libstdc++
basic_string.tcc
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1 // Components for manipulating sequences of characters -*- C++ -*-
2 
3 // Copyright (C) 1997-2021 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  void
59  swap(basic_string& __s) _GLIBCXX_NOEXCEPT
60  {
61  if (this == std::__addressof(__s))
62  return;
63 
64  _Alloc_traits::_S_on_swap(_M_get_allocator(), __s._M_get_allocator());
65 
66  if (_M_is_local())
67  if (__s._M_is_local())
68  {
69  if (length() && __s.length())
70  {
71  _CharT __tmp_data[_S_local_capacity + 1];
72  traits_type::copy(__tmp_data, __s._M_local_buf,
73  _S_local_capacity + 1);
74  traits_type::copy(__s._M_local_buf, _M_local_buf,
75  _S_local_capacity + 1);
76  traits_type::copy(_M_local_buf, __tmp_data,
77  _S_local_capacity + 1);
78  }
79  else if (__s.length())
80  {
81  traits_type::copy(_M_local_buf, __s._M_local_buf,
82  _S_local_capacity + 1);
83  _M_length(__s.length());
84  __s._M_set_length(0);
85  return;
86  }
87  else if (length())
88  {
89  traits_type::copy(__s._M_local_buf, _M_local_buf,
90  _S_local_capacity + 1);
91  __s._M_length(length());
92  _M_set_length(0);
93  return;
94  }
95  }
96  else
97  {
98  const size_type __tmp_capacity = __s._M_allocated_capacity;
99  traits_type::copy(__s._M_local_buf, _M_local_buf,
100  _S_local_capacity + 1);
101  _M_data(__s._M_data());
102  __s._M_data(__s._M_local_buf);
103  _M_capacity(__tmp_capacity);
104  }
105  else
106  {
107  const size_type __tmp_capacity = _M_allocated_capacity;
108  if (__s._M_is_local())
109  {
110  traits_type::copy(_M_local_buf, __s._M_local_buf,
111  _S_local_capacity + 1);
112  __s._M_data(_M_data());
113  _M_data(_M_local_buf);
114  }
115  else
116  {
117  pointer __tmp_ptr = _M_data();
118  _M_data(__s._M_data());
119  __s._M_data(__tmp_ptr);
120  _M_capacity(__s._M_allocated_capacity);
121  }
122  __s._M_capacity(__tmp_capacity);
123  }
124 
125  const size_type __tmp_length = length();
126  _M_length(__s.length());
127  __s._M_length(__tmp_length);
128  }
129 
130  template<typename _CharT, typename _Traits, typename _Alloc>
131  typename basic_string<_CharT, _Traits, _Alloc>::pointer
132  basic_string<_CharT, _Traits, _Alloc>::
133  _M_create(size_type& __capacity, size_type __old_capacity)
134  {
135  // _GLIBCXX_RESOLVE_LIB_DEFECTS
136  // 83. String::npos vs. string::max_size()
137  if (__capacity > max_size())
138  std::__throw_length_error(__N("basic_string::_M_create"));
139 
140  // The below implements an exponential growth policy, necessary to
141  // meet amortized linear time requirements of the library: see
142  // http://gcc.gnu.org/ml/libstdc++/2001-07/msg00085.html.
143  if (__capacity > __old_capacity && __capacity < 2 * __old_capacity)
144  {
145  __capacity = 2 * __old_capacity;
146  // Never allocate a string bigger than max_size.
147  if (__capacity > max_size())
148  __capacity = max_size();
149  }
150 
151  // NB: Need an array of char_type[__capacity], plus a terminating
152  // null char_type() element.
153  return _Alloc_traits::allocate(_M_get_allocator(), __capacity + 1);
154  }
155 
156  // NB: This is the special case for Input Iterators, used in
157  // istreambuf_iterators, etc.
158  // Input Iterators have a cost structure very different from
159  // pointers, calling for a different coding style.
160  template<typename _CharT, typename _Traits, typename _Alloc>
161  template<typename _InIterator>
162  void
163  basic_string<_CharT, _Traits, _Alloc>::
164  _M_construct(_InIterator __beg, _InIterator __end,
166  {
167  size_type __len = 0;
168  size_type __capacity = size_type(_S_local_capacity);
169 
170  while (__beg != __end && __len < __capacity)
171  {
172  _M_data()[__len++] = *__beg;
173  ++__beg;
174  }
175 
176  __try
177  {
178  while (__beg != __end)
179  {
180  if (__len == __capacity)
181  {
182  // Allocate more space.
183  __capacity = __len + 1;
184  pointer __another = _M_create(__capacity, __len);
185  this->_S_copy(__another, _M_data(), __len);
186  _M_dispose();
187  _M_data(__another);
188  _M_capacity(__capacity);
189  }
190  _M_data()[__len++] = *__beg;
191  ++__beg;
192  }
193  }
194  __catch(...)
195  {
196  _M_dispose();
197  __throw_exception_again;
198  }
199 
200  _M_set_length(__len);
201  }
202 
203  template<typename _CharT, typename _Traits, typename _Alloc>
204  template<typename _InIterator>
205  void
206  basic_string<_CharT, _Traits, _Alloc>::
207  _M_construct(_InIterator __beg, _InIterator __end,
209  {
210  // NB: Not required, but considered best practice.
211  if (__gnu_cxx::__is_null_pointer(__beg) && __beg != __end)
212  std::__throw_logic_error(__N("basic_string::"
213  "_M_construct null not valid"));
214 
215  size_type __dnew = static_cast<size_type>(std::distance(__beg, __end));
216 
217  if (__dnew > size_type(_S_local_capacity))
218  {
219  _M_data(_M_create(__dnew, size_type(0)));
220  _M_capacity(__dnew);
221  }
222 
223  // Check for out_of_range and length_error exceptions.
224  __try
225  { this->_S_copy_chars(_M_data(), __beg, __end); }
226  __catch(...)
