libstdc++
basic_string.h
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1 // Components for manipulating sequences of characters -*- C++ -*-
2 
3 // Copyright (C) 1997-2019 Free Software Foundation, Inc.
4 //
5 // This file is part of the GNU ISO C++ Library. This library is free
6 // software; you can redistribute it and/or modify it under the
7 // terms of the GNU General Public License as published by the
8 // Free Software Foundation; either version 3, or (at your option)
9 // any later version.
10 
11 // This library is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 // GNU General Public License for more details.
15 
16 // Under Section 7 of GPL version 3, you are granted additional
17 // permissions described in the GCC Runtime Library Exception, version
18 // 3.1, as published by the Free Software Foundation.
19 
20 // You should have received a copy of the GNU General Public License and
21 // a copy of the GCC Runtime Library Exception along with this program;
22 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23 // <http://www.gnu.org/licenses/>.
24 
25 /** @file bits/basic_string.h
26  * This is an internal header file, included by other library headers.
27  * Do not attempt to use it directly. @headername{string}
28  */
29 
30 //
31 // ISO C++ 14882: 21 Strings library
32 //
33 
34 #ifndef _BASIC_STRING_H
35 #define _BASIC_STRING_H 1
36 
37 #pragma GCC system_header
38 
39 #include <ext/atomicity.h>
40 #include <ext/alloc_traits.h>
41 #include <debug/debug.h>
42 
43 #if __cplusplus >= 201103L
44 #include <initializer_list>
45 #endif
46 
47 #if __cplusplus >= 201703L
48 # include <string_view>
49 #endif
50 
51 
52 namespace std _GLIBCXX_VISIBILITY(default)
53 {
54 _GLIBCXX_BEGIN_NAMESPACE_VERSION
55 
56 #if _GLIBCXX_USE_CXX11_ABI
57 _GLIBCXX_BEGIN_NAMESPACE_CXX11
58  /**
59  * @class basic_string basic_string.h <string>
60  * @brief Managing sequences of characters and character-like objects.
61  *
62  * @ingroup strings
63  * @ingroup sequences
64  *
65  * @tparam _CharT Type of character
66  * @tparam _Traits Traits for character type, defaults to
67  * char_traits<_CharT>.
68  * @tparam _Alloc Allocator type, defaults to allocator<_CharT>.
69  *
70  * Meets the requirements of a <a href="tables.html#65">container</a>, a
71  * <a href="tables.html#66">reversible container</a>, and a
72  * <a href="tables.html#67">sequence</a>. Of the
73  * <a href="tables.html#68">optional sequence requirements</a>, only
74  * @c push_back, @c at, and @c %array access are supported.
75  */
76  template<typename _CharT, typename _Traits, typename _Alloc>
77  class basic_string
78  {
80  rebind<_CharT>::other _Char_alloc_type;
81  typedef __gnu_cxx::__alloc_traits<_Char_alloc_type> _Alloc_traits;
82 
83  // Types:
84  public:
85  typedef _Traits traits_type;
86  typedef typename _Traits::char_type value_type;
87  typedef _Char_alloc_type allocator_type;
88  typedef typename _Alloc_traits::size_type size_type;
89  typedef typename _Alloc_traits::difference_type difference_type;
90  typedef typename _Alloc_traits::reference reference;
91  typedef typename _Alloc_traits::const_reference const_reference;
92  typedef typename _Alloc_traits::pointer pointer;
93  typedef typename _Alloc_traits::const_pointer const_pointer;
94  typedef __gnu_cxx::__normal_iterator<pointer, basic_string> iterator;
95  typedef __gnu_cxx::__normal_iterator<const_pointer, basic_string>
96  const_iterator;
97  typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
98  typedef std::reverse_iterator<iterator> reverse_iterator;
99 
100  /// Value returned by various member functions when they fail.
101  static const size_type npos = static_cast<size_type>(-1);
102 
103  protected:
104  // type used for positions in insert, erase etc.
105 #if __cplusplus < 201103L
106  typedef iterator __const_iterator;
107 #else
108  typedef const_iterator __const_iterator;
109 #endif
110 
111  private:
112 #if __cplusplus >= 201703L
113  // A helper type for avoiding boiler-plate.
114  typedef basic_string_view<_CharT, _Traits> __sv_type;
115 
116  template<typename _Tp, typename _Res>
117  using _If_sv = enable_if_t<
118  __and_<is_convertible<const _Tp&, __sv_type>,
119  __not_<is_convertible<const _Tp*, const basic_string*>>,
120  __not_<is_convertible<const _Tp&, const _CharT*>>>::value,
121  _Res>;
122 
123  // Allows an implicit conversion to __sv_type.
124  static __sv_type
125  _S_to_string_view(__sv_type __svt) noexcept
126  { return __svt; }
127 
128  // Wraps a string_view by explicit conversion and thus
129  // allows to add an internal constructor that does not
130  // participate in overload resolution when a string_view
131  // is provided.
132  struct __sv_wrapper
133  {
134  explicit __sv_wrapper(__sv_type __sv) noexcept : _M_sv(__sv) { }
135  __sv_type _M_sv;
136  };
137 
138  /**
139  * @brief Only internally used: Construct string from a string view
140  * wrapper.
141  * @param __svw string view wrapper.
142  * @param __a Allocator to use.
143  */
144  explicit
145  basic_string(__sv_wrapper __svw, const _Alloc& __a)
146  : basic_string(__svw._M_sv.data(), __svw._M_sv.size(), __a) { }
147 #endif
148 
149  // Use empty-base optimization: http://www.cantrip.org/emptyopt.html
150  struct _Alloc_hider : allocator_type // TODO check __is_final
151  {
152 #if __cplusplus < 201103L
153  _Alloc_hider(pointer __dat, const _Alloc& __a = _Alloc())
154  : allocator_type(__a), _M_p(__dat) { }
155 #else
156  _Alloc_hider(pointer __dat, const _Alloc& __a)
157  : allocator_type(__a), _M_p(__dat) { }
158 
159  _Alloc_hider(pointer __dat, _Alloc&& __a = _Alloc())
160  : allocator_type(std::move(__a)), _M_p(__dat) { }
161 #endif
162 
163  pointer _M_p; // The actual data.
164  };
165 
166  _Alloc_hider _M_dataplus;
167  size_type _M_string_length;
168 
169  enum { _S_local_capacity = 15 / sizeof(_CharT) };
170 
171  union
172  {
173  _CharT _M_local_buf[_S_local_capacity + 1];
174  size_type _M_allocated_capacity;
175  };
176 
177  void
178  _M_data(pointer __p)
179  { _M_dataplus._M_p = __p; }
180 
181  void
182  _M_length(size_type __length)
183  { _M_string_length = __length; }
184 
185  pointer
186  _M_data() const
187  { return _M_dataplus._M_p; }
188 
189  pointer
190  _M_local_data()
191  {
192 #if __cplusplus >= 201103L
193  return std::pointer_traits<pointer>::pointer_to(*_M_local_buf);
194 #else
195  return pointer(_M_local_buf);
196 #endif
197  }
198 
199  const_pointer
200  _M_local_data() const
201  {
202 #if __cplusplus >= 201103L
204 #else
205  return const_pointer(_M_local_buf);
206 #endif
207  }
208 
209  void
210  _M_capacity(size_type __capacity)
211  { _M_allocated_capacity = __capacity; }
212 
213  void
214  _M_set_length(size_type __n)
215  {
216  _M_length(__n);
217  traits_type::assign(_M_data()[__n], _CharT());
218  }
219 
220  bool
221  _M_is_local() const
222  { return _M_data() == _M_local_data(); }
223 
224  // Create & Destroy
225  pointer
226  _M_create(size_type&, size_type);
227 
228  void
229  _M_dispose()
230  {
231  if (!_M_is_local())
232  _M_destroy(_M_allocated_capacity);
233  }
234 
235  void
236  _M_destroy(size_type __size) throw()
237  { _Alloc_traits::deallocate(_M_get_allocator(), _M_data(), __size + 1); }
238 
239  // _M_construct_aux is used to implement the 21.3.1 para 15 which
240  // requires special behaviour if _InIterator is an integral type
241  template<typename _InIterator>
242  void
243  _M_construct_aux(_InIterator __beg, _InIterator __end,
244  std::__false_type)
245  {
246  typedef typename iterator_traits<_InIterator>::iterator_category _Tag;
247  _M_construct(__beg, __end, _Tag());
248  }
249 
250  // _GLIBCXX_RESOLVE_LIB_DEFECTS
251  // 438. Ambiguity in the "do the right thing" clause
252  template<typename _Integer>
253  void
254  _M_construct_aux(_Integer __beg, _Integer __end, std::__true_type)
255  { _M_construct_aux_2(static_cast<size_type>(__beg), __end); }
256 
257  void
258  _M_construct_aux_2(size_type __req, _CharT __c)
259  { _M_construct(__req, __c); }
260 
261  template<typename _InIterator>
262  void
263  _M_construct(_InIterator __beg, _InIterator __end)
264  {
265  typedef typename std::__is_integer<_InIterator>::__type _Integral;
266  _M_construct_aux(__beg, __end, _Integral());
267  }
268 
269  // For Input Iterators, used in istreambuf_iterators, etc.
270  template<typename _InIterator>
271  void
272  _M_construct(_InIterator __beg, _InIterator __end,
274 
275  // For forward_iterators up to random_access_iterators, used for
276  // string::iterator, _CharT*, etc.
277  template<typename _FwdIterator>
278  void
279  _M_construct(_FwdIterator __beg, _FwdIterator __end,
281 
282  void
283  _M_construct(size_type __req, _CharT __c);
284 
285  allocator_type&
286  _M_get_allocator()
287  { return _M_dataplus; }
288 
289  const allocator_type&
290  _M_get_allocator() const
291  { return _M_dataplus; }
292 
293  private:
294 
295 #ifdef _GLIBCXX_DISAMBIGUATE_REPLACE_INST
296  // The explicit instantiations in misc-inst.cc require this due to
297  // https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64063
298  template<typename _Tp, bool _Requires =
299  !__are_same<_Tp, _CharT*>::__value
300  && !__are_same<_Tp, const _CharT*>::__value
301  && !__are_same<_Tp, iterator>::__value
302  && !__are_same<_Tp, const_iterator>::__value>
303  struct __enable_if_not_native_iterator
304  { typedef basic_string& __type; };
305  template<typename _Tp>
306  struct __enable_if_not_native_iterator<_Tp, false> { };
307 #endif
308 
309  size_type
310  _M_check(size_type __pos, const char* __s) const
311  {
312  if (__pos > this->size())
313  __throw_out_of_range_fmt(__N("%s: __pos (which is %zu) > "
314  "this->size() (which is %zu)"),
315  __s, __pos, this->size());
316  return __pos;
317  }
318 
319  void
320  _M_check_length(size_type __n1, size_type __n2, const char* __s) const
321  {
322  if (this->max_size() - (this->size() - __n1) < __n2)
323  __throw_length_error(__N(__s));
324  }
325 
326 
327  // NB: _M_limit doesn't check for a bad __pos value.
328  size_type
329  _M_limit(size_type __pos, size_type __off) const _GLIBCXX_NOEXCEPT
330  {
331  const bool __testoff = __off < this->size() - __pos;
332  return __testoff ? __off : this->size() - __pos;
333  }
334 
335  // True if _Rep and source do not overlap.
336  bool
337  _M_disjunct(const _CharT* __s) const _GLIBCXX_NOEXCEPT
338  {
339  return (less<const _CharT*>()(__s, _M_data())
340  || less<const _CharT*>()(_M_data() + this->size(), __s));
341  }
342 
343  // When __n = 1 way faster than the general multichar
344  // traits_type::copy/move/assign.
345  static void
346  _S_copy(_CharT* __d, const _CharT* __s, size_type __n)
347  {
348  if (__n == 1)
349  traits_type::assign(*__d, *__s);
350  else
351  traits_type::copy(__d, __s, __n);
352  }
353 
354  static void
355  _S_move(_CharT* __d, const _CharT* __s, size_type __n)
356  {
357  if (__n == 1)
358  traits_type::assign(*__d, *__s);
359  else
360  traits_type::move(__d, __s, __n);
361  }
362 
363  static void
364  _S_assign(_CharT* __d, size_type __n, _CharT __c)
365  {
366  if (__n == 1)
367  traits_type::assign(*__d, __c);
368  else
369  traits_type::assign(__d, __n, __c);
370  }
371 
372  // _S_copy_chars is a separate template to permit specialization
373  // to optimize for the common case of pointers as iterators.
374  template<class _Iterator>
375  static void
376  _S_copy_chars(_CharT* __p, _Iterator __k1, _Iterator __k2)
377  {
378  for (; __k1 != __k2; ++__k1, (void)++__p)
379  traits_type::assign(*__p, *__k1); // These types are off.
380  }
381 
382  static void
383  _S_copy_chars(_CharT* __p, iterator __k1, iterator __k2) _GLIBCXX_NOEXCEPT
384  { _S_copy_chars(__p, __k1.base(), __k2.base()); }
385 
386  static void
387  _S_copy_chars(_CharT* __p, const_iterator __k1, const_iterator __k2)
388  _GLIBCXX_NOEXCEPT
389  { _S_copy_chars(__p, __k1.base(), __k2.base()); }
390 
391  static void
392  _S_copy_chars(_CharT* __p, _CharT* __k1, _CharT* __k2) _GLIBCXX_NOEXCEPT
393  { _S_copy(__p, __k1, __k2 - __k1); }
394 
395  static void
396  _S_copy_chars(_CharT* __p, const _CharT* __k1, const _CharT* __k2)
397  _GLIBCXX_NOEXCEPT
398  { _S_copy(__p, __k1, __k2 - __k1); }
399 
400  static int
401  _S_compare(size_type __n1, size_type __n2) _GLIBCXX_NOEXCEPT
402  {
403  const difference_type __d = difference_type(__n1 - __n2);
404 
405  if (__d > __gnu_cxx::__numeric_traits<int>::__max)
406  return __gnu_cxx::__numeric_traits<int>::__max;
407  else if (__d < __gnu_cxx::__numeric_traits<int>::__min)
408  return __gnu_cxx::__numeric_traits<int>::__min;
409  else
410  return int(__d);
411  }
412 
413  void
414  _M_assign(const basic_string&);
415 
416  void
417  _M_mutate(size_type __pos, size_type __len1, const _CharT* __s,
418  size_type __len2);
419 
420  void
421  _M_erase(size_type __pos, size_type __n);
422 
423  public:
424  // Construct/copy/destroy:
425  // NB: We overload ctors in some cases instead of using default
426  // arguments, per 17.4.4.4 para. 2 item 2.
427 
428  /**
429  * @brief Default constructor creates an empty string.
430  */
431  basic_string()
432  _GLIBCXX_NOEXCEPT_IF(is_nothrow_default_constructible<_Alloc>::value)
433  : _M_dataplus(_M_local_data())
434  { _M_set_length(0); }
435 
436  /**
437  * @brief Construct an empty string using allocator @a a.
438  */
439  explicit
440  basic_string(const _Alloc& __a) _GLIBCXX_NOEXCEPT
441  : _M_dataplus(_M_local_data(), __a)
442  { _M_set_length(0); }
443 
444  /**
445  * @brief Construct string with copy of value of @a __str.
446  * @param __str Source string.
447  */
448  basic_string(const basic_string& __str)
449  : _M_dataplus(_M_local_data(),
450  _Alloc_traits::_S_select_on_copy(__str._M_get_allocator()))
451  { _M_construct(__str._M_data(), __str._M_data() + __str.length()); }
452 
453  // _GLIBCXX_RESOLVE_LIB_DEFECTS
454  // 2583. no way to supply an allocator for basic_string(str, pos)
455  /**
456  * @brief Construct string as copy of a substring.
457  * @param __str Source string.
458  * @param __pos Index of first character to copy from.
459  * @param __a Allocator to use.
460  */
461  basic_string(const basic_string& __str, size_type __pos,
462  const _Alloc& __a = _Alloc())
463  : _M_dataplus(_M_local_data(), __a)
464  {
465  const _CharT* __start = __str._M_data()
466  + __str._M_check(__pos, "basic_string::basic_string");
467  _M_construct(__start, __start + __str._M_limit(__pos, npos));
468  }
469 
470  /**
471  * @brief Construct string as copy of a substring.
472  * @param __str Source string.
473  * @param __pos Index of first character to copy from.
474  * @param __n Number of characters to copy.
475  */
476  basic_string(const basic_string& __str, size_type __pos,
477  size_type __n)
478  : _M_dataplus(_M_local_data())
479  {
480  const _CharT* __start = __str._M_data()
481  + __str._M_check(__pos, "basic_string::basic_string");
482  _M_construct(__start, __start + __str._M_limit(__pos, __n));
483  }
484 
485  /**
486  * @brief Construct string as copy of a substring.
487  * @param __str Source string.
488  * @param __pos Index of first character to copy from.
489  * @param __n Number of characters to copy.
490  * @param __a Allocator to use.
491  */
492  basic_string(const basic_string& __str, size_type __pos,
493  size_type __n, const _Alloc& __a)
494  : _M_dataplus(_M_local_data(), __a)
495  {
496  const _CharT* __start
497  = __str._M_data() + __str._M_check(__pos, "string::string");
498  _M_construct(__start, __start + __str._M_limit(__pos, __n));
499  }
500 
501  /**
502  * @brief Construct string initialized by a character %array.
503  * @param __s Source character %array.
504  * @param __n Number of characters to copy.
505  * @param __a Allocator to use (default is default allocator).
506  *
507  * NB: @a __s must have at least @a __n characters, &apos;\\0&apos;
508  * has no special meaning.
509  */
510  basic_string(const _CharT* __s, size_type __n,
511  const _Alloc& __a = _Alloc())
512  : _M_dataplus(_M_local_data(), __a)
513  { _M_construct(__s, __s + __n); }
514 
515  /**
516  * @brief Construct string as copy of a C string.
517  * @param __s Source C string.
518  * @param __a Allocator to use (default is default allocator).
519  */
520 #if __cpp_deduction_guides && ! defined _GLIBCXX_DEFINING_STRING_INSTANTIATIONS
521  // _GLIBCXX_RESOLVE_LIB_DEFECTS
522  // 3076. basic_string CTAD ambiguity
523  template<typename = _RequireAllocator<_Alloc>>
524 #endif
525  basic_string(const _CharT* __s, const _Alloc& __a = _Alloc())
526  : _M_dataplus(_M_local_data(), __a)
527  { _M_construct(__s, __s ? __s + traits_type::length(__s) : __s+npos); }
528 
529  /**
530  * @brief Construct string as multiple characters.
531  * @param __n Number of characters.
532  * @param __c Character to use.
533  * @param __a Allocator to use (default is default allocator).
534  */
535 #if __cpp_deduction_guides && ! defined _GLIBCXX_DEFINING_STRING_INSTANTIATIONS
536  // _GLIBCXX_RESOLVE_LIB_DEFECTS
537  // 3076. basic_string CTAD ambiguity
538  template<typename = _RequireAllocator<_Alloc>>
539 #endif
540  basic_string(size_type __n, _CharT __c, const _Alloc& __a = _Alloc())
541  : _M_dataplus(_M_local_data(), __a)
542  { _M_construct(__n, __c); }
543 
544 #if __cplusplus >= 201103L
545  /**
546  * @brief Move construct string.
547  * @param __str Source string.
548  *
549  * The newly-created string contains the exact contents of @a __str.
550  * @a __str is a valid, but unspecified string.
551  **/
552  basic_string(basic_string&& __str) noexcept
553  : _M_dataplus(_M_local_data(), std::move(__str._M_get_allocator()))
554  {
555  if (__str._M_is_local())
556  {
557  traits_type::copy(_M_local_buf, __str._M_local_buf,
558  _S_local_capacity + 1);
559  }
560  else
561  {
562  _M_data(__str._M_data());
563  _M_capacity(__str._M_allocated_capacity);
564  }
565 
566  // Must use _M_length() here not _M_set_length() because
567  // basic_stringbuf relies on writing into unallocated capacity so
568  // we mess up the contents if we put a '\0' in the string.
569  _M_length(__str.length());
570  __str._M_data(__str._M_local_data());
571  __str._M_set_length(0);
572  }
573 
574  /**
575  * @brief Construct string from an initializer %list.
576  * @param __l std::initializer_list of characters.
577  * @param __a Allocator to use (default is default allocator).
578  */
579  basic_string(initializer_list<_CharT> __l, const _Alloc& __a = _Alloc())
580  : _M_dataplus(_M_local_data(), __a)
581  { _M_construct(__l.begin(), __l.end()); }
582 
583  basic_string(const basic_string& __str, const _Alloc& __a)
584  : _M_dataplus(_M_local_data(), __a)
585  { _M_construct(__str.begin(), __str.end()); }
586 
587  basic_string(basic_string&& __str, const _Alloc& __a)
588  noexcept(_Alloc_traits::_S_always_equal())
589  : _M_dataplus(_M_local_data(), __a)
590  {
591  if (__str._M_is_local())
592  {
593  traits_type::copy(_M_local_buf, __str._M_local_buf,
594  _S_local_capacity + 1);
595  _M_length(__str.length());
596  __str._M_set_length(0);
597  }
598  else if (_Alloc_traits::_S_always_equal()
599  || __str.get_allocator() == __a)
600  {
601  _M_data(__str._M_data());
602  _M_length(__str.length());
603  _M_capacity(__str._M_allocated_capacity);
604  __str._M_data(__str._M_local_buf);
605  __str._M_set_length(0);
606  }
607  else
608  _M_construct(__str.begin(), __str.end());
609  }
610 
611 #endif // C++11
612 
613  /**
614  * @brief Construct string as copy of a range.
615  * @param __beg Start of range.
616  * @param __end End of range.
617  * @param __a Allocator to use (default is default allocator).
618  */
619 #if __cplusplus >= 201103L
620  template<typename _InputIterator,
621  typename = std::_RequireInputIter<_InputIterator>>
622 #else
623  template<typename _InputIterator>
624 #endif
625  basic_string(_InputIterator __beg, _InputIterator __end,
626  const _Alloc& __a = _Alloc())
627  : _M_dataplus(_M_local_data(), __a)
628  { _M_construct(__beg, __end); }
629 
630 #if __cplusplus >= 201703L
631  /**
632  * @brief Construct string from a substring of a string_view.
633  * @param __t Source object convertible to string view.
634  * @param __pos The index of the first character to copy from __t.
635  * @param __n The number of characters to copy from __t.
636  * @param __a Allocator to use.
637  */
638  template<typename _Tp, typename = _If_sv<_Tp, void>>
639  basic_string(const _Tp& __t, size_type __pos, size_type __n,
640  const _Alloc& __a = _Alloc())
641  : basic_string(_S_to_string_view(__t).substr(__pos, __n), __a) { }
642 
643  /**
644  * @brief Construct string from a string_view.
645  * @param __t Source object convertible to string view.
646  * @param __a Allocator to use (default is default allocator).
647  */
648  template<typename _Tp, typename = _If_sv<_Tp, void>>
649  explicit
650  basic_string(const _Tp& __t, const _Alloc& __a = _Alloc())
651  : basic_string(__sv_wrapper(_S_to_string_view(__t)), __a) { }
652 #endif // C++17
653 
654  /**
655  * @brief Destroy the string instance.
656  */
657  ~basic_string()
658  { _M_dispose(); }
659 
660  /**
661  * @brief Assign the value of @a str to this string.
662  * @param __str Source string.
