libstdc++
basic_string.tcc
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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.tcc
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 // Written by Jason Merrill based upon the specification by Takanori Adachi
35 // in ANSI X3J16/94-0013R2. Rewritten by Nathan Myers to ISO-14882.
36 // Non-reference-counted implementation written by Paolo Carlini and
37 // updated by Jonathan Wakely for ISO-14882-2011.
38 
39 #ifndef _BASIC_STRING_TCC
40 #define _BASIC_STRING_TCC 1
41 
42 #ifdef _GLIBCXX_SYSHDR
43 #pragma GCC system_header
44 #endif
45 
46 #pragma GCC diagnostic push
47 #pragma GCC diagnostic ignored "-Wc++11-extensions"
48 
49 #include <bits/cxxabi_forced.h>
50 
51 namespace std _GLIBCXX_VISIBILITY(default)
52 {
53 _GLIBCXX_BEGIN_NAMESPACE_VERSION
54 
55 #if _GLIBCXX_USE_CXX11_ABI
56 
57  template<typename _CharT, typename _Traits, typename _Alloc>
58  const typename basic_string<_CharT, _Traits, _Alloc>::size_type
60 
61  template<typename _CharT, typename _Traits, typename _Alloc>
62  _GLIBCXX20_CONSTEXPR
63  void
65  swap(basic_string& __s) _GLIBCXX_NOEXCEPT
66  {
67  if (this == std::__addressof(__s))
68  return;
69 
70  _Alloc_traits::_S_on_swap(_M_get_allocator(), __s._M_get_allocator());
71 
72  if (_M_is_local())
73  if (__s._M_is_local())
74  {
75  if (length() && __s.length())
76  {
77  _CharT __tmp_data[_S_local_capacity + 1];
78  traits_type::copy(__tmp_data, __s._M_local_buf,
79  __s.length() + 1);
80  traits_type::copy(__s._M_local_buf, _M_local_buf,
81  length() + 1);
82  traits_type::copy(_M_local_buf, __tmp_data,
83  __s.length() + 1);
84  }
85  else if (__s.length())
86  {
87  _M_init_local_buf();
88  traits_type::copy(_M_local_buf, __s._M_local_buf,
89  __s.length() + 1);
90  _M_length(__s.length());
91  __s._M_set_length(0);
92  return;
93  }
94  else if (length())
95  {
96  __s._M_init_local_buf();
97  traits_type::copy(__s._M_local_buf, _M_local_buf,
98  length() + 1);
99  __s._M_length(length());
100  _M_set_length(0);
101  return;
102  }
103  }
104  else
105  {
106  const size_type __tmp_capacity = __s._M_allocated_capacity;
107  __s._M_init_local_buf();
108  traits_type::copy(__s._M_local_buf, _M_local_buf,
109  length() + 1);
110  _M_data(__s._M_data());
111  __s._M_data(__s._M_local_buf);
112  _M_capacity(__tmp_capacity);
113  }
114  else
115  {
116  const size_type __tmp_capacity = _M_allocated_capacity;
117  if (__s._M_is_local())
118  {
119  _M_init_local_buf();
120  traits_type::copy(_M_local_buf, __s._M_local_buf,
121  __s.length() + 1);
122  __s._M_data(_M_data());
123  _M_data(_M_local_buf);
124  }
125  else
126  {
127  pointer __tmp_ptr = _M_data();
128  _M_data(__s._M_data());
129  __s._M_data(__tmp_ptr);
130  _M_capacity(__s._M_allocated_capacity);
131  }
132  __s._M_capacity(__tmp_capacity);
133  }
134 
135  const size_type __tmp_length = length();
136  _M_length(__s.length());
137  __s._M_length(__tmp_length);
138  }
139 
140  template<typename _CharT, typename _Traits, typename _Alloc>
141  _GLIBCXX20_CONSTEXPR
142  typename basic_string<_CharT, _Traits, _Alloc>::pointer
143  basic_string<_CharT, _Traits, _Alloc>::
144  _M_create(size_type& __capacity, size_type __old_capacity)
145  {
146  // _GLIBCXX_RESOLVE_LIB_DEFECTS
147  // 83. String::npos vs. string::max_size()
148  if (__capacity > max_size())
149  std::__throw_length_error(__N("basic_string::_M_create"));
150 
151  // The below implements an exponential growth policy, necessary to
152  // meet amortized linear time requirements of the library: see
153  // http://gcc.gnu.org/ml/libstdc++/2001-07/msg00085.html.
154  if (__capacity > __old_capacity && __capacity < 2 * __old_capacity)
155  {
156  __capacity = 2 * __old_capacity;
157  // Never allocate a string bigger than max_size.
158  if (__capacity > max_size())
159  __capacity = max_size();
160  }
161 
162  // NB: Need an array of char_type[__capacity], plus a terminating
163  // null char_type() element.
164  return _S_allocate(_M_get_allocator(), __capacity + 1);
165  }
166 
167  // NB: This is the special case for Input Iterators, used in
168  // istreambuf_iterators, etc.
169  // Input Iterators have a cost structure very different from
170  // pointers, calling for a different coding style.