227  {
228  _M_dispose();
229  __throw_exception_again;
230  }
231 
232  _M_set_length(__dnew);
233  }
234 
235  template<typename _CharT, typename _Traits, typename _Alloc>
236  void
237  basic_string<_CharT, _Traits, _Alloc>::
238  _M_construct(size_type __n, _CharT __c)
239  {
240  if (__n > size_type(_S_local_capacity))
241  {
242  _M_data(_M_create(__n, size_type(0)));
243  _M_capacity(__n);
244  }
245 
246  if (__n)
247  this->_S_assign(_M_data(), __n, __c);
248 
249  _M_set_length(__n);
250  }
251 
252  template<typename _CharT, typename _Traits, typename _Alloc>
253  void
254  basic_string<_CharT, _Traits, _Alloc>::
255  _M_assign(const basic_string& __str)
256  {
257  if (this != std::__addressof(__str))
258  {
259  const size_type __rsize = __str.length();
260  const size_type __capacity = capacity();
261 
262  if (__rsize > __capacity)
263  {
264  size_type __new_capacity = __rsize;
265  pointer __tmp = _M_create(__new_capacity, __capacity);
266  _M_dispose();
267  _M_data(__tmp);
268  _M_capacity(__new_capacity);
269  }
270 
271  if (__rsize)
272  this->_S_copy(_M_data(), __str._M_data(), __rsize);
273 
274  _M_set_length(__rsize);
275  }
276  }
277 
278  template<typename _CharT, typename _Traits, typename _Alloc>
279  void
281  reserve(size_type __res)
282  {
283  const size_type __capacity = capacity();
284  // _GLIBCXX_RESOLVE_LIB_DEFECTS
285  // 2968. Inconsistencies between basic_string reserve and
286  // vector/unordered_map/unordered_set reserve functions
287  // P0966 reserve should not shrink
288  if (__res <= __capacity)
289  return;
290 
291  pointer __tmp = _M_create(__res, __capacity);
292  this->_S_copy(__tmp, _M_data(), length() + 1);
293  _M_dispose();
294  _M_data(__tmp);
295  _M_capacity(__res);
296  }
297 
298  template<typename _CharT, typename _Traits, typename _Alloc>
299  void
300  basic_string<_CharT, _Traits, _Alloc>::
301  _M_mutate(size_type __pos, size_type __len1, const _CharT* __s,
302  size_type __len2)
303  {
304  const size_type __how_much = length() - __pos - __len1;
305 
306  size_type __new_capacity = length() + __len2 - __len1;
307  pointer __r = _M_create(__new_capacity, capacity());
308 
309  if (__pos)
310  this->_S_copy(__r, _M_data(), __pos);
311  if (__s && __len2)
312  this->_S_copy(__r + __pos, __s, __len2);
313  if (__how_much)
314  this->_S_copy(__r + __pos + __len2,
315  _M_data() + __pos + __len1, __how_much);
316 
317  _M_dispose();
318  _M_data(__r);
319  _M_capacity(__new_capacity);
320  }
321 
322  template<typename _CharT, typename _Traits, typename _Alloc>
323  void
324  basic_string<_CharT, _Traits, _Alloc>::
325  _M_erase(size_type __pos, size_type __n)
326  {
327  const size_type __how_much = length() - __pos - __n;
328 
329  if (__how_much && __n)
330  this->_S_move(_M_data() + __pos, _M_data() + __pos + __n, __how_much);
331 
332  _M_set_length(length() - __n);
333  }
334 
335  template<typename _CharT, typename _Traits, typename _Alloc>
336  void
338  reserve()
339  {
340  if (_M_is_local())
341  return;
342 
343  const size_type __length = length();
344  const size_type __capacity = _M_allocated_capacity;
345 
346  if (__length <= size_type(_S_local_capacity))
347  {
348  this->_S_copy(_M_local_data(), _M_data(), __length + 1);
349  _M_destroy(__capacity);
350  _M_data(_M_local_data());
351  }
352 #if __cpp_exceptions
353  else if (__length < __capacity)
354  try
355  {
356  pointer __tmp
357  = _Alloc_traits::allocate(_M_get_allocator(), __length + 1);
358  this->_S_copy(__tmp, _M_data(), __length + 1);
359  _M_dispose();
360  _M_data(__tmp);
361  _M_capacity(__length);
362  }
363  catch (const __cxxabiv1::__forced_unwind&)
364  { throw; }
365  catch (...)
366  { /* swallow the exception */ }
367 #endif
368  }
369 
370  template<typename _CharT, typename _Traits, typename _Alloc>
371  void
373  resize(size_type __n, _CharT __c)
374  {
375  const size_type __size = this->size();
376  if (__size < __n)
377  this->append(__n - __size, __c);
378  else if (__n < __size)
379  this->_M_set_length(__n);
380  }
381 
382  template<typename _CharT, typename _Traits, typename _Alloc>
383  basic_string<_CharT, _Traits, _Alloc>&
384  basic_string<_CharT, _Traits, _Alloc>::
385  _M_append(const _CharT* __s, size_type __n)
386  {
387  const size_type __len = __n + this->size();
388 
389  if (__len <= this->capacity())
390  {
391  if (__n)
392  this->_S_copy(this->_M_data() + this->size(), __s, __n);
393  }
394  else
395  this->_M_mutate(this->size(), size_type(0), __s, __n);
396 
397  this->_M_set_length(__len);
398  return *this;
399  }
400 
401  template<typename _CharT, typename _Traits, typename _Alloc>
402  template<typename _InputIterator>
403  basic_string<_CharT, _Traits, _Alloc>&
404  basic_string<_CharT, _Traits, _Alloc>::
405  _M_replace_dispatch(const_iterator __i1, const_iterator __i2,
406  _InputIterator __k1, _InputIterator __k2,
407  std::__false_type)
408  {
409  // _GLIBCXX_RESOLVE_LIB_DEFECTS
410  // 2788. unintentionally require a default constructible allocator
411  const basic_string __s(__k1, __k2, this->get_allocator());
412  const size_type __n1 = __i2 - __i1;
413  return _M_replace(__i1 - begin(), __n1, __s._M_data(),
414  __s.size());
415  }
416 
417  template<typename _CharT, typename _Traits, typename _Alloc>
418  basic_string<_CharT, _Traits, _Alloc>&
419  basic_string<_CharT, _Traits, _Alloc>::
420  _M_replace_aux(size_type __pos1, size_type __n1, size_type __n2,
421  _CharT __c)
422  {
423  _M_check_length(__n1, __n2, "basic_string::_M_replace_aux");
424 
425  const size_type __old_size = this->size();
426  const size_type __new_size = __old_size + __n2 - __n1;
427 
428  if (__new_size <= this->capacity())
429  {
430  pointer __p = this->_M_data() + __pos1;
431 
432  const size_type __how_much = __old_size - __pos1 - __n1;
433  if (__how_much && __n1 != __n2)
434  this->_S_move(__p + __n2, __p + __n1, __how_much);
435  }
436  else
437  this->_M_mutate(__pos1, __n1, 0, __n2);
438 
439  if (__n2)
440  this->_S_assign(this->_M_data() + __pos1, __n2, __c);
441 
442  this->_M_set_length(__new_size);
443  return *this;
444  }
445 
446  template<typename _CharT, typename _Traits, typename _Alloc>
447  basic_string<_CharT, _Traits, _Alloc>&
448  basic_string<_CharT, _Traits, _Alloc>::
449  _M_replace(size_type __pos, size_type __len1, const _CharT* __s,
450  const size_type __len2)
451  {
452  _M_check_length(__len1, __len2, "basic_string::_M_replace");
453 
454  const size_type __old_size = this->size();
455  const size_type __new_size = __old_size + __len2 - __len1;
456 
457  if (__new_size <= this->capacity())
458  {
459  pointer __p = this->_M_data() + __pos;
460 
461  const size_type __how_much = __old_size - __pos - __len1;
462  if (_M_disjunct(__s))
463  {
464  if (__how_much && __len1 != __len2)
465  this->_S_move(__p + __len2, __p + __len1, __how_much);
466  if (__len2)
467  this->_S_copy(__p, __s, __len2);
468  }
469  else
470  {
471  // Work in-place.
472  if (__len2 && __len2 <= __len1)
473  this->_S_move(__p, __s, __len2);
474  if (__how_much && __len1 != __len2)
475  this->_S_move(__p + __len2, __p + __len1, __how_much);
476  if (__len2 > __len1)
477  {
478  if (__s + __len2 <= __p + __len1)
479  this->_S_move(__p, __s, __len2);
480  else if (__s >= __p + __len1)
481  {
482  // Hint to middle end that __p and __s overlap
483  // (PR 98465).
484  const size_type __poff = (__s - __p) + (__len2 - __len1);
485  this->_S_copy(__p, __p + __poff, __len2);
486  }
487  else
488  {
489  const size_type __nleft = (__p + __len1) - __s;
490  this->_S_move(__p, __s, __nleft);
491  this->_S_copy(__p + __nleft, __p + __len2,
492  __len2 - __nleft);
493  }
494  }
495  }
496  }
497  else
498  this->_M_mutate(__pos, __len1, __s, __len2);
499 
500  this->_M_set_length(__new_size);
501  return *this;
502  }
503 
504  template<typename _CharT, typename _Traits, typename _Alloc>
505  typename basic_string<_CharT, _Traits, _Alloc>::size_type
507  copy(_CharT* __s, size_type __n, size_type __pos) const
508  {
509  _M_check(__pos, "basic_string::copy");
510  __n = _M_limit(__pos, __n);
511  __glibcxx_requires_string_len(__s, __n);
512  if (__n)
513  _S_copy(__s, _M_data() + __pos, __n);
514  // 21.3.5.7 par 3: do not append null. (good.)
