traits>&
4367 operator<<(basic_ostream<_CharT, _Traits>& __os,
4368 const basic_string<_CharT, _Traits, _Alloc>& __str)
4369 {
4370 // _GLIBCXX_RESOLVE_LIB_DEFECTS
4371 // 586. string inserter not a formatted function
4372 return __ostream_insert(__os, __str.data(), __str.size());
4373 }
4374
4375 /**
4376 * @brief Read a line from stream into a string.
4377 * @param __is Input stream.
4378 * @param __str Buffer to store into.
4379 * @param __delim Character marking end of line.
4380 * @return Reference to the input stream.
4381 *
4382 * Stores characters from @a __is into @a __str until @a __delim is
4383 * found, the end of the stream is encountered, or str.max_size()
4384 * is reached. Any previous contents of @a __str are erased. If
4385 * @a __delim is encountered, it is extracted but not stored into
4386 * @a __str.
4387 */
4388 template<typename _CharT, typename _Traits, typename _Alloc>
4389 basic_istream<_CharT, _Traits>&
4390 getline(basic_istream<_CharT, _Traits>& __is,
4391 basic_string<_CharT, _Traits, _Alloc>& __str, _CharT __delim);
4392
4393 /**
4394 * @brief Read a line from stream into a string.
4395 * @param __is Input stream.
4396 * @param __str Buffer to store into.
4397 * @return Reference to the input stream.
4398 *
4399 * Stores characters from is into @a __str until &apos;\n&apos; is
4400 * found, the end of the stream is encountered, or str.max_size()
4401 * is reached. Any previous contents of @a __str are erased. If
4402 * end of line is encountered, it is extracted but not stored into
4403 * @a __str.
4404 */
4405 template<typename _CharT, typename _Traits, typename _Alloc>
4406 inline basic_istream<_CharT, _Traits>&
4407 getline(basic_istream<_CharT, _Traits>& __is,
4408 basic_string<_CharT, _Traits, _Alloc>& __str)
4409 { return std::getline(__is, __str, __is.widen('\n')); }
4410
4411#if __cplusplus >= 201103L
4412 /// Read a line from an rvalue stream into a string.
4413 template<typename _CharT, typename _Traits, typename _Alloc>
4414 inline basic_istream<_CharT, _Traits>&
4415 getline(basic_istream<_CharT, _Traits>&& __is,
4416 basic_string<_CharT, _Traits, _Alloc>& __str, _CharT __delim)
4417 { return std::getline(__is, __str, __delim); }
4418
4419 /// Read a line from an rvalue stream into a string.
4420 template<typename _CharT, typename _Traits, typename _Alloc>
4421 inline basic_istream<_CharT, _Traits>&
4422 getline(basic_istream<_CharT, _Traits>&& __is,
4423 basic_string<_CharT, _Traits, _Alloc>& __str)
4424 { return std::getline(__is, __str); }
4425#endif
4426
4427 template<>
4428 basic_istream<char>&
4429 getline(basic_istream<char>& __in, basic_string<char>& __str,
4430 char __delim);
4431
4432#ifdef _GLIBCXX_USE_WCHAR_T
4433 template<>
4434 basic_istream<wchar_t>&
4435 getline(basic_istream<wchar_t>& __in, basic_string<wchar_t>& __str,
4436 wchar_t __delim);
4437#endif
4438
4439_GLIBCXX_END_NAMESPACE_VERSION
4440} // namespace
4441
4442#if __cplusplus >= 201103L
4443
4444#include <ext/string_conversions.h>
4445#include <bits/charconv.h>
4446
4447namespace std _GLIBCXX_VISIBILITY(default)
4448{
4449_GLIBCXX_BEGIN_NAMESPACE_VERSION
4450_GLIBCXX_BEGIN_NAMESPACE_CXX11
4451
4452 // 21.4 Numeric Conversions [string.conversions].