171  template<typename _CharT, typename _Traits, typename _Alloc>
172  template<typename _InIterator>
173  _GLIBCXX20_CONSTEXPR
174  void
175  basic_string<_CharT, _Traits, _Alloc>::
176  _M_construct(_InIterator __beg, _InIterator __end,
178  {
179  size_type __len = 0;
180  size_type __capacity = size_type(_S_local_capacity);
181 
182  _M_init_local_buf();
183 
184  while (__beg != __end && __len < __capacity)
185  {
186  _M_local_buf[__len++] = *__beg;
187  ++__beg;
188  }
189 
190  struct _Guard
191  {
192  _GLIBCXX20_CONSTEXPR
193  explicit _Guard(basic_string* __s) : _M_guarded(__s) { }
194 
195  _GLIBCXX20_CONSTEXPR
196  ~_Guard() { if (_M_guarded) _M_guarded->_M_dispose(); }
197 
198  basic_string* _M_guarded;
199  } __guard(this);
200 
201  while (__beg != __end)
202  {
203  if (__len == __capacity)
204  {
205  // Allocate more space.
206  __capacity = __len + 1;
207  pointer __another = _M_create(__capacity, __len);
208  this->_S_copy(__another, _M_data(), __len);
209  _M_dispose();
210  _M_data(__another);
211  _M_capacity(__capacity);
212  }
213  traits_type::assign(_M_data()[__len++],
214  static_cast<_CharT>(*__beg));
215  ++__beg;
216  }
217 
218  __guard._M_guarded = 0;
219 
220  _M_set_length(__len);
221  }
222 
223  template<typename _CharT, typename _Traits, typename _Alloc>
224  template<typename _InIterator>
225  _GLIBCXX20_CONSTEXPR
226  void
227  basic_string<_CharT, _Traits, _Alloc>::
228  _M_construct(_InIterator __beg, _InIterator __end,
230  {
231  size_type __dnew = static_cast<size_type>(std::distance(__beg, __end));
232 
233  if (__dnew > size_type(_S_local_capacity))
234  {
235  _M_data(_M_create(__dnew, size_type(0)));
236  _M_capacity(__dnew);
237  }
238  else
239  _M_init_local_buf();
240 
241  // Check for out_of_range and length_error exceptions.
242  struct _Guard
243  {
244  _GLIBCXX20_CONSTEXPR
245  explicit _Guard(basic_string* __s) : _M_guarded(__s) { }
246 
247  _GLIBCXX20_CONSTEXPR
248  ~_Guard() { if (_M_guarded) _M_guarded->_M_dispose(); }
249 
250  basic_string* _M_guarded;
251  } __guard(this);
252 
253  this->_S_copy_chars(_M_data(), __beg, __end);
254 
255  __guard._M_guarded = 0;
256 
257  _M_set_length(__dnew);
258  }
259 
260  template<typename _CharT, typename _Traits, typename _Alloc>
261  _GLIBCXX20_CONSTEXPR
262  void
263  basic_string<_CharT, _Traits, _Alloc>::
264  _M_construct(size_type __n, _CharT __c)
265  {
266  if (__n > size_type(_S_local_capacity))
267  {
268  _M_data(_M_create(__n, size_type(0)));
269  _M_capacity(__n);
270  }
271  else
272  _M_init_local_buf();
273 
274  if (__n)
275  this->_S_assign(_M_data(), __n, __c);
276 
277  _M_set_length(__n);
278  }
279 
280  // Length of string constructed is easier to propagate inter-procedurally
281  // than difference between iterators.
282  template<typename _CharT, typename _Traits, typename _Alloc>
283  template<bool _Terminated>
284  _GLIBCXX20_CONSTEXPR
285  void
286  basic_string<_CharT, _Traits, _Alloc>::
287  _M_construct(const _CharT* __str, size_type __n)
288  {
289  if (__n > size_type(_S_local_capacity))
290  {
291  _M_data(_M_create(__n, size_type(0)));
292  _M_capacity(__n);
293  }
294  else
295  _M_init_local_buf();
296 
297  if (__n || _Terminated)
298  this->_S_copy(_M_data(), __str, __n + _Terminated);
299 
300  _M_length(__n);
301  if (!_Terminated)
302  traits_type::assign(_M_data()[__n], _CharT());
303  }
304 
305  template<typename _CharT, typename _Traits, typename _Alloc>
306  _GLIBCXX20_CONSTEXPR
307  void
308  basic_string<_CharT, _Traits, _Alloc>::
309  _M_assign(const basic_string& __str)
310  {
311  if (this != std::__addressof(__str))
312  {
313  const size_type __rsize = __str.length();
314  const size_type __capacity = capacity();
315 
316  if (__rsize > __capacity)
317  {
318  size_type __new_capacity = __rsize;
319  pointer __tmp = _M_create(__new_capacity, __capacity);
320  _M_dispose();
321  _M_data(__tmp);
322  _M_capacity(__new_capacity);
323  }
324 
325  if (__rsize)
326  this->_S_copy(_M_data(), __str._M_data(), __rsize);
327 
328  _M_set_length(__rsize);
329  }
330  }
331 
332  template<typename _CharT, typename _Traits, typename _Alloc>
333  _GLIBCXX20_CONSTEXPR
334  void
336  reserve(size_type __res)
337  {
338  const size_type __capacity = capacity();
339  // _GLIBCXX_RESOLVE_LIB_DEFECTS
340  // 2968. Inconsistencies between basic_string reserve and
341  // vector/unordered_map/unordered_set reserve functions
342  // P0966 reserve should not shrink
343  if (__res <= __capacity)
344  return;
345 
346  pointer __tmp = _M_create(__res, __capacity);
347  this->_S_copy(__tmp, _M_data(), length() + 1);
348  _M_dispose();
349  _M_data(__tmp);
350  _M_capacity(__res);
351  }
352 
353  template<typename _CharT, typename _Traits, typename _Alloc>
354  _GLIBCXX20_CONSTEXPR