515  return __n;
516  }
517 
518 #else // !_GLIBCXX_USE_CXX11_ABI
519 
520  template<typename _CharT, typename _Traits, typename _Alloc>
521  const typename basic_string<_CharT, _Traits, _Alloc>::size_type
522  basic_string<_CharT, _Traits, _Alloc>::
523  _Rep::_S_max_size = (((npos - sizeof(_Rep_base))/sizeof(_CharT)) - 1) / 4;
524 
525  template<typename _CharT, typename _Traits, typename _Alloc>
526  const _CharT
527  basic_string<_CharT, _Traits, _Alloc>::
528  _Rep::_S_terminal = _CharT();
529 
530  template<typename _CharT, typename _Traits, typename _Alloc>
531  const typename basic_string<_CharT, _Traits, _Alloc>::size_type
533 
534  // Linker sets _S_empty_rep_storage to all 0s (one reference, empty string)
535  // at static init time (before static ctors are run).
536  template<typename _CharT, typename _Traits, typename _Alloc>
537  typename basic_string<_CharT, _Traits, _Alloc>::size_type
538  basic_string<_CharT, _Traits, _Alloc>::_Rep::_S_empty_rep_storage[
539  (sizeof(_Rep_base) + sizeof(_CharT) + sizeof(size_type) - 1) /
540  sizeof(size_type)];
541 
542  // NB: This is the special case for Input Iterators, used in
543  // istreambuf_iterators, etc.
544  // Input Iterators have a cost structure very different from
545  // pointers, calling for a different coding style.
546  template<typename _CharT, typename _Traits, typename _Alloc>
547  template<typename _InIterator>
548  _CharT*
549  basic_string<_CharT, _Traits, _Alloc>::
550  _S_construct(_InIterator __beg, _InIterator __end, const _Alloc& __a,
551  input_iterator_tag)
552  {
553 #if _GLIBCXX_FULLY_DYNAMIC_STRING == 0
554  if (__beg == __end && __a == _Alloc())
555  return _S_empty_rep()._M_refdata();
556 #endif
557  // Avoid reallocation for common case.
558  _CharT __buf[128];
559  size_type __len = 0;
560  while (__beg != __end && __len < sizeof(__buf) / sizeof(_CharT))
561  {
562  __buf[__len++] = *__beg;
563  ++__beg;
564  }
565  _Rep* __r = _Rep::_S_create(__len, size_type(0), __a);
566  _M_copy(__r->_M_refdata(), __buf, __len);
567  __try
568  {
569  while (__beg != __end)
570  {
571  if (__len == __r->_M_capacity)
572  {
573  // Allocate more space.
574  _Rep* __another = _Rep::_S_create(__len + 1, __len, __a);
575  _M_copy(__another->_M_refdata(), __r->_M_refdata(), __len);
576  __r->_M_destroy(__a);
577  __r = __another;
578  }
579  __r->_M_refdata()[__len++] = *__beg;
580  ++__beg;
581  }
582  }
583  __catch(...)
584  {
585  __r->_M_destroy(__a);
586  __throw_exception_again;
587  }
588  __r->_M_set_length_and_sharable(__len);
589  return __r->_M_refdata();
590  }
591 
592  template<typename _CharT, typename _Traits, typename _Alloc>
593  template <typename _InIterator>
594  _CharT*
595  basic_string<_CharT, _Traits, _Alloc>::
596  _S_construct(_InIterator __beg, _InIterator __end, const _Alloc& __a,
597  forward_iterator_tag)
598  {
599 #if _GLIBCXX_FULLY_DYNAMIC_STRING == 0
600  if (__beg == __end && __a == _Alloc())
601  return _S_empty_rep()._M_refdata();
602 #endif
603  // NB: Not required, but considered best practice.
604  if (__gnu_cxx::__is_null_pointer(__beg) && __beg != __end)
605  __throw_logic_error(__N("basic_string::_S_construct null not valid"));
606 
607  const size_type __dnew = static_cast<size_type>(std::distance(__beg,
608  __end));
609  // Check for out_of_range and length_error exceptions.
610  _Rep* __r = _Rep::_S_create(__dnew, size_type(0), __a);
611  __try
612  { _S_copy_chars(__r->_M_refdata(), __beg, __end); }
613  __catch(...)
614  {
615  __r->_M_destroy(__a);
616  __throw_exception_again;
617  }
618  __r->_M_set_length_and_sharable(__dnew);
619  return __r->_M_refdata();
620  }
621 
622  template<typename _CharT, typename _Traits, typename _Alloc>
623  _CharT*
624  basic_string<_CharT, _Traits, _Alloc>::
625  _S_construct(size_type __n, _CharT __c, const _Alloc& __a)
626  {
627 #if _GLIBCXX_FULLY_DYNAMIC_STRING == 0
628  if (__n == 0 && __a == _Alloc())
629  return _S_empty_rep()._M_refdata();
630 #endif
631  // Check for out_of_range and length_error exceptions.
632  _Rep* __r = _Rep::_S_create(__n, size_type(0), __a);
633  if (__n)
634  _M_assign(__r->_M_refdata(), __n, __c);
635 
636  __r->_M_set_length_and_sharable(__n);
637  return __r->_M_refdata();
638  }
639 
640  template<typename _CharT, typename _Traits, typename _Alloc>
642  basic_string(const basic_string& __str, size_type __pos, const _Alloc& __a)
643  : _M_dataplus(_S_construct(__str._M_data()
644  + __str._M_check(__pos,
645  "basic_string::basic_string"),
646  __str._M_data() + __str._M_limit(__pos, npos)
647  + __pos, __a), __a)
648  { }
649 
650  template<typename _CharT, typename _Traits, typename _Alloc>
652  basic_string(const basic_string& __str, size_type __pos, size_type __n)
653  : _M_dataplus(_S_construct(__str._M_data()
654  + __str._M_check(__pos,
655  "basic_string::basic_string"),
656  __str._M_data() + __str._M_limit(__pos, __n)
657  + __pos, _Alloc()), _Alloc())
658  { }
659 
660  template<typename _CharT, typename _Traits, typename _Alloc>
662  basic_string(const basic_string& __str, size_type __pos,
663  size_type __n, const _Alloc& __a)
664  : _M_dataplus(_S_construct(__str._M_data()
665  + __str._M_check(__pos,
666  "basic_string::basic_string"),
667  __str._M_data() + __str._M_limit(__pos, __n)
668  + __pos, __a), __a)
669  { }
670 
671  template<typename _CharT, typename _Traits, typename _Alloc>
674  assign(const basic_string& __str)
675  {
676  if (_M_rep() != __str._M_rep())
677  {
678  // XXX MT
679  const allocator_type __a = this->get_allocator();
680  _CharT* __tmp = __str._M_rep()->_M_grab(__a, __str.get_allocator());
681  _M_rep()->_M_dispose(__a);
682  _M_data(__tmp);
683  }
684  return *this;
685  }
686 
687  template<typename _CharT, typename _Traits, typename _Alloc>
690  assign(const _CharT* __s, size_type __n)
691  {
692  __glibcxx_requires_string_len(__s, __n);
693  _M_check_length(this->size(), __n, "basic_string::assign");
694  if (_M_disjunct(__s) || _M_rep()->_M_is_shared())
695  return _M_replace_safe(size_type(0), this->size(), __s, __n);
696  else
697  {
698  // Work in-place.