4453 inline int
4454 stoi(const string& __str, size_t* __idx = 0, int __base = 10)
4455 { return __gnu_cxx::__stoa<long, int>(convf: &std::strtol, name: "stoi", str: __str.c_str(),
4456 __idx, __base); }
4457
4458 inline long
4459 stol(const string& __str, size_t* __idx = 0, int __base = 10)
4460 { return __gnu_cxx::__stoa(convf: &std::strtol, name: "stol", str: __str.c_str(),
4461 __idx, __base); }
4462
4463 inline unsigned long
4464 stoul(const string& __str, size_t* __idx = 0, int __base = 10)
4465 { return __gnu_cxx::__stoa(convf: &std::strtoul, name: "stoul", str: __str.c_str(),
4466 __idx, __base); }
4467
4468#if _GLIBCXX_USE_C99_STDLIB
4469 inline long long
4470 stoll(const string& __str, size_t* __idx = 0, int __base = 10)
4471 { return __gnu_cxx::__stoa(convf: &std::strtoll, name: "stoll", str: __str.c_str(),
4472 __idx, __base); }
4473
4474 inline unsigned long long
4475 stoull(const string& __str, size_t* __idx = 0, int __base = 10)
4476 { return __gnu_cxx::__stoa(convf: &std::strtoull, name: "stoull", str: __str.c_str(),
4477 __idx, __base); }
4478#elif __LONG_WIDTH__ == __LONG_LONG_WIDTH__
4479 inline long long
4480 stoll(const string& __str, size_t* __idx = 0, int __base = 10)
4481 { return std::stol(__str, __idx, __base); }
4482
4483 inline unsigned long long
4484 stoull(const string& __str, size_t* __idx = 0, int __base = 10)
4485 { return std::stoul(__str, __idx, __base); }
4486#endif
4487
4488 inline double
4489 stod(const string& __str, size_t* __idx = 0)
4490 { return __gnu_cxx::__stoa(convf: &std::strtod, name: "stod", str: __str.c_str(), __idx); }
4491
4492#if _GLIBCXX_HAVE_STRTOF
4493 // NB: strtof vs strtod.
4494 inline float
4495 stof(const string& __str, size_t* __idx = 0)
4496 { return __gnu_cxx::__stoa(convf: &std::strtof, name: "stof", str: __str.c_str(), __idx); }
4497#else
4498 inline float
4499 stof(const string& __str, size_t* __idx = 0)
4500 {
4501 double __d = std::stod(__str, __idx);
4502 if (__builtin_isfinite(__d) && __d != 0.0)
4503 {
4504 double __abs_d = __builtin_fabs(__d);
4505 if (__abs_d < __FLT_MIN__ || __abs_d > __FLT_MAX__)
4506 {
4507 errno = ERANGE;
4508 std::__throw_out_of_range("stof");
4509 }
4510 }
4511 return __d;
4512 }
4513#endif
4514
4515#if _GLIBCXX_HAVE_STRTOLD && ! _GLIBCXX_HAVE_BROKEN_STRTOLD
4516 inline long double
4517 stold(const string& __str, size_t* __idx = 0)
4518 { return __gnu_cxx::__stoa(convf: &std::strtold, name: "stold", str: __str.c_str(), __idx); }
4519#elif __DBL_MANT_DIG__ == __LDBL_MANT_DIG__
4520 inline long double
4521 stold(const string& __str, size_t* __idx = 0)
4522 { return std::stod(__str, __idx); }
4523#endif
4524
4525 // _GLIBCXX_RESOLVE_LIB_DEFECTS
4526 // DR 1261. Insufficent overloads for to_string / to_wstring
4527
4528 _GLIBCXX_NODISCARD
4529 inline string
4530 to_string(int __val)
4531#if _GLIBCXX_USE_CXX11_ABI && (__CHAR_BIT__ * __SIZEOF_INT__) <= 32
4532 noexcept // any 32-bit value fits in the SSO buffer
4533#endif
4534 {
4535 const bool __neg = __val < 0;
4536 const unsigned __uval = __neg ? (unsigned)~__val + 1u : __val;
4537 const auto __len = __detail::__to_chars_len(value: __uval);
4538 string __str;
4539 __str.__resize_and_overwrite(n: __neg + __len, op: [=](char* __p, size_t __n) {
4540 __p[0] = '-';
4541 __detail::__to_chars_10_impl(first: __p + (int)__neg, __len, val: __uval);
4542 return __n;
4543 });
4544 return __str;
4545 }
4546
4547 _GLIBCXX_NODISCARD
4548 inline string
4549 to_string(unsigned __val)
4550#if _GLIBCXX_USE_CXX11_ABI && (__CHAR_BIT__ * __SIZEOF_INT__) <= 32
4551 noexcept // any 32-bit value fits in the SSO buffer
4552#endif
4553 {
4554 const auto __len = __detail::__to_chars_len(value: __val);
4555 string __str;
4556 __str.__resize_and_overwrite(n: __len, op: [__val](char* __p, size_t __n) {