355  void
356  basic_string<_CharT, _Traits, _Alloc>::
357  _M_mutate(size_type __pos, size_type __len1, const _CharT* __s,
358  size_type __len2)
359  {
360  const size_type __how_much = length() - __pos - __len1;
361 
362  size_type __new_capacity = length() + __len2 - __len1;
363  pointer __r = _M_create(__new_capacity, capacity());
364 
365  if (__pos)
366  this->_S_copy(__r, _M_data(), __pos);
367  if (__s && __len2)
368  this->_S_copy(__r + __pos, __s, __len2);
369  if (__how_much)
370  this->_S_copy(__r + __pos + __len2,
371  _M_data() + __pos + __len1, __how_much);
372 
373  _M_dispose();
374  _M_data(__r);
375  _M_capacity(__new_capacity);
376  }
377 
378  template<typename _CharT, typename _Traits, typename _Alloc>
379  _GLIBCXX20_CONSTEXPR
380  void
381  basic_string<_CharT, _Traits, _Alloc>::
382  _M_erase(size_type __pos, size_type __n)
383  {
384  const size_type __how_much = length() - __pos - __n;
385 
386  if (__how_much && __n)
387  this->_S_move(_M_data() + __pos, _M_data() + __pos + __n, __how_much);
388 
389  _M_set_length(length() - __n);
390  }
391 
392  template<typename _CharT, typename _Traits, typename _Alloc>
393  _GLIBCXX20_CONSTEXPR
394  void
396  reserve()
397  {
398  if (_M_is_local())
399  return;
400 
401  const size_type __length = length();
402  const size_type __capacity = _M_allocated_capacity;
403 
404  if (__length <= size_type(_S_local_capacity))
405  {
406  _M_init_local_buf();
407  this->_S_copy(_M_local_buf, _M_data(), __length + 1);
408  _M_destroy(__capacity);
409  _M_data(_M_local_data());
410  }
411 #if __cpp_exceptions
412  else if (__length < __capacity)
413  try
414  {
415  pointer __tmp = _S_allocate(_M_get_allocator(), __length + 1);
416  this->_S_copy(__tmp, _M_data(), __length + 1);
417  _M_dispose();
418  _M_data(__tmp);
419  _M_capacity(__length);
420  }
421  catch (const __cxxabiv1::__forced_unwind&)
422  { throw; }
423  catch (...)
424  { /* swallow the exception */ }
425 #endif
426  }
427 
428  template<typename _CharT, typename _Traits, typename _Alloc>
429  _GLIBCXX20_CONSTEXPR
430  void
432  resize(size_type __n, _CharT __c)
433  {
434  const size_type __size = this->size();
435  if (__size < __n)
436  this->append(__n - __size, __c);
437  else if (__n < __size)
438  this->_M_set_length(__n);
439  }
440 
441  template<typename _CharT, typename _Traits, typename _Alloc>
442  _GLIBCXX20_CONSTEXPR
443  basic_string<_CharT, _Traits, _Alloc>&
444  basic_string<_CharT, _Traits, _Alloc>::
445  _M_append(const _CharT* __s, size_type __n)
446  {
447  const size_type __len = __n + this->size();
448 
449  if (__len <= this->capacity())
450  {
451  if (__n)
452  this->_S_copy(this->_M_data() + this->size(), __s, __n);
453  }
454  else
455  this->_M_mutate(this->size(), size_type(0), __s, __n);
456 
457  this->_M_set_length(__len);
458  return *this;
459  }
460 
461  template<typename _CharT, typename _Traits, typename _Alloc>
462  template<typename _InputIterator>
463  _GLIBCXX20_CONSTEXPR
464  basic_string<_CharT, _Traits, _Alloc>&
465  basic_string<_CharT, _Traits, _Alloc>::
466  _M_replace_dispatch(const_iterator __i1, const_iterator __i2,
467  _InputIterator __k1, _InputIterator __k2,
468  std::__false_type)
469  {
470  // _GLIBCXX_RESOLVE_LIB_DEFECTS
471  // 2788. unintentionally require a default constructible allocator
472  const basic_string __s(__k1, __k2, this->get_allocator());
473  const size_type __n1 = __i2 - __i1;
474  return _M_replace(__i1 - begin(), __n1, __s._M_data(),
475  __s.size());
476  }
477 
478  template<typename _CharT, typename _Traits, typename _Alloc>
479  _GLIBCXX20_CONSTEXPR
480  basic_string<_CharT, _Traits, _Alloc>&
481  basic_string<_CharT, _Traits, _Alloc>::
482  _M_replace_aux(size_type __pos1, size_type __n1, size_type __n2,
483  _CharT __c)
484  {
485  _M_check_length(__n1, __n2, "basic_string::_M_replace_aux");
486 
487  const size_type __old_size = this->size();
488  const size_type __new_size = __old_size + __n2 - __n1;
489 
490  if (__new_size <= this->capacity())
491  {
492  pointer __p = this->_M_data() + __pos1;
493 
494  const size_type __how_much = __old_size - __pos1 - __n1;
495  if (__how_much && __n1 != __n2)
496  this->_S_move(__p + __n2, __p + __n1, __how_much);
497  }
498  else
499  this->_M_mutate(__pos1, __n1, 0, __n2);
500 
501  if (__n2)
502  this->_S_assign(this->_M_data() + __pos1, __n2, __c);
503 
504  this->_M_set_length(__new_size);
505  return *this;
506  }
507 
508  template<typename _CharT, typename _Traits, typename _Alloc>
509  __attribute__((__noinline__, __noclone__, __cold__)) void
510  basic_string<_CharT, _Traits, _Alloc>::
511  _M_replace_cold(pointer __p, size_type __len1, const _CharT* __s,
512  const size_type __len2, const size_type __how_much)
513  {
514  // Work in-place.