699  const size_type __pos = __s - _M_data();
700  if (__pos >= __n)
701  _M_copy(_M_data(), __s, __n);
702  else if (__pos)
703  _M_move(_M_data(), __s, __n);
704  _M_rep()->_M_set_length_and_sharable(__n);
705  return *this;
706  }
707  }
708 
709  template<typename _CharT, typename _Traits, typename _Alloc>
712  append(size_type __n, _CharT __c)
713  {
714  if (__n)
715  {
716  _M_check_length(size_type(0), __n, "basic_string::append");
717  const size_type __len = __n + this->size();
718  if (__len > this->capacity() || _M_rep()->_M_is_shared())
719  this->reserve(__len);
720  _M_assign(_M_data() + this->size(), __n, __c);
721  _M_rep()->_M_set_length_and_sharable(__len);
722  }
723  return *this;
724  }
725 
726  template<typename _CharT, typename _Traits, typename _Alloc>
729  append(const _CharT* __s, size_type __n)
730  {
731  __glibcxx_requires_string_len(__s, __n);
732  if (__n)
733  {
734  _M_check_length(size_type(0), __n, "basic_string::append");
735  const size_type __len = __n + this->size();
736  if (__len > this->capacity() || _M_rep()->_M_is_shared())
737  {
738  if (_M_disjunct(__s))
739  this->reserve(__len);
740  else
741  {
742  const size_type __off = __s - _M_data();
743  this->reserve(__len);
744  __s = _M_data() + __off;
745  }
746  }
747  _M_copy(_M_data() + this->size(), __s, __n);
748  _M_rep()->_M_set_length_and_sharable(__len);
749  }
750  return *this;
751  }
752 
753  template<typename _CharT, typename _Traits, typename _Alloc>
756  append(const basic_string& __str)
757  {
758  const size_type __size = __str.size();
759  if (__size)
760  {
761  const size_type __len = __size + this->size();
762  if (__len > this->capacity() || _M_rep()->_M_is_shared())
763  this->reserve(__len);
764  _M_copy(_M_data() + this->size(), __str._M_data(), __size);
765  _M_rep()->_M_set_length_and_sharable(__len);
766  }
767  return *this;
768  }
769 
770  template<typename _CharT, typename _Traits, typename _Alloc>
773  append(const basic_string& __str, size_type __pos, size_type __n)
774  {
775  __str._M_check(__pos, "basic_string::append");
776  __n = __str._M_limit(__pos, __n);
777  if (__n)
778  {
779  const size_type __len = __n + this->size();
780  if (__len > this->capacity() || _M_rep()->_M_is_shared())
781  this->reserve(__len);
782  _M_copy(_M_data() + this->size(), __str._M_data() + __pos, __n);
783  _M_rep()->_M_set_length_and_sharable(__len);
784  }
785  return *this;
786  }
787 
788  template<typename _CharT, typename _Traits, typename _Alloc>
791  insert(size_type __pos, const _CharT* __s, size_type __n)
792  {
793  __glibcxx_requires_string_len(__s, __n);
794  _M_check(__pos, "basic_string::insert");
795  _M_check_length(size_type(0), __n, "basic_string::insert");
796  if (_M_disjunct(__s) || _M_rep()->_M_is_shared())
797  return _M_replace_safe(__pos, size_type(0), __s, __n);
798  else
799  {
800  // Work in-place.
801  const size_type __off = __s - _M_data();
802  _M_mutate(__pos, 0, __n);
803  __s = _M_data() + __off;
804  _CharT* __p = _M_data() + __pos;
805  if (__s + __n <= __p)
806  _M_copy(__p, __s, __n);
807  else if (__s >= __p)
808  _M_copy(__p, __s + __n, __n);
809  else
810  {
811  const size_type __nleft = __p - __s;
812  _M_copy(__p, __s, __nleft);
813  _M_copy(__p + __nleft, __p + __n, __n - __nleft);
814  }
815  return *this;
816  }
817  }
818 
819  template<typename _CharT, typename _Traits, typename _Alloc>
820  typename basic_string<_CharT, _Traits, _Alloc>::iterator
822  erase(iterator __first, iterator __last)
823  {
824  _GLIBCXX_DEBUG_PEDASSERT(__first >= _M_ibegin() && __first <= __last
825  && __last <= _M_iend());
826 
827  // NB: This isn't just an optimization (bail out early when
828  // there is nothing to do, really), it's also a correctness
829  // issue vs MT, see libstdc++/40518.
830  const size_type __size = __last - __first;
831  if (__size)
832  {
833  const size_type __pos = __first - _M_ibegin();
834  _M_mutate(__pos, __size, size_type(0));
835  _M_rep()->_M_set_leaked();
836  return iterator(_M_data() + __pos);
837  }
838  else
839  return __first;
840  }
841 
842  template<typename _CharT, typename _Traits, typename _Alloc>
845  replace(size_type __pos, size_type __n1, const _CharT* __s,
846  size_type __n2)
847  {
848  __glibcxx_requires_string_len(__s, __n2);
849  _M_check(__pos, "basic_string::replace");
850  __n1 = _M_limit(__pos, __n1);
851  _M_check_length(__n1, __n2, "basic_string::replace");
852  bool __left;
853  if (_M_disjunct(__s) || _M_rep()->_M_is_shared())
854  return _M_replace_safe(__pos, __n1, __s, __n2);
855  else if ((__left = __s + __n2 <= _M_data() + __pos)
856  || _M_data() + __pos + __n1 <= __s)
857  {
858  // Work in-place: non-overlapping case.
859  size_type __off = __s - _M_data();
860  __left ? __off : (__off += __n2 - __n1);
861  _M_mutate(__pos, __n1, __n2);
862  _M_copy(_M_data() + __pos, _M_data() + __off, __n2);
863  return *this;
864  }
865  else
866  {
867  // Todo: overlapping case.
868  const basic_string __tmp(__s, __n2);
869  return _M_replace_safe(__pos, __n1, __tmp._M_data(), __n2);
870  }
871  }
872 
873  template<typename _CharT, typename _Traits, typename _Alloc>
874  void
876  _M_destroy(const _Alloc& __a) throw ()
877  {
878  const size_type __size = sizeof(_Rep_base) +
879  (this->_M_capacity + 1) * sizeof(_CharT);
880  _Raw_bytes_alloc(__a).deallocate(reinterpret_cast<char*>(this), __size);
881  }
882 
883  template<typename _CharT, typename _Traits, typename _Alloc>
884  void
885  basic_string<_CharT, _Traits, _Alloc>::
886  _M_leak_hard()
887  {
888 #if _GLIBCXX_FULLY_DYNAMIC_STRING == 0
889  if (_M_rep() == &_S_empty_rep())
890  return;
891 #endif
892  if (_M_rep()->_M_is_shared())
893  _M_mutate(0, 0, 0);
894  _M_rep()->_M_set_leaked();
895  }
896 
897  template<typename _CharT, typename _Traits, typename _Alloc>
898  void
899  basic_string<_CharT, _Traits, _Alloc>::
900  _M_mutate(size_type __pos, size_type __len1, size_type __len2)
901  {
902  const size_type __old_size = this->size();
903  const size_type __new_size = __old_size + __len2 - __len1;
904  const size_type __how_much = __old_size - __pos - __len1;
905 
906  if (__new_size > this->capacity() || _M_rep()->_M_is_shared())
907  {
908  // Must reallocate.
909  const allocator_type __a = get_allocator();
910  _Rep* __r = _Rep::_S_create(__new_size, this->capacity(), __a);
911 
912  if (__pos)
913  _M_copy(__r->_M_refdata(), _M_data(), __pos);
914  if (__how_much)
915  _M_copy(__r->_M_refdata() + __pos + __len2,
916  _M_data() + __pos + __len1, __how_much);
917 
918  _M_rep()->_M_dispose(__a);
919  _M_data(__r->_M_refdata());
920  }
921  else if (__how_much && __len1 != __len2)
922  {
923  // Work in-place.
924  _M_move(_M_data() + __pos + __len2,
925  _M_data() + __pos + __len1, __how_much);
926  }
927  _M_rep()->_M_set_length_and_sharable(__new_size);
928  }
929 
930  template<typename _CharT, typename _Traits, typename _Alloc>
931  void
933  reserve(size_type __res)
934  {
935  const size_type __capacity = capacity();
936 
937  // _GLIBCXX_RESOLVE_LIB_DEFECTS
938  // 2968. Inconsistencies between basic_string reserve and
939  // vector/unordered_map/unordered_set reserve functions
940  // P0966 reserve should not shrink
941  if (__res <= __capacity)
942  {
943  if (!_M_rep()->_M_is_shared())
944  return;
945 
946  // unshare, but keep same capacity
947  __res = __capacity;
948  }
949 
950  const allocator_type __a = get_allocator();
951  _CharT* __tmp = _M_rep()->_M_clone(__a, __res - this->size());
952  _M_rep()->_M_dispose(__a);
953  _M_data(__tmp);
954  }
955 
956  template<typename _CharT, typename _Traits, typename _Alloc>
957  void
959  swap(basic_string& __s)
961  {
962  if (_M_rep()->_M_is_leaked())
963  _M_rep()->_M_set_sharable();
964  if (__s._M_rep()->_M_is_leaked())
965  __s._M_rep()->_M_set_sharable();
966  if (this->get_allocator() == __s.get_allocator())
967  {
968  _CharT* __tmp = _M_data();
969  _M_data(__s._M_data());
970  __s._M_data(__tmp);
971  }
972  // The code below can usually be optimized away.