4557 __detail::__to_chars_10_impl(first: __p, len: __n, __val);
4558 return __n;
4559 });
4560 return __str;
4561 }
4562
4563 _GLIBCXX_NODISCARD
4564 inline string
4565 to_string(long __val)
4566#if _GLIBCXX_USE_CXX11_ABI && (__CHAR_BIT__ * __SIZEOF_LONG__) <= 32
4567 noexcept // any 32-bit value fits in the SSO buffer
4568#endif
4569 {
4570 const bool __neg = __val < 0;
4571 const unsigned long __uval = __neg ? (unsigned long)~__val + 1ul : __val;
4572 const auto __len = __detail::__to_chars_len(value: __uval);
4573 string __str;
4574 __str.__resize_and_overwrite(n: __neg + __len, op: [=](char* __p, size_t __n) {
4575 __p[0] = '-';
4576 __detail::__to_chars_10_impl(first: __p + (int)__neg, __len, val: __uval);
4577 return __n;
4578 });
4579 return __str;
4580 }
4581
4582 _GLIBCXX_NODISCARD
4583 inline string
4584 to_string(unsigned long __val)
4585#if _GLIBCXX_USE_CXX11_ABI && (__CHAR_BIT__ * __SIZEOF_LONG__) <= 32
4586 noexcept // any 32-bit value fits in the SSO buffer
4587#endif
4588 {
4589 const auto __len = __detail::__to_chars_len(value: __val);
4590 string __str;
4591 __str.__resize_and_overwrite(n: __len, op: [__val](char* __p, size_t __n) {
4592 __detail::__to_chars_10_impl(first: __p, len: __n, __val);
4593 return __n;
4594 });
4595 return __str;
4596 }
4597
4598 _GLIBCXX_NODISCARD
4599 inline string
4600 to_string(long long __val)
4601 {
4602 const bool __neg = __val < 0;
4603 const unsigned long long __uval
4604 = __neg ? (unsigned long long)~__val + 1ull : __val;
4605 const auto __len = __detail::__to_chars_len(value: __uval);
4606 string __str;
4607 __str.__resize_and_overwrite(n: __neg + __len, op: [=](char* __p, size_t __n) {
4608 __p[0] = '-';
4609 __detail::__to_chars_10_impl(first: __p + (int)__neg, __len, val: __uval);
4610 return __n;
4611 });
4612 return __str;
4613 }
4614
4615 _GLIBCXX_NODISCARD
4616 inline string
4617 to_string(unsigned long long __val)
4618 {
4619 const auto __len = __detail::__to_chars_len(value: __val);
4620 string __str;
4621 __str.__resize_and_overwrite(n: __len, op: [__val](char* __p, size_t __n) {
4622 __detail::__to_chars_10_impl(first: __p, len: __n, __val);
4623 return __n;
4624 });
4625 return __str;
4626 }
4627
4628#if __glibcxx_to_string >= 202306L // C++ >= 26
4629
4630 [[nodiscard]]
4631 inline string
4632 to_string(float __val)
4633 {
4634 string __str;
4635 size_t __len = 15;
4636 do {
4637 __str.resize_and_overwrite(__len,
4638 [__val, &__len] (char* __p, size_t __n) {
4639 auto [__end, __err] = std::to_chars(__p, __p + __n, __val);
4640 if (__err == errc{}) [[likely]]
4641 return __end - __p;
4642 __len *= 2;
4643 return __p - __p;;
4644 });
4645 } while (__str.empty());
4646 return __str;
4647 }
4648
4649 [[nodiscard]]
4650 inline string
4651 to_string(double __val)
4652 {
4653 string __str;
4654 size_t __len = 15;
4655 do {
4656 __str.resize_and_overwrite(__len,
4657 [__val, &__len] (char* __p, size_t __n) {
4658 auto [__end, __err] = std::to_chars(__p, __p + __n, __val);
4659 if (__err == errc{}) [[likely]]
4660 return __end - __p;
4661 __len *= 2;
4662 return __p - __p;;
4663 });
4664 } while (__str.empty());
4665 return __str;
4666 }
4667
4668 [[nodiscard]]
4669 inline string
4670 to_string(long double __val)
4671 {
4672 string __str;
4673 size_t __len = 15;
4674 do {
4675 __str.resize_and_overwrite(__len,
4676 [__val, &__len] (char* __p, size_t __n) {
4677 auto [__end, __err] = std::to_chars(__p, __p + __n, __val);
4678 if (__err == errc{}) [[likely]]
4679 return __end - __p;
4680 __len *= 2;
4681 return __p - __p;;
4682 });
4683 } while (__str.empty());
4684 return __str;
4685 }
4686#elif _GLIBCXX_USE_C99_STDIO
4687#pragma GCC diagnostic push
4688#pragma GCC diagnostic ignored "-Wsuggest-attribute=format"
4689 // NB: (v)snprintf vs sprintf.