663  */
664  basic_string&
665  operator=(const basic_string& __str)
666  {
667 #if __cplusplus >= 201103L
668  if (_Alloc_traits::_S_propagate_on_copy_assign())
669  {
670  if (!_Alloc_traits::_S_always_equal() && !_M_is_local()
671  && _M_get_allocator() != __str._M_get_allocator())
672  {
673  // Propagating allocator cannot free existing storage so must
674  // deallocate it before replacing current allocator.
675  if (__str.size() <= _S_local_capacity)
676  {
677  _M_destroy(_M_allocated_capacity);
678  _M_data(_M_local_data());
679  _M_set_length(0);
680  }
681  else
682  {
683  const auto __len = __str.size();
684  auto __alloc = __str._M_get_allocator();
685  // If this allocation throws there are no effects:
686  auto __ptr = _Alloc_traits::allocate(__alloc, __len + 1);
687  _M_destroy(_M_allocated_capacity);
688  _M_data(__ptr);
689  _M_capacity(__len);
690  _M_set_length(__len);
691  }
692  }
693  std::__alloc_on_copy(_M_get_allocator(), __str._M_get_allocator());
694  }
695 #endif
696  return this->assign(__str);
697  }
698 
699  /**
700  * @brief Copy contents of @a s into this string.
701  * @param __s Source null-terminated string.
702  */
703  basic_string&
704  operator=(const _CharT* __s)
705  { return this->assign(__s); }
706 
707  /**
708  * @brief Set value to string of length 1.
709  * @param __c Source character.
710  *
711  * Assigning to a character makes this string length 1 and
712  * (*this)[0] == @a c.
713  */
714  basic_string&
715  operator=(_CharT __c)
716  {
717  this->assign(1, __c);
718  return *this;
719  }
720 
721 #if __cplusplus >= 201103L
722  /**
723  * @brief Move assign the value of @a str to this string.
724  * @param __str Source string.
725  *
726  * The contents of @a str are moved into this string (without copying).
727  * @a str is a valid, but unspecified string.
728  **/
729  // _GLIBCXX_RESOLVE_LIB_DEFECTS
730  // 2063. Contradictory requirements for string move assignment
731  basic_string&
732  operator=(basic_string&& __str)
733  noexcept(_Alloc_traits::_S_nothrow_move())
734  {
735  if (!_M_is_local() && _Alloc_traits::_S_propagate_on_move_assign()
736  && !_Alloc_traits::_S_always_equal()
737  && _M_get_allocator() != __str._M_get_allocator())
738  {
739  // Destroy existing storage before replacing allocator.
740  _M_destroy(_M_allocated_capacity);
741  _M_data(_M_local_data());
742  _M_set_length(0);
743  }
744  // Replace allocator if POCMA is true.
745  std::__alloc_on_move(_M_get_allocator(), __str._M_get_allocator());
746 
747  if (__str._M_is_local())
748  {
749  // We've always got room for a short string, just copy it.
750  if (__str.size())
751  this->_S_copy(_M_data(), __str._M_data(), __str.size());
752  _M_set_length(__str.size());
753  }
754  else if (_Alloc_traits::_S_propagate_on_move_assign()
755  || _Alloc_traits::_S_always_equal()
756  || _M_get_allocator() == __str._M_get_allocator())
757  {
758  // Just move the allocated pointer, our allocator can free it.
759  pointer __data = nullptr;
760  size_type __capacity;
761  if (!_M_is_local())
762  {
763  if (_Alloc_traits::_S_always_equal())
764  {
765  // __str can reuse our existing storage.
766  __data = _M_data();
767  __capacity = _M_allocated_capacity;
768  }
769  else // __str can't use it, so free it.
770  _M_destroy(_M_allocated_capacity);
771  }
772 
773  _M_data(__str._M_data());
774  _M_length(__str.length());
775  _M_capacity(__str._M_allocated_capacity);
776  if (__data)
777  {
778  __str._M_data(__data);
779  __str._M_capacity(__capacity);
780  }
781  else
782  __str._M_data(__str._M_local_buf);
783  }
784  else // Need to do a deep copy
785  assign(__str);
786  __str.clear();
787  return *this;
788  }
789 
790  /**
791  * @brief Set value to string constructed from initializer %list.
792  * @param __l std::initializer_list.
793  */
794  basic_string&
795  operator=(initializer_list<_CharT> __l)
796  {
797  this->assign(__l.begin(), __l.size());
798  return *this;
799  }
800 #endif // C++11
801 
802 #if __cplusplus >= 201703L
803  /**
804  * @brief Set value to string constructed from a string_view.
805  * @param __svt An object convertible to string_view.
806  */
807  template<typename _Tp>
808  _If_sv<_Tp, basic_string&>
809  operator=(const _Tp& __svt)
810  { return this->assign(__svt); }
811 
812  /**
813  * @brief Convert to a string_view.
814  * @return A string_view.
815  */
816  operator __sv_type() const noexcept
817  { return __sv_type(data(), size()); }
818 #endif // C++17
819 
820  // Iterators:
821  /**
822  * Returns a read/write iterator that points to the first character in
823  * the %string.
824  */
825  iterator
826  begin() _GLIBCXX_NOEXCEPT
827  { return iterator(_M_data()); }
828 
829  /**
830  * Returns a read-only (constant) iterator that points to the first
831  * character in the %string.
832  */
833  const_iterator
834  begin() const _GLIBCXX_NOEXCEPT
835  { return const_iterator(_M_data()); }
836 
837  /**
838  * Returns a read/write iterator that points one past the last
839  * character in the %string.
840  */
841  iterator
842  end() _GLIBCXX_NOEXCEPT
843  { return iterator(_M_data() + this->size()); }
844 
845  /**
846  * Returns a read-only (constant) iterator that points one past the
847  * last character in the %string.
848  */
849  const_iterator
850  end() const _GLIBCXX_NOEXCEPT
851  { return const_iterator(_M_data() + this->size()); }
852 
853  /**
854  * Returns a read/write reverse iterator that points to the last
855  * character in the %string. Iteration is done in reverse element
856  * order.
857  */
858  reverse_iterator
859  rbegin() _GLIBCXX_NOEXCEPT
860  { return reverse_iterator(this->end()); }
861 
862  /**
863  * Returns a read-only (constant) reverse iterator that points
864  * to the last character in the %string. Iteration is done in
865  * reverse element order.
866  */
867  const_reverse_iterator
868  rbegin() const _GLIBCXX_NOEXCEPT
869  { return const_reverse_iterator(this->end()); }
870 
871  /**
872  * Returns a read/write reverse iterator that points to one before the
873  * first character in the %string. Iteration is done in reverse
874  * element order.
875  */
876  reverse_iterator
877  rend() _GLIBCXX_NOEXCEPT
878  { return reverse_iterator(this->begin()); }
879 
880  /**
881  * Returns a read-only (constant) reverse iterator that points
882  * to one before the first character in the %string. Iteration
883  * is done in reverse element order.
884  */
885  const_reverse_iterator
886  rend() const _GLIBCXX_NOEXCEPT
887  { return const_reverse_iterator(this->begin()); }
888 
889 #if __cplusplus >= 201103L
890  /**
891  * Returns a read-only (constant) iterator that points to the first
892  * character in the %string.
893  */
894  const_iterator
895  cbegin() const noexcept
896  { return const_iterator(this->_M_data()); }
897 
898  /**
899  * Returns a read-only (constant) iterator that points one past the
900  * last character in the %string.
901  */
902  const_iterator
903  cend() const noexcept
904  { return const_iterator(this->_M_data() + this->size()); }
905 
906  /**
907  * Returns a read-only (constant) reverse iterator that points
908  * to the last character in the %string. Iteration is done in
909  * reverse element order.
910  */
911  const_reverse_iterator
912  crbegin() const noexcept
913  { return const_reverse_iterator(this->end()); }
914 
915  /**
916  * Returns a read-only (constant) reverse iterator that points
917  * to one before the first character in the %string. Iteration
918  * is done in reverse element order.
919  */
920  const_reverse_iterator
921  crend() const noexcept
922  { return const_reverse_iterator(this->begin()); }
923 #endif
924 
925  public:
926  // Capacity:
927  /// Returns the number of characters in the string, not including any
928  /// null-termination.
929  size_type
930  size() const _GLIBCXX_NOEXCEPT
931  { return _M_string_length; }
932 
933  /// Returns the number of characters in the string, not including any
934  /// null-termination.
935  size_type
936  length() const _GLIBCXX_NOEXCEPT
937  { return _M_string_length; }
938 
939  /// Returns the size() of the largest possible %string.
940  size_type
941  max_size() const _GLIBCXX_NOEXCEPT
942  { return (_Alloc_traits::max_size(_M_get_allocator()) - 1) / 2; }
943 
944  /**
945  * @brief Resizes the %string to the specified number of characters.
946  * @param __n Number of characters the %string should contain.
947  * @param __c Character to fill any new elements.
948  *
949  * This function will %resize the %string to the specified
950  * number of characters. If the number is smaller than the
951  * %string's current size the %string is truncated, otherwise
952  * the %string is extended and new elements are %set to @a __c.
953  */
954  void
955  resize(size_type __n, _CharT __c);
956 
957  /**
958  * @brief Resizes the %string to the specified number of characters.
959  * @param __n Number of characters the %string should contain.
960  *
961  * This function will resize the %string to the specified length. If
962  * the new size is smaller than the %string's current size the %string
963  * is truncated, otherwise the %string is extended and new characters
964  * are default-constructed. For basic types such as char, this means
965  * setting them to 0.
966  */
967  void
968  resize(size_type __n)
969  { this->resize(__n, _CharT()); }
970 
971 #if __cplusplus >= 201103L
972  /// A non-binding request to reduce capacity() to size().
973  void
974  shrink_to_fit() noexcept
975  {
976 #if __cpp_exceptions
977  if (capacity() > size())
978  {
979  try
980  { reserve(0); }
981  catch(...)
982  { }
983  }
984 #endif
985  }
986 #endif
987 
988  /**
989  * Returns the total number of characters that the %string can hold
990  * before needing to allocate more memory.
991  */
992  size_type
993  capacity() const _GLIBCXX_NOEXCEPT
994  {
995  return _M_is_local() ? size_type(_S_local_capacity)
996  : _M_allocated_capacity;
997  }
998 
999  /**
1000  * @brief Attempt to preallocate enough memory for specified number of
1001  * characters.
1002  * @param __res_arg Number of characters required.
1003  * @throw std::length_error If @a __res_arg exceeds @c max_size().
1004  *
1005  * This function attempts to reserve enough memory for the
1006  * %string to hold the specified number of characters. If the
1007  * number requested is more than max_size(), length_error is
1008  * thrown.
1009  *
1010  * The advantage of this function is that if optimal code is a
1011  * necessity and the user can determine the string length that will be
1012  * required, the user can reserve the memory in %advance, and thus
1013  * prevent a possible reallocation of memory and copying of %string
1014  * data.
1015  */
1016  void
1017  reserve(size_type __res_arg = 0);
1018 
1019  /**
1020  * Erases the string, making it empty.
1021  */
1022  void
1023  clear() _GLIBCXX_NOEXCEPT
1024  { _M_set_length(0); }
1025 
1026  /**
1027  * Returns true if the %string is empty. Equivalent to
1028  * <code>*this == ""</code>.
1029  */
1030  _GLIBCXX_NODISCARD bool
1031  empty() const _GLIBCXX_NOEXCEPT
1032  { return this->size() == 0; }
1033 
1034  // Element access:
1035  /**
1036  * @brief Subscript access to the data contained in the %string.
1037  * @param __pos The index of the character to access.
1038  * @return Read-only (constant) reference to the character.
1039  *
1040  * This operator allows for easy, array-style, data access.
1041  * Note that data access with this operator is unchecked and
1042  * out_of_range lookups are not defined. (For checked lookups
1043  * see at().)
1044  */
1045  const_reference
1046  operator[] (size_type __pos) const _GLIBCXX_NOEXCEPT
1047  {
1048  __glibcxx_assert(__pos <= size());
1049  return _M_data()[__pos];
1050  }
1051 
1052  /**
1053  * @brief Subscript access to the data contained in the %string.
1054  * @param __pos The index of the character to access.
1055  * @return Read/write reference to the character.
1056  *
1057  * This operator allows for easy, array-style, data access.
1058  * Note that data access with this operator is unchecked and
1059  * out_of_range lookups are not defined. (For checked lookups
1060  * see at().)
1061  */
1062  reference
1063  operator[](size_type __pos)
1064  {
1065  // Allow pos == size() both in C++98 mode, as v3 extension,
1066  // and in C++11 mode.
1067  __glibcxx_assert(__pos <= size());
1068  // In pedantic mode be strict in C++98 mode.
1069  _GLIBCXX_DEBUG_PEDASSERT(__cplusplus >= 201103L || __pos < size());
1070  return _M_data()[__pos];
1071  }
1072 
1073  /**
1074  * @brief Provides access to the data contained in the %string.
1075  * @param __n The index of the character to access.
1076  * @return Read-only (const) reference to the character.
1077  * @throw std::out_of_range If @a n is an invalid index.
1078  *
1079  * This function provides for safer data access. The parameter is
1080  * first checked that it is in the range of the string. The function
1081  * throws out_of_range if the check fails.
1082  */
1083  const_reference
1084  at(size_type __n) const
1085  {
1086  if (__n >= this->size())
1087  __throw_out_of_range_fmt(__N("basic_string::at: __n "
1088  "(which is %zu) >= this->size() "
1089  "(which is %zu)"),
1090  __n, this->size());
1091  return _M_data()[__n];
1092  }
1093 
1094  /**
1095  * @brief Provides access to the data contained in the %string.
1096  * @param __n The index of the character to access.
1097  * @return Read/write reference to the character.
1098  * @throw std::out_of_range If @a n is an invalid index.
1099  *
1100  * This function provides for safer data access. The parameter is
1101  * first checked that it is in the range of the string. The function
1102  * throws out_of_range if the check fails.
1103  */
1104  reference
1105  at(size_type __n)
1106  {
1107  if (__n >= size())
1108  __throw_out_of_range_fmt(__N("basic_string::at: __n "
1109  "(which is %zu) >= this->size() "
1110  "(which is %zu)"),
1111  __n, this->size());
1112  return _M_data()[__n];
1113  }
1114 
1115 #if __cplusplus >= 201103L
1116  /**
1117  * Returns a read/write reference to the data at the first
1118  * element of the %string.
1119  */
1120  reference
1121  front() noexcept
1122  {
1123  __glibcxx_assert(!empty());
1124  return operator[](0);
1125  }
1126 
1127  /**
1128  * Returns a read-only (constant) reference to the data at the first
1129  * element of the %string.
1130  */
1131  const_reference
1132  front() const noexcept
1133  {
1134  __glibcxx_assert(!empty());
1135  return operator[](0);
1136  }
1137 
1138  /**
1139  * Returns a read/write reference to the data at the last
1140  * element of the %string.
1141  */
1142  reference
1143  back() noexcept
1144  {
1145  __glibcxx_assert(!empty());
1146  return operator[](this->size() - 1);
1147  }
1148 
1149  /**
1150  * Returns a read-only (constant) reference to the data at the
1151  * last element of the %string.
1152  */
1153  const_reference
1154  back() const noexcept
1155  {
1156  __glibcxx_assert(!empty());
1157  return operator[](this->size() - 1);
1158  }
1159 #endif
1160 
1161  // Modifiers:
1162  /**
1163  * @brief Append a string to this string.
1164  * @param __str The string to append.
1165  * @return Reference to this string.
1166  */
1167  basic_string&
1168  operator+=(const basic_string& __str)
1169  { return this->append(__str); }
1170 
1171  /**
1172  * @brief Append a C string.
1173  * @param __s The C string to append.
1174  * @return Reference to this string.
1175  */
1176  basic_string&
1177  operator+=(const _CharT* __s)
1178  { return this->append(__s); }
1179 
1180  /**
1181  * @brief Append a character.
1182  * @param __c The character to append.
1183  * @return Reference to this string.
1184  */
1185  basic_string&
1186  operator+=(_CharT __c)
1187  {
1188  this->push_back(__c);
1189  return *this;
1190  }
1191 
1192 #if __cplusplus >= 201103L
1193  /**
1194  * @brief Append an initializer_list of characters.
1195  * @param __l The initializer_list of characters to be appended.
1196  * @return Reference to this string.
1197  */
1198  basic_string&
1199  operator+=(initializer_list<_CharT> __l)
1200  { return this->append(__l.begin(), __l.size()); }
1201 #endif // C++11
1202 
1203 #if __cplusplus >= 201703L
1204  /**
1205  * @brief Append a string_view.
1206  * @param __svt An object convertible to string_view to be appended.
1207  * @return Reference to this string.
1208  */
1209  template<typename _Tp>
1210  _If_sv<_Tp, basic_string&>
1211  operator+=(const _Tp& __svt)
1212  { return this->append(__svt); }
1213 #endif // C++17
1214 
1215  /**
1216  * @brief Append a string to this string.
1217  * @param __str The string to append.
1218  * @return Reference to this string.
1219  */
1220  basic_string&
1221  append(const basic_string& __str)
1222  { return _M_append(__str._M_data(), __str.size()); }
1223 
1224  /**
1225  * @brief Append a substring.
1226  * @param __str The string to append.
1227  * @param __pos Index of the first character of str to append.
1228  * @param __n The number of characters to append.
1229  * @return Reference to this string.
1230  * @throw std::out_of_range if @a __pos is not a valid index.
1231  *
1232  * This function appends @a __n characters from @a __str
1233  * starting at @a __pos to this string. If @a __n is is larger
1234  * than the number of available characters in @a __str, the
1235  * remainder of @a __str is appended.
1236  */
1237  basic_string&
1238  append(const basic_string& __str, size_type __pos, size_type __n = npos)
1239  { return _M_append(__str._M_data()
1240  + __str._M_check(__pos, "basic_string::append"),
1241  __str._M_limit(__pos, __n)); }
1242 
1243  /**
1244  * @brief Append a C substring.
1245  * @param __s The C string to append.
1246  * @param __n The number of characters to append.
1247  * @return Reference to this string.
1248  */
1249  basic_string&
1250  append(const _CharT* __s, size_type __n)
1251  {
1252  __glibcxx_requires_string_len(__s, __n);
1253  _M_check_length(size_type(0), __n, "basic_string::append");
1254  return _M_append(__s, __n);
1255  }
1256 
1257  /**
1258  * @brief Append a C string.
1259  * @param __s The C string to append.
1260  * @return Reference to this string.
1261  */
1262  basic_string&
1263  append(const _CharT* __s)
1264  {
1265  __glibcxx_requires_string(__s);
1266  const size_type __n = traits_type::length(__s);
1267  _M_check_length(size_type(0), __n, "basic_string::append");
1268  return _M_append(__s, __n);
1269  }
1270 
1271  /**
1272  * @brief Append multiple characters.
1273  * @param __n The number of characters to append.
1274  * @param __c The character to use.
1275  * @return Reference to this string.
1276  *
1277  * Appends __n copies of __c to this string.
1278  */
1279  basic_string&
1280  append(size_type __n, _CharT __c)
1281  { return _M_replace_aux(this->size(), size_type(0), __n, __c); }
1282 
1283 #if __cplusplus >= 201103L
1284  /**
1285  * @brief Append an initializer_list of characters.
1286  * @param __l The initializer_list of characters to append.
1287  * @return Reference to this string.
1288  */
1289  basic_string&
1290  append(initializer_list<_CharT> __l)
1291  { return this->append(__l.begin(), __l.size()); }
1292 #endif // C++11
1293 
1294  /**
1295  * @brief Append a range of characters.
1296  * @param __first Iterator referencing the first character to append.
1297  * @param __last Iterator marking the end of the range.
1298  * @return Reference to this string.
1299  *
1300  * Appends characters in the range [__first,__last) to this string.
1301  */
1302 #if __cplusplus >= 201103L
1303  template<class _InputIterator,
1304  typename = std::_RequireInputIter<_InputIterator>>
1305 #else
1306  template<class _InputIterator>
1307 #endif
1308  basic_string&
1309  append(_InputIterator __first, _InputIterator __last)
1310  { return this->replace(end(), end(), __first, __last); }
1311 
1312 #if __cplusplus >= 201703L
1313  /**
1314  * @brief Append a string_view.
1315  * @param __svt An object convertible to string_view to be appended.
1316  * @return Reference to this string.
1317  */
1318  template<typename _Tp>
1319  _If_sv<_Tp, basic_string&>
1320  append(const _Tp& __svt)
1321  {
1322  __sv_type __sv = __svt;
1323  return this->append(__sv.data(), __sv.size());
1324  }
1325 
1326  /**
1327  * @brief Append a range of characters from a string_view.
1328  * @param __svt An object convertible to string_view to be appended from.
1329  * @param __pos The position in the string_view to append from.
1330  * @param __n The number of characters to append from the string_view.
1331  * @return Reference to this string.
1332  */
1333  template<typename _Tp>
1334  _If_sv<_Tp, basic_string&>
1335  append(const _Tp& __svt, size_type __pos, size_type __n = npos)
1336  {
1337  __sv_type __sv = __svt;
1338  return _M_append(__sv.data()
1339  + std::__sv_check(__sv.size(), __pos, "basic_string::append"),
1340  std::__sv_limit(__sv.size(), __pos, __n));
1341  }
1342 #endif // C++17
1343 
1344  /**
1345  * @brief Append a single character.
1346  * @param __c Character to append.
1347  */
1348  void
1349  push_back(_CharT __c)
1350  {
1351  const size_type __size = this->size();
1352  if (__size + 1 > this->capacity())
1353  this->_M_mutate(__size, size_type(0), 0, size_type(1));
1354  traits_type::assign(this->_M_data()[__size], __c);
1355  this->_M_set_length(__size + 1);
1356  }
1357 
1358  /**
1359  * @brief Set value to contents of another string.
1360  * @param __str Source string to use.
1361  * @return Reference to this string.
1362  */
1363  basic_string&
1364  assign(const basic_string& __str)
1365  {
1366  this->_M_assign(__str);
1367  return *this;
1368  }
1369 
1370 #if __cplusplus >= 201103L
1371  /**
1372  * @brief Set value to contents of another string.
1373  * @param __str Source string to use.
1374  * @return Reference to this string.
1375  *
1376  * This function sets this string to the exact contents of @a __str.
1377  * @a __str is a valid, but unspecified string.
1378  */
1379  basic_string&
1380  assign(basic_string&& __str)
1381  noexcept(_Alloc_traits::_S_nothrow_move())
1382  {
1383  // _GLIBCXX_RESOLVE_LIB_DEFECTS
1384  // 2063. Contradictory requirements for string move assignment
1385  return *this = std::move(__str);
1386  }
1387 #endif // C++11
1388 
1389  /**
1390  * @brief Set value to a substring of a string.
1391  * @param __str The string to use.
1392  * @param __pos Index of the first character of str.
1393  * @param __n Number of characters to use.
1394  * @return Reference to this string.
1395  * @throw std::out_of_range if @a pos is not a valid index.
1396  *
1397  * This function sets this string to the substring of @a __str
1398  * consisting of @a __n characters at @a __pos. If @a __n is
1399  * is larger than the number of available characters in @a
1400  * __str, the remainder of @a __str is used.
1401  */
1402  basic_string&
1403  assign(const basic_string& __str, size_type __pos, size_type __n = npos)
1404  { return _M_replace(size_type(0), this->size(), __str._M_data()
1405  + __str._M_check(__pos, "basic_string::assign"),
1406  __str._M_limit(__pos, __n)); }
1407 
1408  /**
1409  * @brief Set value to a C substring.