973  else
974  {
975  const basic_string __tmp1(_M_ibegin(), _M_iend(),
976  __s.get_allocator());
977  const basic_string __tmp2(__s._M_ibegin(), __s._M_iend(),
978  this->get_allocator());
979  *this = __tmp2;
980  __s = __tmp1;
981  }
982  }
983 
984  template<typename _CharT, typename _Traits, typename _Alloc>
987  _S_create(size_type __capacity, size_type __old_capacity,
988  const _Alloc& __alloc)
989  {
990  // _GLIBCXX_RESOLVE_LIB_DEFECTS
991  // 83. String::npos vs. string::max_size()
992  if (__capacity > _S_max_size)
993  __throw_length_error(__N("basic_string::_S_create"));
994 
995  // The standard places no restriction on allocating more memory
996  // than is strictly needed within this layer at the moment or as
997  // requested by an explicit application call to reserve(n).
998 
999  // Many malloc implementations perform quite poorly when an
1000  // application attempts to allocate memory in a stepwise fashion
1001  // growing each allocation size by only 1 char. Additionally,
1002  // it makes little sense to allocate less linear memory than the
1003  // natural blocking size of the malloc implementation.
1004  // Unfortunately, we would need a somewhat low-level calculation
1005  // with tuned parameters to get this perfect for any particular
1006  // malloc implementation. Fortunately, generalizations about
1007  // common features seen among implementations seems to suffice.
1008 
1009  // __pagesize need not match the actual VM page size for good
1010  // results in practice, thus we pick a common value on the low
1011  // side. __malloc_header_size is an estimate of the amount of
1012  // overhead per memory allocation (in practice seen N * sizeof
1013  // (void*) where N is 0, 2 or 4). According to folklore,
1014  // picking this value on the high side is better than
1015  // low-balling it (especially when this algorithm is used with
1016  // malloc implementations that allocate memory blocks rounded up
1017  // to a size which is a power of 2).
1018  const size_type __pagesize = 4096;
1019  const size_type __malloc_header_size = 4 * sizeof(void*);
1020 
1021  // The below implements an exponential growth policy, necessary to
1022  // meet amortized linear time requirements of the library: see
1023  // http://gcc.gnu.org/ml/libstdc++/2001-07/msg00085.html.
1024  // It's active for allocations requiring an amount of memory above
1025  // system pagesize. This is consistent with the requirements of the
1026  // standard: http://gcc.gnu.org/ml/libstdc++/2001-07/msg00130.html
1027  if (__capacity > __old_capacity && __capacity < 2 * __old_capacity)
1028  __capacity = 2 * __old_capacity;
1029 
1030  // NB: Need an array of char_type[__capacity], plus a terminating
1031  // null char_type() element, plus enough for the _Rep data structure.
1032  // Whew. Seemingly so needy, yet so elemental.
1033  size_type __size = (__capacity + 1) * sizeof(_CharT) + sizeof(_Rep);
1034 
1035  const size_type __adj_size = __size + __malloc_header_size;
1036  if (__adj_size > __pagesize && __capacity > __old_capacity)
1037  {
1038  const size_type __extra = __pagesize - __adj_size % __pagesize;
1039  __capacity += __extra / sizeof(_CharT);
1040  // Never allocate a string bigger than _S_max_size.
1041  if (__capacity > _S_max_size)
1042  __capacity = _S_max_size;
1043  __size = (__capacity + 1) * sizeof(_CharT) + sizeof(_Rep);
1044  }
1045 
1046  // NB: Might throw, but no worries about a leak, mate: _Rep()
1047  // does not throw.
1048  void* __place = _Raw_bytes_alloc(__alloc).allocate(__size);
1049  _Rep *__p = new (__place) _Rep;
1050  __p->_M_capacity = __capacity;
1051  // ABI compatibility - 3.4.x set in _S_create both
1052  // _M_refcount and _M_length. All callers of _S_create
1053  // in basic_string.tcc then set just _M_length.
1054  // In 4.0.x and later both _M_refcount and _M_length
1055  // are initialized in the callers, unfortunately we can
1056  // have 3.4.x compiled code with _S_create callers inlined
1057  // calling 4.0.x+ _S_create.
1058  __p->_M_set_sharable();
1059  return __p;
1060  }
1061 
1062  template<typename _CharT, typename _Traits, typename _Alloc>
1063  _CharT*
1064  basic_string<_CharT, _Traits, _Alloc>::_Rep::
1065  _M_clone(const _Alloc& __alloc, size_type __res)
1066  {
1067  // Requested capacity of the clone.
1068  const size_type __requested_cap = this->_M_length + __res;
1069  _Rep* __r = _Rep::_S_create(__requested_cap, this->_M_capacity,
1070  __alloc);
1071  if (this->_M_length)
1072  _M_copy(__r->_M_refdata(), _M_refdata(), this->_M_length);
1073 
1074  __r->_M_set_length_and_sharable(this->_M_length);
1075  return __r->_M_refdata();
1076  }
1077 
1078  template<typename _CharT, typename _Traits, typename _Alloc>
1079  void
1081  resize(size_type __n, _CharT __c)
1082  {
1083  const size_type __size = this->size();
1084  _M_check_length(__size, __n, "basic_string::resize");
1085  if (__size < __n)
1086  this->append(__n - __size, __c);
1087  else if (__n < __size)
1088  this->erase(__n);
1089  // else nothing (in particular, avoid calling _M_mutate() unnecessarily.)
1090  }
1091 
1092  template<typename _CharT, typename _Traits, typename _Alloc>
1093  template<typename _InputIterator>
1096  _M_replace_dispatch(iterator __i1, iterator __i2, _InputIterator __k1,
1097  _InputIterator __k2, __false_type)
1098  {
1099  const basic_string __s(__k1, __k2);
1100  const size_type __n1 = __i2 - __i1;
1101  _M_check_length(__n1, __s.size(), "basic_string::_M_replace_dispatch");
1102  return _M_replace_safe(__i1 - _M_ibegin(), __n1, __s._M_data(),
1103  __s.size());
1104  }
1105 
1106  template<typename _CharT, typename _Traits, typename _Alloc>
1107  basic_string<_CharT, _Traits, _Alloc>&
1108  basic_string<_CharT, _Traits, _Alloc>::
1109  _M_replace_aux(size_type __pos1, size_type __n1, size_type __n2,
1110  _CharT __c)
1111  {
1112  _M_check_length(__n1, __n2, "basic_string::_M_replace_aux");
1113  _M_mutate(__pos1, __n1, __n2);
1114  if (__n2)
1115  _M_assign(_M_data() + __pos1, __n2, __c);
1116  return *this;
1117  }
1118 
1119  template<typename _CharT, typename _Traits, typename _Alloc>
1120  basic_string<_CharT, _Traits, _Alloc>&
1121  basic_string<_CharT, _Traits, _Alloc>::
1122  _M_replace_safe(size_type __pos1, size_type __n1, const _CharT* __s,
1123  size_type __n2)
1124  {
1125  _M_mutate(__pos1, __n1, __n2);
1126  if (__n2)
1127  _M_copy(_M_data() + __pos1, __s, __n2);
1128  return *this;
1129  }
1130 
1131  template<typename _CharT, typename _Traits, typename _Alloc>
1132  void
1134  reserve()
1135  {
1136 #if __cpp_exceptions
1137  if (length() < capacity() || _M_rep()->_M_is_shared())
1138  try
1139  {
1140  const allocator_type __a = get_allocator();
1141  _CharT* __tmp = _M_rep()->_M_clone(__a);
1142  _M_rep()->_M_dispose(__a);
1143  _M_data(__tmp);
1144  }
1145  catch (const __cxxabiv1::__forced_unwind&)
1146  { throw; }
1147  catch (...)