4690
4691 _GLIBCXX_NODISCARD
4692 inline string
4693 to_string(float __val)
4694 {
4695 const int __n =
4696 __gnu_cxx::__numeric_traits<float>::__max_exponent10 + 20;
4697 return __gnu_cxx::__to_xstring<string>(convf: &std::vsnprintf, __n,
4698 fmt: "%f", __val);
4699 }
4700
4701 _GLIBCXX_NODISCARD
4702 inline string
4703 to_string(double __val)
4704 {
4705 const int __n =
4706 __gnu_cxx::__numeric_traits<double>::__max_exponent10 + 20;
4707 return __gnu_cxx::__to_xstring<string>(convf: &std::vsnprintf, __n,
4708 fmt: "%f", __val);
4709 }
4710
4711 _GLIBCXX_NODISCARD
4712 inline string
4713 to_string(long double __val)
4714 {
4715 const int __n =
4716 __gnu_cxx::__numeric_traits<long double>::__max_exponent10 + 20;
4717 return __gnu_cxx::__to_xstring<string>(convf: &std::vsnprintf, __n,
4718 fmt: "%Lf", __val);
4719 }
4720#pragma GCC diagnostic pop
4721#endif // _GLIBCXX_USE_C99_STDIO
4722
4723#if defined(_GLIBCXX_USE_WCHAR_T) && _GLIBCXX_USE_C99_WCHAR
4724 inline int
4725 stoi(const wstring& __str, size_t* __idx = 0, int __base = 10)
4726 { return __gnu_cxx::__stoa<long, int>(convf: &std::wcstol, name: "stoi", str: __str.c_str(),
4727 __idx, __base); }
4728
4729 inline long
4730 stol(const wstring& __str, size_t* __idx = 0, int __base = 10)
4731 { return __gnu_cxx::__stoa(convf: &std::wcstol, name: "stol", str: __str.c_str(),
4732 __idx, __base); }
4733
4734 inline unsigned long
4735 stoul(const wstring& __str, size_t* __idx = 0, int __base = 10)
4736 { return __gnu_cxx::__stoa(convf: &std::wcstoul, name: "stoul", str: __str.c_str(),
4737 __idx, __base); }
4738
4739 inline long long
4740 stoll(const wstring& __str, size_t* __idx = 0, int __base = 10)
4741 { return __gnu_cxx::__stoa(convf: &std::wcstoll, name: "stoll", str: __str.c_str(),
4742 __idx, __base); }
4743
4744 inline unsigned long long
4745 stoull(const wstring& __str, size_t* __idx = 0, int __base = 10)
4746 { return __gnu_cxx::__stoa(convf: &std::wcstoull, name: "stoull", str: __str.c_str(),
4747 __idx, __base); }
4748
4749 // NB: wcstof vs wcstod.