515  if (__len2 && __len2 <= __len1)
516  this->_S_move(__p, __s, __len2);
517  if (__how_much && __len1 != __len2)
518  this->_S_move(__p + __len2, __p + __len1, __how_much);
519  if (__len2 > __len1)
520  {
521  if (__s + __len2 <= __p + __len1)
522  this->_S_move(__p, __s, __len2);
523  else if (__s >= __p + __len1)
524  {
525  // Hint to middle end that __p and __s overlap
526  // (PR 98465).
527  const size_type __poff = (__s - __p) + (__len2 - __len1);
528  this->_S_copy(__p, __p + __poff, __len2);
529  }
530  else
531  {
532  const size_type __nleft = (__p + __len1) - __s;
533  this->_S_move(__p, __s, __nleft);
534  this->_S_copy(__p + __nleft, __p + __len2, __len2 - __nleft);
535  }
536  }
537  }
538 
539  template<typename _CharT, typename _Traits, typename _Alloc>
540  _GLIBCXX20_CONSTEXPR
541  basic_string<_CharT, _Traits, _Alloc>&
542  basic_string<_CharT, _Traits, _Alloc>::
543  _M_replace(size_type __pos, size_type __len1, const _CharT* __s,
544  const size_type __len2)
545  {
546  _M_check_length(__len1, __len2, "basic_string::_M_replace");
547 
548  const size_type __old_size = this->size();
549  const size_type __new_size = __old_size + __len2 - __len1;
550 
551  if (__new_size <= this->capacity())
552  {
553  pointer __p = this->_M_data() + __pos;
554 
555  const size_type __how_much = __old_size - __pos - __len1;
556 #if __cpp_lib_is_constant_evaluated
557  if (std::is_constant_evaluated())
558  {
559  auto __newp = _S_allocate(_M_get_allocator(), __new_size);
560  _S_copy(__newp, this->_M_data(), __pos);
561  _S_copy(__newp + __pos, __s, __len2);
562  _S_copy(__newp + __pos + __len2, __p + __len1, __how_much);
563  _S_copy(this->_M_data(), __newp, __new_size);
564  this->_M_get_allocator().deallocate(__newp, __new_size);
565  }
566  else
567 #endif
568  if (__builtin_expect(_M_disjunct(__s), true))
569  {
570  if (__how_much && __len1 != __len2)
571  this->_S_move(__p + __len2, __p + __len1, __how_much);
572  if (__len2)
573  this->_S_copy(__p, __s, __len2);
574  }
575  else
576  _M_replace_cold(__p, __len1, __s, __len2, __how_much);
577  }
578  else
579  this->_M_mutate(__pos, __len1, __s, __len2);
580 
581  this->_M_set_length(__new_size);
582  return *this;
583  }
584 
585  template<typename _CharT, typename _Traits, typename _Alloc>
586  _GLIBCXX20_CONSTEXPR
587  typename basic_string<_CharT, _Traits, _Alloc>::size_type
589  copy(_CharT* __s, size_type __n, size_type __pos) const
590  {
591  _M_check(__pos, "basic_string::copy");
592  __n = _M_limit(__pos, __n);
593  __glibcxx_requires_string_len(__s, __n);
594  if (__n)
595  _S_copy(__s, _M_data() + __pos, __n);
596  // 21.3.5.7 par 3: do not append null. (good.)
