libstdc++
basic_string.tcc
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1 // Components for manipulating sequences of characters -*- C++ -*-
2 
3 // Copyright (C) 1997-2023 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 #pragma GCC system_header
43 
44 #include <bits/cxxabi_forced.h>
45 
46 namespace std _GLIBCXX_VISIBILITY(default)
47 {
48 _GLIBCXX_BEGIN_NAMESPACE_VERSION
49 
50 #if _GLIBCXX_USE_CXX11_ABI
51 
52  template<typename _CharT, typename _Traits, typename _Alloc>
53  const typename basic_string<_CharT, _Traits, _Alloc>::size_type
55 
56  template<typename _CharT, typename _Traits, typename _Alloc>
57  _GLIBCXX20_CONSTEXPR
58  void
60  swap(basic_string& __s) _GLIBCXX_NOEXCEPT
61  {
62  if (this == std::__addressof(__s))
63  return;
64 
65  _Alloc_traits::_S_on_swap(_M_get_allocator(), __s._M_get_allocator());
66 
67  if (_M_is_local())
68  if (__s._M_is_local())
69  {
70  if (length() && __s.length())
71  {
72  _CharT __tmp_data[_S_local_capacity + 1];
73  traits_type::copy(__tmp_data, __s._M_local_buf,
74  __s.length() + 1);
75  traits_type::copy(__s._M_local_buf, _M_local_buf,
76  length() + 1);
77  traits_type::copy(_M_local_buf, __tmp_data,
78  __s.length() + 1);
79  }
80  else if (__s.length())
81  {
82  traits_type::copy(_M_local_buf, __s._M_local_buf,
83  __s.length() + 1);
84  _M_length(__s.length());
85  __s._M_set_length(0);
86  return;
87  }
88  else if (length())
89  {
90  traits_type::copy(__s._M_local_buf, _M_local_buf,
91  length() + 1);
92  __s._M_length(length());
93  _M_set_length(0);
94  return;
95  }
96  }
97  else
98  {
99  const size_type __tmp_capacity = __s._M_allocated_capacity;
100  traits_type::copy(__s._M_local_buf, _M_local_buf,
101  length() + 1);
102  _M_data(__s._M_data());
103  __s._M_data(__s._M_local_buf);
104  _M_capacity(__tmp_capacity);
105  }
106  else
107  {
108  const size_type __tmp_capacity = _M_allocated_capacity;
109  if (__s._M_is_local())
110  {
111  traits_type::copy(_M_local_buf, __s._M_local_buf,
112  __s.length() + 1);
113  __s._M_data(_M_data());
114  _M_data(_M_local_buf);
115  }
116  else
117  {
118  pointer __tmp_ptr = _M_data();
119  _M_data(__s._M_data());
120  __s._M_data(__tmp_ptr);
121  _M_capacity(__s._M_allocated_capacity);
122  }
123  __s._M_capacity(__tmp_capacity);
124  }
125 
126  const size_type __tmp_length = length();
127  _M_length(__s.length());
128  __s._M_length(__tmp_length);
129  }
130 
131  template<typename _CharT, typename _Traits, typename _Alloc>
132  _GLIBCXX20_CONSTEXPR
133  typename basic_string<_CharT, _Traits, _Alloc>::pointer
134  basic_string<_CharT, _Traits, _Alloc>::
135  _M_create(size_type& __capacity, size_type __old_capacity)
136  {
137  // _GLIBCXX_RESOLVE_LIB_DEFECTS
138  // 83. String::npos vs. string::max_size()
139  if (__capacity > max_size())
140  std::__throw_length_error(__N("basic_string::_M_create"));
141 
142  // The below implements an exponential growth policy, necessary to
143  // meet amortized linear time requirements of the library: see
144  // http://gcc.gnu.org/ml/libstdc++/2001-07/msg00085.html.
145  if (__capacity > __old_capacity && __capacity < 2 * __old_capacity)
146  {
147  __capacity = 2 * __old_capacity;
148  // Never allocate a string bigger than max_size.
149  if (__capacity > max_size())
150  __capacity = max_size();
151  }
152 
153  // NB: Need an array of char_type[__capacity], plus a terminating
154  // null char_type() element.
155  return _S_allocate(_M_get_allocator(), __capacity + 1);
156  }
157 
158  // NB: This is the special case for Input Iterators, used in
159  // istreambuf_iterators, etc.
160  // Input Iterators have a cost structure very different from
161  // pointers, calling for a different coding style.