4750 inline float
4751 stof(const wstring& __str, size_t* __idx = 0)
4752 { return __gnu_cxx::__stoa(convf: &std::wcstof, name: "stof", str: __str.c_str(), __idx); }
4753
4754 inline double
4755 stod(const wstring& __str, size_t* __idx = 0)
4756 { return __gnu_cxx::__stoa(convf: &std::wcstod, name: "stod", str: __str.c_str(), __idx); }
4757
4758 inline long double
4759 stold(const wstring& __str, size_t* __idx = 0)
4760 { return __gnu_cxx::__stoa(convf: &std::wcstold, name: "stold", str: __str.c_str(), __idx); }
4761#endif
4762
4763#ifdef _GLIBCXX_USE_WCHAR_T
4764#pragma GCC diagnostic push
4765#pragma GCC diagnostic ignored "-Wc++17-extensions"
4766 _GLIBCXX20_CONSTEXPR
4767 inline void
4768 __to_wstring_numeric(const char* __s, int __len, wchar_t* __wout)
4769 {
4770 // This condition is true if exec-charset and wide-exec-charset share the
4771 // same values for the ASCII subset or the EBCDIC invariant character set.
4772 if constexpr (wchar_t('0') == L'0' && wchar_t('-') == L'-'
4773 && wchar_t('.') == L'.' && wchar_t('e') == L'e')
4774 {
4775 for (int __i = 0; __i < __len; ++__i)
4776 __wout[__i] = (wchar_t) __s[__i];
4777 }
4778 else
4779 {
4780 wchar_t __wc[256];
4781 for (int __i = '0'; __i <= '9'; ++__i)
4782 __wc[__i] = L'0' + __i;
4783 __wc['.'] = L'.';
4784 __wc['+'] = L'+';
4785 __wc['-'] = L'-';
4786 __wc['a'] = L'a';
4787 __wc['b'] = L'b';
4788 __wc['c'] = L'c';
4789 __wc['d'] = L'd';
4790 __wc['e'] = L'e';
4791 __wc['f'] = L'f';
4792 __wc['i'] = L'i'; // for "inf"
4793 __wc['n'] = L'n'; // for "nan" and "inf"
4794 __wc['p'] = L'p'; // for hexfloats "0x1p1"
4795 __wc['x'] = L'x';
4796 __wc['A'] = L'A';
4797 __wc['B'] = L'B';
4798 __wc['C'] = L'C';
4799 __wc['D'] = L'D';
4800 __wc['E'] = L'E';
4801 __wc['F'] = L'F';
4802 __wc['I'] = L'I';
4803 __wc['N'] = L'N';
4804 __wc['P'] = L'P';
4805 __wc['X'] = L'X';
4806
4807 for (int __i = 0; __i < __len; ++__i)
4808 __wout[__i] = __wc[(int)__s[__i]];
4809 }
4810 }
4811
4812#if __glibcxx_constexpr_string >= 201907L
4813 constexpr
4814#endif
4815 inline wstring
4816#ifdef __glibcxx_string_view // >= C++17
4817 __to_wstring_numeric(string_view __s)
4818#else
4819 __to_wstring_numeric(const string& __s)
4820#endif
4821 {
4822 if constexpr (wchar_t('0') == L'0' && wchar_t('-') == L'-'
4823 && wchar_t('.') == L'.' && wchar_t('e') == L'e')
4824 return wstring(__s.data(), __s.data() + __s.size());
4825 else
4826 {
4827 wstring __ws;
4828 auto __f = __s.data();
4829 __ws.__resize_and_overwrite(n: __s.size(),
4830 op: [__f] (wchar_t* __to, int __n) {
4831 std::__to_wstring_numeric(s: __f, len: __n, wout: __to);
4832 return __n;
4833 });
4834 return __ws;
4835 }
4836 }
4837#pragma GCC diagnostic pop
4838
4839 _GLIBCXX_NODISCARD
4840 inline wstring
4841 to_wstring(int __val)
4842 { return std::__to_wstring_numeric(s: std::to_string(__val)); }
4843
4844 _GLIBCXX_NODISCARD
4845 inline wstring
4846 to_wstring(unsigned __val)
4847 { return std::__to_wstring_numeric(s: std::to_string(__val)); }
4848
4849 _GLIBCXX_NODISCARD
4850 inline wstring
4851 to_wstring(long __val)
4852 { return std::__to_wstring_numeric(s: std::to_string(__val)); }
4853
4854 _GLIBCXX_NODISCARD
4855 inline wstring