597  return __n;
598  }
599 
600 #ifdef __glibcxx_string_resize_and_overwrite // C++ >= 23
601  template<typename _CharT, typename _Traits, typename _Alloc>
602  template<typename _Operation>
603  [[__gnu__::__always_inline__]]
604  constexpr void
606  __resize_and_overwrite(const size_type __n, _Operation __op)
607  { resize_and_overwrite<_Operation&>(__n, __op); }
608 #endif
609 
610 #if __cplusplus >= 201103L
611  template<typename _CharT, typename _Traits, typename _Alloc>
612  template<typename _Operation>
613  _GLIBCXX20_CONSTEXPR void
614  basic_string<_CharT, _Traits, _Alloc>::
615 #ifdef __glibcxx_string_resize_and_overwrite // C++ >= 23
616  resize_and_overwrite(const size_type __n, _Operation __op)
617 #else
618  __resize_and_overwrite(const size_type __n, _Operation __op)
619 #endif
620  {
621  reserve(__n);
622  _CharT* const __p = _M_data();
623 #if __cpp_lib_is_constant_evaluated
624  if (std::__is_constant_evaluated() && __n > size())
625  traits_type::assign(__p + size(), __n - size(), _CharT());
626 #endif
627  struct _Terminator {
628  _GLIBCXX20_CONSTEXPR ~_Terminator() { _M_this->_M_set_length(_M_r); }
629  basic_string* _M_this;
630  size_type _M_r;
631  };
632  _Terminator __term{this, 0};
633  auto __r = std::move(__op)(__p + 0, __n + 0);
634 #ifdef __cpp_lib_concepts
635  static_assert(ranges::__detail::__is_integer_like<decltype(__r)>);
636 #else
637  static_assert(__gnu_cxx::__is_integer_nonstrict<decltype(__r)>::__value,
638  "resize_and_overwrite operation must return an integer");
639 #endif
640  _GLIBCXX_DEBUG_ASSERT(__r >= 0 && size_type(__r) <= __n);
641  __term._M_r = size_type(__r);
642  if (__term._M_r > __n)
643  __builtin_unreachable();
644  }
645 #endif // C++11
646 
647 #endif // _GLIBCXX_USE_CXX11_ABI
648 
649 #if __glibcxx_constexpr_string >= 201907L
650 # define _GLIBCXX_STRING_CONSTEXPR constexpr
651 #else
652 # define _GLIBCXX_STRING_CONSTEXPR
653 #endif
654  template<typename _CharT, typename _Traits, typename _Alloc>
655  _GLIBCXX_STRING_CONSTEXPR
656  typename basic_string<_CharT, _Traits, _Alloc>::size_type
658  find(const _CharT* __s, size_type __pos, size_type __n) const
659  _GLIBCXX_NOEXCEPT
660  {
661  __glibcxx_requires_string_len(__s, __n);
662  const size_type __size = this->size();
663 
664  if (__n == 0)
665  return __pos <= __size ? __pos : npos;
666  if (__pos >= __size)
667  return npos;
668 
669  const _CharT __elem0 = __s[0];
670  const _CharT* const __data = data();
671  const _CharT* __first = __data + __pos;
672  const _CharT* const __last = __data + __size;
673  size_type __len = __size - __pos;
674 
675  while (__len >= __n)
676  {
677  // Find the first occurrence of __elem0:
678  __first = traits_type::find(__first, __len - __n + 1, __elem0);
679  if (!__first)
680  return npos;
681  // Compare the full strings from the first occurrence of __elem0.
682  // We already know that __first[0] == __s[0] but compare them again
683  // anyway because __s is probably aligned, which helps memcmp.
684  if (traits_type::compare(__first, __s, __n) == 0)
685  return __first - __data;
686  __len = __last - ++__first;
687  }
688  return npos;
689  }
690 
691  template<typename _CharT, typename _Traits, typename _Alloc>
692  _GLIBCXX_STRING_CONSTEXPR
693  typename basic_string<_CharT, _Traits, _Alloc>::size_type
695  find(_CharT __c, size_type __pos) const _GLIBCXX_NOEXCEPT
696  {
697  size_type __ret = npos;
698  const size_type __size = this->size();
699  if (__pos < __size)
700  {
701  const _CharT* __data = _M_data();
702  const size_type __n = __size - __pos;
703  const _CharT* __p = traits_type::find(__data + __pos, __n, __c);
704  if (__p)
705  __ret = __p - __data;
706  }
707  return __ret;
708  }
709 
710  template<typename _CharT, typename _Traits, typename _Alloc>
711  _GLIBCXX_STRING_CONSTEXPR
712  typename basic_string<_CharT, _Traits, _Alloc>::size_type
714  rfind(const _CharT* __s, size_type __pos, size_type __n) const
715  _GLIBCXX_NOEXCEPT
716  {
717  __glibcxx_requires_string_len(__s, __n);
718  const size_type __size = this->size();
719  if (__n <= __size)
720  {
721  __pos = std::min(size_type(__size - __n), __pos);
722  const _CharT* __data = _M_data();
723  do
724  {
725  if (traits_type::compare(__data + __pos, __s, __n) == 0)
726  return __pos;
727  }
728  while (__pos-- > 0);
729  }
730  return npos;
731  }
732 
733  template<typename _CharT, typename _Traits, typename _Alloc>
734  _GLIBCXX_STRING_CONSTEXPR
735  typename basic_string<_CharT, _Traits, _Alloc>::size_type
737  rfind(_CharT __c, size_type __pos) const _GLIBCXX_NOEXCEPT
738  {
739  size_type __size = this->size();
740  if (__size)
741  {
742  if (--__size > __pos)
743  __size = __pos;
744  for (++__size; __size-- > 0; )
745  if (traits_type::eq(_M_data()[__size], __c))
746  return __size;
747  }
748  return npos;
749  }
750 