1410  * @param __s The C string to use.
1411  * @param __n Number of characters to use.
1412  * @return Reference to this string.
1413  *
1414  * This function sets the value of this string to the first @a __n
1415  * characters of @a __s. If @a __n is is larger than the number of
1416  * available characters in @a __s, the remainder of @a __s is used.
1417  */
1418  basic_string&
1419  assign(const _CharT* __s, size_type __n)
1420  {
1421  __glibcxx_requires_string_len(__s, __n);
1422  return _M_replace(size_type(0), this->size(), __s, __n);
1423  }
1424 
1425  /**
1426  * @brief Set value to contents of a C string.
1427  * @param __s The C string to use.
1428  * @return Reference to this string.
1429  *
1430  * This function sets the value of this string to the value of @a __s.
1431  * The data is copied, so there is no dependence on @a __s once the
1432  * function returns.
1433  */
1434  basic_string&
1435  assign(const _CharT* __s)
1436  {
1437  __glibcxx_requires_string(__s);
1438  return _M_replace(size_type(0), this->size(), __s,
1439  traits_type::length(__s));
1440  }
1441 
1442  /**
1443  * @brief Set value to multiple characters.
1444  * @param __n Length of the resulting string.
1445  * @param __c The character to use.
1446  * @return Reference to this string.
1447  *
1448  * This function sets the value of this string to @a __n copies of
1449  * character @a __c.
1450  */
1451  basic_string&
1452  assign(size_type __n, _CharT __c)
1453  { return _M_replace_aux(size_type(0), this->size(), __n, __c); }
1454 
1455  /**
1456  * @brief Set value to a range of characters.
1457  * @param __first Iterator referencing the first character to append.
1458  * @param __last Iterator marking the end of the range.
1459  * @return Reference to this string.
1460  *
1461  * Sets value of string to characters in the range [__first,__last).
1462  */
1463 #if __cplusplus >= 201103L
1464  template<class _InputIterator,
1465  typename = std::_RequireInputIter<_InputIterator>>
1466 #else
1467  template<class _InputIterator>
1468 #endif
1469  basic_string&
1470  assign(_InputIterator __first, _InputIterator __last)
1471  { return this->replace(begin(), end(), __first, __last); }
1472 
1473 #if __cplusplus >= 201103L
1474  /**
1475  * @brief Set value to an initializer_list of characters.
1476  * @param __l The initializer_list of characters to assign.
1477  * @return Reference to this string.
1478  */
1479  basic_string&
1480  assign(initializer_list<_CharT> __l)
1481  { return this->assign(__l.begin(), __l.size()); }
1482 #endif // C++11
1483 
1484 #if __cplusplus >= 201703L
1485  /**
1486  * @brief Set value from a string_view.
1487  * @param __svt The source object convertible to string_view.
1488  * @return Reference to this string.
1489  */
1490  template<typename _Tp>
1491  _If_sv<_Tp, basic_string&>
1492  assign(const _Tp& __svt)
1493  {
1494  __sv_type __sv = __svt;
1495  return this->assign(__sv.data(), __sv.size());
1496  }
1497 
1498  /**
1499  * @brief Set value from a range of characters in a string_view.
1500  * @param __svt The source object convertible to string_view.
1501  * @param __pos The position in the string_view to assign from.
1502  * @param __n The number of characters to assign.
1503  * @return Reference to this string.
1504  */
1505  template<typename _Tp>
1506  _If_sv<_Tp, basic_string&>
1507  assign(const _Tp& __svt, size_type __pos, size_type __n = npos)
1508  {
1509  __sv_type __sv = __svt;
1510  return _M_replace(size_type(0), this->size(),
1511  __sv.data()
1512  + std::__sv_check(__sv.size(), __pos, "basic_string::assign"),
1513  std::__sv_limit(__sv.size(), __pos, __n));
1514  }
1515 #endif // C++17
1516 
1517 #if __cplusplus >= 201103L
1518  /**
1519  * @brief Insert multiple characters.
1520  * @param __p Const_iterator referencing location in string to
1521  * insert at.
1522  * @param __n Number of characters to insert
1523  * @param __c The character to insert.
1524  * @return Iterator referencing the first inserted char.
1525  * @throw std::length_error If new length exceeds @c max_size().
1526  *
1527  * Inserts @a __n copies of character @a __c starting at the
1528  * position referenced by iterator @a __p. If adding
1529  * characters causes the length to exceed max_size(),
1530  * length_error is thrown. The value of the string doesn't
1531  * change if an error is thrown.
1532  */
1533  iterator
1534  insert(const_iterator __p, size_type __n, _CharT __c)
1535  {
1536  _GLIBCXX_DEBUG_PEDASSERT(__p >= begin() && __p <= end());
1537  const size_type __pos = __p - begin();
1538  this->replace(__p, __p, __n, __c);
1539  return iterator(this->_M_data() + __pos);
1540  }
1541 #else
1542  /**
1543  * @brief Insert multiple characters.
1544  * @param __p Iterator referencing location in string to insert at.
1545  * @param __n Number of characters to insert
1546  * @param __c The character to insert.
1547  * @throw std::length_error If new length exceeds @c max_size().
1548  *
1549  * Inserts @a __n copies of character @a __c starting at the
1550  * position referenced by iterator @a __p. If adding
1551  * characters causes the length to exceed max_size(),
1552  * length_error is thrown. The value of the string doesn't
1553  * change if an error is thrown.
1554  */
1555  void
1556  insert(iterator __p, size_type __n, _CharT __c)
1557  { this->replace(__p, __p, __n, __c); }
1558 #endif
1559 
1560 #if __cplusplus >= 201103L
1561  /**
1562  * @brief Insert a range of characters.
1563  * @param __p Const_iterator referencing location in string to
1564  * insert at.
1565  * @param __beg Start of range.
1566  * @param __end End of range.
1567  * @return Iterator referencing the first inserted char.
1568  * @throw std::length_error If new length exceeds @c max_size().
1569  *
1570  * Inserts characters in range [beg,end). If adding characters
1571  * causes the length to exceed max_size(), length_error is
1572  * thrown. The value of the string doesn't change if an error
1573  * is thrown.
1574  */
1575  template<class _InputIterator,
1576  typename = std::_RequireInputIter<_InputIterator>>
1577  iterator
1578  insert(const_iterator __p, _InputIterator __beg, _InputIterator __end)
1579  {
1580  _GLIBCXX_DEBUG_PEDASSERT(__p >= begin() && __p <= end());
1581  const size_type __pos = __p - begin();
1582  this->replace(__p, __p, __beg, __end);
1583  return iterator(this->_M_data() + __pos);
1584  }
1585 #else
1586  /**
1587  * @brief Insert a range of characters.
1588  * @param __p Iterator referencing location in string to insert at.
1589  * @param __beg Start of range.
1590  * @param __end End of range.
1591  * @throw std::length_error If new length exceeds @c max_size().
1592  *
1593  * Inserts characters in range [__beg,__end). If adding
1594  * characters causes the length to exceed max_size(),
1595  * length_error is thrown. The value of the string doesn't
1596  * change if an error is thrown.
1597  */
1598  template<class _InputIterator>
1599  void
1600  insert(iterator __p, _InputIterator __beg, _InputIterator __end)
1601  { this->replace(__p, __p, __beg, __end); }
1602 #endif
1603 
1604 #if __cplusplus >= 201103L
1605  /**
1606  * @brief Insert an initializer_list of characters.
1607  * @param __p Iterator referencing location in string to insert at.
1608  * @param __l The initializer_list of characters to insert.
1609  * @throw std::length_error If new length exceeds @c max_size().
1610  */
1611  iterator
1612  insert(const_iterator __p, initializer_list<_CharT> __l)
1613  { return this->insert(__p, __l.begin(), __l.end()); }
1614 
1615 #ifdef _GLIBCXX_DEFINING_STRING_INSTANTIATIONS
1616  // See PR libstdc++/83328
1617  void
1618  insert(iterator __p, initializer_list<_CharT> __l)
1619  {
1620  _GLIBCXX_DEBUG_PEDASSERT(__p >= begin() && __p <= end());
1621  this->insert(__p - begin(), __l.begin(), __l.size());
1622  }
1623 #endif
1624 #endif // C++11
1625 
1626  /**
1627  * @brief Insert value of a string.
1628  * @param __pos1 Iterator referencing location in string to insert at.
1629  * @param __str The string to insert.
1630  * @return Reference to this string.
1631  * @throw std::length_error If new length exceeds @c max_size().
1632  *
1633  * Inserts value of @a __str starting at @a __pos1. If adding
1634  * characters causes the length to exceed max_size(),
1635  * length_error is thrown. The value of the string doesn't
1636  * change if an error is thrown.
1637  */
1638  basic_string&
1639  insert(size_type __pos1, const basic_string& __str)
1640  { return this->replace(__pos1, size_type(0),
1641  __str._M_data(), __str.size()); }
1642 
1643  /**
1644  * @brief Insert a substring.
1645  * @param __pos1 Iterator referencing location in string to insert at.
1646  * @param __str The string to insert.
1647  * @param __pos2 Start of characters in str to insert.
1648  * @param __n Number of characters to insert.
1649  * @return Reference to this string.
1650  * @throw std::length_error If new length exceeds @c max_size().
1651  * @throw std::out_of_range If @a pos1 > size() or
1652  * @a __pos2 > @a str.size().
1653  *
1654  * Starting at @a pos1, insert @a __n character of @a __str
1655  * beginning with @a __pos2. If adding characters causes the
1656  * length to exceed max_size(), length_error is thrown. If @a
1657  * __pos1 is beyond the end of this string or @a __pos2 is
1658  * beyond the end of @a __str, out_of_range is thrown. The
1659  * value of the string doesn't change if an error is thrown.
1660  */
1661  basic_string&
1662  insert(size_type __pos1, const basic_string& __str,
1663  size_type __pos2, size_type __n = npos)
1664  { return this->replace(__pos1, size_type(0), __str._M_data()
1665  + __str._M_check(__pos2, "basic_string::insert"),
1666  __str._M_limit(__pos2, __n)); }
1667 
1668  /**
1669  * @brief Insert a C substring.
1670  * @param __pos Iterator referencing location in string to insert at.
1671  * @param __s The C string to insert.
1672  * @param __n The number of characters to insert.
1673  * @return Reference to this string.
1674  * @throw std::length_error If new length exceeds @c max_size().
1675  * @throw std::out_of_range If @a __pos is beyond the end of this
1676  * string.
1677  *
1678  * Inserts the first @a __n characters of @a __s starting at @a
1679  * __pos. If adding characters causes the length to exceed
1680  * max_size(), length_error is thrown. If @a __pos is beyond
1681  * end(), out_of_range is thrown. The value of the string
1682  * doesn't change if an error is thrown.
1683  */
1684  basic_string&
1685  insert(size_type __pos, const _CharT* __s, size_type __n)
1686  { return this->replace(__pos, size_type(0), __s, __n); }
1687 
1688  /**
1689  * @brief Insert a C string.
1690  * @param __pos Iterator referencing location in string to insert at.
1691  * @param __s The C string to insert.
1692  * @return Reference to this string.
1693  * @throw std::length_error If new length exceeds @c max_size().
1694  * @throw std::out_of_range If @a pos is beyond the end of this
1695  * string.
1696  *
1697  * Inserts the first @a n characters of @a __s starting at @a __pos. If
1698  * adding characters causes the length to exceed max_size(),
1699  * length_error is thrown. If @a __pos is beyond end(), out_of_range is
1700  * thrown. The value of the string doesn't change if an error is
1701  * thrown.
1702  */
1703  basic_string&
1704  insert(size_type __pos, const _CharT* __s)
1705  {
1706  __glibcxx_requires_string(__s);
1707  return this->replace(__pos, size_type(0), __s,
1708  traits_type::length(__s));
1709  }
1710 
1711  /**
1712  * @brief Insert multiple characters.
1713  * @param __pos Index in string to insert at.
1714  * @param __n Number of characters to insert
1715  * @param __c The character to insert.
1716  * @return Reference to this string.
1717  * @throw std::length_error If new length exceeds @c max_size().
1718  * @throw std::out_of_range If @a __pos is beyond the end of this
1719  * string.
1720  *
1721  * Inserts @a __n copies of character @a __c starting at index
1722  * @a __pos. If adding characters causes the length to exceed
1723  * max_size(), length_error is thrown. If @a __pos > length(),
1724  * out_of_range is thrown. The value of the string doesn't
1725  * change if an error is thrown.
1726  */
1727  basic_string&
1728  insert(size_type __pos, size_type __n, _CharT __c)
1729  { return _M_replace_aux(_M_check(__pos, "basic_string::insert"),
1730  size_type(0), __n, __c); }
1731 
1732  /**
1733  * @brief Insert one character.
1734  * @param __p Iterator referencing position in string to insert at.
1735  * @param __c The character to insert.
1736  * @return Iterator referencing newly inserted char.
1737  * @throw std::length_error If new length exceeds @c max_size().
1738  *
1739  * Inserts character @a __c at position referenced by @a __p.
1740  * If adding character causes the length to exceed max_size(),
1741  * length_error is thrown. If @a __p is beyond end of string,
1742  * out_of_range is thrown. The value of the string doesn't
1743  * change if an error is thrown.
1744  */
1745  iterator
1746  insert(__const_iterator __p, _CharT __c)
1747  {
1748  _GLIBCXX_DEBUG_PEDASSERT(__p >= begin() && __p <= end());
1749  const size_type __pos = __p - begin();
1750  _M_replace_aux(__pos, size_type(0), size_type(1), __c);
1751  return iterator(_M_data() + __pos);
1752  }
1753 
1754 #if __cplusplus >= 201703L
1755  /**
1756  * @brief Insert a string_view.
1757  * @param __pos Iterator referencing position in string to insert at.
1758  * @param __svt The object convertible to string_view to insert.
1759  * @return Reference to this string.
1760  */
1761  template<typename _Tp>
1762  _If_sv<_Tp, basic_string&>
1763  insert(size_type __pos, const _Tp& __svt)
1764  {
1765  __sv_type __sv = __svt;
1766  return this->insert(__pos, __sv.data(), __sv.size());
1767  }
1768 
1769  /**
1770  * @brief Insert a string_view.
1771  * @param __pos Iterator referencing position in string to insert at.
1772  * @param __svt The object convertible to string_view to insert from.
1773  * @param __pos Iterator referencing position in string_view to insert
1774  * from.
1775  * @param __n The number of characters to insert.
1776  * @return Reference to this string.
1777  */
1778  template<typename _Tp>
1779  _If_sv<_Tp, basic_string&>
1780  insert(size_type __pos1, const _Tp& __svt,
1781  size_type __pos2, size_type __n = npos)
1782  {
1783  __sv_type __sv = __svt;
1784  return this->replace(__pos1, size_type(0),
1785  __sv.data()
1786  + std::__sv_check(__sv.size(), __pos2, "basic_string::insert"),
1787  std::__sv_limit(__sv.size(), __pos2, __n));
1788  }
1789 #endif // C++17
1790 
1791  /**
1792  * @brief Remove characters.
1793  * @param __pos Index of first character to remove (default 0).
1794  * @param __n Number of characters to remove (default remainder).
1795  * @return Reference to this string.
1796  * @throw std::out_of_range If @a pos is beyond the end of this
1797  * string.
1798  *
1799  * Removes @a __n characters from this string starting at @a
1800  * __pos. The length of the string is reduced by @a __n. If
1801  * there are < @a __n characters to remove, the remainder of
1802  * the string is truncated. If @a __p is beyond end of string,
1803  * out_of_range is thrown. The value of the string doesn't
1804  * change if an error is thrown.
1805  */
1806  basic_string&
1807  erase(size_type __pos = 0, size_type __n = npos)
1808  {
1809  _M_check(__pos, "basic_string::erase");
1810  if (__n == npos)
1811  this->_M_set_length(__pos);
1812  else if (__n != 0)
1813  this->_M_erase(__pos, _M_limit(__pos, __n));
1814  return *this;
1815  }
1816 
1817  /**
1818  * @brief Remove one character.
1819  * @param __position Iterator referencing the character to remove.
1820  * @return iterator referencing same location after removal.
1821  *
1822  * Removes the character at @a __position from this string. The value
1823  * of the string doesn't change if an error is thrown.
1824  */
1825  iterator
1826  erase(__const_iterator __position)
1827  {
1828  _GLIBCXX_DEBUG_PEDASSERT(__position >= begin()
1829  && __position < end());
1830  const size_type __pos = __position - begin();
1831  this->_M_erase(__pos, size_type(1));
1832  return iterator(_M_data() + __pos);
1833  }
1834 
1835  /**
1836  * @brief Remove a range of characters.
1837  * @param __first Iterator referencing the first character to remove.
1838  * @param __last Iterator referencing the end of the range.
1839  * @return Iterator referencing location of first after removal.
1840  *
1841  * Removes the characters in the range [first,last) from this string.
1842  * The value of the string doesn't change if an error is thrown.
1843  */
1844  iterator
1845  erase(__const_iterator __first, __const_iterator __last)
1846  {
1847  _GLIBCXX_DEBUG_PEDASSERT(__first >= begin() && __first <= __last
1848  && __last <= end());
1849  const size_type __pos = __first - begin();
1850  if (__last == end())
1851  this->_M_set_length(__pos);
1852  else
1853  this->_M_erase(__pos, __last - __first);
1854  return iterator(this->_M_data() + __pos);
1855  }
1856 
1857 #if __cplusplus >= 201103L
1858  /**
1859  * @brief Remove the last character.
1860  *
1861  * The string must be non-empty.
1862  */
1863  void
1864  pop_back() noexcept
1865  {
1866  __glibcxx_assert(!empty());
1867  _M_erase(size() - 1, 1);
1868  }
1869 #endif // C++11
1870 
1871  /**
1872  * @brief Replace characters with value from another string.
1873  * @param __pos Index of first character to replace.
1874  * @param __n Number of characters to be replaced.
1875  * @param __str String to insert.
1876  * @return Reference to this string.
1877  * @throw std::out_of_range If @a pos is beyond the end of this
1878  * string.
1879  * @throw std::length_error If new length exceeds @c max_size().
1880  *
1881  * Removes the characters in the range [__pos,__pos+__n) from
1882  * this string. In place, the value of @a __str is inserted.
1883  * If @a __pos is beyond end of string, out_of_range is thrown.
1884  * If the length of the result exceeds max_size(), length_error
1885  * is thrown. The value of the string doesn't change if an
1886  * error is thrown.
1887  */
1888  basic_string&
1889  replace(size_type __pos, size_type __n, const basic_string& __str)
1890  { return this->replace(__pos, __n, __str._M_data(), __str.size()); }
1891 
1892  /**
1893  * @brief Replace characters with value from another string.
1894  * @param __pos1 Index of first character to replace.
1895  * @param __n1 Number of characters to be replaced.
1896  * @param __str String to insert.
1897  * @param __pos2 Index of first character of str to use.
1898  * @param __n2 Number of characters from str to use.
1899  * @return Reference to this string.
1900  * @throw std::out_of_range If @a __pos1 > size() or @a __pos2 >
1901  * __str.size().
1902  * @throw std::length_error If new length exceeds @c max_size().
1903  *
1904  * Removes the characters in the range [__pos1,__pos1 + n) from this
1905  * string. In place, the value of @a __str is inserted. If @a __pos is
1906  * beyond end of string, out_of_range is thrown. If the length of the
1907  * result exceeds max_size(), length_error is thrown. The value of the
1908  * string doesn't change if an error is thrown.
1909  */
1910  basic_string&
1911  replace(size_type __pos1, size_type __n1, const basic_string& __str,
1912  size_type __pos2, size_type __n2 = npos)
1913  { return this->replace(__pos1, __n1, __str._M_data()
1914  + __str._M_check(__pos2, "basic_string::replace"),
1915  __str._M_limit(__pos2, __n2)); }
1916 
1917  /**
1918  * @brief Replace characters with value of a C substring.
1919  * @param __pos Index of first character to replace.
1920  * @param __n1 Number of characters to be replaced.
1921  * @param __s C string to insert.
1922  * @param __n2 Number of characters from @a s to use.
1923  * @return Reference to this string.
1924  * @throw std::out_of_range If @a pos1 > size().
1925  * @throw std::length_error If new length exceeds @c max_size().
1926  *
1927  * Removes the characters in the range [__pos,__pos + __n1)
1928  * from this string. In place, the first @a __n2 characters of
1929  * @a __s are inserted, or all of @a __s if @a __n2 is too large. If
1930  * @a __pos is beyond end of string, out_of_range is thrown. If
1931  * the length of result exceeds max_size(), length_error is
1932  * thrown. The value of the string doesn't change if an error
1933  * is thrown.
1934  */
1935  basic_string&
1936  replace(size_type __pos, size_type __n1, const _CharT* __s,
1937  size_type __n2)
1938  {
1939  __glibcxx_requires_string_len(__s, __n2);
1940  return _M_replace(_M_check(__pos, "basic_string::replace"),
1941  _M_limit(__pos, __n1), __s, __n2);
1942  }
1943 
1944  /**
1945  * @brief Replace characters with value of a C string.
1946  * @param __pos Index of first character to replace.
1947  * @param __n1 Number of characters to be replaced.
1948  * @param __s C string to insert.
1949  * @return Reference to this string.
1950  * @throw std::out_of_range If @a pos > size().
1951  * @throw std::length_error If new length exceeds @c max_size().
1952  *
1953  * Removes the characters in the range [__pos,__pos + __n1)
1954  * from this string. In place, the characters of @a __s are
1955  * inserted. If @a __pos is beyond end of string, out_of_range
1956  * is thrown. If the length of result exceeds max_size(),
1957  * length_error is thrown. The value of the string doesn't
1958  * change if an error is thrown.
1959  */
1960  basic_string&
1961  replace(size_type __pos, size_type __n1, const _CharT* __s)
1962  {
1963  __glibcxx_requires_string(__s);
1964  return this->replace(__pos, __n1, __s, traits_type::length(__s));
1965  }
1966 
1967  /**
1968  * @brief Replace characters with multiple characters.
1969  * @param __pos Index of first character to replace.
1970  * @param __n1 Number of characters to be replaced.
1971  * @param __n2 Number of characters to insert.
1972  * @param __c Character to insert.
1973  * @return Reference to this string.
1974  * @throw std::out_of_range If @a __pos > size().
1975  * @throw std::length_error If new length exceeds @c max_size().
1976  *
1977  * Removes the characters in the range [pos,pos + n1) from this
1978  * string. In place, @a __n2 copies of @a __c are inserted.
1979  * If @a __pos is beyond end of string, out_of_range is thrown.
1980  * If the length of result exceeds max_size(), length_error is
1981  * thrown. The value of the string doesn't change if an error
1982  * is thrown.
1983  */
1984  basic_string&
1985  replace(size_type __pos, size_type __n1, size_type __n2, _CharT __c)
1986  { return _M_replace_aux(_M_check(__pos, "basic_string::replace"),
1987  _M_limit(__pos, __n1), __n2, __c); }
1988 
1989  /**
1990  * @brief Replace range of characters with string.
1991  * @param __i1 Iterator referencing start of range to replace.
1992  * @param __i2 Iterator referencing end of range to replace.
1993  * @param __str String value to insert.
1994  * @return Reference to this string.
1995  * @throw std::length_error If new length exceeds @c max_size().