1148  { /* swallow the exception */ }
1149 #endif
1150  }
1151 
1152  template<typename _CharT, typename _Traits, typename _Alloc>
1153  typename basic_string<_CharT, _Traits, _Alloc>::size_type
1155  copy(_CharT* __s, size_type __n, size_type __pos) const
1156  {
1157  _M_check(__pos, "basic_string::copy");
1158  __n = _M_limit(__pos, __n);
1159  __glibcxx_requires_string_len(__s, __n);
1160  if (__n)
1161  _M_copy(__s, _M_data() + __pos, __n);
1162  // 21.3.5.7 par 3: do not append null. (good.)
1163  return __n;
1164  }
1165 #endif // !_GLIBCXX_USE_CXX11_ABI
1166 
1167  template<typename _CharT, typename _Traits, typename _Alloc>
1169  operator+(const _CharT* __lhs,
1171  {
1172  __glibcxx_requires_string(__lhs);
1173  typedef basic_string<_CharT, _Traits, _Alloc> __string_type;
1174  typedef typename __string_type::size_type __size_type;
1176  rebind<_CharT>::other _Char_alloc_type;
1177  typedef __gnu_cxx::__alloc_traits<_Char_alloc_type> _Alloc_traits;
1178  const __size_type __len = _Traits::length(__lhs);
1179  __string_type __str(_Alloc_traits::_S_select_on_copy(
1180  __rhs.get_allocator()));
1181  __str.reserve(__len + __rhs.size());
1182  __str.append(__lhs, __len);
1183  __str.append(__rhs);
1184  return __str;
1185  }
1186 
1187  template<typename _CharT, typename _Traits, typename _Alloc>
1188  basic_string<_CharT, _Traits, _Alloc>
1190  {
1191  typedef basic_string<_CharT, _Traits, _Alloc> __string_type;
1192  typedef typename __string_type::size_type __size_type;
1194  rebind<_CharT>::other _Char_alloc_type;
1195  typedef __gnu_cxx::__alloc_traits<_Char_alloc_type> _Alloc_traits;
1196  __string_type __str(_Alloc_traits::_S_select_on_copy(
1197  __rhs.get_allocator()));
1198  const __size_type __len = __rhs.size();
1199  __str.reserve(__len + 1);
1200  __str.append(__size_type(1), __lhs);
1201  __str.append(__rhs);
1202  return __str;
1203  }
1204 
1205  template<typename _CharT, typename _Traits, typename _Alloc>
1206  typename basic_string<_CharT, _Traits, _Alloc>::size_type
1208  find(const _CharT* __s, size_type __pos, size_type __n) const
1209  _GLIBCXX_NOEXCEPT
1210  {
1211  __glibcxx_requires_string_len(__s, __n);
1212  const size_type __size = this->size();
1213 
1214  if (__n == 0)
1215  return __pos <= __size ? __pos : npos;
1216  if (__pos >= __size)
1217  return npos;
1218 
1219  const _CharT __elem0 = __s[0];
1220  const _CharT* const __data = data();
1221  const _CharT* __first = __data + __pos;
1222  const _CharT* const __last = __data + __size;
1223  size_type __len = __size - __pos;
1224 
1225  while (__len >= __n)
1226  {
1227  // Find the first occurrence of __elem0:
1228  __first = traits_type::find(__first, __len - __n + 1, __elem0);
1229  if (!__first)
1230  return npos;
1231  // Compare the full strings from the first occurrence of __elem0.
1232  // We already know that __first[0] == __s[0] but compare them again
1233  // anyway because __s is probably aligned, which helps memcmp.
1234  if (traits_type::compare(__first, __s, __n) == 0)
1235  return __first - __data;
1236  __len = __last - ++__first;
1237  }
1238  return npos;
1239  }
1240 
1241  template<typename _CharT, typename _Traits, typename _Alloc>
1242  typename basic_string<_CharT, _Traits, _Alloc>::size_type
1244  find(_CharT __c, size_type __pos) const _GLIBCXX_NOEXCEPT
1245  {
1246  size_type __ret = npos;
1247  const size_type __size = this->size();
1248  if (__pos < __size)
1249  {
1250  const _CharT* __data = _M_data();
1251  const size_type __n = __size - __pos;
1252  const _CharT* __p = traits_type::find(__data + __pos, __n, __c);
1253  if (__p)
1254  __ret = __p - __data;
1255  }
1256  return __ret;
1257  }
1258 
1259  template<typename _CharT, typename _Traits, typename _Alloc>
1260  typename basic_string<_CharT, _Traits, _Alloc>::size_type
1262  rfind(const _CharT* __s, size_type __pos, size_type __n) const
1263  _GLIBCXX_NOEXCEPT
1264  {
1265  __glibcxx_requires_string_len(__s, __n);
1266  const size_type __size = this->size();
1267  if (__n <= __size)
1268  {
1269  __pos = std::min(size_type(__size - __n), __pos);
1270  const _CharT* __data = _M_data();
1271  do
1272  {
1273  if (traits_type::compare(__data + __pos, __s, __n) == 0)
1274  return __pos;
1275  }
1276  while (__pos-- > 0);
1277  }
1278  return npos;
1279  }
1280 
1281  template<typename _CharT, typename _Traits, typename _Alloc>
1282  typename basic_string<_CharT, _Traits, _Alloc>::size_type
1284  rfind(_CharT __c, size_type __pos) const _GLIBCXX_NOEXCEPT
1285  {
1286  size_type __size = this->size();
1287  if (__size)
1288  {
1289  if (--__size > __pos)
1290  __size = __pos;
1291  for (++__size; __size-- > 0; )
1292  if (traits_type::eq(_M_data()[__size], __c))
1293  return __size;
1294  }
1295  return npos;
1296  }
1297 
1298  template<typename _CharT, typename _Traits, typename _Alloc>
1299  typename basic_string<_CharT, _Traits, _Alloc>::size_type
1301  find_first_of(const _CharT* __s, size_type __pos, size_type __n) const
1302  _GLIBCXX_NOEXCEPT
1303  {
1304  __glibcxx_requires_string_len(__s, __n);
1305  for (; __n && __pos < this->size(); ++__pos)
1306  {
1307  const _CharT* __p = traits_type::find(__s, __n, _M_data()[__pos]);
1308  if (__p)
1309  return __pos;
1310  }
1311  return npos;
1312  }
1313 
1314  template<typename _CharT, typename _Traits, typename _Alloc>
1315  typename basic_string<_CharT, _Traits, _Alloc>::size_type
1317  find_last_of(const _CharT* __s, size_type __pos, size_type __n) const
1318  _GLIBCXX_NOEXCEPT
1319  {
1320  __glibcxx_requires_string_len(__s, __n);
1321  size_type __size = this->size();
1322  if (__size && __n)
1323  {
1324  if (--__size > __pos)
1325  __size = __pos;
1326  do
1327  {
1328  if (traits_type::find(__s, __n, _M_data()[__size]))
1329  return __size;
1330  }
1331  while (__size-- != 0);
1332  }
1333  return npos;
1334  }
1335 
1336  template<typename _CharT, typename _Traits, typename _Alloc>
1337  typename basic_string<_CharT, _Traits, _Alloc>::size_type
1339  find_first_not_of(const _CharT* __s, size_type __pos, size_type __n) const
1340  _GLIBCXX_NOEXCEPT
1341  {
1342  __glibcxx_requires_string_len(__s, __n);