751  template<typename _CharT, typename _Traits, typename _Alloc>
752  _GLIBCXX_STRING_CONSTEXPR
753  typename basic_string<_CharT, _Traits, _Alloc>::size_type
755  find_first_of(const _CharT* __s, size_type __pos, size_type __n) const
756  _GLIBCXX_NOEXCEPT
757  {
758  __glibcxx_requires_string_len(__s, __n);
759  for (; __n && __pos < this->size(); ++__pos)
760  {
761  const _CharT* __p = traits_type::find(__s, __n, _M_data()[__pos]);
762  if (__p)
763  return __pos;
764  }
765  return npos;
766  }
767 
768  template<typename _CharT, typename _Traits, typename _Alloc>
769  _GLIBCXX_STRING_CONSTEXPR
770  typename basic_string<_CharT, _Traits, _Alloc>::size_type
772  find_last_of(const _CharT* __s, size_type __pos, size_type __n) const
773  _GLIBCXX_NOEXCEPT
774  {
775  __glibcxx_requires_string_len(__s, __n);
776  size_type __size = this->size();
777  if (__size && __n)
778  {
779  if (--__size > __pos)
780  __size = __pos;
781  do
782  {
783  if (traits_type::find(__s, __n, _M_data()[__size]))
784  return __size;
785  }
786  while (__size-- != 0);
787  }
788  return npos;
789  }
790 
791  template<typename _CharT, typename _Traits, typename _Alloc>
792  _GLIBCXX_STRING_CONSTEXPR
793  typename basic_string<_CharT, _Traits, _Alloc>::size_type
795  find_first_not_of(const _CharT* __s, size_type __pos, size_type __n) const
796  _GLIBCXX_NOEXCEPT
797  {
798  __glibcxx_requires_string_len(__s, __n);
799  for (; __pos < this->size(); ++__pos)
800  if (!traits_type::find(__s, __n, _M_data()[__pos]))
801  return __pos;
802  return npos;
803  }
804 
805  template<typename _CharT, typename _Traits, typename _Alloc>
806  _GLIBCXX_STRING_CONSTEXPR
807  typename basic_string<_CharT, _Traits, _Alloc>::size_type
809  find_first_not_of(_CharT __c, size_type __pos) const _GLIBCXX_NOEXCEPT
810  {
811  for (; __pos < this->size(); ++__pos)
812  if (!traits_type::eq(_M_data()[__pos], __c))
813  return __pos;
814  return npos;
815  }
816 
817  template<typename _CharT, typename _Traits, typename _Alloc>
818  _GLIBCXX_STRING_CONSTEXPR
819  typename basic_string<_CharT, _Traits, _Alloc>::size_type
821  find_last_not_of(const _CharT* __s, size_type __pos, size_type __n) const
822  _GLIBCXX_NOEXCEPT
823  {
824  __glibcxx_requires_string_len(__s, __n);
825  size_type __size = this->size();
826  if (__size)
827  {
828  if (--__size > __pos)
829  __size = __pos;
830  do
831  {
832  if (!traits_type::find(__s, __n, _M_data()[__size]))
833  return __size;
834  }
835  while (__size--);
836  }
837  return npos;
838  }
839 
840  template<typename _CharT, typename _Traits, typename _Alloc>
841  _GLIBCXX_STRING_CONSTEXPR
842  typename basic_string<_CharT, _Traits, _Alloc>::size_type
844  find_last_not_of(_CharT __c, size_type __pos) const _GLIBCXX_NOEXCEPT
845  {
846  size_type __size = this->size();
847  if (__size)
848  {
849  if (--__size > __pos)
850  __size = __pos;
851  do
852  {
853  if (!traits_type::eq(_M_data()[__size], __c))
854  return __size;
855  }
856  while (__size--);
857  }
858  return npos;
859  }
860 
861 #undef _GLIBCXX_STRING_CONSTEXPR
862 
863  // 21.3.7.9 basic_string::getline and operators
864  template<typename _CharT, typename _Traits, typename _Alloc>
868  {
869  typedef basic_istream<_CharT, _Traits> __istream_type;
870  typedef basic_string<_CharT, _Traits, _Alloc> __string_type;
871  typedef typename __istream_type::ios_base __ios_base;
872  typedef typename __istream_type::int_type __int_type;
873  typedef typename __string_type::size_type __size_type;
874  typedef ctype<_CharT> __ctype_type;
875  typedef typename __ctype_type::ctype_base __ctype_base;
876 
877  __size_type __extracted = 0;
878  typename __ios_base::iostate __err = __ios_base::goodbit;
879  typename __istream_type::sentry __cerb(__in, false);
880  if (__cerb)
881  {
882  __try
883  {
884  // Avoid reallocation for common case.
885  __str.erase();
886  _CharT __buf[128];
887  __size_type __len = 0;
888  const streamsize __w = __in.width();
889  const __size_type __n = __w > 0 ? static_cast<__size_type>(__w)
890  : __str.max_size();
891  const __ctype_type& __ct = use_facet<__ctype_type>(__in.getloc());
892  const __int_type __eof = _Traits::eof();
893  __int_type __c = __in.rdbuf()->sgetc();
894 
895  while (__extracted < __n
896  && !_Traits::eq_int_type(__c, __eof)
897  && !__ct.is(__ctype_base::space,
898  _Traits::to_char_type(__c)))
899  {
900  if (__len == sizeof(__buf) / sizeof(_CharT))
901  {
902  __str.append(__buf, sizeof(__buf) / sizeof(_CharT));
903  __len = 0;
904  }
905  __buf[__len++] = _Traits::to_char_type(__c);
906  ++__extracted;
907  __c = __in.rdbuf()->snextc();
908  }
909  __str.append(__buf, __len);
910 
911  if (__extracted < __n && _Traits::eq_int_type(__c, __eof))
912  __err |= __ios_base::eofbit;
913  __in.width(0);
914  }
916  {
917  __in._M_setstate(__ios_base::badbit);
918  __throw_exception_again;
919  }
920  __catch(...)