1996  *
1997  * Removes the characters in the range [__i1,__i2). In place,
1998  * the value of @a __str is inserted. If the length of result
1999  * exceeds max_size(), length_error is thrown. The value of
2000  * the string doesn't change if an error is thrown.
2001  */
2002  basic_string&
2003  replace(__const_iterator __i1, __const_iterator __i2,
2004  const basic_string& __str)
2005  { return this->replace(__i1, __i2, __str._M_data(), __str.size()); }
2006 
2007  /**
2008  * @brief Replace range of characters with C substring.
2009  * @param __i1 Iterator referencing start of range to replace.
2010  * @param __i2 Iterator referencing end of range to replace.
2011  * @param __s C string value to insert.
2012  * @param __n Number of characters from s to insert.
2013  * @return Reference to this string.
2014  * @throw std::length_error If new length exceeds @c max_size().
2015  *
2016  * Removes the characters in the range [__i1,__i2). In place,
2017  * the first @a __n characters of @a __s are inserted. If the
2018  * length of result exceeds max_size(), length_error is thrown.
2019  * The value of the string doesn't change if an error is
2020  * thrown.
2021  */
2022  basic_string&
2023  replace(__const_iterator __i1, __const_iterator __i2,
2024  const _CharT* __s, size_type __n)
2025  {
2026  _GLIBCXX_DEBUG_PEDASSERT(begin() <= __i1 && __i1 <= __i2
2027  && __i2 <= end());
2028  return this->replace(__i1 - begin(), __i2 - __i1, __s, __n);
2029  }
2030 
2031  /**
2032  * @brief Replace range of characters with C string.
2033  * @param __i1 Iterator referencing start of range to replace.
2034  * @param __i2 Iterator referencing end of range to replace.
2035  * @param __s C string value to insert.
2036  * @return Reference to this string.
2037  * @throw std::length_error If new length exceeds @c max_size().
2038  *
2039  * Removes the characters in the range [__i1,__i2). In place,
2040  * the characters of @a __s are inserted. If the length of
2041  * result exceeds max_size(), length_error is thrown. The
2042  * value of the string doesn't change if an error is thrown.
2043  */
2044  basic_string&
2045  replace(__const_iterator __i1, __const_iterator __i2, const _CharT* __s)
2046  {
2047  __glibcxx_requires_string(__s);
2048  return this->replace(__i1, __i2, __s, traits_type::length(__s));
2049  }
2050 
2051  /**
2052  * @brief Replace range of characters with multiple characters
2053  * @param __i1 Iterator referencing start of range to replace.
2054  * @param __i2 Iterator referencing end of range to replace.
2055  * @param __n Number of characters to insert.
2056  * @param __c Character to insert.
2057  * @return Reference to this string.
2058  * @throw std::length_error If new length exceeds @c max_size().
2059  *
2060  * Removes the characters in the range [__i1,__i2). In place,
2061  * @a __n copies of @a __c are inserted. If the length of
2062  * result exceeds max_size(), length_error is thrown. The
2063  * value of the string doesn't change if an error is thrown.
2064  */
2065  basic_string&
2066  replace(__const_iterator __i1, __const_iterator __i2, size_type __n,
2067  _CharT __c)
2068  {
2069  _GLIBCXX_DEBUG_PEDASSERT(begin() <= __i1 && __i1 <= __i2
2070  && __i2 <= end());
2071  return _M_replace_aux(__i1 - begin(), __i2 - __i1, __n, __c);
2072  }
2073 
2074  /**
2075  * @brief Replace range of characters with range.
2076  * @param __i1 Iterator referencing start of range to replace.
2077  * @param __i2 Iterator referencing end of range to replace.
2078  * @param __k1 Iterator referencing start of range to insert.
2079  * @param __k2 Iterator referencing end of range to insert.
2080  * @return Reference to this string.
2081  * @throw std::length_error If new length exceeds @c max_size().
2082  *
2083  * Removes the characters in the range [__i1,__i2). In place,
2084  * characters in the range [__k1,__k2) are inserted. If the
2085  * length of result exceeds max_size(), length_error is thrown.
2086  * The value of the string doesn't change if an error is
2087  * thrown.
2088  */
2089 #if __cplusplus >= 201103L
2090  template<class _InputIterator,
2091  typename = std::_RequireInputIter<_InputIterator>>
2092  basic_string&
2093  replace(const_iterator __i1, const_iterator __i2,
2094  _InputIterator __k1, _InputIterator __k2)
2095  {
2096  _GLIBCXX_DEBUG_PEDASSERT(begin() <= __i1 && __i1 <= __i2
2097  && __i2 <= end());
2098  __glibcxx_requires_valid_range(__k1, __k2);
2099  return this->_M_replace_dispatch(__i1, __i2, __k1, __k2,
2100  std::__false_type());
2101  }
2102 #else
2103  template<class _InputIterator>
2104 #ifdef _GLIBCXX_DISAMBIGUATE_REPLACE_INST
2105  typename __enable_if_not_native_iterator<_InputIterator>::__type
2106 #else
2107  basic_string&
2108 #endif
2109  replace(iterator __i1, iterator __i2,
2110  _InputIterator __k1, _InputIterator __k2)
2111  {
2112  _GLIBCXX_DEBUG_PEDASSERT(begin() <= __i1 && __i1 <= __i2
2113  && __i2 <= end());
2114  __glibcxx_requires_valid_range(__k1, __k2);
2115  typedef typename std::__is_integer<_InputIterator>::__type _Integral;
2116  return _M_replace_dispatch(__i1, __i2, __k1, __k2, _Integral());
2117  }
2118 #endif
2119 
2120  // Specializations for the common case of pointer and iterator:
2121  // useful to avoid the overhead of temporary buffering in _M_replace.
2122  basic_string&
2123  replace(__const_iterator __i1, __const_iterator __i2,
2124  _CharT* __k1, _CharT* __k2)
2125  {
2126  _GLIBCXX_DEBUG_PEDASSERT(begin() <= __i1 && __i1 <= __i2
2127  && __i2 <= end());
2128  __glibcxx_requires_valid_range(__k1, __k2);
2129  return this->replace(__i1 - begin(), __i2 - __i1,
2130  __k1, __k2 - __k1);
2131  }
2132 
2133  basic_string&
2134  replace(__const_iterator __i1, __const_iterator __i2,
2135  const _CharT* __k1, const _CharT* __k2)
2136  {
2137  _GLIBCXX_DEBUG_PEDASSERT(begin() <= __i1 && __i1 <= __i2
2138  && __i2 <= end());
2139  __glibcxx_requires_valid_range(__k1, __k2);
2140  return this->replace(__i1 - begin(), __i2 - __i1,
2141  __k1, __k2 - __k1);
2142  }
2143 
2144  basic_string&
2145  replace(__const_iterator __i1, __const_iterator __i2,
2146  iterator __k1, iterator __k2)
2147  {
2148  _GLIBCXX_DEBUG_PEDASSERT(begin() <= __i1 && __i1 <= __i2
2149  && __i2 <= end());
2150  __glibcxx_requires_valid_range(__k1, __k2);
2151  return this->replace(__i1 - begin(), __i2 - __i1,
2152  __k1.base(), __k2 - __k1);
2153  }
2154 
2155  basic_string&
2156  replace(__const_iterator __i1, __const_iterator __i2,
2157  const_iterator __k1, const_iterator __k2)
2158  {
2159  _GLIBCXX_DEBUG_PEDASSERT(begin() <= __i1 && __i1 <= __i2
2160  && __i2 <= end());
2161  __glibcxx_requires_valid_range(__k1, __k2);
2162  return this->replace(__i1 - begin(), __i2 - __i1,
2163  __k1.base(), __k2 - __k1);
2164  }
2165 
2166 #if __cplusplus >= 201103L
2167  /**
2168  * @brief Replace range of characters with initializer_list.
2169  * @param __i1 Iterator referencing start of range to replace.
2170  * @param __i2 Iterator referencing end of range to replace.
2171  * @param __l The initializer_list of characters to insert.
2172  * @return Reference to this string.
2173  * @throw std::length_error If new length exceeds @c max_size().
2174  *
2175  * Removes the characters in the range [__i1,__i2). In place,
2176  * characters in the range [__k1,__k2) are inserted. If the
2177  * length of result exceeds max_size(), length_error is thrown.
2178  * The value of the string doesn't change if an error is
2179  * thrown.
2180  */
2181  basic_string& replace(const_iterator __i1, const_iterator __i2,
2182  initializer_list<_CharT> __l)
2183  { return this->replace(__i1, __i2, __l.begin(), __l.size()); }
2184 #endif // C++11
2185 
2186 #if __cplusplus >= 201703L
2187  /**
2188  * @brief Replace range of characters with string_view.
2189  * @param __pos The position to replace at.
2190  * @param __n The number of characters to replace.
2191  * @param __svt The object convertible to string_view to insert.
2192  * @return Reference to this string.
2193  */
2194  template<typename _Tp>
2195  _If_sv<_Tp, basic_string&>
2196  replace(size_type __pos, size_type __n, const _Tp& __svt)
2197  {
2198  __sv_type __sv = __svt;
2199  return this->replace(__pos, __n, __sv.data(), __sv.size());
2200  }
2201 
2202  /**
2203  * @brief Replace range of characters with string_view.
2204  * @param __pos1 The position to replace at.
2205  * @param __n1 The number of characters to replace.
2206  * @param __svt The object convertible to string_view to insert from.
2207  * @param __pos2 The position in the string_view to insert from.
2208  * @param __n2 The number of characters to insert.
2209  * @return Reference to this string.
2210  */
2211  template<typename _Tp>
2212  _If_sv<_Tp, basic_string&>
2213  replace(size_type __pos1, size_type __n1, const _Tp& __svt,
2214  size_type __pos2, size_type __n2 = npos)
2215  {
2216  __sv_type __sv = __svt;
2217  return this->replace(__pos1, __n1,
2218  __sv.data()
2219  + std::__sv_check(__sv.size(), __pos2, "basic_string::replace"),
2220  std::__sv_limit(__sv.size(), __pos2, __n2));
2221  }
2222 
2223  /**
2224  * @brief Replace range of characters with string_view.
2225  * @param __i1 An iterator referencing the start position
2226  to replace at.
2227  * @param __i2 An iterator referencing the end position
2228  for the replace.
2229  * @param __svt The object convertible to string_view to insert from.
2230  * @return Reference to this string.
2231  */
2232  template<typename _Tp>
2233  _If_sv<_Tp, basic_string&>
2234  replace(const_iterator __i1, const_iterator __i2, const _Tp& __svt)
2235  {
2236  __sv_type __sv = __svt;
2237  return this->replace(__i1 - begin(), __i2 - __i1, __sv);
2238  }
2239 #endif // C++17
2240 
2241  private:
2242  template<class _Integer>
2243  basic_string&
2244  _M_replace_dispatch(const_iterator __i1, const_iterator __i2,
2245  _Integer __n, _Integer __val, __true_type)
2246  { return _M_replace_aux(__i1 - begin(), __i2 - __i1, __n, __val); }
2247 
2248  template<class _InputIterator>
2249  basic_string&
2250  _M_replace_dispatch(const_iterator __i1, const_iterator __i2,
2251  _InputIterator __k1, _InputIterator __k2,
2252  __false_type);
2253 
2254  basic_string&
2255  _M_replace_aux(size_type __pos1, size_type __n1, size_type __n2,
2256  _CharT __c);
2257 
2258  basic_string&
2259  _M_replace(size_type __pos, size_type __len1, const _CharT* __s,
2260  const size_type __len2);
2261 
2262  basic_string&
2263  _M_append(const _CharT* __s, size_type __n);
2264 
2265  public:
2266 
2267  /**
2268  * @brief Copy substring into C string.
2269  * @param __s C string to copy value into.
2270  * @param __n Number of characters to copy.
2271  * @param __pos Index of first character to copy.
2272  * @return Number of characters actually copied
2273  * @throw std::out_of_range If __pos > size().
2274  *
2275  * Copies up to @a __n characters starting at @a __pos into the
2276  * C string @a __s. If @a __pos is %greater than size(),
2277  * out_of_range is thrown.
2278  */
2279  size_type
2280  copy(_CharT* __s, size_type __n, size_type __pos = 0) const;
2281 
2282  /**
2283  * @brief Swap contents with another string.
2284  * @param __s String to swap with.
2285  *
2286  * Exchanges the contents of this string with that of @a __s in constant
2287  * time.
2288  */
2289  void
2290  swap(basic_string& __s) _GLIBCXX_NOEXCEPT;
2291 
2292  // String operations:
2293  /**
2294  * @brief Return const pointer to null-terminated contents.
2295  *
2296  * This is a handle to internal data. Do not modify or dire things may
2297  * happen.
2298  */
2299  const _CharT*
2300  c_str() const _GLIBCXX_NOEXCEPT
2301  { return _M_data(); }
2302 
2303  /**
2304  * @brief Return const pointer to contents.
2305  *
2306  * This is a pointer to internal data. It is undefined to modify
2307  * the contents through the returned pointer. To get a pointer that
2308  * allows modifying the contents use @c &str[0] instead,
2309  * (or in C++17 the non-const @c str.data() overload).
2310  */
2311  const _CharT*
2312  data() const _GLIBCXX_NOEXCEPT
2313  { return _M_data(); }
2314 
2315 #if __cplusplus >= 201703L
2316  /**
2317  * @brief Return non-const pointer to contents.
2318  *
2319  * This is a pointer to the character sequence held by the string.
2320  * Modifying the characters in the sequence is allowed.
2321  */
2322  _CharT*
2323  data() noexcept
2324  { return _M_data(); }
2325 #endif
2326 
2327  /**
2328  * @brief Return copy of allocator used to construct this string.
2329  */
2330  allocator_type
2331  get_allocator() const _GLIBCXX_NOEXCEPT
2332  { return _M_get_allocator(); }
2333 
2334  /**
2335  * @brief Find position of a C substring.
2336  * @param __s C string to locate.
2337  * @param __pos Index of character to search from.
2338  * @param __n Number of characters from @a s to search for.
2339  * @return Index of start of first occurrence.
2340  *
2341  * Starting from @a __pos, searches forward for the first @a
2342  * __n characters in @a __s within this string. If found,
2343  * returns the index where it begins. If not found, returns
2344  * npos.
2345  */
2346  size_type
2347  find(const _CharT* __s, size_type __pos, size_type __n) const
2348  _GLIBCXX_NOEXCEPT;
2349 
2350  /**
2351  * @brief Find position of a string.
2352  * @param __str String to locate.
2353  * @param __pos Index of character to search from (default 0).
2354  * @return Index of start of first occurrence.
2355  *
2356  * Starting from @a __pos, searches forward for value of @a __str within
2357  * this string. If found, returns the index where it begins. If not
2358  * found, returns npos.
2359  */
2360  size_type
2361  find(const basic_string& __str, size_type __pos = 0) const
2362  _GLIBCXX_NOEXCEPT
2363  { return this->find(__str.data(), __pos, __str.size()); }
2364 
2365 #if __cplusplus >= 201703L
2366  /**
2367  * @brief Find position of a string_view.
2368  * @param __svt The object convertible to string_view to locate.
2369  * @param __pos Index of character to search from (default 0).
2370  * @return Index of start of first occurrence.
2371  */
2372  template<typename _Tp>
2373  _If_sv<_Tp, size_type>
2374  find(const _Tp& __svt, size_type __pos = 0) const
2375  noexcept(is_same<_Tp, __sv_type>::value)
2376  {
2377  __sv_type __sv = __svt;
2378  return this->find(__sv.data(), __pos, __sv.size());
2379  }
2380 #endif // C++17
2381 
2382  /**
2383  * @brief Find position of a C string.
2384  * @param __s C string to locate.
2385  * @param __pos Index of character to search from (default 0).
2386  * @return Index of start of first occurrence.
2387  *
2388  * Starting from @a __pos, searches forward for the value of @a
2389  * __s within this string. If found, returns the index where
2390  * it begins. If not found, returns npos.
2391  */
2392  size_type
2393  find(const _CharT* __s, size_type __pos = 0) const _GLIBCXX_NOEXCEPT
2394  {
2395  __glibcxx_requires_string(__s);
2396  return this->find(__s, __pos, traits_type::length(__s));
2397  }
2398 
2399  /**
2400  * @brief Find position of a character.
2401  * @param __c Character to locate.
2402  * @param __pos Index of character to search from (default 0).
2403  * @return Index of first occurrence.
2404  *
2405  * Starting from @a __pos, searches forward for @a __c within
2406  * this string. If found, returns the index where it was
2407  * found. If not found, returns npos.
2408  */
2409  size_type
2410  find(_CharT __c, size_type __pos = 0) const _GLIBCXX_NOEXCEPT;
2411 
2412  /**
2413  * @brief Find last position of a string.
2414  * @param __str String to locate.
2415  * @param __pos Index of character to search back from (default end).
2416  * @return Index of start of last occurrence.
2417  *
2418  * Starting from @a __pos, searches backward for value of @a
2419  * __str within this string. If found, returns the index where
2420  * it begins. If not found, returns npos.
2421  */
2422  size_type
2423  rfind(const basic_string& __str, size_type __pos = npos) const
2424  _GLIBCXX_NOEXCEPT
2425  { return this->rfind(__str.data(), __pos, __str.size()); }
2426 
2427 #if __cplusplus >= 201703L
2428  /**
2429  * @brief Find last position of a string_view.
2430  * @param __svt The object convertible to string_view to locate.
2431  * @param __pos Index of character to search back from (default end).
2432  * @return Index of start of last occurrence.
2433  */
2434  template<typename _Tp>
2435  _If_sv<_Tp, size_type>
2436  rfind(const _Tp& __svt, size_type __pos = npos) const
2437  noexcept(is_same<_Tp, __sv_type>::value)
2438  {
2439  __sv_type __sv = __svt;
2440  return this->rfind(__sv.data(), __pos, __sv.size());
2441  }
2442 #endif // C++17
2443 
2444  /**
2445  * @brief Find last position of a C substring.
2446  * @param __s C string to locate.
2447  * @param __pos Index of character to search back from.
2448  * @param __n Number of characters from s to search for.
2449  * @return Index of start of last occurrence.
2450  *
2451  * Starting from @a __pos, searches backward for the first @a
2452  * __n characters in @a __s within this string. If found,
2453  * returns the index where it begins. If not found, returns
2454  * npos.
2455  */
2456  size_type
2457  rfind(const _CharT* __s, size_type __pos, size_type __n) const
2458  _GLIBCXX_NOEXCEPT;
2459 
2460  /**
2461  * @brief Find last position of a C string.
2462  * @param __s C string to locate.
2463  * @param __pos Index of character to start search at (default end).
2464  * @return Index of start of last occurrence.
2465  *
2466  * Starting from @a __pos, searches backward for the value of
2467  * @a __s within this string. If found, returns the index
2468  * where it begins. If not found, returns npos.
2469  */
2470  size_type
2471  rfind(const _CharT* __s, size_type __pos = npos) const
2472  {
2473  __glibcxx_requires_string(__s);
2474  return this->rfind(__s, __pos, traits_type::length(__s));
2475  }
2476 
2477  /**
2478  * @brief Find last position of a character.
2479  * @param __c Character to locate.
2480  * @param __pos Index of character to search back from (default end).
2481  * @return Index of last occurrence.
2482  *
2483  * Starting from @a __pos, searches backward for @a __c within
2484  * this string. If found, returns the index where it was
2485  * found. If not found, returns npos.
2486  */
2487  size_type
2488  rfind(_CharT __c, size_type __pos = npos) const _GLIBCXX_NOEXCEPT;
2489 
2490  /**
2491  * @brief Find position of a character of string.
2492  * @param __str String containing characters to locate.
2493  * @param __pos Index of character to search from (default 0).
2494  * @return Index of first occurrence.
2495  *
2496  * Starting from @a __pos, searches forward for one of the
2497  * characters of @a __str within this string. If found,
2498  * returns the index where it was found. If not found, returns
2499  * npos.
2500  */
2501  size_type
2502  find_first_of(const basic_string& __str, size_type __pos = 0) const
2503  _GLIBCXX_NOEXCEPT
2504  { return this->find_first_of(__str.data(), __pos, __str.size()); }
2505 
2506 #if __cplusplus >= 201703L
2507  /**
2508  * @brief Find position of a character of a string_view.
2509  * @param __svt An object convertible to string_view containing
2510  * characters to locate.
2511  * @param __pos Index of character to search from (default 0).
2512  * @return Index of first occurrence.
2513  */
2514  template<typename _Tp>
2515  _If_sv<_Tp, size_type>
2516  find_first_of(const _Tp& __svt, size_type __pos = 0) const
2517  noexcept(is_same<_Tp, __sv_type>::value)
2518  {
2519  __sv_type __sv = __svt;
2520  return this->find_first_of(__sv.data(), __pos, __sv.size());
2521  }
2522 #endif // C++17
2523 
2524  /**
2525  * @brief Find position of a character of C substring.
2526  * @param __s String containing characters to locate.
2527  * @param __pos Index of character to search from.
2528  * @param __n Number of characters from s to search for.
2529  * @return Index of first occurrence.
2530  *
2531  * Starting from @a __pos, searches forward for one of the
2532  * first @a __n characters of @a __s within this string. If
2533  * found, returns the index where it was found. If not found,
2534  * returns npos.
2535  */
2536  size_type
2537  find_first_of(const _CharT* __s, size_type __pos, size_type __n) const
2538  _GLIBCXX_NOEXCEPT;
2539 
2540  /**
2541  * @brief Find position of a character of C string.
2542  * @param __s String containing characters to locate.
2543  * @param __pos Index of character to search from (default 0).
2544  * @return Index of first occurrence.
2545  *
2546  * Starting from @a __pos, searches forward for one of the
2547  * characters of @a __s within this string. If found, returns
2548  * the index where it was found. If not found, returns npos.
2549  */
2550  size_type
2551  find_first_of(const _CharT* __s, size_type __pos = 0) const
2552  _GLIBCXX_NOEXCEPT
2553  {
2554  __glibcxx_requires_string(__s);
2555  return this->find_first_of(__s, __pos, traits_type::length(__s));
2556  }
2557 
2558  /**
2559  * @brief Find position of a character.
2560  * @param __c Character to locate.
2561  * @param __pos Index of character to search from (default 0).
2562  * @return Index of first occurrence.
2563  *
2564  * Starting from @a __pos, searches forward for the character
2565  * @a __c within this string. If found, returns the index
2566  * where it was found. If not found, returns npos.
2567  *
2568  * Note: equivalent to find(__c, __pos).
2569  */
2570  size_type
2571  find_first_of(_CharT __c, size_type __pos = 0) const _GLIBCXX_NOEXCEPT
2572  { return this->find(__c, __pos); }
2573 
2574  /**
2575  * @brief Find last position of a character of string.
2576  * @param __str String containing characters to locate.
2577  * @param __pos Index of character to search back from (default end).
2578  * @return Index of last occurrence.
2579  *
2580  * Starting from @a __pos, searches backward for one of the
2581  * characters of @a __str within this string. If found,
2582  * returns the index where it was found. If not found, returns
2583  * npos.
2584  */
2585  size_type
2586  find_last_of(const basic_string& __str, size_type __pos = npos) const
2587  _GLIBCXX_NOEXCEPT
2588  { return this->find_last_of(__str.data(), __pos, __str.size()); }
2589 
2590 #if __cplusplus >= 201703L
2591  /**
2592  * @brief Find last position of a character of string.