4856 to_wstring(unsigned long __val)
4857 { return std::__to_wstring_numeric(s: std::to_string(__val)); }
4858
4859 _GLIBCXX_NODISCARD
4860 inline wstring
4861 to_wstring(long long __val)
4862 { return std::__to_wstring_numeric(s: std::to_string(__val)); }
4863
4864 _GLIBCXX_NODISCARD
4865 inline wstring
4866 to_wstring(unsigned long long __val)
4867 { return std::__to_wstring_numeric(s: std::to_string(__val)); }
4868
4869#if __glibcxx_to_string || _GLIBCXX_USE_C99_STDIO
4870 _GLIBCXX_NODISCARD
4871 inline wstring
4872 to_wstring(float __val)
4873 { return std::__to_wstring_numeric(s: std::to_string(__val)); }
4874
4875 _GLIBCXX_NODISCARD
4876 inline wstring
4877 to_wstring(double __val)
4878 { return std::__to_wstring_numeric(s: std::to_string(__val)); }
4879
4880 _GLIBCXX_NODISCARD
4881 inline wstring
4882 to_wstring(long double __val)
4883 { return std::__to_wstring_numeric(s: std::to_string(__val)); }
4884#endif
4885#endif // _GLIBCXX_USE_WCHAR_T
4886
4887_GLIBCXX_END_NAMESPACE_CXX11
4888_GLIBCXX_END_NAMESPACE_VERSION
4889} // namespace
4890
4891#endif /* C++11 */
4892
4893#if __cplusplus >= 201103L
4894
4895#include <bits/functional_hash.h>
4896
4897namespace std _GLIBCXX_VISIBILITY(default)
4898{
4899_GLIBCXX_BEGIN_NAMESPACE_VERSION
4900
4901 // _GLIBCXX_RESOLVE_LIB_DEFECTS
4902 // 3705. Hashability shouldn't depend on basic_string's allocator
4903
4904 template<typename _CharT, typename _Alloc,
4905 typename _StrT = basic_string<_CharT, char_traits<_CharT>, _Alloc>>
4906 struct __str_hash_base
4907 : public __hash_base<size_t, _StrT>
4908 {
4909 [[__nodiscard__]]
4910 size_t
4911 operator()(const _StrT& __s) const noexcept
4912 { return _Hash_impl::hash(__s.data(), __s.length() * sizeof(_CharT)); }
4913 };
4914
4915#ifndef _GLIBCXX_COMPATIBILITY_CXX0X
4916 /// std::hash specialization for string.
4917 template<typename _Alloc>
4918 struct hash<basic_string<char, char_traits<char>, _Alloc>>
4919 : public __str_hash_base<char, _Alloc>
4920 { };
4921
4922 /// std::hash specialization for wstring.
4923 template<typename _Alloc>
4924 struct hash<basic_string<wchar_t, char_traits<wchar_t>, _Alloc>>
4925 : public __str_hash_base<wchar_t, _Alloc>
4926 { };
4927
4928 template<typename _Alloc>
4929 struct __is_fast_hash<hash<basic_string<wchar_t, char_traits<wchar_t>,
4930 _Alloc>>>
4931 : std::false_type
4932 { };
4933#endif /* _GLIBCXX_COMPATIBILITY_CXX0X */
4934
4935#ifdef _GLIBCXX_USE_CHAR8_T
4936 /// std::hash specialization for u8string.
4937 template<typename _Alloc>
4938 struct hash<basic_string<char8_t, char_traits<char8_t>, _Alloc>>
4939 : public __str_hash_base<char8_t, _Alloc>
4940 { };
4941#endif
4942
4943 /// std::hash specialization for u16string.
4944 template<typename _Alloc>
4945 struct hash<basic_string<char16_t, char_traits<char16_t>, _Alloc>>
4946 : public __str_hash_base<char16_t, _Alloc>
4947 { };
4948
4949 /// std::hash specialization for u32string.
4950 template<typename _Alloc>
4951 struct hash<basic_string<char32_t, char_traits<char32_t>, _Alloc>>
4952 : public __str_hash_base<char32_t, _Alloc>
4953 { };
4954
4955#if ! _GLIBCXX_INLINE_VERSION
4956 // PR libstdc++/105907 - __is_fast_hash affects unordered container ABI.