162  template<typename _CharT, typename _Traits, typename _Alloc>
163  template<typename _InIterator>
164  _GLIBCXX20_CONSTEXPR
165  void
166  basic_string<_CharT, _Traits, _Alloc>::
167  _M_construct(_InIterator __beg, _InIterator __end,
169  {
170  size_type __len = 0;
171  size_type __capacity = size_type(_S_local_capacity);
172 
173  pointer __p = _M_use_local_data();
174 
175  while (__beg != __end && __len < __capacity)
176  {
177  __p[__len++] = *__beg;
178  ++__beg;
179  }
180 
181  struct _Guard
182  {
183  _GLIBCXX20_CONSTEXPR
184  explicit _Guard(basic_string* __s) : _M_guarded(__s) { }
185 
186  _GLIBCXX20_CONSTEXPR
187  ~_Guard() { if (_M_guarded) _M_guarded->_M_dispose(); }
188 
189  basic_string* _M_guarded;
190  } __guard(this);
191 
192  while (__beg != __end)
193  {
194  if (__len == __capacity)
195  {
196  // Allocate more space.
197  __capacity = __len + 1;
198  pointer __another = _M_create(__capacity, __len);
199  this->_S_copy(__another, _M_data(), __len);
200  _M_dispose();
201  _M_data(__another);
202  _M_capacity(__capacity);
203  }
204  traits_type::assign(_M_data()[__len++], *__beg);
205  ++__beg;
206  }
207 
208  __guard._M_guarded = 0;
209 
210  _M_set_length(__len);
211  }
212 
213  template<typename _CharT, typename _Traits, typename _Alloc>
214  template<typename _InIterator>
215  _GLIBCXX20_CONSTEXPR
216  void
217  basic_string<_CharT, _Traits, _Alloc>::
218  _M_construct(_InIterator __beg, _InIterator __end,
220  {
221  size_type __dnew = static_cast<size_type>(std::distance(__beg, __end));
222 
223  if (__dnew > size_type(_S_local_capacity))
224  {
225  _M_data(_M_create(__dnew, size_type(0)));
226  _M_capacity(__dnew);
227  }
228  else
229  _M_use_local_data();
230 
231  // Check for out_of_range and length_error exceptions.
232  struct _Guard
233  {
234  _GLIBCXX20_CONSTEXPR
235  explicit _Guard(basic_string* __s) : _M_guarded(__s) { }
236 
237  _GLIBCXX20_CONSTEXPR
238  ~_Guard() { if (_M_guarded) _M_guarded->_M_dispose(); }
239 
240  basic_string* _M_guarded;
241  } __guard(this);
242 
243  this->_S_copy_chars(_M_data(), __beg, __end);
244 
245  __guard._M_guarded = 0;
246 
247  _M_set_length(__dnew);
248  }
249 
250  template<typename _CharT, typename _Traits, typename _Alloc>
251  _GLIBCXX20_CONSTEXPR
252  void
253  basic_string<_CharT, _Traits, _Alloc>::
254  _M_construct(size_type __n, _CharT __c)
255  {
256  if (__n > size_type(_S_local_capacity))
257  {
258  _M_data(_M_create(__n, size_type(0)));
259  _M_capacity(__n);
260  }
261  else
262  _M_use_local_data();
263 
264  if (__n)
265  this->_S_assign(_M_data(), __n, __c);
266 
267  _M_set_length(__n);
268  }
269 
270  template<typename _CharT, typename _Traits, typename _Alloc>
271  _GLIBCXX20_CONSTEXPR
272  void
273  basic_string<_CharT, _Traits, _Alloc>::
274  _M_assign(const basic_string& __str)
275  {
276  if (this != std::__addressof(__str))
277  {
278  const size_type __rsize = __str.length();
279  const size_type __capacity = capacity();
280 
281  if (__rsize > __capacity)
282  {
283  size_type __new_capacity = __rsize;
284  pointer __tmp = _M_create(__new_capacity, __capacity);
285  _M_dispose();
286  _M_data(__tmp);
287  _M_capacity(__new_capacity);
288  }
289 
290  if (__rsize)
291  this->_S_copy(_M_data(), __str._M_data(), __rsize);
292 
293  _M_set_length(__rsize);
294  }
295  }
296 
297  template<typename _CharT, typename _Traits, typename _Alloc>
298  _GLIBCXX20_CONSTEXPR
299  void
301  reserve(size_type __res)
302  {
303  const size_type __capacity = capacity();
304  // _GLIBCXX_RESOLVE_LIB_DEFECTS
305  // 2968. Inconsistencies between basic_string reserve and
306  // vector/unordered_map/unordered_set reserve functions
307  // P0966 reserve should not shrink
308  if (__res <= __capacity)
309  return;
310 
311  pointer __tmp = _M_create(__res, __capacity);
312  this->_S_copy(__tmp, _M_data(), length() + 1);
313  _M_dispose();
314  _M_data(__tmp);
315  _M_capacity(__res);
316  }
317 
318  template<typename _CharT, typename _Traits, typename _Alloc>
319  _GLIBCXX20_CONSTEXPR
320  void
321  basic_string<_CharT, _Traits, _Alloc>::
322  _M_mutate(size_type __pos, size_type __len1, const _CharT* __s,
323  size_type __len2)
324  {
325  const size_type __how_much = length() - __pos - __len1;
326 
327  size_type __new_capacity = length() + __len2 - __len1;
328  pointer __r = _M_create(__new_capacity, capacity());
329 
330  if (__pos)