1343  for (; __pos < this->size(); ++__pos)
1344  if (!traits_type::find(__s, __n, _M_data()[__pos]))
1345  return __pos;
1346  return npos;
1347  }
1348 
1349  template<typename _CharT, typename _Traits, typename _Alloc>
1350  typename basic_string<_CharT, _Traits, _Alloc>::size_type
1352  find_first_not_of(_CharT __c, size_type __pos) const _GLIBCXX_NOEXCEPT
1353  {
1354  for (; __pos < this->size(); ++__pos)
1355  if (!traits_type::eq(_M_data()[__pos], __c))
1356  return __pos;
1357  return npos;
1358  }
1359 
1360  template<typename _CharT, typename _Traits, typename _Alloc>
1361  typename basic_string<_CharT, _Traits, _Alloc>::size_type
1363  find_last_not_of(const _CharT* __s, size_type __pos, size_type __n) const
1364  _GLIBCXX_NOEXCEPT
1365  {
1366  __glibcxx_requires_string_len(__s, __n);
1367  size_type __size = this->size();
1368  if (__size)
1369  {
1370  if (--__size > __pos)
1371  __size = __pos;
1372  do
1373  {
1374  if (!traits_type::find(__s, __n, _M_data()[__size]))
1375  return __size;
1376  }
1377  while (__size--);
1378  }
1379  return npos;
1380  }
1381 
1382  template<typename _CharT, typename _Traits, typename _Alloc>
1383  typename basic_string<_CharT, _Traits, _Alloc>::size_type
1385  find_last_not_of(_CharT __c, size_type __pos) const _GLIBCXX_NOEXCEPT
1386  {
1387  size_type __size = this->size();
1388  if (__size)
1389  {
1390  if (--__size > __pos)
1391  __size = __pos;
1392  do
1393  {
1394  if (!traits_type::eq(_M_data()[__size], __c))
1395  return __size;
1396  }
1397  while (__size--);
1398  }
1399  return npos;
1400  }
1401 
1402  template<typename _CharT, typename _Traits, typename _Alloc>
1403  int
1405  compare(size_type __pos, size_type __n, const basic_string& __str) const
1406  {
1407  _M_check(__pos, "basic_string::compare");
1408  __n = _M_limit(__pos, __n);
1409  const size_type __osize = __str.size();
1410  const size_type __len = std::min(__n, __osize);
1411  int __r = traits_type::compare(_M_data() + __pos, __str.data(), __len);
1412  if (!__r)
1413  __r = _S_compare(__n, __osize);
1414  return __r;
1415  }
1416 
1417  template<typename _CharT, typename _Traits, typename _Alloc>
1418  int
1420  compare(size_type __pos1, size_type __n1, const basic_string& __str,
1421  size_type __pos2, size_type __n2) const
1422  {
1423  _M_check(__pos1, "basic_string::compare");
1424  __str._M_check(__pos2, "basic_string::compare");
1425  __n1 = _M_limit(__pos1, __n1);
1426  __n2 = __str._M_limit(__pos2, __n2);
1427  const size_type __len = std::min(__n1, __n2);
1428  int __r = traits_type::compare(_M_data() + __pos1,
1429  __str.data() + __pos2, __len);
1430  if (!__r)
1431  __r = _S_compare(__n1, __n2);
1432  return __r;
1433  }
1434 
1435  template<typename _CharT, typename _Traits, typename _Alloc>
1436  int
1438  compare(const _CharT* __s) const _GLIBCXX_NOEXCEPT
1439  {
1440  __glibcxx_requires_string(__s);
1441  const size_type __size = this->size();
1442  const size_type __osize = traits_type::length(__s);
1443  const size_type __len = std::min(__size, __osize);
1444  int __r = traits_type::compare(_M_data(), __s, __len);
1445  if (!__r)
1446  __r = _S_compare(__size, __osize);
1447  return __r;
1448  }
1449 
1450  template<typename _CharT, typename _Traits, typename _Alloc>
1451  int
1453  compare(size_type __pos, size_type __n1, const _CharT* __s) const
1454  {
1455  __glibcxx_requires_string(__s);
1456  _M_check(__pos, "basic_string::compare");
1457  __n1 = _M_limit(__pos, __n1);
1458  const size_type __osize = traits_type::length(__s);
1459  const size_type __len = std::min(__n1, __osize);
1460  int __r = traits_type::compare(_M_data() + __pos, __s, __len);
1461  if (!__r)
1462  __r = _S_compare(__n1, __osize);
1463  return __r;
1464  }
1465 
1466  template<typename _CharT, typename _Traits, typename _Alloc>
1467  int
1469  compare(size_type __pos, size_type __n1, const _CharT* __s,
1470  size_type __n2) const
1471  {
1472  __glibcxx_requires_string_len(__s, __n2);
1473  _M_check(__pos, "basic_string::compare");
1474  __n1 = _M_limit(__pos, __n1);
1475  const size_type __len = std::min(__n1, __n2);
1476  int __r = traits_type::compare(_M_data() + __pos, __s, __len);
1477  if (!__r)
1478  __r = _S_compare(__n1, __n2);
1479  return __r;
1480  }
1481 
1482  // 21.3.7.9 basic_string::getline and operators
1483  template<typename _CharT, typename _Traits, typename _Alloc>
1487  {
1488  typedef basic_istream<_CharT, _Traits> __istream_type;
1489  typedef basic_string<_CharT, _Traits, _Alloc> __string_type;
1490  typedef typename __istream_type::ios_base __ios_base;
1491  typedef typename __istream_type::int_type __int_type;
1492  typedef typename __string_type::size_type __size_type;
1493  typedef ctype<_CharT> __ctype_type;
1494  typedef typename __ctype_type::ctype_base __ctype_base;
1495 
1496  __size_type __extracted = 0;
1497  typename __ios_base::iostate __err = __ios_base::goodbit;
1498  typename __istream_type::sentry __cerb(__in, false);
1499  if (__cerb)
1500  {
1501  __try
1502  {
1503  // Avoid reallocation for common case.
1504  __str.erase();
1505  _CharT __buf[128];
1506  __size_type __len = 0;
1507  const streamsize __w = __in.width();
1508  const __size_type __n = __w > 0 ? static_cast<__size_type>(__w)
1509  : __str.max_size();
1510  const __ctype_type& __ct = use_facet<__ctype_type>(__in.getloc());
1511  const __int_type __eof = _Traits::eof();
1512  __int_type __c = __in.rdbuf()->sgetc();
1513 
1514  while (__extracted < __n
1515  && !_Traits::eq_int_type(__c, __eof)
1516  && !__ct.is(__ctype_base::space,
1517  _Traits::to_char_type(__c)))
1518  {
1519  if (__len == sizeof(__buf) / sizeof(_CharT))
1520  {
1521  __str.append(__buf, sizeof(__buf) / sizeof(_CharT));
1522  __len = 0;
1523  }
1524  __buf[__len++] = _Traits::to_char_type(__c);
1525  ++__extracted;
1526  __c = __in.rdbuf()->snextc();
1527  }
1528  __str.append(__buf, __len);
1529 
1530  if (__extracted < __n && _Traits::eq_int_type(__c, __eof))
1531  __err |= __ios_base::eofbit;
1532  __in.width(0);
1533  }
1534  __catch(__cxxabiv1::__forced_unwind&)
1535  {
1536  __in._M_setstate(__ios_base::badbit);
1537  __throw_exception_again;
1538  }
1539  __catch(...)