921  {
922  // _GLIBCXX_RESOLVE_LIB_DEFECTS
923  // 91. Description of operator>> and getline() for string<>
924  // might cause endless loop
925  __in._M_setstate(__ios_base::badbit);
926  }
927  }
928  // 211. operator>>(istream&, string&) doesn't set failbit
929  if (!__extracted)
930  __err |= __ios_base::failbit;
931  if (__err)
932  __in.setstate(__err);
933  return __in;
934  }
935 
936  template<typename _CharT, typename _Traits, typename _Alloc>
937  basic_istream<_CharT, _Traits>&
939  basic_string<_CharT, _Traits, _Alloc>& __str, _CharT __delim)
940  {
941  typedef basic_istream<_CharT, _Traits> __istream_type;
942  typedef basic_string<_CharT, _Traits, _Alloc> __string_type;
943  typedef typename __istream_type::ios_base __ios_base;
944  typedef typename __istream_type::int_type __int_type;
945  typedef typename __string_type::size_type __size_type;
946 
947  __size_type __extracted = 0;
948  const __size_type __n = __str.max_size();
949  typename __ios_base::iostate __err = __ios_base::goodbit;
950  typename __istream_type::sentry __cerb(__in, true);
951  if (__cerb)
952  {
953  __try
954  {
955  __str.erase();
956  const __int_type __idelim = _Traits::to_int_type(__delim);
957  const __int_type __eof = _Traits::eof();
958  __int_type __c = __in.rdbuf()->sgetc();
959 
960  while (__extracted < __n
961  && !_Traits::eq_int_type(__c, __eof)
962  && !_Traits::eq_int_type(__c, __idelim))
963  {
964  __str += _Traits::to_char_type(__c);
965  ++__extracted;
966  __c = __in.rdbuf()->snextc();
967  }
968 
969  if (_Traits::eq_int_type(__c, __eof))
970  __err |= __ios_base::eofbit;
971  else if (_Traits::eq_int_type(__c, __idelim))
972  {
973  ++__extracted;
974  __in.rdbuf()->sbumpc();
975  }
976  else
977  __err |= __ios_base::failbit;
978  }
980  {
981  __in._M_setstate(__ios_base::badbit);
982  __throw_exception_again;
983  }
984  __catch(...)
985  {
986  // _GLIBCXX_RESOLVE_LIB_DEFECTS
987  // 91. Description of operator>> and getline() for string<>
988  // might cause endless loop
989  __in._M_setstate(__ios_base::badbit);
990  }
991  }
992  if (!__extracted)
993  __err |= __ios_base::failbit;
994  if (__err)
995  __in.setstate(__err);
996  return __in;
997  }
998 
999  // Inhibit implicit instantiations for required instantiations,
1000  // which are defined via explicit instantiations elsewhere.
1001 #if _GLIBCXX_EXTERN_TEMPLATE
1002  // The explicit instantiation definitions in src/c++11/string-inst.cc and
1003  // src/c++17/string-inst.cc only instantiate the members required for C++17
1004  // and earlier standards (so not C++20's starts_with and ends_with).
1005  // Suppress the explicit instantiation declarations for C++20, so C++20
1006  // code will implicitly instantiate std::string and std::wstring as needed.
1007 # if __cplusplus <= 201703L && _GLIBCXX_EXTERN_TEMPLATE > 0
1008  extern template class basic_string<char>;
1009 # elif ! _GLIBCXX_USE_CXX11_ABI
1010  // Still need to prevent implicit instantiation of the COW empty rep,
1011  // to ensure the definition in libstdc++.so is unique (PR 86138).
1012  extern template basic_string<char>::size_type
1013  basic_string<char>::_Rep::_S_empty_rep_storage[];
1014 # elif _GLIBCXX_EXTERN_TEMPLATE > 0
1015  // Export _M_replace_cold even for C++20.
1016  extern template void
1017  basic_string<char>::_M_replace_cold(char *, size_type, const char*,
1018  const size_type, const size_type);
1019 # endif
1020 
1021  extern template
1022  basic_istream<char>&
1023  operator>>(basic_istream<char>&, string&);
1024  extern template
1025  basic_ostream<char>&
1026  operator<<(basic_ostream<char>&, const string&);
1027  extern template
1028  basic_istream<char>&
1029  getline(basic_istream<char>&, string&, char);
1030  extern template
1031  basic_istream<char>&
1032  getline(basic_istream<char>&, string&);
1033 
1034 #ifdef _GLIBCXX_USE_WCHAR_T
1035 # if __cplusplus <= 201703L && _GLIBCXX_EXTERN_TEMPLATE > 0
1036  extern template class basic_string<wchar_t>;
1037 # elif ! _GLIBCXX_USE_CXX11_ABI
1038  extern template basic_string<wchar_t>::size_type
1039  basic_string<wchar_t>::_Rep::_S_empty_rep_storage[];
1040 # elif _GLIBCXX_EXTERN_TEMPLATE > 0
1041  // Export _M_replace_cold even for C++20.