331  this->_S_copy(__r, _M_data(), __pos);
332  if (__s && __len2)
333  this->_S_copy(__r + __pos, __s, __len2);
334  if (__how_much)
335  this->_S_copy(__r + __pos + __len2,
336  _M_data() + __pos + __len1, __how_much);
337 
338  _M_dispose();
339  _M_data(__r);
340  _M_capacity(__new_capacity);
341  }
342 
343  template<typename _CharT, typename _Traits, typename _Alloc>
344  _GLIBCXX20_CONSTEXPR
345  void
346  basic_string<_CharT, _Traits, _Alloc>::
347  _M_erase(size_type __pos, size_type __n)
348  {
349  const size_type __how_much = length() - __pos - __n;
350 
351  if (__how_much && __n)
352  this->_S_move(_M_data() + __pos, _M_data() + __pos + __n, __how_much);
353 
354  _M_set_length(length() - __n);
355  }
356 
357  template<typename _CharT, typename _Traits, typename _Alloc>
358  _GLIBCXX20_CONSTEXPR
359  void
361  reserve()
362  {
363  if (_M_is_local())
364  return;
365 
366  const size_type __length = length();
367  const size_type __capacity = _M_allocated_capacity;
368 
369  if (__length <= size_type(_S_local_capacity))
370  {
371  this->_S_copy(_M_use_local_data(), _M_data(), __length + 1);
372  _M_destroy(__capacity);
373  _M_data(_M_local_data());
374  }
375 #if __cpp_exceptions
376  else if (__length < __capacity)
377  try
378  {
379  pointer __tmp = _S_allocate(_M_get_allocator(), __length + 1);
380  this->_S_copy(__tmp, _M_data(), __length + 1);
381  _M_dispose();
382  _M_data(__tmp);
383  _M_capacity(__length);
384  }
385  catch (const __cxxabiv1::__forced_unwind&)
386  { throw; }
387  catch (...)
388  { /* swallow the exception */ }
389 #endif
390  }
391 
392  template<typename _CharT, typename _Traits, typename _Alloc>
393  _GLIBCXX20_CONSTEXPR
394  void
396  resize(size_type __n, _CharT __c)
397  {
398  const size_type __size = this->size();
399  if (__size < __n)
400  this->append(__n - __size, __c);
401  else if (__n < __size)
402  this->_M_set_length(__n);
403  }
404 
405  template<typename _CharT, typename _Traits, typename _Alloc>
406  _GLIBCXX20_CONSTEXPR
407  basic_string<_CharT, _Traits, _Alloc>&
408  basic_string<_CharT, _Traits, _Alloc>::
409  _M_append(const _CharT* __s, size_type __n)
410  {
411  const size_type __len = __n + this->size();
412 
413  if (__len <= this->capacity())
414  {
415  if (__n)
416  this->_S_copy(this->_M_data() + this->size(), __s, __n);
417  }
418  else
419  this->_M_mutate(this->size(), size_type(0), __s, __n);
420 
421  this->_M_set_length(__len);
422  return *this;
423  }
424 
425  template<typename _CharT, typename _Traits, typename _Alloc>
426  template<typename _InputIterator>
427  _GLIBCXX20_CONSTEXPR
428  basic_string<_CharT, _Traits, _Alloc>&
429  basic_string<_CharT, _Traits, _Alloc>::
430  _M_replace_dispatch(const_iterator __i1, const_iterator __i2,
431  _InputIterator __k1, _InputIterator __k2,
432  std::__false_type)
433  {
434  // _GLIBCXX_RESOLVE_LIB_DEFECTS
435  // 2788. unintentionally require a default constructible allocator
436  const basic_string __s(__k1, __k2, this->get_allocator());
437  const size_type __n1 = __i2 - __i1;
438  return _M_replace(__i1 - begin(), __n1, __s._M_data(),
439  __s.size());
440  }
441 
442  template<typename _CharT, typename _Traits, typename _Alloc>
443  _GLIBCXX20_CONSTEXPR
444  basic_string<_CharT, _Traits, _Alloc>&
445  basic_string<_CharT, _Traits, _Alloc>::
446  _M_replace_aux(size_type __pos1, size_type __n1, size_type __n2,
447  _CharT __c)
448  {
449  _M_check_length(__n1, __n2, "basic_string::_M_replace_aux");
450 
451  const size_type __old_size = this->size();
452  const size_type __new_size = __old_size + __n2 - __n1;
453 
454  if (__new_size <= this->capacity())
455  {
456  pointer __p = this->_M_data() + __pos1;
457 
458  const size_type __how_much = __old_size - __pos1 - __n1;
459  if (__how_much && __n1 != __n2)
460  this->_S_move(__p + __n2, __p + __n1, __how_much);
461  }
462  else
463  this->_M_mutate(__pos1, __n1, 0, __n2);
464 
465  if (__n2)
466  this->_S_assign(this->_M_data() + __pos1, __n2, __c);
467 
468  this->_M_set_length(__new_size);
469  return *this;
470  }
471 
472  template<typename _CharT, typename _Traits, typename _Alloc>
473  __attribute__((__noinline__, __noclone__, __cold__)) void
474  basic_string<_CharT, _Traits, _Alloc>::
475  _M_replace_cold(pointer __p, size_type __len1, const _CharT* __s,
476  const size_type __len2, const size_type __how_much)
477  {
478  // Work in-place.