1540  {
1541  // _GLIBCXX_RESOLVE_LIB_DEFECTS
1542  // 91. Description of operator>> and getline() for string<>
1543  // might cause endless loop
1544  __in._M_setstate(__ios_base::badbit);
1545  }
1546  }
1547  // 211. operator>>(istream&, string&) doesn't set failbit
1548  if (!__extracted)
1549  __err |= __ios_base::failbit;
1550  if (__err)
1551  __in.setstate(__err);
1552  return __in;
1553  }
1554 
1555  template<typename _CharT, typename _Traits, typename _Alloc>
1556  basic_istream<_CharT, _Traits>&
1558  basic_string<_CharT, _Traits, _Alloc>& __str, _CharT __delim)
1559  {
1560  typedef basic_istream<_CharT, _Traits> __istream_type;
1561  typedef basic_string<_CharT, _Traits, _Alloc> __string_type;
1562  typedef typename __istream_type::ios_base __ios_base;
1563  typedef typename __istream_type::int_type __int_type;
1564  typedef typename __string_type::size_type __size_type;
1565 
1566  __size_type __extracted = 0;
1567  const __size_type __n = __str.max_size();
1568  typename __ios_base::iostate __err = __ios_base::goodbit;
1569  typename __istream_type::sentry __cerb(__in, true);
1570  if (__cerb)
1571  {
1572  __try
1573  {
1574  __str.erase();
1575  const __int_type __idelim = _Traits::to_int_type(__delim);
1576  const __int_type __eof = _Traits::eof();
1577  __int_type __c = __in.rdbuf()->sgetc();
1578 
1579  while (__extracted < __n
1580  && !_Traits::eq_int_type(__c, __eof)
1581  && !_Traits::eq_int_type(__c, __idelim))
1582  {
1583  __str += _Traits::to_char_type(__c);
1584  ++__extracted;
1585  __c = __in.rdbuf()->snextc();
1586  }
1587 
1588  if (_Traits::eq_int_type(__c, __eof))
1589  __err |= __ios_base::eofbit;
1590  else if (_Traits::eq_int_type(__c, __idelim))
1591  {
1592  ++__extracted;
1593  __in.rdbuf()->sbumpc();
1594  }
1595  else
1596  __err |= __ios_base::failbit;
1597  }
1598  __catch(__cxxabiv1::__forced_unwind&)
1599  {
1600  __in._M_setstate(__ios_base::badbit);
1601  __throw_exception_again;
1602  }
1603  __catch(...)
1604  {
1605  // _GLIBCXX_RESOLVE_LIB_DEFECTS
1606  // 91. Description of operator>> and getline() for string<>
1607  // might cause endless loop
1608  __in._M_setstate(__ios_base::badbit);
1609  }
1610  }
1611  if (!__extracted)
1612  __err |= __ios_base::failbit;
1613  if (__err)
1614  __in.setstate(__err);
1615  return __in;
1616  }
1617 
1618  // Inhibit implicit instantiations for required instantiations,
1619  // which are defined via explicit instantiations elsewhere.
1620 #if _GLIBCXX_EXTERN_TEMPLATE
1621  // The explicit instantiation definitions in src/c++11/string-inst.cc and
1622  // src/c++17/string-inst.cc only instantiate the members required for C++17
1623  // and earlier standards (so not C++20's starts_with and ends_with).
1624  // Suppress the explicit instantiation declarations for C++20, so C++20
1625  // code will implicitly instantiate std::string and std::wstring as needed.
1626 # if __cplusplus <= 201703L && _GLIBCXX_EXTERN_TEMPLATE > 0
1627  extern template class basic_string<char>;
1628 # elif ! _GLIBCXX_USE_CXX11_ABI
1629  // Still need to prevent implicit instantiation of the COW empty rep,
1630  // to ensure the definition in libstdc++.so is unique (PR 86138).
1631  extern template basic_string<char>::size_type
1632  basic_string<char>::_Rep::_S_empty_rep_storage[];
1633 # endif
1634 
1635  extern template
1636  basic_istream<char>&
1637  operator>>(basic_istream<char>&, string&);
1638  extern template
1639  basic_ostream<char>&
1640  operator<<(basic_ostream<char>&, const string&);
1641  extern template
1642  basic_istream<char>&
1643  getline(basic_istream<char>&, string&, char);
1644  extern template
1645  basic_istream<char>&
1646  getline(basic_istream<char>&, string&);
1647 
1648 #ifdef _GLIBCXX_USE_WCHAR_T
1649 # if __cplusplus <= 201703L && _GLIBCXX_EXTERN_TEMPLATE > 0
1650  extern template class basic_string<wchar_t>;
1651 # elif ! _GLIBCXX_USE_CXX11_ABI
1652  extern template basic_string<wchar_t>::size_type
1653  basic_string<wchar_t>::_Rep::_S_empty_rep_storage[];
1654 # endif
1655 
1656  extern template
1657  basic_istream<wchar_t>&
1658  operator>>(basic_istream<wchar_t>&, wstring&);
1659  extern template
1660  basic_ostream<wchar_t>&
1661  operator<<(basic_ostream<wchar_t>&, const wstring&);
1662  extern template
1663  basic_istream<wchar_t>&
1664  getline(basic_istream<wchar_t>&, wstring&, wchar_t);
1665  extern template
1666  basic_istream<wchar_t>&
1667  getline(basic_istream<wchar_t>&, wstring&);
1668 #endif // _GLIBCXX_USE_WCHAR_T
1669 #endif // _GLIBCXX_EXTERN_TEMPLATE
1670 
1671 _GLIBCXX_END_NAMESPACE_VERSION
1672 } // namespace std
1673 
1674 #endif
constexpr complex< _Tp > operator+(const complex< _Tp > &__x, const complex< _Tp > &__y)
Return new complex value x plus y.
Definition: complex:332
constexpr _Tp * __addressof(_Tp &__r) noexcept
Same as C++11 std::addressof.
Definition: move.h:49
_Tp * begin(valarray< _Tp > &__va)
Return an iterator pointing to the first element of the valarray.
Definition: valarray:1214
constexpr const _Tp & min(const _Tp &, const _Tp &)
This does what you think it does.
Definition: stl_algobase.h:230
basic_string< wchar_t > wstring
A string of wchar_t.
Definition: stringfwd.h:83
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:1472
ptrdiff_t streamsize
Integral type for I/O operation counts and buffer sizes.
Definition: postypes.h:68
std::basic_ostream< _CharT, _Traits > & operator<<(std::basic_ostream< _CharT, _Traits > &__os, const bitset< _Nb > &__x)
Global I/O operators for bitsets.
Definition: bitset:1540
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:245
constexpr auto data(_Container &__cont) noexcept(noexcept(__cont.data())) -> decltype(__cont.data())
Return the data pointer of a container.
Definition: range_access.h:290
basic_streambuf< _CharT, _Traits > * rdbuf() const
Accessing the underlying buffer.
Definition: basic_ios.h:321
void setstate(iostate __state)
Sets additional flags in the error state.
Definition: basic_ios.h:157
Template class basic_istream.
Definition: istream:59
Uniform interface to all allocator types.
Managing sequences of characters and character-like objects.
void swap(basic_string &__s) noexcept(/*conditional */)
Swap contents with another string.
size_type find_first_of(const basic_string &__str, size_type __pos=0) const noexcept
Find position of a character of string.
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.
int compare(const basic_string &__str) const
Compare to a string.
size_type find_first_not_of(const basic_string &__str, size_type __pos=0) const noexcept
Find position of a character not in string.
void insert(iterator __p, size_type __n, _CharT __c)
Insert multiple characters.
basic_string & assign(const basic_string &__str)
Set value to contents of another string.
basic_string & replace(size_type __pos, size_type __n, const basic_string &__str)
Replace characters with value from another string.
size_type copy(_CharT *__s, size_type __n, size_type __pos=0) const
Copy substring into C string.
size_type find_last_of(const basic_string &__str, size_type __pos=npos) const noexcept
Find last position of a character of string.
size_type size() const noexcept
Returns the number of characters in the string, not including any null-termination.
size_type rfind(const basic_string &__str, size_type __pos=npos) const noexcept
Find last position of a string.
void resize(size_type __n, _CharT __c)
Resizes the string to the specified number of characters.
void reserve()
Equivalent to shrink_to_fit().
const _CharT * data() const noexcept
Return const pointer to contents.
basic_string & append(const basic_string &__str)
Append a string to this string.
static const size_type npos
Value returned by various member functions when they fail.
allocator_type get_allocator() const noexcept
Return copy of allocator used to construct this string.
basic_string & erase(size_type __pos=0, size_type __n=npos)
Remove characters.
basic_string() noexcept
Default constructor creates an empty string.
size_type max_size() const noexcept
Returns the size() of the largest possible string.
Thrown as part of forced unwinding.
Definition: cxxabi_forced.h:49
streamsize width() const
Flags access.
Definition: ios_base.h:742
locale getloc() const
Locale access.
Definition: ios_base.h:793
Primary class template ctype facet.
Marking input iterators.
Forward iterators support a superset of input iterator operations.
Common iterator class.
Uniform interface to C++98 and C++11 allocators.