2593  * @param __svt An object convertible to string_view containing
2594  * characters to locate.
2595  * @param __pos Index of character to search back from (default end).
2596  * @return Index of last occurrence.
2597  */
2598  template<typename _Tp>
2599  _If_sv<_Tp, size_type>
2600  find_last_of(const _Tp& __svt, size_type __pos = npos) const
2601  noexcept(is_same<_Tp, __sv_type>::value)
2602  {
2603  __sv_type __sv = __svt;
2604  return this->find_last_of(__sv.data(), __pos, __sv.size());
2605  }
2606 #endif // C++17
2607 
2608  /**
2609  * @brief Find last position of a character of C substring.
2610  * @param __s C string containing characters to locate.
2611  * @param __pos Index of character to search back from.
2612  * @param __n Number of characters from s to search for.
2613  * @return Index of last occurrence.
2614  *
2615  * Starting from @a __pos, searches backward for one of the
2616  * first @a __n characters of @a __s within this string. If
2617  * found, returns the index where it was found. If not found,
2618  * returns npos.
2619  */
2620  size_type
2621  find_last_of(const _CharT* __s, size_type __pos, size_type __n) const
2622  _GLIBCXX_NOEXCEPT;
2623 
2624  /**
2625  * @brief Find last position of a character of C string.
2626  * @param __s C string containing characters to locate.
2627  * @param __pos Index of character to search back from (default end).
2628  * @return Index of last occurrence.
2629  *
2630  * Starting from @a __pos, searches backward for one of the
2631  * characters of @a __s within this string. If found, returns
2632  * the index where it was found. If not found, returns npos.
2633  */
2634  size_type
2635  find_last_of(const _CharT* __s, size_type __pos = npos) const
2636  _GLIBCXX_NOEXCEPT
2637  {
2638  __glibcxx_requires_string(__s);
2639  return this->find_last_of(__s, __pos, traits_type::length(__s));
2640  }
2641 
2642  /**
2643  * @brief Find last position of a character.
2644  * @param __c Character to locate.
2645  * @param __pos Index of character to search back from (default end).
2646  * @return Index of last occurrence.
2647  *
2648  * Starting from @a __pos, searches backward for @a __c within
2649  * this string. If found, returns the index where it was
2650  * found. If not found, returns npos.
2651  *
2652  * Note: equivalent to rfind(__c, __pos).
2653  */
2654  size_type
2655  find_last_of(_CharT __c, size_type __pos = npos) const _GLIBCXX_NOEXCEPT
2656  { return this->rfind(__c, __pos); }
2657 
2658  /**
2659  * @brief Find position of a character not in string.
2660  * @param __str String containing characters to avoid.
2661  * @param __pos Index of character to search from (default 0).
2662  * @return Index of first occurrence.
2663  *
2664  * Starting from @a __pos, searches forward for a character not contained
2665  * in @a __str within this string. If found, returns the index where it
2666  * was found. If not found, returns npos.
2667  */
2668  size_type
2669  find_first_not_of(const basic_string& __str, size_type __pos = 0) const
2670  _GLIBCXX_NOEXCEPT
2671  { return this->find_first_not_of(__str.data(), __pos, __str.size()); }
2672 
2673 #if __cplusplus >= 201703L
2674  /**
2675  * @brief Find position of a character not in a string_view.
2676  * @param __svt A object convertible to string_view containing
2677  * characters to avoid.
2678  * @param __pos Index of character to search from (default 0).
2679  * @return Index of first occurrence.
2680  */
2681  template<typename _Tp>
2682  _If_sv<_Tp, size_type>
2683  find_first_not_of(const _Tp& __svt, size_type __pos = 0) const
2684  noexcept(is_same<_Tp, __sv_type>::value)
2685  {
2686  __sv_type __sv = __svt;
2687  return this->find_first_not_of(__sv.data(), __pos, __sv.size());
2688  }
2689 #endif // C++17
2690 
2691  /**
2692  * @brief Find position of a character not in C substring.
2693  * @param __s C string containing characters to avoid.
2694  * @param __pos Index of character to search from.
2695  * @param __n Number of characters from __s to consider.
2696  * @return Index of first occurrence.
2697  *
2698  * Starting from @a __pos, searches forward for a character not
2699  * contained in the first @a __n characters of @a __s within
2700  * this string. If found, returns the index where it was
2701  * found. If not found, returns npos.
2702  */
2703  size_type
2704  find_first_not_of(const _CharT* __s, size_type __pos,
2705  size_type __n) const _GLIBCXX_NOEXCEPT;
2706 
2707  /**
2708  * @brief Find position of a character not in C string.
2709  * @param __s C string containing characters to avoid.
2710  * @param __pos Index of character to search from (default 0).
2711  * @return Index of first occurrence.
2712  *
2713  * Starting from @a __pos, searches forward for a character not
2714  * contained in @a __s within this string. If found, returns
2715  * the index where it was found. If not found, returns npos.
2716  */
2717  size_type
2718  find_first_not_of(const _CharT* __s, size_type __pos = 0) const
2719  _GLIBCXX_NOEXCEPT
2720  {
2721  __glibcxx_requires_string(__s);
2722  return this->find_first_not_of(__s, __pos, traits_type::length(__s));
2723  }
2724 
2725  /**
2726  * @brief Find position of a different character.
2727  * @param __c Character to avoid.
2728  * @param __pos Index of character to search from (default 0).
2729  * @return Index of first occurrence.
2730  *
2731  * Starting from @a __pos, searches forward for a character
2732  * other than @a __c within this string. If found, returns the
2733  * index where it was found. If not found, returns npos.
2734  */
2735  size_type
2736  find_first_not_of(_CharT __c, size_type __pos = 0) const
2737  _GLIBCXX_NOEXCEPT;
2738 
2739  /**
2740  * @brief Find last position of a character not in string.
2741  * @param __str String containing characters to avoid.
2742  * @param __pos Index of character to search back from (default end).
2743  * @return Index of last occurrence.
2744  *
2745  * Starting from @a __pos, searches backward for a character
2746  * not contained in @a __str within this string. If found,
2747  * returns the index where it was found. If not found, returns
2748  * npos.
2749  */
2750  size_type
2751  find_last_not_of(const basic_string& __str, size_type __pos = npos) const
2752  _GLIBCXX_NOEXCEPT
2753  { return this->find_last_not_of(__str.data(), __pos, __str.size()); }
2754 
2755 #if __cplusplus >= 201703L
2756  /**
2757  * @brief Find last position of a character not in a string_view.
2758  * @param __svt An object convertible to string_view containing
2759  * characters to avoid.
2760  * @param __pos Index of character to search back from (default end).
2761  * @return Index of last occurrence.
2762  */
2763  template<typename _Tp>
2764  _If_sv<_Tp, size_type>
2765  find_last_not_of(const _Tp& __svt, size_type __pos = npos) const
2766  noexcept(is_same<_Tp, __sv_type>::value)
2767  {
2768  __sv_type __sv = __svt;
2769  return this->find_last_not_of(__sv.data(), __pos, __sv.size());
2770  }
2771 #endif // C++17
2772 
2773  /**
2774  * @brief Find last position of a character not in C substring.
2775  * @param __s C string containing characters to avoid.
2776  * @param __pos Index of character to search back from.
2777  * @param __n Number of characters from s to consider.
2778  * @return Index of last occurrence.
2779  *
2780  * Starting from @a __pos, searches backward for a character not
2781  * contained in the first @a __n characters of @a __s within this string.
2782  * If found, returns the index where it was found. If not found,
2783  * returns npos.
2784  */
2785  size_type
2786  find_last_not_of(const _CharT* __s, size_type __pos,
2787  size_type __n) const _GLIBCXX_NOEXCEPT;
2788  /**
2789  * @brief Find last position of a character not in C string.
2790  * @param __s C string containing characters to avoid.
2791  * @param __pos Index of character to search back from (default end).
2792  * @return Index of last occurrence.
2793  *
2794  * Starting from @a __pos, searches backward for a character
2795  * not contained in @a __s within this string. If found,
2796  * returns the index where it was found. If not found, returns
2797  * npos.
2798  */
2799  size_type
2800  find_last_not_of(const _CharT* __s, size_type __pos = npos) const
2801  _GLIBCXX_NOEXCEPT
2802  {
2803  __glibcxx_requires_string(__s);
2804  return this->find_last_not_of(__s, __pos, traits_type::length(__s));
2805  }
2806 
2807  /**
2808  * @brief Find last position of a different character.
2809  * @param __c Character to avoid.
2810  * @param __pos Index of character to search back from (default end).
2811  * @return Index of last occurrence.
2812  *
2813  * Starting from @a __pos, searches backward for a character other than
2814  * @a __c within this string. If found, returns the index where it was
2815  * found. If not found, returns npos.
2816  */
2817  size_type
2818  find_last_not_of(_CharT __c, size_type __pos = npos) const
2819  _GLIBCXX_NOEXCEPT;
2820 
2821  /**
2822  * @brief Get a substring.
2823  * @param __pos Index of first character (default 0).
2824  * @param __n Number of characters in substring (default remainder).
2825  * @return The new string.
2826  * @throw std::out_of_range If __pos > size().
2827  *
2828  * Construct and return a new string using the @a __n
2829  * characters starting at @a __pos. If the string is too
2830  * short, use the remainder of the characters. If @a __pos is
2831  * beyond the end of the string, out_of_range is thrown.
2832  */
2833  basic_string
2834  substr(size_type __pos = 0, size_type __n = npos) const
2835  { return basic_string(*this,
2836  _M_check(__pos, "basic_string::substr"), __n); }
2837 
2838  /**
2839  * @brief Compare to a string.
2840  * @param __str String to compare against.
2841  * @return Integer < 0, 0, or > 0.
2842  *
2843  * Returns an integer < 0 if this string is ordered before @a
2844  * __str, 0 if their values are equivalent, or > 0 if this
2845  * string is ordered after @a __str. Determines the effective
2846  * length rlen of the strings to compare as the smallest of
2847  * size() and str.size(). The function then compares the two
2848  * strings by calling traits::compare(data(), str.data(),rlen).
2849  * If the result of the comparison is nonzero returns it,
2850  * otherwise the shorter one is ordered first.
2851  */
2852  int
2853  compare(const basic_string& __str) const
2854  {
2855  const size_type __size = this->size();
2856  const size_type __osize = __str.size();
2857  const size_type __len = std::min(__size, __osize);
2858 
2859  int __r = traits_type::compare(_M_data(), __str.data(), __len);
2860  if (!__r)
2861  __r = _S_compare(__size, __osize);
2862  return __r;
2863  }
2864 
2865 #if __cplusplus >= 201703L
2866  /**
2867  * @brief Compare to a string_view.
2868  * @param __svt An object convertible to string_view to compare against.
2869  * @return Integer < 0, 0, or > 0.
2870  */
2871  template<typename _Tp>
2872  _If_sv<_Tp, int>
2873  compare(const _Tp& __svt) const
2874  noexcept(is_same<_Tp, __sv_type>::value)
2875  {
2876  __sv_type __sv = __svt;
2877  const size_type __size = this->size();
2878  const size_type __osize = __sv.size();
2879  const size_type __len = std::min(__size, __osize);
2880 
2881  int __r = traits_type::compare(_M_data(), __sv.data(), __len);
2882  if (!__r)
2883  __r = _S_compare(__size, __osize);
2884  return __r;
2885  }
2886 
2887  /**
2888  * @brief Compare to a string_view.
2889  * @param __pos A position in the string to start comparing from.
2890  * @param __n The number of characters to compare.
2891  * @param __svt An object convertible to string_view to compare
2892  * against.
2893  * @return Integer < 0, 0, or > 0.
2894  */
2895  template<typename _Tp>
2896  _If_sv<_Tp, int>
2897  compare(size_type __pos, size_type __n, const _Tp& __svt) const
2898  noexcept(is_same<_Tp, __sv_type>::value)
2899  {
2900  __sv_type __sv = __svt;
2901  return __sv_type(*this).substr(__pos, __n).compare(__sv);
2902  }
2903 
2904  /**
2905  * @brief Compare to a string_view.
2906  * @param __pos1 A position in the string to start comparing from.
2907  * @param __n1 The number of characters to compare.
2908  * @param __svt An object convertible to string_view to compare
2909  * against.
2910  * @param __pos2 A position in the string_view to start comparing from.
2911  * @param __n2 The number of characters to compare.
2912  * @return Integer < 0, 0, or > 0.
2913  */
2914  template<typename _Tp>
2915  _If_sv<_Tp, int>
2916  compare(size_type __pos1, size_type __n1, const _Tp& __svt,
2917  size_type __pos2, size_type __n2 = npos) const
2918  noexcept(is_same<_Tp, __sv_type>::value)
2919  {
2920  __sv_type __sv = __svt;
2921  return __sv_type(*this)
2922  .substr(__pos1, __n1).compare(__sv.substr(__pos2, __n2));
2923  }
2924 #endif // C++17
2925 
2926  /**
2927  * @brief Compare substring to a string.
2928  * @param __pos Index of first character of substring.
2929  * @param __n Number of characters in substring.
2930  * @param __str String to compare against.
2931  * @return Integer < 0, 0, or > 0.
2932  *
2933  * Form the substring of this string from the @a __n characters
2934  * starting at @a __pos. Returns an integer < 0 if the
2935  * substring is ordered before @a __str, 0 if their values are
2936  * equivalent, or > 0 if the substring is ordered after @a
2937  * __str. Determines the effective length rlen of the strings
2938  * to compare as the smallest of the length of the substring
2939  * and @a __str.size(). The function then compares the two
2940  * strings by calling
2941  * traits::compare(substring.data(),str.data(),rlen). If the
2942  * result of the comparison is nonzero returns it, otherwise
2943  * the shorter one is ordered first.
2944  */
2945  int
2946  compare(size_type __pos, size_type __n, const basic_string& __str) const;
2947 
2948  /**
2949  * @brief Compare substring to a substring.
2950  * @param __pos1 Index of first character of substring.
2951  * @param __n1 Number of characters in substring.
2952  * @param __str String to compare against.
2953  * @param __pos2 Index of first character of substring of str.
2954  * @param __n2 Number of characters in substring of str.
2955  * @return Integer < 0, 0, or > 0.
2956  *
2957  * Form the substring of this string from the @a __n1
2958  * characters starting at @a __pos1. Form the substring of @a
2959  * __str from the @a __n2 characters starting at @a __pos2.
2960  * Returns an integer < 0 if this substring is ordered before
2961  * the substring of @a __str, 0 if their values are equivalent,
2962  * or > 0 if this substring is ordered after the substring of
2963  * @a __str. Determines the effective length rlen of the
2964  * strings to compare as the smallest of the lengths of the
2965  * substrings. The function then compares the two strings by
2966  * calling
2967  * traits::compare(substring.data(),str.substr(pos2,n2).data(),rlen).
2968  * If the result of the comparison is nonzero returns it,
2969  * otherwise the shorter one is ordered first.
2970  */
2971  int
2972  compare(size_type __pos1, size_type __n1, const basic_string& __str,
2973  size_type __pos2, size_type __n2 = npos) const;
2974 
2975  /**
2976  * @brief Compare to a C string.
2977  * @param __s C string to compare against.
2978  * @return Integer < 0, 0, or > 0.
2979  *
2980  * Returns an integer < 0 if this string is ordered before @a __s, 0 if
2981  * their values are equivalent, or > 0 if this string is ordered after
2982  * @a __s. Determines the effective length rlen of the strings to
2983  * compare as the smallest of size() and the length of a string
2984  * constructed from @a __s. The function then compares the two strings
2985  * by calling traits::compare(data(),s,rlen). If the result of the
2986  * comparison is nonzero returns it, otherwise the shorter one is
2987  * ordered first.
2988  */
2989  int
2990  compare(const _CharT* __s) const _GLIBCXX_NOEXCEPT;
2991 
2992  // _GLIBCXX_RESOLVE_LIB_DEFECTS
2993  // 5 String::compare specification questionable
2994  /**
2995  * @brief Compare substring to a C string.
2996  * @param __pos Index of first character of substring.
2997  * @param __n1 Number of characters in substring.
2998  * @param __s C string to compare against.
2999  * @return Integer < 0, 0, or > 0.
3000  *
3001  * Form the substring of this string from the @a __n1
3002  * characters starting at @a pos. Returns an integer < 0 if
3003  * the substring is ordered before @a __s, 0 if their values
3004  * are equivalent, or > 0 if the substring is ordered after @a
3005  * __s. Determines the effective length rlen of the strings to
3006  * compare as the smallest of the length of the substring and
3007  * the length of a string constructed from @a __s. The
3008  * function then compares the two string by calling
3009  * traits::compare(substring.data(),__s,rlen). If the result of
3010  * the comparison is nonzero returns it, otherwise the shorter
3011  * one is ordered first.
3012  */
3013  int
3014  compare(size_type __pos, size_type __n1, const _CharT* __s) const;
3015 
3016  /**
3017  * @brief Compare substring against a character %array.
3018  * @param __pos Index of first character of substring.
3019  * @param __n1 Number of characters in substring.
3020  * @param __s character %array to compare against.
3021  * @param __n2 Number of characters of s.
3022  * @return Integer < 0, 0, or > 0.
3023  *
3024  * Form the substring of this string from the @a __n1
3025  * characters starting at @a __pos. Form a string from the
3026  * first @a __n2 characters of @a __s. Returns an integer < 0
3027  * if this substring is ordered before the string from @a __s,
3028  * 0 if their values are equivalent, or > 0 if this substring
3029  * is ordered after the string from @a __s. Determines the
3030  * effective length rlen of the strings to compare as the
3031  * smallest of the length of the substring and @a __n2. The
3032  * function then compares the two strings by calling
3033  * traits::compare(substring.data(),s,rlen). If the result of
3034  * the comparison is nonzero returns it, otherwise the shorter
3035  * one is ordered first.
3036  *
3037  * NB: s must have at least n2 characters, &apos;\\0&apos; has
3038  * no special meaning.
3039  */
3040  int
3041  compare(size_type __pos, size_type __n1, const _CharT* __s,
3042  size_type __n2) const;
3043 
3044 #if __cplusplus > 201703L
3045  bool
3046  starts_with(basic_string_view<_CharT, _Traits> __x) const noexcept
3047  { return __sv_type(this->data(), this->size()).starts_with(__x); }
3048 
3049  bool
3050  starts_with(_CharT __x) const noexcept
3051  { return __sv_type(this->data(), this->size()).starts_with(__x); }
3052 
3053  bool
3054  starts_with(const _CharT* __x) const noexcept
3055  { return __sv_type(this->data(), this->size()).starts_with(__x); }
3056 
3057  bool
3058  ends_with(basic_string_view<_CharT, _Traits> __x) const noexcept
3059  { return __sv_type(this->data(), this->size()).ends_with(__x); }
3060 
3061  bool
3062  ends_with(_CharT __x) const noexcept
3063  { return __sv_type(this->data(), this->size()).ends_with(__x); }
3064 
3065  bool
3066  ends_with(const _CharT* __x) const noexcept
3067  { return __sv_type(this->data(), this->size()).ends_with(__x); }
3068 #endif // C++20
3069 
3070  // Allow basic_stringbuf::__xfer_bufptrs to call _M_length:
3071  template<typename, typename, typename> friend class basic_stringbuf;
3072  };
3073 _GLIBCXX_END_NAMESPACE_CXX11
3074 #else // !_GLIBCXX_USE_CXX11_ABI
3075  // Reference-counted COW string implentation
3076 
3077  /**
3078  * @class basic_string basic_string.h <string>
3079  * @brief Managing sequences of characters and character-like objects.
3080  *
3081  * @ingroup strings
3082  * @ingroup sequences
3083  *
3084  * @tparam _CharT Type of character
3085  * @tparam _Traits Traits for character type, defaults to
3086  * char_traits<_CharT>.
3087  * @tparam _Alloc Allocator type, defaults to allocator<_CharT>.
3088  *
3089  * Meets the requirements of a <a href="tables.html#65">container</a>, a
3090  * <a href="tables.html#66">reversible container</a>, and a
3091  * <a href="tables.html#67">sequence</a>. Of the
3092  * <a href="tables.html#68">optional sequence requirements</a>, only
3093  * @c push_back, @c at, and @c %array access are supported.
3094  *
3095  * @doctodo
3096  *
3097  *
3098  * Documentation? What's that?
3099  * Nathan Myers <[email protected]>.
3100  *
3101  * A string looks like this:
3102  *
3103  * @code
3104  * [_Rep]
3105  * _M_length
3106  * [basic_string<char_type>] _M_capacity
3107  * _M_dataplus _M_refcount
3108  * _M_p ----------------> unnamed array of char_type
3109  * @endcode
3110  *
3111  * Where the _M_p points to the first character in the string, and
3112  * you cast it to a pointer-to-_Rep and subtract 1 to get a
3113  * pointer to the header.
3114  *
3115  * This approach has the enormous advantage that a string object
3116  * requires only one allocation. All the ugliness is confined
3117  * within a single %pair of inline functions, which each compile to
3118  * a single @a add instruction: _Rep::_M_data(), and
3119  * string::_M_rep(); and the allocation function which gets a
3120  * block of raw bytes and with room enough and constructs a _Rep
3121  * object at the front.
3122  *
3123  * The reason you want _M_data pointing to the character %array and
3124  * not the _Rep is so that the debugger can see the string
3125  * contents. (Probably we should add a non-inline member to get
3126  * the _Rep for the debugger to use, so users can check the actual
3127  * string length.)
3128  *
3129  * Note that the _Rep object is a POD so that you can have a
3130  * static <em>empty string</em> _Rep object already @a constructed before
3131  * static constructors have run. The reference-count encoding is
3132  * chosen so that a 0 indicates one reference, so you never try to
3133  * destroy the empty-string _Rep object.
3134  *
3135  * All but the last paragraph is considered pretty conventional
3136  * for a C++ string implementation.
3137  */
3138  // 21.3 Template class basic_string
3139  template<typename _CharT, typename _Traits, typename _Alloc>
3141  {
3142  typedef typename _Alloc::template rebind<_CharT>::other _CharT_alloc_type;
3143 
3144  // Types:
3145  public:
3146  typedef _Traits traits_type;
3147  typedef typename _Traits::char_type value_type;
3148  typedef _Alloc allocator_type;
3149  typedef typename _CharT_alloc_type::size_type size_type;
3150  typedef typename _CharT_alloc_type::difference_type difference_type;
3151 #if __cplusplus < 201103L
3152  typedef typename _CharT_alloc_type::reference reference;
3153  typedef typename _CharT_alloc_type::const_reference const_reference;
3154 #else
3155  typedef value_type& reference;
3156  typedef const value_type& const_reference;
3157 #endif
3158  typedef typename _CharT_alloc_type::pointer pointer;
3159  typedef typename _CharT_alloc_type::const_pointer const_pointer;
3160  typedef __gnu_cxx::__normal_iterator<pointer, basic_string> iterator;
3161  typedef __gnu_cxx::__normal_iterator<const_pointer, basic_string>
3162  const_iterator;
3165 
3166  protected:
3167  // type used for positions in insert, erase etc.
3168  typedef iterator __const_iterator;
3169 
3170  private:
3171  // _Rep: string representation
3172  // Invariants:
3173  // 1. String really contains _M_length + 1 characters: due to 21.3.4
3174  // must be kept null-terminated.
3175  // 2. _M_capacity >= _M_length
3176  // Allocated memory is always (_M_capacity + 1) * sizeof(_CharT).