479  if (__len2 && __len2 <= __len1)
480  this->_S_move(__p, __s, __len2);
481  if (__how_much && __len1 != __len2)
482  this->_S_move(__p + __len2, __p + __len1, __how_much);
483  if (__len2 > __len1)
484  {
485  if (__s + __len2 <= __p + __len1)
486  this->_S_move(__p, __s, __len2);
487  else if (__s >= __p + __len1)
488  {
489  // Hint to middle end that __p and __s overlap
490  // (PR 98465).
491  const size_type __poff = (__s - __p) + (__len2 - __len1);
492  this->_S_copy(__p, __p + __poff, __len2);
493  }
494  else
495  {
496  const size_type __nleft = (__p + __len1) - __s;
497  this->_S_move(__p, __s, __nleft);
498  this->_S_copy(__p + __nleft, __p + __len2, __len2 - __nleft);
499  }
500  }
501  }
502 
503  template<typename _CharT, typename _Traits, typename _Alloc>
504  _GLIBCXX20_CONSTEXPR
505  basic_string<_CharT, _Traits, _Alloc>&
506  basic_string<_CharT, _Traits, _Alloc>::
507  _M_replace(size_type __pos, size_type __len1, const _CharT* __s,
508  const size_type __len2)
509  {
510  _M_check_length(__len1, __len2, "basic_string::_M_replace");
511 
512  const size_type __old_size = this->size();
513  const size_type __new_size = __old_size + __len2 - __len1;
514 
515  if (__new_size <= this->capacity())
516  {
517  pointer __p = this->_M_data() + __pos;
518 
519  const size_type __how_much = __old_size - __pos - __len1;
520 #if __cpp_lib_is_constant_evaluated
522  {
523  auto __newp = _S_allocate(_M_get_allocator(), __new_size);
524  _S_copy(__newp, this->_M_data(), __pos);
525  _S_copy(__newp + __pos, __s, __len2);
526  _S_copy(__newp + __pos + __len2, __p + __len1, __how_much);
527  _S_copy(this->_M_data(), __newp, __new_size);
528  this->_M_get_allocator().deallocate(__newp, __new_size);
529  }
530  else
531 #endif
532  if (__builtin_expect(_M_disjunct(__s), true))
533  {
534  if (__how_much && __len1 != __len2)
535  this->_S_move(__p + __len2, __p + __len1, __how_much);
536  if (__len2)
537  this->_S_copy(__p, __s, __len2);
538  }
539  else
540  _M_replace_cold(__p, __len1, __s, __len2, __how_much);
541  }
542  else
543  this->_M_mutate(__pos, __len1, __s, __len2);
544 
545  this->_M_set_length(__new_size);
546  return *this;
547  }
548 
549  template<typename _CharT, typename _Traits, typename _Alloc>
550  _GLIBCXX20_CONSTEXPR
551  typename basic_string<_CharT, _Traits, _Alloc>::size_type
553  copy(_CharT* __s, size_type __n, size_type __pos) const
554  {
555  _M_check(__pos, "basic_string::copy");
556  __n = _M_limit(__pos, __n);
557  __glibcxx_requires_string_len(__s, __n);
558  if (__n)
559  _S_copy(__s, _M_data() + __pos, __n);
560  // 21.3.5.7 par 3: do not append null. (good.)