4957 template<> struct __is_fast_hash<hash<string>> : std::false_type { };
4958 template<> struct __is_fast_hash<hash<wstring>> : std::false_type { };
4959 template<> struct __is_fast_hash<hash<u16string>> : std::false_type { };
4960 template<> struct __is_fast_hash<hash<u32string>> : std::false_type { };
4961#ifdef _GLIBCXX_USE_CHAR8_T
4962 template<> struct __is_fast_hash<hash<u8string>> : std::false_type { };
4963#endif
4964#else
4965 // For versioned namespace, assume every std::hash<basic_string<>> is slow.
4966 template<typename _CharT, typename _Traits, typename _Alloc>
4967 struct __is_fast_hash<hash<basic_string<_CharT, _Traits, _Alloc>>>
4968 : std::false_type
4969 { };
4970#endif
4971
4972#ifdef __glibcxx_string_udls // C++ >= 14
4973 inline namespace literals
4974 {
4975 inline namespace string_literals
4976 {
4977#pragma GCC diagnostic push
4978#pragma GCC diagnostic ignored "-Wliteral-suffix"
4979
4980#if __glibcxx_constexpr_string >= 201907L
4981# define _GLIBCXX_STRING_CONSTEXPR constexpr
4982#else
4983# define _GLIBCXX_STRING_CONSTEXPR
4984#endif
4985
4986 _GLIBCXX_DEFAULT_ABI_TAG _GLIBCXX_STRING_CONSTEXPR
4987 inline basic_string<char>
4988 operator""s(const char* __str, size_t __len)
4989 { return basic_string<char>{__str, __len}; }
4990
4991 _GLIBCXX_DEFAULT_ABI_TAG _GLIBCXX_STRING_CONSTEXPR
4992 inline basic_string<wchar_t>
4993 operator""s(const wchar_t* __str, size_t __len)
4994 { return basic_string<wchar_t>{__str, __len}; }
4995
4996#ifdef _GLIBCXX_USE_CHAR8_T
4997 _GLIBCXX_DEFAULT_ABI_TAG _GLIBCXX_STRING_CONSTEXPR
4998 inline basic_string<char8_t>
4999 operator""s(const char8_t* __str, size_t __len)
5000 { return basic_string<char8_t>{__str, __len}; }
5001#endif
5002
5003 _GLIBCXX_DEFAULT_ABI_TAG _GLIBCXX_STRING_CONSTEXPR
5004 inline basic_string<char16_t>
5005 operator""s(const char16_t* __str, size_t __len)
5006 { return basic_string<char16_t>{__str, __len}; }
5007
5008 _GLIBCXX_DEFAULT_ABI_TAG _GLIBCXX_STRING_CONSTEXPR
5009 inline basic_string<char32_t>
5010 operator""s(const char32_t* __str, size_t __len)
5011 { return basic_string<char32_t>{__str, __len}; }
5012
5013#undef _GLIBCXX_STRING_CONSTEXPR
5014#pragma GCC diagnostic pop
5015 } // inline namespace string_literals
5016 } // inline namespace literals
5017#endif // __glibcxx_string_udls
5018
5019#ifdef __glibcxx_variant // >= C++17
5020 namespace __detail::__variant
5021 {
5022 template<typename> struct _Never_valueless_alt; // see <variant>
5023
5024 // Provide the strong exception-safety guarantee when emplacing a
5025 // basic_string into a variant, but only if moving the string cannot throw.
5026 template<typename _Tp, typename _Traits, typename _Alloc>
5027 struct _Never_valueless_alt<std::basic_string<_Tp, _Traits, _Alloc>>
5028 : __and_<
5029 is_nothrow_move_constructible<std::basic_string<_Tp, _Traits, _Alloc>>,
5030 is_nothrow_move_assignable<std::basic_string<_Tp, _Traits, _Alloc>>
5031 >::type
5032 { };
5033 } // namespace __detail::__variant
5034#endif // C++17
5035
5036_GLIBCXX_END_NAMESPACE_VERSION
5037} // namespace std
5038
5039#endif // C++11
5040
5041#endif /* _BASIC_STRING_H */
5042