3177  // 3. _M_refcount has three states:
3178  // -1: leaked, one reference, no ref-copies allowed, non-const.
3179  // 0: one reference, non-const.
3180  // n>0: n + 1 references, operations require a lock, const.
3181  // 4. All fields==0 is an empty string, given the extra storage
3182  // beyond-the-end for a null terminator; thus, the shared
3183  // empty string representation needs no constructor.
3184 
3185  struct _Rep_base
3186  {
3187  size_type _M_length;
3188  size_type _M_capacity;
3189  _Atomic_word _M_refcount;
3190  };
3191 
3192  struct _Rep : _Rep_base
3193  {
3194  // Types:
3195  typedef typename _Alloc::template rebind<char>::other _Raw_bytes_alloc;
3196 
3197  // (Public) Data members:
3198 
3199  // The maximum number of individual char_type elements of an
3200  // individual string is determined by _S_max_size. This is the
3201  // value that will be returned by max_size(). (Whereas npos
3202  // is the maximum number of bytes the allocator can allocate.)
3203  // If one was to divvy up the theoretical largest size string,
3204  // with a terminating character and m _CharT elements, it'd
3205  // look like this:
3206  // npos = sizeof(_Rep) + (m * sizeof(_CharT)) + sizeof(_CharT)
3207  // Solving for m:
3208  // m = ((npos - sizeof(_Rep))/sizeof(CharT)) - 1
3209  // In addition, this implementation quarters this amount.
3210  static const size_type _S_max_size;
3211  static const _CharT _S_terminal;
3212 
3213  // The following storage is init'd to 0 by the linker, resulting
3214  // (carefully) in an empty string with one reference.
3215  static size_type _S_empty_rep_storage[];
3216 
3217  static _Rep&
3218  _S_empty_rep() _GLIBCXX_NOEXCEPT
3219  {
3220  // NB: Mild hack to avoid strict-aliasing warnings. Note that
3221  // _S_empty_rep_storage is never modified and the punning should
3222  // be reasonably safe in this case.
3223  void* __p = reinterpret_cast<void*>(&_S_empty_rep_storage);
3224  return *reinterpret_cast<_Rep*>(__p);
3225  }
3226 
3227  bool
3228  _M_is_leaked() const _GLIBCXX_NOEXCEPT
3229  {
3230 #if defined(__GTHREADS)
3231  // _M_refcount is mutated concurrently by _M_refcopy/_M_dispose,
3232  // so we need to use an atomic load. However, _M_is_leaked
3233  // predicate does not change concurrently (i.e. the string is either
3234  // leaked or not), so a relaxed load is enough.
3235  return __atomic_load_n(&this->_M_refcount, __ATOMIC_RELAXED) < 0;
3236 #else
3237  return this->_M_refcount < 0;
3238 #endif
3239  }
3240 
3241  bool
3242  _M_is_shared() const _GLIBCXX_NOEXCEPT
3243  {
3244 #if defined(__GTHREADS)
3245  // _M_refcount is mutated concurrently by _M_refcopy/_M_dispose,
3246  // so we need to use an atomic load. Another thread can drop last
3247  // but one reference concurrently with this check, so we need this
3248  // load to be acquire to synchronize with release fetch_and_add in
3249  // _M_dispose.
3250  return __atomic_load_n(&this->_M_refcount, __ATOMIC_ACQUIRE) > 0;
3251 #else
3252  return this->_M_refcount > 0;
3253 #endif
3254  }
3255 
3256  void
3257  _M_set_leaked() _GLIBCXX_NOEXCEPT
3258  { this->_M_refcount = -1; }
3259 
3260  void
3261  _M_set_sharable() _GLIBCXX_NOEXCEPT
3262  { this->_M_refcount = 0; }
3263 
3264  void
3265  _M_set_length_and_sharable(size_type __n) _GLIBCXX_NOEXCEPT
3266  {
3267 #if _GLIBCXX_FULLY_DYNAMIC_STRING == 0
3268  if (__builtin_expect(this != &_S_empty_rep(), false))
3269 #endif
3270  {
3271  this->_M_set_sharable(); // One reference.
3272  this->_M_length = __n;
3273  traits_type::assign(this->_M_refdata()[__n], _S_terminal);
3274  // grrr. (per 21.3.4)
3275  // You cannot leave those LWG people alone for a second.
3276  }
3277  }
3278 
3279  _CharT*
3280  _M_refdata() throw()
3281  { return reinterpret_cast<_CharT*>(this + 1); }
3282 
3283  _CharT*
3284  _M_grab(const _Alloc& __alloc1, const _Alloc& __alloc2)
3285  {
3286  return (!_M_is_leaked() && __alloc1 == __alloc2)
3287  ? _M_refcopy() : _M_clone(__alloc1);
3288  }
3289 
3290  // Create & Destroy
3291  static _Rep*
3292  _S_create(size_type, size_type, const _Alloc&);
3293 
3294  void
3295  _M_dispose(const _Alloc& __a) _GLIBCXX_NOEXCEPT
3296  {
3297 #if _GLIBCXX_FULLY_DYNAMIC_STRING == 0
3298  if (__builtin_expect(this != &_S_empty_rep(), false))
3299 #endif
3300  {
3301  // Be race-detector-friendly. For more info see bits/c++config.
3302  _GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&this->_M_refcount);
3303  // Decrement of _M_refcount is acq_rel, because:
3304  // - all but last decrements need to release to synchronize with
3305  // the last decrement that will delete the object.
3306  // - the last decrement needs to acquire to synchronize with
3307  // all the previous decrements.
3308  // - last but one decrement needs to release to synchronize with
3309  // the acquire load in _M_is_shared that will conclude that
3310  // the object is not shared anymore.
3311  if (__gnu_cxx::__exchange_and_add_dispatch(&this->_M_refcount,
3312  -1) <= 0)
3313  {
3314  _GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&this->_M_refcount);
3315  _M_destroy(__a);
3316  }
3317  }
3318  } // XXX MT
3319 
3320  void
3321  _M_destroy(const _Alloc&) throw();
3322 
3323  _CharT*
3324  _M_refcopy() throw()
3325  {
3326 #if _GLIBCXX_FULLY_DYNAMIC_STRING == 0
3327  if (__builtin_expect(this != &_S_empty_rep(), false))
3328 #endif
3329  __gnu_cxx::__atomic_add_dispatch(&this->_M_refcount, 1);
3330  return _M_refdata();
3331  } // XXX MT
3332 
3333  _CharT*
3334  _M_clone(const _Alloc&, size_type __res = 0);
3335  };
3336 
3337  // Use empty-base optimization: http://www.cantrip.org/emptyopt.html
3338  struct _Alloc_hider : _Alloc
3339  {
3340  _Alloc_hider(_CharT* __dat, const _Alloc& __a) _GLIBCXX_NOEXCEPT
3341  : _Alloc(__a), _M_p(__dat) { }
3342 
3343  _CharT* _M_p; // The actual data.
3344  };
3345 
3346  public:
3347  // Data Members (public):
3348  // NB: This is an unsigned type, and thus represents the maximum
3349  // size that the allocator can hold.
3350  /// Value returned by various member functions when they fail.
3351  static const size_type npos = static_cast<size_type>(-1);
3352 
3353  private:
3354  // Data Members (private):
3355  mutable _Alloc_hider _M_dataplus;
3356 
3357  _CharT*
3358  _M_data() const _GLIBCXX_NOEXCEPT
3359  { return _M_dataplus._M_p; }
3360 
3361  _CharT*
3362  _M_data(_CharT* __p) _GLIBCXX_NOEXCEPT
3363  { return (_M_dataplus._M_p = __p); }
3364 
3365  _Rep*
3366  _M_rep() const _GLIBCXX_NOEXCEPT
3367  { return &((reinterpret_cast<_Rep*> (_M_data()))[-1]); }
3368 
3369  // For the internal use we have functions similar to `begin'/`end'
3370  // but they do not call _M_leak.
3371  iterator
3372  _M_ibegin() const _GLIBCXX_NOEXCEPT
3373  { return iterator(_M_data()); }
3374 
3375  iterator
3376  _M_iend() const _GLIBCXX_NOEXCEPT
3377  { return iterator(_M_data() + this->size()); }
3378 
3379  void
3380  _M_leak() // for use in begin() & non-const op[]
3381  {
3382  if (!_M_rep()->_M_is_leaked())
3383  _M_leak_hard();
3384  }
3385 
3386  size_type
3387  _M_check(size_type __pos, const char* __s) const
3388  {
3389  if (__pos > this->size())
3390  __throw_out_of_range_fmt(__N("%s: __pos (which is %zu) > "
3391  "this->size() (which is %zu)"),
3392  __s, __pos, this->size());
3393  return __pos;
3394  }
3395 
3396  void
3397  _M_check_length(size_type __n1, size_type __n2, const char* __s) const
3398  {
3399  if (this->max_size() - (this->size() - __n1) < __n2)
3400  __throw_length_error(__N(__s));
3401  }
3402 
3403  // NB: _M_limit doesn't check for a bad __pos value.
3404  size_type
3405  _M_limit(size_type __pos, size_type __off) const _GLIBCXX_NOEXCEPT
3406  {
3407  const bool __testoff = __off < this->size() - __pos;
3408  return __testoff ? __off : this->size() - __pos;
3409  }
3410 
3411  // True if _Rep and source do not overlap.
3412  bool
3413  _M_disjunct(const _CharT* __s) const _GLIBCXX_NOEXCEPT
3414  {
3415  return (less<const _CharT*>()(__s, _M_data())
3416  || less<const _CharT*>()(_M_data() + this->size(), __s));
3417  }
3418 
3419  // When __n = 1 way faster than the general multichar
3420  // traits_type::copy/move/assign.
3421  static void
3422  _M_copy(_CharT* __d, const _CharT* __s, size_type __n) _GLIBCXX_NOEXCEPT
3423  {
3424  if (__n == 1)
3425  traits_type::assign(*__d, *__s);
3426  else
3427  traits_type::copy(__d, __s, __n);
3428  }
3429 
3430  static void
3431  _M_move(_CharT* __d, const _CharT* __s, size_type __n) _GLIBCXX_NOEXCEPT
3432  {
3433  if (__n == 1)
3434  traits_type::assign(*__d, *__s);
3435  else
3436  traits_type::move(__d, __s, __n);
3437  }
3438 
3439  static void
3440  _M_assign(_CharT* __d, size_type __n, _CharT __c) _GLIBCXX_NOEXCEPT
3441  {
3442  if (__n == 1)
3443  traits_type::assign(*__d, __c);
3444  else
3445  traits_type::assign(__d, __n, __c);
3446  }
3447 
3448  // _S_copy_chars is a separate template to permit specialization
3449  // to optimize for the common case of pointers as iterators.
3450  template<class _Iterator>
3451  static void
3452  _S_copy_chars(_CharT* __p, _Iterator __k1, _Iterator __k2)
3453  {
3454  for (; __k1 != __k2; ++__k1, (void)++__p)
3455  traits_type::assign(*__p, *__k1); // These types are off.
3456  }
3457 
3458  static void
3459  _S_copy_chars(_CharT* __p, iterator __k1, iterator __k2) _GLIBCXX_NOEXCEPT
3460  { _S_copy_chars(__p, __k1.base(), __k2.base()); }
3461 
3462  static void
3463  _S_copy_chars(_CharT* __p, const_iterator __k1, const_iterator __k2)
3464  _GLIBCXX_NOEXCEPT
3465  { _S_copy_chars(__p, __k1.base(), __k2.base()); }
3466 
3467  static void
3468  _S_copy_chars(_CharT* __p, _CharT* __k1, _CharT* __k2) _GLIBCXX_NOEXCEPT
3469  { _M_copy(__p, __k1, __k2 - __k1); }
3470 
3471  static void
3472  _S_copy_chars(_CharT* __p, const _CharT* __k1, const _CharT* __k2)
3473  _GLIBCXX_NOEXCEPT
3474  { _M_copy(__p, __k1, __k2 - __k1); }
3475 
3476  static int
3477  _S_compare(size_type __n1, size_type __n2) _GLIBCXX_NOEXCEPT
3478  {
3479  const difference_type __d = difference_type(__n1 - __n2);
3480 
3481  if (__d > __gnu_cxx::__numeric_traits<int>::__max)
3482  return __gnu_cxx::__numeric_traits<int>::__max;
3483  else if (__d < __gnu_cxx::__numeric_traits<int>::__min)
3484  return __gnu_cxx::__numeric_traits<int>::__min;
3485  else
3486  return int(__d);
3487  }
3488 
3489  void
3490  _M_mutate(size_type __pos, size_type __len1, size_type __len2);
3491 
3492  void
3493  _M_leak_hard();
3494 
3495  static _Rep&
3496  _S_empty_rep() _GLIBCXX_NOEXCEPT
3497  { return _Rep::_S_empty_rep(); }
3498 
3499 #if __cplusplus >= 201703L
3500  // A helper type for avoiding boiler-plate.
3501  typedef basic_string_view<_CharT, _Traits> __sv_type;
3502 
3503  template<typename _Tp, typename _Res>
3504  using _If_sv = enable_if_t<
3505  __and_<is_convertible<const _Tp&, __sv_type>,
3506  __not_<is_convertible<const _Tp*, const basic_string*>>,
3507  __not_<is_convertible<const _Tp&, const _CharT*>>>::value,
3508  _Res>;
3509 
3510  // Allows an implicit conversion to __sv_type.
3511  static __sv_type
3512  _S_to_string_view(__sv_type __svt) noexcept
3513  { return __svt; }
3514 
3515  // Wraps a string_view by explicit conversion and thus
3516  // allows to add an internal constructor that does not
3517  // participate in overload resolution when a string_view
3518  // is provided.
3519  struct __sv_wrapper
3520  {
3521  explicit __sv_wrapper(__sv_type __sv) noexcept : _M_sv(__sv) { }
3522  __sv_type _M_sv;
3523  };
3524 
3525  /**
3526  * @brief Only internally used: Construct string from a string view
3527  * wrapper.
3528  * @param __svw string view wrapper.
3529  * @param __a Allocator to use.
3530  */
3531  explicit
3532  basic_string(__sv_wrapper __svw, const _Alloc& __a)
3533  : basic_string(__svw._M_sv.data(), __svw._M_sv.size(), __a) { }
3534 #endif
3535 
3536  public:
3537  // Construct/copy/destroy:
3538  // NB: We overload ctors in some cases instead of using default
3539  // arguments, per 17.4.4.4 para. 2 item 2.
3540 
3541  /**
3542  * @brief Default constructor creates an empty string.
3543  */
3545 #if _GLIBCXX_FULLY_DYNAMIC_STRING == 0
3546  _GLIBCXX_NOEXCEPT
3547  : _M_dataplus(_S_empty_rep()._M_refdata(), _Alloc())
3548 #else
3549  : _M_dataplus(_S_construct(size_type(), _CharT(), _Alloc()), _Alloc())
3550 #endif
3551  { }
3552 
3553  /**
3554  * @brief Construct an empty string using allocator @a a.
3555  */
3556  explicit
3557  basic_string(const _Alloc& __a);
3558 
3559  // NB: per LWG issue 42, semantics different from IS:
3560  /**
3561  * @brief Construct string with copy of value of @a str.
3562  * @param __str Source string.
3563  */
3564  basic_string(const basic_string& __str);
3565 
3566  // _GLIBCXX_RESOLVE_LIB_DEFECTS
3567  // 2583. no way to supply an allocator for basic_string(str, pos)
3568  /**
3569  * @brief Construct string as copy of a substring.
3570  * @param __str Source string.
3571  * @param __pos Index of first character to copy from.
3572  * @param __a Allocator to use.
3573  */
3574  basic_string(const basic_string& __str, size_type __pos,
3575  const _Alloc& __a = _Alloc());
3576 
3577  /**
3578  * @brief Construct string as copy of a substring.
3579  * @param __str Source string.
3580  * @param __pos Index of first character to copy from.
3581  * @param __n Number of characters to copy.
3582  */
3583  basic_string(const basic_string& __str, size_type __pos,
3584  size_type __n);
3585  /**
3586  * @brief Construct string as copy of a substring.
3587  * @param __str Source string.
3588  * @param __pos Index of first character to copy from.
3589  * @param __n Number of characters to copy.
3590  * @param __a Allocator to use.
3591  */
3592  basic_string(const basic_string& __str, size_type __pos,
3593  size_type __n, const _Alloc& __a);
3594 
3595  /**
3596  * @brief Construct string initialized by a character %array.
3597  * @param __s Source character %array.
3598  * @param __n Number of characters to copy.
3599  * @param __a Allocator to use (default is default allocator).
3600  *
3601  * NB: @a __s must have at least @a __n characters, &apos;\\0&apos;
3602  * has no special meaning.
3603  */
3604  basic_string(const _CharT* __s, size_type __n,
3605  const _Alloc& __a = _Alloc());
3606  /**
3607  * @brief Construct string as copy of a C string.
3608  * @param __s Source C string.
3609  * @param __a Allocator to use (default is default allocator).
3610  */
3611  basic_string(const _CharT* __s, const _Alloc& __a = _Alloc());
3612  /**
3613  * @brief Construct string as multiple characters.
3614  * @param __n Number of characters.
3615  * @param __c Character to use.
3616  * @param __a Allocator to use (default is default allocator).
3617  */
3618  basic_string(size_type __n, _CharT __c, const _Alloc& __a = _Alloc());
3619 
3620 #if __cplusplus >= 201103L
3621  /**
3622  * @brief Move construct string.
3623  * @param __str Source string.
3624  *
3625  * The newly-created string contains the exact contents of @a __str.
3626  * @a __str is a valid, but unspecified string.
3627  **/
3629 #if _GLIBCXX_FULLY_DYNAMIC_STRING == 0
3630  noexcept // FIXME C++11: should always be noexcept.
3631 #endif
3632  : _M_dataplus(std::move(__str._M_dataplus))
3633  {
3634 #if _GLIBCXX_FULLY_DYNAMIC_STRING == 0
3635  __str._M_data(_S_empty_rep()._M_refdata());
3636 #else
3637  __str._M_data(_S_construct(size_type(), _CharT(), get_allocator()));
3638 #endif
3639  }
3640 
3641  /**
3642  * @brief Construct string from an initializer %list.
3643  * @param __l std::initializer_list of characters.
3644  * @param __a Allocator to use (default is default allocator).
3645  */
3646  basic_string(initializer_list<_CharT> __l, const _Alloc& __a = _Alloc());
3647 
3648  basic_string(const basic_string& __str, const _Alloc& __a)
3649  : _M_dataplus(__str._M_rep()->_M_grab(__a, __str.get_allocator()), __a)
3650  { }
3651 
3652  basic_string(basic_string&& __str, const _Alloc& __a)
3653  : _M_dataplus(__str._M_data(), __a)
3654  {
3655  if (__a == __str.get_allocator())
3656  {
3657 #if _GLIBCXX_FULLY_DYNAMIC_STRING == 0
3658  __str._M_data(_S_empty_rep()._M_refdata());
3659 #else
3660  __str._M_data(_S_construct(size_type(), _CharT(), __a));
3661 #endif
3662  }
3663  else
3664  _M_dataplus._M_p = _S_construct(__str.begin(), __str.end(), __a);
3665  }
3666 #endif // C++11
3667 
3668  /**
3669  * @brief Construct string as copy of a range.
3670  * @param __beg Start of range.
3671  * @param __end End of range.
3672  * @param __a Allocator to use (default is default allocator).
3673  */
3674  template<class _InputIterator>
3675  basic_string(_InputIterator __beg, _InputIterator __end,
3676  const _Alloc& __a = _Alloc());
3677 
3678 #if __cplusplus >= 201703L
3679  /**
3680  * @brief Construct string from a substring of a string_view.
3681  * @param __t Source object convertible to string view.
3682  * @param __pos The index of the first character to copy from __t.
3683  * @param __n The number of characters to copy from __t.
3684  * @param __a Allocator to use.
3685  */
3686  template<typename _Tp, typename = _If_sv<_Tp, void>>
3687  basic_string(const _Tp& __t, size_type __pos, size_type __n,
3688  const _Alloc& __a = _Alloc())
3689  : basic_string(_S_to_string_view(__t).substr(__pos, __n), __a) { }
3690 
3691  /**
3692  * @brief Construct string from a string_view.
3693  * @param __t Source object convertible to string view.
3694  * @param __a Allocator to use (default is default allocator).
3695  */
3696  template<typename _Tp, typename = _If_sv<_Tp, void>>
3697  explicit
3698  basic_string(const _Tp& __t, const _Alloc& __a = _Alloc())
3699  : basic_string(__sv_wrapper(_S_to_string_view(__t)), __a) { }
3700 #endif // C++17
3701 
3702  /**
3703  * @brief Destroy the string instance.
3704  */
3705  ~basic_string() _GLIBCXX_NOEXCEPT
3706  { _M_rep()->_M_dispose(this->get_allocator()); }
3707 
3708  /**
3709  * @brief Assign the value of @a str to this string.
3710  * @param __str Source string.
3711  */
3712  basic_string&
3713  operator=(const basic_string& __str)
3714  { return this->assign(__str); }
3715 
3716  /**
3717  * @brief Copy contents of @a s into this string.
3718  * @param __s Source null-terminated string.
3719  */
3720  basic_string&
3721  operator=(const _CharT* __s)
3722  { return this->assign(__s); }
3723 
3724  /**
3725  * @brief Set value to string of length 1.
3726  * @param __c Source character.
3727  *
3728  * Assigning to a character makes this string length 1 and
3729  * (*this)[0] == @a c.
3730  */
3731  basic_string&
3732  operator=(_CharT __c)
3733  {
3734  this->assign(1, __c);
3735  return *this;
3736  }
3737 
3738 #if __cplusplus >= 201103L
3739  /**
3740  * @brief Move assign the value of @a str to this string.
3741  * @param __str Source string.
3742  *
3743  * The contents of @a str are moved into this string (without copying).
3744  * @a str is a valid, but unspecified string.
3745  **/
3746  basic_string&
3749  {
3750  // NB: DR 1204.
3751  this->swap(__str);
3752  return *this;
3753  }
3754 
3755  /**
3756  * @brief Set value to string constructed from initializer %list.
3757  * @param __l std::initializer_list.
3758  */
3759  basic_string&
3761  {
3762  this->assign(__l.begin(), __l.size());
3763  return *this;
3764  }
3765 #endif // C++11
3766 
3767 #if __cplusplus >= 201703L
3768  /**
3769  * @brief Set value to string constructed from a string_view.
3770  * @param __svt An object convertible to string_view.
3771  */
3772  template<typename _Tp>
3773  _If_sv<_Tp, basic_string&>
3774  operator=(const _Tp& __svt)
3775  { return this->assign(__svt); }
3776 
3777  /**
3778  * @brief Convert to a string_view.
3779  * @return A string_view.
3780  */
3781  operator __sv_type() const noexcept
3782  { return __sv_type(data(), size()); }
3783 #endif // C++17
3784 
3785  // Iterators:
3786  /**
3787  * Returns a read/write iterator that points to the first character in
3788  * the %string. Unshares the string.
3789  */
3790  iterator
3791  begin() // FIXME C++11: should be noexcept.
3792  {
3793  _M_leak();
3794  return iterator(_M_data());
3795  }
3796 
3797  /**
3798  * Returns a read-only (constant) iterator that points to the first
3799  * character in the %string.