561  return __n;
562  }
563 
564 #if __cplusplus > 202002L
565  template<typename _CharT, typename _Traits, typename _Alloc>
566  template<typename _Operation>
567  constexpr void
568  basic_string<_CharT, _Traits, _Alloc>::
569  resize_and_overwrite(size_type __n, _Operation __op)
570  {
571  const size_type __capacity = capacity();
572  _CharT* __p;
573  if (__n > __capacity)
574  {
575  __p = _M_create(__n, __capacity);
576  this->_S_copy(__p, _M_data(), length()); // exclude trailing null
577 #if __cpp_lib_is_constant_evaluated
579  traits_type::assign(__p + length(), __n - length(), _CharT());
580 #endif
581  _M_dispose();
582  _M_data(__p);
583  _M_capacity(__n);
584  }
585  else
586  __p = _M_data();
587  struct _Terminator {
588  constexpr ~_Terminator() { _M_this->_M_set_length(_M_r); }
589  basic_string* _M_this;
590  size_type _M_r;
591  };
592  _Terminator __term{this};
593  auto __r = std::move(__op)(auto(__p), auto(__n));
594  static_assert(ranges::__detail::__is_integer_like<decltype(__r)>);
595  _GLIBCXX_DEBUG_ASSERT(__r >= 0 && __r <= __n);
596  __term._M_r = size_type(__r);
597  if (__term._M_r > __n)
598  __builtin_unreachable();
599  }
600 #endif // C++23
601 
602 #endif // _GLIBCXX_USE_CXX11_ABI
603 
604 #if __cpp_lib_constexpr_string >= 201907L
605 # define _GLIBCXX_STRING_CONSTEXPR constexpr
606 #else
607 # define _GLIBCXX_STRING_CONSTEXPR
608 #endif
609  template<typename _CharT, typename _Traits, typename _Alloc>
610  _GLIBCXX_STRING_CONSTEXPR
611  typename basic_string<_CharT, _Traits, _Alloc>::size_type
613  find(const _CharT* __s, size_type __pos, size_type __n) const
614  _GLIBCXX_NOEXCEPT
615  {
616  __glibcxx_requires_string_len(__s, __n);
617  const size_type __size = this->size();
618 
619  if (__n == 0)
620  return __pos <= __size ? __pos : npos;
621  if (__pos >= __size)
622  return npos;
623 
624  const _CharT __elem0 = __s[0];
625  const _CharT* const __data = data();
626  const _CharT* __first = __data + __pos;
627  const _CharT* const __last = __data + __size;
628  size_type __len = __size - __pos;
629 
630  while (__len >= __n)
631  {
632  // Find the first occurrence of __elem0:
633  __first = traits_type::find(__first, __len - __n + 1, __elem0);
634  if (!__first)
635  return npos;
636  // Compare the full strings from the first occurrence of __elem0.
637  // We already know that __first[0] == __s[0] but compare them again
638  // anyway because __s is probably aligned, which helps memcmp.
639  if (traits_type::compare(__first, __s, __n) == 0)
640  return __first - __data;
641  __len = __last - ++__first;
642  }
643  return npos;
644  }
645 
646  template<typename _CharT, typename _Traits, typename _Alloc>
647  _GLIBCXX_STRING_CONSTEXPR
648  typename basic_string<_CharT, _Traits, _Alloc>::size_type
650  find(_CharT __c, size_type __pos) const _GLIBCXX_NOEXCEPT
651  {
652  size_type __ret = npos;
653  const size_type __size = this->size();
654  if (__pos < __size)
655  {
656  const _CharT* __data = _M_data();
657  const size_type __n = __size - __pos;
658  const _CharT* __p = traits_type::find(__data + __pos, __n, __c);
659  if (__p)
660  __ret = __p - __data;
661  }
662  return __ret;
663  }
664 
665  template<typename _CharT, typename _Traits, typename _Alloc>
666  _GLIBCXX_STRING_CONSTEXPR
667  typename basic_string<_CharT, _Traits, _Alloc>::size_type
669  rfind(const _CharT* __s, size_type __pos, size_type __n) const
670  _GLIBCXX_NOEXCEPT
671  {
672  __glibcxx_requires_string_len(__s, __n);
673  const size_type __size = this->size();
674  if (__n <= __size)
675  {
676  __pos = std::min(size_type(__size - __n), __pos);
677  const _CharT* __data = _M_data();
678  do
679  {
680  if (traits_type::compare(__data + __pos, __s, __n) == 0)
681  return __pos;
682  }
683  while (__pos-- > 0);
684  }
685  return npos;
686  }
687 
688  template<typename _CharT, typename _Traits, typename _Alloc>
689  _GLIBCXX_STRING_CONSTEXPR
690  typename basic_string<_CharT, _Traits, _Alloc>::size_type
692  rfind(_CharT __c, size_type __pos) const _GLIBCXX_NOEXCEPT
693  {
694  size_type __size = this->size();
695  if (__size)
696  {
697  if (--__size > __pos)
698  __size = __pos;
699  for (++__size; __size-- > 0; )
700  if (traits_type::eq(_M_data()[__size], __c))
701  return __size;
702  }
703  return npos;
704  }
705 
706  template<typename _CharT, typename _Traits, typename _Alloc>
707  _GLIBCXX_STRING_CONSTEXPR
708  typename basic_string<_CharT, _Traits, _Alloc>::size_type
710  find_first_of(const _CharT* __s, size_type __pos, size_type __n) const
711  _GLIBCXX_NOEXCEPT
712  {
713  __glibcxx_requires_string_len(__s, __n);