1042  extern template void
1043  basic_string<wchar_t>::_M_replace_cold(wchar_t*, size_type, const wchar_t*,
1044  const size_type, const size_type);
1045 # endif
1046 
1047  extern template
1048  basic_istream<wchar_t>&
1049  operator>>(basic_istream<wchar_t>&, wstring&);
1050  extern template
1051  basic_ostream<wchar_t>&
1052  operator<<(basic_ostream<wchar_t>&, const wstring&);
1053  extern template
1054  basic_istream<wchar_t>&
1055  getline(basic_istream<wchar_t>&, wstring&, wchar_t);
1056  extern template
1057  basic_istream<wchar_t>&
1058  getline(basic_istream<wchar_t>&, wstring&);
1059 #endif // _GLIBCXX_USE_WCHAR_T
1060 #endif // _GLIBCXX_EXTERN_TEMPLATE
1061 
1062 _GLIBCXX_END_NAMESPACE_VERSION
1063 } // namespace std
1064 
1065 #pragma GCC diagnostic pop
1066 #endif
constexpr _Tp * __addressof(_Tp &__r) noexcept
Same as C++11 std::addressof.
Definition: move.h:52
constexpr std::remove_reference< _Tp >::type && move(_Tp &&__t) noexcept
Convert a value to an rvalue.
Definition: move.h:138
_Tp * begin(valarray< _Tp > &__va) noexcept
Return an iterator pointing to the first element of the valarray.
Definition: valarray:1229
constexpr const _Tp & min(const _Tp &, const _Tp &)
This does what you think it does.
Definition: stl_algobase.h:234
basic_string< wchar_t > wstring
A string of wchar_t.
Definition: stringfwd.h:82
ISO C++ entities toplevel namespace is std.
std::basic_istream< _CharT, _Traits > & operator>>(std::basic_istream< _CharT, _Traits > &__is, bitset< _Nb > &__x)
Global I/O operators for bitsets.
Definition: bitset:1602
ptrdiff_t streamsize
Integral type for I/O operation counts and buffer sizes.
Definition: postypes.h:73
constexpr iterator_traits< _InputIterator >::difference_type distance(_InputIterator __first, _InputIterator __last)
A generalization of pointer arithmetic.
std::basic_ostream< _CharT, _Traits > & operator<<(std::basic_ostream< _CharT, _Traits > &__os, const bitset< _Nb > &__x)
Global I/O operators for bitsets.
Definition: bitset:1692
basic_istream< _CharT, _Traits > & getline(basic_istream< _CharT, _Traits > &__is, basic_string< _CharT, _Traits, _Alloc > &__str, _CharT __delim)
Read a line from stream into a string.
constexpr auto size(const _Container &__cont) noexcept(noexcept(__cont.size())) -> decltype(__cont.size())
Return the size of a container.
Definition: range_access.h:274
constexpr auto data(_Container &__cont) noexcept(noexcept(__cont.data())) -> decltype(__cont.data())
Return the data pointer of a container.
Definition: range_access.h:324
basic_streambuf< _CharT, _Traits > * rdbuf() const
Accessing the underlying buffer.
Definition: basic_ios.h:337
void setstate(iostate __state)
Sets additional flags in the error state.
Definition: basic_ios.h:166
Template class basic_istream.
Definition: istream:63
Managing sequences of characters and character-like objects.
Definition: cow_string.h:109
void swap(basic_string &__s) noexcept(/*conditional */)
Swap contents with another string.
Definition: cow_string.h:3679
size_type find_first_of(const basic_string &__str, size_type __pos=0) const noexcept
Find position of a character of string.
Definition: cow_string.h:2586
void __resize_and_overwrite(size_type __n, _Operation __op)
Non-standard version of resize_and_overwrite for C++11 and above.
size_type find(const _CharT *__s, size_type __pos, size_type __n) const noexcept
Find position of a C substring.
size_type find_last_not_of(const basic_string &__str, size_type __pos=npos) const noexcept
Find last position of a character not in string.
Definition: cow_string.h:2835
size_type find_first_not_of(const basic_string &__str, size_type __pos=0) const noexcept
Find position of a character not in string.
Definition: cow_string.h:2753
size_type copy(_CharT *__s, size_type __n, size_type __pos=0) const
Copy substring into C string.
Definition: cow_string.h:3875
size_type find_last_of(const basic_string &__str, size_type __pos=npos) const noexcept
Find last position of a character of string.
Definition: cow_string.h:2670
size_type rfind(const basic_string &__str, size_type __pos=npos) const noexcept
Find last position of a string.
Definition: cow_string.h:2507
void resize(size_type __n, _CharT __c)
Resizes the string to the specified number of characters.
Definition: cow_string.h:3801
void reserve()
Equivalent to shrink_to_fit().
Definition: cow_string.h:3854
basic_string & append(const basic_string &__str)
Append a string to this string.
Definition: cow_string.h:3473
static const size_type npos
Value returned by various member functions when they fail.
Definition: cow_string.h:322
basic_string & erase(size_type __pos=0, size_type __n=npos)
Remove characters.
Definition: cow_string.h:1858
size_type max_size() const noexcept
Returns the size() of the largest possible string.
Definition: cow_string.h:972
Thrown as part of forced unwinding.
Definition: cxxabi_forced.h:51
streamsize width() const
Flags access.
Definition: ios_base.h:789
locale getloc() const
Locale access.
Definition: ios_base.h:841
Primary class template ctype facet.
Marking input iterators.
Forward iterators support a superset of input iterator operations.