3800  */
3801  const_iterator
3802  begin() const _GLIBCXX_NOEXCEPT
3803  { return const_iterator(_M_data()); }
3804 
3805  /**
3806  * Returns a read/write iterator that points one past the last
3807  * character in the %string. Unshares the string.
3808  */
3809  iterator
3810  end() // FIXME C++11: should be noexcept.
3811  {
3812  _M_leak();
3813  return iterator(_M_data() + this->size());
3814  }
3815 
3816  /**
3817  * Returns a read-only (constant) iterator that points one past the
3818  * last character in the %string.
3819  */
3820  const_iterator
3821  end() const _GLIBCXX_NOEXCEPT
3822  { return const_iterator(_M_data() + this->size()); }
3823 
3824  /**
3825  * Returns a read/write reverse iterator that points to the last
3826  * character in the %string. Iteration is done in reverse element
3827  * order. Unshares the string.
3828  */
3829  reverse_iterator
3830  rbegin() // FIXME C++11: should be noexcept.
3831  { return reverse_iterator(this->end()); }
3832 
3833  /**
3834  * Returns a read-only (constant) reverse iterator that points
3835  * to the last character in the %string. Iteration is done in
3836  * reverse element order.
3837  */
3838  const_reverse_iterator
3839  rbegin() const _GLIBCXX_NOEXCEPT
3840  { return const_reverse_iterator(this->end()); }
3841 
3842  /**
3843  * Returns a read/write reverse iterator that points to one before the
3844  * first character in the %string. Iteration is done in reverse
3845  * element order. Unshares the string.
3846  */
3847  reverse_iterator
3848  rend() // FIXME C++11: should be noexcept.
3849  { return reverse_iterator(this->begin()); }
3850 
3851  /**
3852  * Returns a read-only (constant) reverse iterator that points
3853  * to one before the first character in the %string. Iteration
3854  * is done in reverse element order.
3855  */
3856  const_reverse_iterator
3857  rend() const _GLIBCXX_NOEXCEPT
3858  { return const_reverse_iterator(this->begin()); }
3859 
3860 #if __cplusplus >= 201103L
3861  /**
3862  * Returns a read-only (constant) iterator that points to the first
3863  * character in the %string.
3864  */
3865  const_iterator
3866  cbegin() const noexcept
3867  { return const_iterator(this->_M_data()); }
3868 
3869  /**
3870  * Returns a read-only (constant) iterator that points one past the
3871  * last character in the %string.
3872  */
3873  const_iterator
3874  cend() const noexcept
3875  { return const_iterator(this->_M_data() + this->size()); }
3876 
3877  /**
3878  * Returns a read-only (constant) reverse iterator that points
3879  * to the last character in the %string. Iteration is done in
3880  * reverse element order.
3881  */
3882  const_reverse_iterator
3883  crbegin() const noexcept
3884  { return const_reverse_iterator(this->end()); }
3885 
3886  /**
3887  * Returns a read-only (constant) reverse iterator that points
3888  * to one before the first character in the %string. Iteration
3889  * is done in reverse element order.
3890  */
3891  const_reverse_iterator
3892  crend() const noexcept
3893  { return const_reverse_iterator(this->begin()); }
3894 #endif
3895 
3896  public:
3897  // Capacity:
3898  /// Returns the number of characters in the string, not including any
3899  /// null-termination.
3900  size_type
3901  size() const _GLIBCXX_NOEXCEPT
3902  { return _M_rep()->_M_length; }
3903 
3904  /// Returns the number of characters in the string, not including any
3905  /// null-termination.
3906  size_type
3907  length() const _GLIBCXX_NOEXCEPT
3908  { return _M_rep()->_M_length; }
3909 
3910  /// Returns the size() of the largest possible %string.
3911  size_type
3912  max_size() const _GLIBCXX_NOEXCEPT
3913  { return _Rep::_S_max_size; }
3914 
3915  /**
3916  * @brief Resizes the %string to the specified number of characters.
3917  * @param __n Number of characters the %string should contain.
3918  * @param __c Character to fill any new elements.
3919  *
3920  * This function will %resize the %string to the specified
3921  * number of characters. If the number is smaller than the
3922  * %string's current size the %string is truncated, otherwise
3923  * the %string is extended and new elements are %set to @a __c.
3924  */
3925  void
3926  resize(size_type __n, _CharT __c);
3927 
3928  /**
3929  * @brief Resizes the %string to the specified number of characters.
3930  * @param __n Number of characters the %string should contain.
3931  *
3932  * This function will resize the %string to the specified length. If
3933  * the new size is smaller than the %string's current size the %string
3934  * is truncated, otherwise the %string is extended and new characters
3935  * are default-constructed. For basic types such as char, this means
3936  * setting them to 0.
3937  */
3938  void
3939  resize(size_type __n)
3940  { this->resize(__n, _CharT()); }
3941 
3942 #if __cplusplus >= 201103L
3943  /// A non-binding request to reduce capacity() to size().
3944  void
3945  shrink_to_fit() _GLIBCXX_NOEXCEPT
3946  {
3947 #if __cpp_exceptions
3948  if (capacity() > size())
3949  {
3950  try
3951  { reserve(0); }
3952  catch(...)
3953  { }
3954  }
3955 #endif
3956  }
3957 #endif
3958 
3959  /**
3960  * Returns the total number of characters that the %string can hold
3961  * before needing to allocate more memory.
3962  */
3963  size_type
3964  capacity() const _GLIBCXX_NOEXCEPT
3965  { return _M_rep()->_M_capacity; }
3966 
3967  /**
3968  * @brief Attempt to preallocate enough memory for specified number of
3969  * characters.
3970  * @param __res_arg Number of characters required.
3971  * @throw std::length_error If @a __res_arg exceeds @c max_size().
3972  *
3973  * This function attempts to reserve enough memory for the
3974  * %string to hold the specified number of characters. If the
3975  * number requested is more than max_size(), length_error is
3976  * thrown.
3977  *
3978  * The advantage of this function is that if optimal code is a
3979  * necessity and the user can determine the string length that will be
3980  * required, the user can reserve the memory in %advance, and thus
3981  * prevent a possible reallocation of memory and copying of %string
3982  * data.
3983  */
3984  void
3985  reserve(size_type __res_arg = 0);
3986 
3987  /**
3988  * Erases the string, making it empty.
3989  */
3990 #if _GLIBCXX_FULLY_DYNAMIC_STRING == 0
3991  void
3992  clear() _GLIBCXX_NOEXCEPT
3993  {
3994  if (_M_rep()->_M_is_shared())
3995  {
3996  _M_rep()->_M_dispose(this->get_allocator());
3997  _M_data(_S_empty_rep()._M_refdata());
3998  }
3999  else
4000  _M_rep()->_M_set_length_and_sharable(0);
4001  }
4002 #else
4003  // PR 56166: this should not throw.
4004  void
4005  clear()
4006  { _M_mutate(0, this->size(), 0); }
4007 #endif
4008 
4009  /**
4010  * Returns true if the %string is empty. Equivalent to
4011  * <code>*this == ""</code>.
4012  */
4013  _GLIBCXX_NODISCARD bool
4014  empty() const _GLIBCXX_NOEXCEPT
4015  { return this->size() == 0; }
4016 
4017  // Element access:
4018  /**
4019  * @brief Subscript access to the data contained in the %string.
4020  * @param __pos The index of the character to access.
4021  * @return Read-only (constant) reference to the character.
4022  *
4023  * This operator allows for easy, array-style, data access.
4024  * Note that data access with this operator is unchecked and
4025  * out_of_range lookups are not defined. (For checked lookups
4026  * see at().)
4027  */
4028  const_reference
4029  operator[] (size_type __pos) const _GLIBCXX_NOEXCEPT
4030  {
4031  __glibcxx_assert(__pos <= size());
4032  return _M_data()[__pos];
4033  }
4034 
4035  /**
4036  * @brief Subscript access to the data contained in the %string.
4037  * @param __pos The index of the character to access.
4038  * @return Read/write reference to the character.
4039  *
4040  * This operator allows for easy, array-style, data access.
4041  * Note that data access with this operator is unchecked and
4042  * out_of_range lookups are not defined. (For checked lookups
4043  * see at().) Unshares the string.
4044  */
4045  reference
4046  operator[](size_type __pos)
4047  {
4048  // Allow pos == size() both in C++98 mode, as v3 extension,
4049  // and in C++11 mode.
4050  __glibcxx_assert(__pos <= size());
4051  // In pedantic mode be strict in C++98 mode.
4052  _GLIBCXX_DEBUG_PEDASSERT(__cplusplus >= 201103L || __pos < size());
4053  _M_leak();
4054  return _M_data()[__pos];
4055  }
4056 
4057  /**
4058  * @brief Provides access to the data contained in the %string.
4059  * @param __n The index of the character to access.
4060  * @return Read-only (const) reference to the character.
4061  * @throw std::out_of_range If @a n is an invalid index.
4062  *
4063  * This function provides for safer data access. The parameter is
4064  * first checked that it is in the range of the string. The function
4065  * throws out_of_range if the check fails.
4066  */
4067  const_reference
4068  at(size_type __n) const
4069  {
4070  if (__n >= this->size())
4071  __throw_out_of_range_fmt(__N("basic_string::at: __n "
4072  "(which is %zu) >= this->size() "
4073  "(which is %zu)"),
4074  __n, this->size());
4075  return _M_data()[__n];
4076  }
4077 
4078  /**
4079  * @brief Provides access to the data contained in the %string.
4080  * @param __n The index of the character to access.
4081  * @return Read/write reference to the character.
4082  * @throw std::out_of_range If @a n is an invalid index.
4083  *
4084  * This function provides for safer data access. The parameter is
4085  * first checked that it is in the range of the string. The function
4086  * throws out_of_range if the check fails. Success results in
4087  * unsharing the string.
4088  */
4089  reference
4090  at(size_type __n)
4091  {
4092  if (__n >= size())
4093  __throw_out_of_range_fmt(__N("basic_string::at: __n "
4094  "(which is %zu) >= this->size() "
4095  "(which is %zu)"),
4096  __n, this->size());
4097  _M_leak();
4098  return _M_data()[__n];
4099  }
4100 
4101 #if __cplusplus >= 201103L
4102  /**
4103  * Returns a read/write reference to the data at the first
4104  * element of the %string.
4105  */
4106  reference
4108  {
4109  __glibcxx_assert(!empty());
4110  return operator[](0);
4111  }
4112 
4113  /**
4114  * Returns a read-only (constant) reference to the data at the first
4115  * element of the %string.
4116  */
4117  const_reference
4118  front() const noexcept
4119  {
4120  __glibcxx_assert(!empty());
4121  return operator[](0);
4122  }
4123 
4124  /**
4125  * Returns a read/write reference to the data at the last
4126  * element of the %string.
4127  */
4128  reference
4130  {
4131  __glibcxx_assert(!empty());
4132  return operator[](this->size() - 1);
4133  }
4134 
4135  /**
4136  * Returns a read-only (constant) reference to the data at the
4137  * last element of the %string.
4138  */
4139  const_reference
4140  back() const noexcept
4141  {
4142  __glibcxx_assert(!empty());
4143  return operator[](this->size() - 1);
4144  }
4145 #endif
4146 
4147  // Modifiers:
4148  /**
4149  * @brief Append a string to this string.
4150  * @param __str The string to append.
4151  * @return Reference to this string.
4152  */
4153  basic_string&
4154  operator+=(const basic_string& __str)
4155  { return this->append(__str); }
4156 
4157  /**
4158  * @brief Append a C string.
4159  * @param __s The C string to append.
4160  * @return Reference to this string.
4161  */
4162  basic_string&
4163  operator+=(const _CharT* __s)
4164  { return this->append(__s); }
4165 
4166  /**
4167  * @brief Append a character.
4168  * @param __c The character to append.
4169  * @return Reference to this string.
4170  */
4171  basic_string&
4172  operator+=(_CharT __c)
4173  {
4174  this->push_back(__c);
4175  return *this;
4176  }
4177 
4178 #if __cplusplus >= 201103L
4179  /**
4180  * @brief Append an initializer_list of characters.
4181  * @param __l The initializer_list of characters to be appended.
4182  * @return Reference to this string.
4183  */
4184  basic_string&
4186  { return this->append(__l.begin(), __l.size()); }
4187 #endif // C++11
4188 
4189 #if __cplusplus >= 201703L
4190  /**
4191  * @brief Append a string_view.
4192  * @param __svt The object convertible to string_view to be appended.
4193  * @return Reference to this string.
4194  */
4195  template<typename _Tp>
4196  _If_sv<_Tp, basic_string&>
4197  operator+=(const _Tp& __svt)
4198  { return this->append(__svt); }
4199 #endif // C++17
4200 
4201  /**
4202  * @brief Append a string to this string.
4203  * @param __str The string to append.
4204  * @return Reference to this string.
4205  */
4206  basic_string&
4207  append(const basic_string& __str);
4208 
4209  /**
4210  * @brief Append a substring.
4211  * @param __str The string to append.
4212  * @param __pos Index of the first character of str to append.
4213  * @param __n The number of characters to append.
4214  * @return Reference to this string.
4215  * @throw std::out_of_range if @a __pos is not a valid index.
4216  *
4217  * This function appends @a __n characters from @a __str
4218  * starting at @a __pos to this string. If @a __n is is larger
4219  * than the number of available characters in @a __str, the
4220  * remainder of @a __str is appended.
4221  */
4222  basic_string&
4223  append(const basic_string& __str, size_type __pos, size_type __n = npos);
4224 
4225  /**
4226  * @brief Append a C substring.
4227  * @param __s The C string to append.
4228  * @param __n The number of characters to append.
4229  * @return Reference to this string.
4230  */
4231  basic_string&
4232  append(const _CharT* __s, size_type __n);
4233 
4234  /**
4235  * @brief Append a C string.
4236  * @param __s The C string to append.
4237  * @return Reference to this string.
4238  */
4239  basic_string&
4240  append(const _CharT* __s)
4241  {
4242  __glibcxx_requires_string(__s);
4243  return this->append(__s, traits_type::length(__s));
4244  }
4245 
4246  /**
4247  * @brief Append multiple characters.
4248  * @param __n The number of characters to append.
4249  * @param __c The character to use.
4250  * @return Reference to this string.
4251  *
4252  * Appends __n copies of __c to this string.
4253  */
4254  basic_string&
4255  append(size_type __n, _CharT __c);
4256 
4257 #if __cplusplus >= 201103L
4258  /**
4259  * @brief Append an initializer_list of characters.
4260  * @param __l The initializer_list of characters to append.
4261  * @return Reference to this string.
4262  */
4263  basic_string&
4265  { return this->append(__l.begin(), __l.size()); }
4266 #endif // C++11
4267 
4268  /**
4269  * @brief Append a range of characters.
4270  * @param __first Iterator referencing the first character to append.
4271  * @param __last Iterator marking the end of the range.
4272  * @return Reference to this string.
4273  *
4274  * Appends characters in the range [__first,__last) to this string.
4275  */
4276  template<class _InputIterator>
4277  basic_string&
4278  append(_InputIterator __first, _InputIterator __last)
4279  { return this->replace(_M_iend(), _M_iend(), __first, __last); }
4280 
4281 #if __cplusplus >= 201703L
4282  /**
4283  * @brief Append a string_view.
4284  * @param __svt The object convertible to string_view to be appended.
4285  * @return Reference to this string.
4286  */
4287  template<typename _Tp>
4288  _If_sv<_Tp, basic_string&>
4289  append(const _Tp& __svt)
4290  {
4291  __sv_type __sv = __svt;
4292  return this->append(__sv.data(), __sv.size());
4293  }
4294 
4295  /**
4296  * @brief Append a range of characters from a string_view.
4297  * @param __svt The object convertible to string_view to be appended
4298  * from.
4299  * @param __pos The position in the string_view to append from.
4300  * @param __n The number of characters to append from the string_view.
4301  * @return Reference to this string.
4302  */
4303  template<typename _Tp>
4304  _If_sv<_Tp, basic_string&>
4305  append(const _Tp& __svt, size_type __pos, size_type __n = npos)
4306  {
4307  __sv_type __sv = __svt;
4308  return append(__sv.data()
4309  + std::__sv_check(__sv.size(), __pos, "basic_string::append"),
4310  std::__sv_limit(__sv.size(), __pos, __n));
4311  }
4312 #endif // C++17
4313 
4314  /**
4315  * @brief Append a single character.
4316  * @param __c Character to append.
4317  */
4318  void
4319  push_back(_CharT __c)
4320  {
4321  const size_type __len = 1 + this->size();
4322  if (__len > this->capacity() || _M_rep()->_M_is_shared())
4323  this->reserve(__len);
4324  traits_type::assign(_M_data()[this->size()], __c);
4325  _M_rep()->_M_set_length_and_sharable(__len);
4326  }
4327 
4328  /**
4329  * @brief Set value to contents of another string.
4330  * @param __str Source string to use.
4331  * @return Reference to this string.
4332  */
4333  basic_string&
4334  assign(const basic_string& __str);
4335 
4336 #if __cplusplus >= 201103L
4337  /**
4338  * @brief Set value to contents of another string.
4339  * @param __str Source string to use.
4340  * @return Reference to this string.
4341  *
4342  * This function sets this string to the exact contents of @a __str.
4343  * @a __str is a valid, but unspecified string.
4344  */
4345  basic_string&
4348  {
4349  this->swap(__str);
4350  return *this;
4351  }
4352 #endif // C++11
4353 
4354  /**
4355  * @brief Set value to a substring of a string.
4356  * @param __str The string to use.
4357  * @param __pos Index of the first character of str.
4358  * @param __n Number of characters to use.
4359  * @return Reference to this string.
4360  * @throw std::out_of_range if @a pos is not a valid index.
4361  *
4362  * This function sets this string to the substring of @a __str
4363  * consisting of @a __n characters at @a __pos. If @a __n is
4364  * is larger than the number of available characters in @a
4365  * __str, the remainder of @a __str is used.
4366  */
4367  basic_string&
4368  assign(const basic_string& __str, size_type __pos, size_type __n = npos)
4369  { return this->assign(__str._M_data()
4370  + __str._M_check(__pos, "basic_string::assign"),
4371  __str._M_limit(__pos, __n)); }
4372 
4373  /**
4374  * @brief Set value to a C substring.
4375  * @param __s The C string to use.
4376  * @param __n Number of characters to use.
4377  * @return Reference to this string.
4378  *
4379  * This function sets the value of this string to the first @a __n
4380  * characters of @a __s. If @a __n is is larger than the number of
4381  * available characters in @a __s, the remainder of @a __s is used.
4382  */
4383  basic_string&
4384  assign(const _CharT* __s, size_type __n);
4385 
4386  /**
4387  * @brief Set value to contents of a C string.
4388  * @param __s The C string to use.
4389  * @return Reference to this string.
4390  *
4391  * This function sets the value of this string to the value of @a __s.
4392  * The data is copied, so there is no dependence on @a __s once the
4393  * function returns.
4394  */
4395  basic_string&
4396  assign(const _CharT* __s)
4397  {
4398  __glibcxx_requires_string(__s);
4399  return this->assign(__s, traits_type::length(__s));
4400  }
4401 
4402  /**
4403  * @brief Set value to multiple characters.
4404  * @param __n Length of the resulting string.
4405  * @param __c The character to use.
4406  * @return Reference to this string.
4407  *
4408  * This function sets the value of this string to @a __n copies of
4409  * character @a __c.
4410  */
4411  basic_string&
4412  assign(size_type __n, _CharT __c)
4413  { return _M_replace_aux(size_type(0), this->size(), __n, __c); }
4414 
4415  /**
4416  * @brief Set value to a range of characters.
4417  * @param __first Iterator referencing the first character to append.
4418  * @param __last Iterator marking the end of the range.
4419  * @return Reference to this string.
4420  *
4421  * Sets value of string to characters in the range [__first,__last).
4422  */
4423  template<class _InputIterator>
4424  basic_string&
4425  assign(_InputIterator __first, _InputIterator __last)
4426  { return this->replace(_M_ibegin(), _M_iend(), __first, __last); }
4427 
4428 #if __cplusplus >= 201103L
4429  /**
4430  * @brief Set value to an initializer_list of characters.
4431  * @param __l The initializer_list of characters to assign.
4432  * @return Reference to this string.
4433  */
4434  basic_string&
4436  { return this->assign(__l.begin(), __l.size()); }
4437 #endif // C++11
4438 
4439 #if __cplusplus >= 201703L
4440  /**
4441  * @brief Set value from a string_view.
4442  * @param __svt The source object convertible to string_view.
4443  * @return Reference to this string.
4444  */
4445  template<typename _Tp>
4446  _If_sv<_Tp, basic_string&>
4447  assign(const _Tp& __svt)
4448  {
4449  __sv_type __sv = __svt;
4450  return this->assign(__sv.data(), __sv.size());
4451  }
4452 
4453  /**
4454  * @brief Set value from a range of characters in a string_view.
4455  * @param __svt The source object convertible to string_view.
4456  * @param __pos The position in the string_view to assign from.
4457  * @param __n The number of characters to assign.
4458  * @return Reference to this string.
4459  */
4460  template<typename _Tp>
4461  _If_sv<_Tp, basic_string&>
4462  assign(const _Tp& __svt, size_type __pos, size_type __n = npos)
4463  {
4464  __sv_type __sv = __svt;
4465  return assign(__sv.data()
4466  + std::__sv_check(__sv.size(), __pos, "basic_string::assign"),
4467  std::__sv_limit(__sv.size(), __pos, __n));
4468  }
4469 #endif // C++17
4470 
4471  /**
4472  * @brief Insert multiple characters.
4473  * @param __p Iterator referencing location in string to insert at.
4474  * @param __n Number of characters to insert
4475  * @param __c The character to insert.
4476  * @throw std::length_error If new length exceeds @c max_size().
4477  *
4478  * Inserts @a __n copies of character @a __c starting at the
4479  * position referenced by iterator @a __p. If adding
4480  * characters causes the length to exceed max_size(),
4481  * length_error is thrown. The value of the string doesn't
4482  * change if an error is thrown.
4483  */
4484  void
4485  insert(iterator __p, size_type __n, _CharT __c)
4486  { this->replace(__p, __p, __n, __c); }
4487 
4488  /**
4489  * @brief Insert a range of characters.
4490  * @param __p Iterator referencing location in string to insert at.
4491  * @param __beg Start of range.
4492  * @param __end End of range.
4493  * @throw std::length_error If new length exceeds @c max_size().
4494  *
4495  * Inserts characters in range [__beg,__end). If adding
4496  * characters causes the length to exceed max_size(),
4497  * length_error is thrown. The value of the string doesn't
4498  * change if an error is thrown.
4499  */
4500  template<class _InputIterator>
4501  void
4502  insert(iterator __p, _InputIterator __beg, _InputIterator __end)
4503  { this->replace(__p, __p, __beg, __end); }
4504 
4505 #if __cplusplus >= 201103L
4506  /**
4507  * @brief Insert an initializer_list of characters.
4508  * @param __p Iterator referencing location in string to insert at.
4509  * @param __l The initializer_list of characters to insert.
4510  * @throw std::length_error If new length exceeds @c max_size().
4511  */
4512  void
4514  {
4515  _GLIBCXX_DEBUG_PEDASSERT(__p >= _M_ibegin() && __p <= _M_iend());
4516  this->insert(__p - _M_ibegin(), __l.begin(), __l.size());
4517  }
4518 #endif // C++11
4519 
4520  /**
4521  * @brief Insert value of a string.
4522  * @param __pos1 Iterator referencing location in string to insert at.