714  for (; __n && __pos < this->size(); ++__pos)
715  {
716  const _CharT* __p = traits_type::find(__s, __n, _M_data()[__pos]);
717  if (__p)
718  return __pos;
719  }
720  return npos;
721  }
722 
723  template<typename _CharT, typename _Traits, typename _Alloc>
724  _GLIBCXX_STRING_CONSTEXPR
725  typename basic_string<_CharT, _Traits, _Alloc>::size_type
727  find_last_of(const _CharT* __s, size_type __pos, size_type __n) const
728  _GLIBCXX_NOEXCEPT
729  {
730  __glibcxx_requires_string_len(__s, __n);
731  size_type __size = this->size();
732  if (__size && __n)
733  {
734  if (--__size > __pos)
735  __size = __pos;
736  do
737  {
738  if (traits_type::find(__s, __n, _M_data()[__size]))
739  return __size;
740  }
741  while (__size-- != 0);
742  }
743  return npos;
744  }
745 
746  template<typename _CharT, typename _Traits, typename _Alloc>
747  _GLIBCXX_STRING_CONSTEXPR
748  typename basic_string<_CharT, _Traits, _Alloc>::size_type
750  find_first_not_of(const _CharT* __s, size_type __pos, size_type __n) const
751  _GLIBCXX_NOEXCEPT
752  {
753  __glibcxx_requires_string_len(__s, __n);
754  for (; __pos < this->size(); ++__pos)
755  if (!traits_type::find(__s, __n, _M_data()[__pos]))
756  return __pos;
757  return npos;
758  }
759 
760  template<typename _CharT, typename _Traits, typename _Alloc>
761  _GLIBCXX_STRING_CONSTEXPR
762  typename basic_string<_CharT, _Traits, _Alloc>::size_type
764  find_first_not_of(_CharT __c, size_type __pos) const _GLIBCXX_NOEXCEPT
765  {
766  for (; __pos < this->size(); ++__pos)
767  if (!traits_type::eq(_M_data()[__pos], __c))
768  return __pos;
769  return npos;
770  }
771 
772  template<typename _CharT, typename _Traits, typename _Alloc>
773  _GLIBCXX_STRING_CONSTEXPR
774  typename basic_string<_CharT, _Traits, _Alloc>::size_type
776  find_last_not_of(const _CharT* __s, size_type __pos, size_type __n) const
777  _GLIBCXX_NOEXCEPT
778  {
779  __glibcxx_requires_string_len(__s, __n);
780  size_type __size = this->size();
781  if (__size)
782  {
783  if (--__size > __pos)
784  __size = __pos;
785  do
786  {
787  if (!traits_type::find(__s, __n, _M_data()[__size]))
788  return __size;
789  }
790  while (__size--);
791  }
792  return npos;
793  }
794 
795  template<typename _CharT, typename _Traits, typename _Alloc>
796  _GLIBCXX_STRING_CONSTEXPR
797  typename basic_string<_CharT, _Traits, _Alloc>::size_type
799  find_last_not_of(_CharT __c, size_type __pos) const _GLIBCXX_NOEXCEPT
800  {
801  size_type __size = this->size();
802  if (__size)
803  {
804  if (--__size > __pos)
805  __size = __pos;
806  do
807  {
808  if (!traits_type::eq(_M_data()[__size], __c))
809  return __size;
810  }
811  while (__size--);
812  }
813  return npos;
814  }
815 
816 #undef _GLIBCXX_STRING_CONSTEXPR
817 
818  // 21.3.7.9 basic_string::getline and operators
819  template<typename _CharT, typename _Traits, typename _Alloc>
823  {
824  typedef basic_istream<_CharT, _Traits> __istream_type;
825  typedef basic_string<_CharT, _Traits, _Alloc> __string_type;
826  typedef typename __istream_type::ios_base __ios_base;
827  typedef typename __istream_type::int_type __int_type;
828  typedef typename __string_type::size_type __size_type;
829  typedef ctype<_CharT> __ctype_type;
830  typedef typename __ctype_type::ctype_base __ctype_base;
831 
832  __size_type __extracted = 0;
833  typename __ios_base::iostate __err = __ios_base::goodbit;
834  typename __istream_type::sentry __cerb(__in, false);
835  if (__cerb)
836  {
837  __try
838  {
839  // Avoid reallocation for common case.
840  __str.erase();
841  _CharT __buf[128];
842  __size_type __len = 0;
843  const streamsize __w = __in.width();
844  const __size_type __n = __w > 0 ? static_cast<__size_type>(__w)
845  : __str.max_size();
846  const __ctype_type& __ct = use_facet<__ctype_type>(__in.getloc());
847  const __int_type __eof = _Traits::eof();
848  __int_type __c = __in.rdbuf()->sgetc();
849 
850  while (__extracted < __n
851  && !_Traits::eq_int_type(__c, __eof)
852  && !__ct.is(__ctype_base::space,
853  _Traits::to_char_type(__c)))
854  {
855  if (__len == sizeof(__buf) / sizeof(_CharT))
856  {
857  __str.append(__buf, sizeof(__buf) / sizeof(_CharT));
858  __len = 0;
859  }
860  __buf[__len++] = _Traits::to_char_type(__c);
861  ++__extracted;
862  __c = __in.rdbuf()->snextc();
863  }
864  __str.append(__buf, __len);
865 
866  if (__extracted < __n && _Traits::eq_int_type(__c, __eof))
867  __err |= __ios_base::eofbit;
868  __in.width(0);
869  }
871  {
872  __in._M_setstate(__ios_base::badbit);
873  __throw_exception_again;
874  }
875  __catch(...)
876  {
877  // _GLIBCXX_RESOLVE_LIB_DEFECTS
878  // 91. Description of operator>> and getline() for string<>
879  // might cause endless loop
880  __in._M_setstate(__ios_base::badbit);
881  }
882  }
883  // 211. operator>>(istream&, string&) doesn't set failbit
884  if (!__extracted)
885  __err |= __ios_base::failbit;
886  if (__err)
887  __in.setstate(__err);
888  return __in;
889  }
890 
891  template<typename _CharT, typename _Traits, typename _Alloc>
892  basic_istream<_CharT, _Traits>&
894  basic_string<_CharT, _Traits, _Alloc>& __str, _CharT __delim)
895  {
896  typedef basic_istream<_CharT, _Traits> __istream_type;
897  typedef basic_string<_CharT, _Traits, _Alloc> __string_type;
898  typedef typename __istream_type::ios_base __ios_base;
899  typedef typename __istream_type::int_type __int_type;
900  typedef typename __string_type::size_type __size_type;
901 
902  __size_type __extracted = 0;
903  const __size_type __n = __str.max_size();
904  typename __ios_base::iostate __err = __ios_base::goodbit;
905  typename __istream_type::sentry __cerb(__in, true);
906  if (__cerb)
907  {
908  __try
909  {
910  __str.erase();
911  const __int_type __idelim = _Traits::to_int_type(__delim);
912  const __int_type __eof = _Traits::eof();
913  __int_type __c = __in.rdbuf()->sgetc();
914 
915  while (__extracted < __n
916  && !_Traits::eq_int_type(__c, __eof)
917  && !_Traits::eq_int_type(__c, __idelim))
918  {
919  __str += _Traits::to_char_type(__c);
920  ++__extracted;
921  __c = __in.rdbuf()->snextc();
922  }
923 
924  if (_Traits::eq_int_type(__c, __eof))
925  __err |= __ios_base::eofbit;
926  else if (_Traits::eq_int_type(__c, __idelim))
927  {
928  ++__extracted;
929  __in.rdbuf()->sbumpc();
930  }
931  else
932  __err |= __ios_base::failbit;
933  }
935  {
936  __in._M_setstate(__ios_base::badbit);
937  __throw_exception_again;
938  }
939  __catch(...)
940  {
941  // _GLIBCXX_RESOLVE_LIB_DEFECTS
942  // 91. Description of operator>> and getline() for string<>
943  // might cause endless loop
944  __in._M_setstate(__ios_base::badbit);
945  }
946  }
947  if (!__extracted)
948  __err |= __ios_base::failbit;
949  if (__err)
950  __in.setstate(__err);
951  return __in;
952  }
953 
954  // Inhibit implicit instantiations for required instantiations,
955  // which are defined via explicit instantiations elsewhere.
956 #if _GLIBCXX_EXTERN_TEMPLATE
957  // The explicit instantiation definitions in src/c++11/string-inst.cc and
958  // src/c++17/string-inst.cc only instantiate the members required for C++17
959  // and earlier standards (so not C++20's starts_with and ends_with).
960  // Suppress the explicit instantiation declarations for C++20, so C++20
961  // code will implicitly instantiate std::string and std::wstring as needed.
962 # if __cplusplus <= 201703L && _GLIBCXX_EXTERN_TEMPLATE > 0
963  extern template class basic_string<char>;
964 # elif ! _GLIBCXX_USE_CXX11_ABI
965  // Still need to prevent implicit instantiation of the COW empty rep,
966  // to ensure the definition in libstdc++.so is unique (PR 86138).
967  extern template basic_string<char>::size_type
968  basic_string<char>::_Rep::_S_empty_rep_storage[];
969 # elif _GLIBCXX_EXTERN_TEMPLATE > 0
970  // Export _M_replace_cold even for C++20.
971  extern template void
972  basic_string<char>::_M_replace_cold(char *, size_type, const char*,
973  const size_type, const size_type);
974 # endif
975 
976  extern template
977  basic_istream<char>&
978  operator>>(basic_istream<char>&, string&);
979  extern template
980  basic_ostream<char>&
981  operator<<(basic_ostream<char>&, const string&);
982  extern template
983  basic_istream<char>&
984  getline(basic_istream<char>&, string&, char);
985  extern template
986  basic_istream<char>&
987  getline(basic_istream<char>&, string&);
988 
989 #ifdef _GLIBCXX_USE_WCHAR_T
990 # if __cplusplus <= 201703L && _GLIBCXX_EXTERN_TEMPLATE > 0
991  extern template class basic_string<wchar_t>;
992 # elif ! _GLIBCXX_USE_CXX11_ABI
993  extern template basic_string<wchar_t>::size_type
994  basic_string<wchar_t>::_Rep::_S_empty_rep_storage[];
995 # elif _GLIBCXX_EXTERN_TEMPLATE > 0
996  // Export _M_replace_cold even for C++20.
997  extern template void
998  basic_string<wchar_t>::_M_replace_cold(wchar_t*, size_type, const wchar_t*,
999  const size_type, const size_type);
1000 # endif
1001 
1002  extern template
1003  basic_istream<wchar_t>&
1004  operator>>(basic_istream<wchar_t>&, wstring&);
1005  extern template
1006  basic_ostream<wchar_t>&
1007  operator<<(basic_ostream<wchar_t>&, const wstring&);
1008  extern template
1009  basic_istream<wchar_t>&
1010  getline(basic_istream<wchar_t>&, wstring&, wchar_t);
1011  extern template
1012  basic_istream<wchar_t>&
1013  getline(basic_istream<wchar_t>&, wstring&);
1014 #endif // _GLIBCXX_USE_WCHAR_T
1015 #endif // _GLIBCXX_EXTERN_TEMPLATE
1016 
1017 _GLIBCXX_END_NAMESPACE_VERSION
1018 } // namespace std
1019 
1020 #endif
constexpr iterator_traits< _InputIterator >::difference_type distance(_InputIterator __first, _InputIterator __last)
A generalization of pointer arithmetic.
locale getloc() const
Locale access.
Definition: ios_base.h:806
Marking input iterators.
_Tp * begin(valarray< _Tp > &__va) noexcept
Return an iterator pointing to the first element of the valarray.
Definition: valarray:1221
size_type max_size() const noexcept
Returns the size() of the largest possible string.
Definition: cow_string.h:933
constexpr _Tp * __addressof(_Tp &__r) noexcept
Same as C++11 std::addressof.
Definition: move.h:51
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:2504
std::basic_istream< _CharT, _Traits > & operator>>(std::basic_istream< _CharT, _Traits > &__is, bitset< _Nb > &__x)
Global I/O operators for bitsets.
Definition: bitset:1593
basic_string< wchar_t > wstring
A string of wchar_t.
Definition: stringfwd.h:80
ptrdiff_t streamsize
Integral type for I/O operation counts and buffer sizes.
Definition: postypes.h:68
streamsize width() const
Flags access.
Definition: ios_base.h:755
constexpr const _Tp & min(const _Tp &, const _Tp &)
This does what you think it does.
Definition: stl_algobase.h:233
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:2587
size_type copy(_CharT *__s, size_type __n, size_type __pos=0) const
Copy substring into C string.
Definition: cow_string.h:3709
Primary class template ctype facet.This template class defines classification and conversion function...
void swap(basic_string &__s) noexcept(/*conditional */)
Swap contents with another string.
Definition: cow_string.h:3513
Forward iterators support a superset of input iterator operations.
constexpr auto data(_Container &__cont) noexcept(noexcept(__cont.data())) -> decltype(__cont.data())
Return the data pointer of a container.
Definition: range_access.h:314
void setstate(iostate __state)
Sets additional flags in the error state.
Definition: basic_ios.h:157
static const size_type npos
Value returned by various member functions when they fail.
Definition: cow_string.h:330
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:2420
basic_streambuf< _CharT, _Traits > * rdbuf() const
Accessing the underlying buffer.
Definition: basic_ios.h:321
constexpr auto size(const _Container &__cont) noexcept(noexcept(__cont.size())) -> decltype(__cont.size())
Return the size of a container.
Definition: range_access.h:264
size_type rfind(const basic_string &__str, size_type __pos=npos) const noexcept
Find last position of a string.
Definition: cow_string.h:2341
ISO C++ entities toplevel namespace is std.
Thrown as part of forced unwinding.A magic placeholder class that can be caught by reference to recog...
Definition: cxxabi_forced.h:48
Template class basic_istream.
Definition: iosfwd:85
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.
size_type find(const _CharT *__s, size_type __pos, size_type __n) const noexcept
Find position of a C substring.
basic_string & append(const basic_string &__str)
Append a string to this string.
Definition: cow_string.h:3307
void reserve()
Equivalent to shrink_to_fit().
Definition: cow_string.h:3688
constexpr std::remove_reference< _Tp >::type && move(_Tp &&__t) noexcept
Convert a value to an rvalue.
Definition: move.h:97
void resize(size_type __n, _CharT __c)
Resizes the string to the specified number of characters.
Definition: cow_string.h:3635
Managing sequences of characters and character-like objects.
Definition: cow_string.h:116
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:2669
constexpr bool is_constant_evaluated() noexcept
Returns true only when called during constant evaluation.
Definition: type_traits:3644
basic_string & erase(size_type __pos=0, size_type __n=npos)
Remove characters.
Definition: cow_string.h:1718