4523  * @param __str The string to insert.
4524  * @return Reference to this string.
4525  * @throw std::length_error If new length exceeds @c max_size().
4526  *
4527  * Inserts value of @a __str starting at @a __pos1. If adding
4528  * characters causes the length to exceed max_size(),
4529  * length_error is thrown. The value of the string doesn't
4530  * change if an error is thrown.
4531  */
4532  basic_string&
4533  insert(size_type __pos1, const basic_string& __str)
4534  { return this->insert(__pos1, __str, size_type(0), __str.size()); }
4535 
4536  /**
4537  * @brief Insert a substring.
4538  * @param __pos1 Iterator referencing location in string to insert at.
4539  * @param __str The string to insert.
4540  * @param __pos2 Start of characters in str to insert.
4541  * @param __n Number of characters to insert.
4542  * @return Reference to this string.
4543  * @throw std::length_error If new length exceeds @c max_size().
4544  * @throw std::out_of_range If @a pos1 > size() or
4545  * @a __pos2 > @a str.size().
4546  *
4547  * Starting at @a pos1, insert @a __n character of @a __str
4548  * beginning with @a __pos2. If adding characters causes the
4549  * length to exceed max_size(), length_error is thrown. If @a
4550  * __pos1 is beyond the end of this string or @a __pos2 is
4551  * beyond the end of @a __str, out_of_range is thrown. The
4552  * value of the string doesn't change if an error is thrown.
4553  */
4554  basic_string&
4555  insert(size_type __pos1, const basic_string& __str,
4556  size_type __pos2, size_type __n = npos)
4557  { return this->insert(__pos1, __str._M_data()
4558  + __str._M_check(__pos2, "basic_string::insert"),
4559  __str._M_limit(__pos2, __n)); }
4560 
4561  /**
4562  * @brief Insert a C substring.
4563  * @param __pos Iterator referencing location in string to insert at.
4564  * @param __s The C string to insert.
4565  * @param __n The number of characters to insert.
4566  * @return Reference to this string.
4567  * @throw std::length_error If new length exceeds @c max_size().
4568  * @throw std::out_of_range If @a __pos is beyond the end of this
4569  * string.
4570  *
4571  * Inserts the first @a __n characters of @a __s starting at @a
4572  * __pos. If adding characters causes the length to exceed
4573  * max_size(), length_error is thrown. If @a __pos is beyond
4574  * end(), out_of_range is thrown. The value of the string
4575  * doesn't change if an error is thrown.
4576  */
4577  basic_string&
4578  insert(size_type __pos, const _CharT* __s, size_type __n);
4579 
4580  /**
4581  * @brief Insert a C string.
4582  * @param __pos Iterator referencing location in string to insert at.
4583  * @param __s The C string to insert.
4584  * @return Reference to this string.
4585  * @throw std::length_error If new length exceeds @c max_size().
4586  * @throw std::out_of_range If @a pos is beyond the end of this
4587  * string.
4588  *
4589  * Inserts the first @a n characters of @a __s starting at @a __pos. If
4590  * adding characters causes the length to exceed max_size(),
4591  * length_error is thrown. If @a __pos is beyond end(), out_of_range is
4592  * thrown. The value of the string doesn't change if an error is
4593  * thrown.
4594  */
4595  basic_string&
4596  insert(size_type __pos, const _CharT* __s)
4597  {
4598  __glibcxx_requires_string(__s);
4599  return this->insert(__pos, __s, traits_type::length(__s));
4600  }
4601 
4602  /**
4603  * @brief Insert multiple characters.
4604  * @param __pos Index in string to insert at.
4605  * @param __n Number of characters to insert
4606  * @param __c The character to insert.
4607  * @return Reference to this string.
4608  * @throw std::length_error If new length exceeds @c max_size().
4609  * @throw std::out_of_range If @a __pos is beyond the end of this
4610  * string.
4611  *
4612  * Inserts @a __n copies of character @a __c starting at index
4613  * @a __pos. If adding characters causes the length to exceed
4614  * max_size(), length_error is thrown. If @a __pos > length(),
4615  * out_of_range is thrown. The value of the string doesn't
4616  * change if an error is thrown.
4617  */
4618  basic_string&
4619  insert(size_type __pos, size_type __n, _CharT __c)
4620  { return _M_replace_aux(_M_check(__pos, "basic_string::insert"),
4621  size_type(0), __n, __c); }
4622 
4623  /**
4624  * @brief Insert one character.
4625  * @param __p Iterator referencing position in string to insert at.
4626  * @param __c The character to insert.
4627  * @return Iterator referencing newly inserted char.
4628  * @throw std::length_error If new length exceeds @c max_size().
4629  *
4630  * Inserts character @a __c at position referenced by @a __p.
4631  * If adding character causes the length to exceed max_size(),
4632  * length_error is thrown. If @a __p is beyond end of string,
4633  * out_of_range is thrown. The value of the string doesn't
4634  * change if an error is thrown.
4635  */
4636  iterator
4637  insert(iterator __p, _CharT __c)
4638  {
4639  _GLIBCXX_DEBUG_PEDASSERT(__p >= _M_ibegin() && __p <= _M_iend());
4640  const size_type __pos = __p - _M_ibegin();
4641  _M_replace_aux(__pos, size_type(0), size_type(1), __c);
4642  _M_rep()->_M_set_leaked();
4643  return iterator(_M_data() + __pos);
4644  }
4645 
4646 #if __cplusplus >= 201703L
4647  /**
4648  * @brief Insert a string_view.
4649  * @param __pos Iterator referencing position in string to insert at.
4650  * @param __svt The object convertible to string_view to insert.
4651  * @return Reference to this string.
4652  */
4653  template<typename _Tp>
4654  _If_sv<_Tp, basic_string&>
4655  insert(size_type __pos, const _Tp& __svt)
4656  {
4657  __sv_type __sv = __svt;
4658  return this->insert(__pos, __sv.data(), __sv.size());
4659  }
4660 
4661  /**
4662  * @brief Insert a string_view.
4663  * @param __pos Iterator referencing position in string to insert at.
4664  * @param __svt The object convertible to string_view to insert from.
4665  * @param __pos Iterator referencing position in string_view to insert
4666  * from.
4667  * @param __n The number of characters to insert.
4668  * @return Reference to this string.
4669  */
4670  template<typename _Tp>
4671  _If_sv<_Tp, basic_string&>
4672  insert(size_type __pos1, const _Tp& __svt,
4673  size_type __pos2, size_type __n = npos)
4674  {
4675  __sv_type __sv = __svt;
4676  return this->replace(__pos1, size_type(0), __sv.data()
4677  + std::__sv_check(__sv.size(), __pos2, "basic_string::insert"),
4678  std::__sv_limit(__sv.size(), __pos2, __n));
4679  }
4680 #endif // C++17
4681 
4682  /**
4683  * @brief Remove characters.
4684  * @param __pos Index of first character to remove (default 0).
4685  * @param __n Number of characters to remove (default remainder).
4686  * @return Reference to this string.
4687  * @throw std::out_of_range If @a pos is beyond the end of this
4688  * string.
4689  *
4690  * Removes @a __n characters from this string starting at @a
4691  * __pos. The length of the string is reduced by @a __n. If
4692  * there are < @a __n characters to remove, the remainder of
4693  * the string is truncated. If @a __p is beyond end of string,
4694  * out_of_range is thrown. The value of the string doesn't
4695  * change if an error is thrown.
4696  */
4697  basic_string&
4698  erase(size_type __pos = 0, size_type __n = npos)
4699  {
4700  _M_mutate(_M_check(__pos, "basic_string::erase"),
4701  _M_limit(__pos, __n), size_type(0));
4702  return *this;
4703  }
4704 
4705  /**
4706  * @brief Remove one character.
4707  * @param __position Iterator referencing the character to remove.
4708  * @return iterator referencing same location after removal.
4709  *
4710  * Removes the character at @a __position from this string. The value
4711  * of the string doesn't change if an error is thrown.
4712  */
4713  iterator
4714  erase(iterator __position)
4715  {
4716  _GLIBCXX_DEBUG_PEDASSERT(__position >= _M_ibegin()
4717  && __position < _M_iend());
4718  const size_type __pos = __position - _M_ibegin();
4719  _M_mutate(__pos, size_type(1), size_type(0));
4720  _M_rep()->_M_set_leaked();
4721  return iterator(_M_data() + __pos);
4722  }
4723 
4724  /**
4725  * @brief Remove a range of characters.
4726  * @param __first Iterator referencing the first character to remove.
4727  * @param __last Iterator referencing the end of the range.
4728  * @return Iterator referencing location of first after removal.
4729  *
4730  * Removes the characters in the range [first,last) from this string.
4731  * The value of the string doesn't change if an error is thrown.
4732  */
4733  iterator
4734  erase(iterator __first, iterator __last);
4735 
4736 #if __cplusplus >= 201103L
4737  /**
4738  * @brief Remove the last character.
4739  *
4740  * The string must be non-empty.
4741  */
4742  void
4743  pop_back() // FIXME C++11: should be noexcept.
4744  {
4745  __glibcxx_assert(!empty());
4746  erase(size() - 1, 1);
4747  }
4748 #endif // C++11
4749 
4750  /**
4751  * @brief Replace characters with value from another string.
4752  * @param __pos Index of first character to replace.
4753  * @param __n Number of characters to be replaced.
4754  * @param __str String to insert.
4755  * @return Reference to this string.
4756  * @throw std::out_of_range If @a pos is beyond the end of this
4757  * string.
4758  * @throw std::length_error If new length exceeds @c max_size().
4759  *
4760  * Removes the characters in the range [__pos,__pos+__n) from
4761  * this string. In place, the value of @a __str is inserted.
4762  * If @a __pos is beyond end of string, out_of_range is thrown.
4763  * If the length of the result exceeds max_size(), length_error
4764  * is thrown. The value of the string doesn't change if an
4765  * error is thrown.
4766  */
4767  basic_string&
4768  replace(size_type __pos, size_type __n, const basic_string& __str)
4769  { return this->replace(__pos, __n, __str._M_data(), __str.size()); }
4770 
4771  /**
4772  * @brief Replace characters with value from another string.
4773  * @param __pos1 Index of first character to replace.
4774  * @param __n1 Number of characters to be replaced.
4775  * @param __str String to insert.
4776  * @param __pos2 Index of first character of str to use.
4777  * @param __n2 Number of characters from str to use.
4778  * @return Reference to this string.
4779  * @throw std::out_of_range If @a __pos1 > size() or @a __pos2 >
4780  * __str.size().
4781  * @throw std::length_error If new length exceeds @c max_size().
4782  *
4783  * Removes the characters in the range [__pos1,__pos1 + n) from this
4784  * string. In place, the value of @a __str is inserted. If @a __pos is
4785  * beyond end of string, out_of_range is thrown. If the length of the
4786  * result exceeds max_size(), length_error is thrown. The value of the
4787  * string doesn't change if an error is thrown.
4788  */
4789  basic_string&
4790  replace(size_type __pos1, size_type __n1, const basic_string& __str,
4791  size_type __pos2, size_type __n2 = npos)
4792  { return this->replace(__pos1, __n1, __str._M_data()
4793  + __str._M_check(__pos2, "basic_string::replace"),
4794  __str._M_limit(__pos2, __n2)); }
4795 
4796  /**
4797  * @brief Replace characters with value of a C substring.
4798  * @param __pos Index of first character to replace.
4799  * @param __n1 Number of characters to be replaced.
4800  * @param __s C string to insert.
4801  * @param __n2 Number of characters from @a s to use.
4802  * @return Reference to this string.
4803  * @throw std::out_of_range If @a pos1 > size().
4804  * @throw std::length_error If new length exceeds @c max_size().
4805  *
4806  * Removes the characters in the range [__pos,__pos + __n1)
4807  * from this string. In place, the first @a __n2 characters of
4808  * @a __s are inserted, or all of @a __s if @a __n2 is too large. If
4809  * @a __pos is beyond end of string, out_of_range is thrown. If
4810  * the length of result exceeds max_size(), length_error is
4811  * thrown. The value of the string doesn't change if an error
4812  * is thrown.
4813  */
4814  basic_string&
4815  replace(size_type __pos, size_type __n1, const _CharT* __s,
4816  size_type __n2);
4817 
4818  /**
4819  * @brief Replace characters with value of a C string.
4820  * @param __pos Index of first character to replace.
4821  * @param __n1 Number of characters to be replaced.
4822  * @param __s C string to insert.
4823  * @return Reference to this string.
4824  * @throw std::out_of_range If @a pos > size().
4825  * @throw std::length_error If new length exceeds @c max_size().
4826  *
4827  * Removes the characters in the range [__pos,__pos + __n1)
4828  * from this string. In place, the characters of @a __s are
4829  * inserted. If @a __pos is beyond end of string, out_of_range
4830  * is thrown. If the length of result exceeds max_size(),
4831  * length_error is thrown. The value of the string doesn't
4832  * change if an error is thrown.
4833  */
4834  basic_string&
4835  replace(size_type __pos, size_type __n1, const _CharT* __s)
4836  {
4837  __glibcxx_requires_string(__s);
4838  return this->replace(__pos, __n1, __s, traits_type::length(__s));
4839  }
4840 
4841  /**
4842  * @brief Replace characters with multiple characters.
4843  * @param __pos Index of first character to replace.
4844  * @param __n1 Number of characters to be replaced.
4845  * @param __n2 Number of characters to insert.
4846  * @param __c Character to insert.
4847  * @return Reference to this string.
4848  * @throw std::out_of_range If @a __pos > size().
4849  * @throw std::length_error If new length exceeds @c max_size().
4850  *
4851  * Removes the characters in the range [pos,pos + n1) from this
4852  * string. In place, @a __n2 copies of @a __c are inserted.
4853  * If @a __pos is beyond end of string, out_of_range is thrown.
4854  * If the length of result exceeds max_size(), length_error is
4855  * thrown. The value of the string doesn't change if an error
4856  * is thrown.
4857  */
4858  basic_string&
4859  replace(size_type __pos, size_type __n1, size_type __n2, _CharT __c)
4860  { return _M_replace_aux(_M_check(__pos, "basic_string::replace"),
4861  _M_limit(__pos, __n1), __n2, __c); }
4862 
4863  /**
4864  * @brief Replace range of characters with string.
4865  * @param __i1 Iterator referencing start of range to replace.
4866  * @param __i2 Iterator referencing end of range to replace.
4867  * @param __str String value to insert.
4868  * @return Reference to this string.
4869  * @throw std::length_error If new length exceeds @c max_size().
4870  *
4871  * Removes the characters in the range [__i1,__i2). In place,
4872  * the value of @a __str is inserted. If the length of result
4873  * exceeds max_size(), length_error is thrown. The value of
4874  * the string doesn't change if an error is thrown.
4875  */
4876  basic_string&
4877  replace(iterator __i1, iterator __i2, const basic_string& __str)
4878  { return this->replace(__i1, __i2, __str._M_data(), __str.size()); }
4879 
4880  /**
4881  * @brief Replace range of characters with C substring.
4882  * @param __i1 Iterator referencing start of range to replace.
4883  * @param __i2 Iterator referencing end of range to replace.
4884  * @param __s C string value to insert.
4885  * @param __n Number of characters from s to insert.
4886  * @return Reference to this string.
4887  * @throw std::length_error If new length exceeds @c max_size().
4888  *
4889  * Removes the characters in the range [__i1,__i2). In place,
4890  * the first @a __n characters of @a __s are inserted. If the
4891  * length of result exceeds max_size(), length_error is thrown.
4892  * The value of the string doesn't change if an error is
4893  * thrown.
4894  */
4895  basic_string&
4896  replace(iterator __i1, iterator __i2, const _CharT* __s, size_type __n)
4897  {
4898  _GLIBCXX_DEBUG_PEDASSERT(_M_ibegin() <= __i1 && __i1 <= __i2
4899  && __i2 <= _M_iend());
4900  return this->replace(__i1 - _M_ibegin(), __i2 - __i1, __s, __n);
4901  }
4902 
4903  /**
4904  * @brief Replace range of characters with C string.
4905  * @param __i1 Iterator referencing start of range to replace.
4906  * @param __i2 Iterator referencing end of range to replace.
4907  * @param __s C string value to insert.
4908  * @return Reference to this string.
4909  * @throw std::length_error If new length exceeds @c max_size().
4910  *
4911  * Removes the characters in the range [__i1,__i2). In place,
4912  * the characters of @a __s are inserted. If the length of
4913  * result exceeds max_size(), length_error is thrown. The
4914  * value of the string doesn't change if an error is thrown.
4915  */
4916  basic_string&
4917  replace(iterator __i1, iterator __i2, const _CharT* __s)
4918  {
4919  __glibcxx_requires_string(__s);
4920  return this->replace(__i1, __i2, __s, traits_type::length(__s));
4921  }
4922 
4923  /**
4924  * @brief Replace range of characters with multiple characters
4925  * @param __i1 Iterator referencing start of range to replace.
4926  * @param __i2 Iterator referencing end of range to replace.
4927  * @param __n Number of characters to insert.
4928  * @param __c Character to insert.
4929  * @return Reference to this string.
4930  * @throw std::length_error If new length exceeds @c max_size().
4931  *
4932  * Removes the characters in the range [__i1,__i2). In place,
4933  * @a __n copies of @a __c are inserted. If the length of
4934  * result exceeds max_size(), length_error is thrown. The
4935  * value of the string doesn't change if an error is thrown.
4936  */
4937  basic_string&
4938  replace(iterator __i1, iterator __i2, size_type __n, _CharT __c)
4939  {
4940  _GLIBCXX_DEBUG_PEDASSERT(_M_ibegin() <= __i1 && __i1 <= __i2
4941  && __i2 <= _M_iend());
4942  return _M_replace_aux(__i1 - _M_ibegin(), __i2 - __i1, __n, __c);
4943  }
4944 
4945  /**
4946  * @brief Replace range of characters with range.
4947  * @param __i1 Iterator referencing start of range to replace.
4948  * @param __i2 Iterator referencing end of range to replace.
4949  * @param __k1 Iterator referencing start of range to insert.
4950  * @param __k2 Iterator referencing end of range to insert.
4951  * @return Reference to this string.
4952  * @throw std::length_error If new length exceeds @c max_size().
4953  *
4954  * Removes the characters in the range [__i1,__i2). In place,
4955  * characters in the range [__k1,__k2) are inserted. If the
4956  * length of result exceeds max_size(), length_error is thrown.
4957  * The value of the string doesn't change if an error is
4958  * thrown.
4959  */
4960  template<class _InputIterator>
4961  basic_string&
4962  replace(iterator __i1, iterator __i2,
4963  _InputIterator __k1, _InputIterator __k2)
4964  {
4965  _GLIBCXX_DEBUG_PEDASSERT(_M_ibegin() <= __i1 && __i1 <= __i2
4966  && __i2 <= _M_iend());
4967  __glibcxx_requires_valid_range(__k1, __k2);
4968  typedef typename std::__is_integer<_InputIterator>::__type _Integral;
4969  return _M_replace_dispatch(__i1, __i2, __k1, __k2, _Integral());
4970  }
4971 
4972  // Specializations for the common case of pointer and iterator:
4973  // useful to avoid the overhead of temporary buffering in _M_replace.
4974  basic_string&
4975  replace(iterator __i1, iterator __i2, _CharT* __k1, _CharT* __k2)
4976  {
4977  _GLIBCXX_DEBUG_PEDASSERT(_M_ibegin() <= __i1 && __i1 <= __i2
4978  && __i2 <= _M_iend());
4979  __glibcxx_requires_valid_range(__k1, __k2);
4980  return this->replace(__i1 - _M_ibegin(), __i2 - __i1,
4981  __k1, __k2 - __k1);
4982  }
4983 
4984  basic_string&
4985  replace(iterator __i1, iterator __i2,
4986  const _CharT* __k1, const _CharT* __k2)
4987  {
4988  _GLIBCXX_DEBUG_PEDASSERT(_M_ibegin() <= __i1 && __i1 <= __i2
4989  && __i2 <= _M_iend());
4990  __glibcxx_requires_valid_range(__k1, __k2);
4991  return this->replace(__i1 - _M_ibegin(), __i2 - __i1,
4992  __k1, __k2 - __k1);
4993  }
4994 
4995  basic_string&
4996  replace(iterator __i1, iterator __i2, iterator __k1, iterator __k2)
4997  {
4998  _GLIBCXX_DEBUG_PEDASSERT(_M_ibegin() <= __i1 && __i1 <= __i2
4999  && __i2 <= _M_iend());
5000  __glibcxx_requires_valid_range(__k1, __k2);
5001  return this->replace(__i1 - _M_ibegin(), __i2 - __i1,
5002  __k1.base(), __k2 - __k1);
5003  }
5004 
5005  basic_string&
5006  replace(iterator __i1, iterator __i2,
5007  const_iterator __k1, const_iterator __k2)
5008  {
5009  _GLIBCXX_DEBUG_PEDASSERT(_M_ibegin() <= __i1 && __i1 <= __i2
5010  && __i2 <= _M_iend());
5011  __glibcxx_requires_valid_range(__k1, __k2);
5012  return this->replace(__i1 - _M_ibegin(), __i2 - __i1,
5013  __k1.base(), __k2 - __k1);
5014  }
5015 
5016 #if __cplusplus >= 201103L
5017  /**
5018  * @brief Replace range of characters with initializer_list.
5019  * @param __i1 Iterator referencing start of range to replace.
5020  * @param __i2 Iterator referencing end of range to replace.
5021  * @param __l The initializer_list of characters to insert.
5022  * @return Reference to this string.
5023  * @throw std::length_error If new length exceeds @c max_size().
5024  *
5025  * Removes the characters in the range [__i1,__i2). In place,
5026  * characters in the range [__k1,__k2) are inserted. If the
5027  * length of result exceeds max_size(), length_error is thrown.
5028  * The value of the string doesn't change if an error is
5029  * thrown.
5030  */
5031  basic_string& replace(iterator __i1, iterator __i2,
5033  { return this->replace(__i1, __i2, __l.begin(), __l.end()); }
5034 #endif // C++11
5035 
5036 #if __cplusplus >= 201703L
5037  /**
5038  * @brief Replace range of characters with string_view.
5039  * @param __pos The position to replace at.
5040  * @param __n The number of characters to replace.
5041  * @param __svt The object convertible to string_view to insert.
5042  * @return Reference to this string.
5043  */
5044  template<typename _Tp>
5045  _If_sv<_Tp, basic_string&>
5046  replace(size_type __pos, size_type __n, const _Tp& __svt)
5047  {
5048  __sv_type __sv = __svt;
5049  return this->replace(__pos, __n, __sv.data(), __sv.size());
5050  }
5051 
5052  /**
5053  * @brief Replace range of characters with string_view.
5054  * @param __pos1 The position to replace at.
5055  * @param __n1 The number of characters to replace.
5056  * @param __svt The object convertible to string_view to insert from.
5057  * @param __pos2 The position in the string_view to insert from.
5058  * @param __n2 The number of characters to insert.
5059  * @return Reference to this string.
5060  */
5061  template<typename _Tp>
5062  _If_sv<_Tp, basic_string&>
5063  replace(size_type __pos1, size_type __n1, const _Tp& __svt,
5064  size_type __pos2, size_type __n2 = npos)
5065  {
5066  __sv_type __sv = __svt;
5067  return this->replace(__pos1, __n1,
5068  __sv.data()
5069  + std::__sv_check(__sv.size(), __pos2, "basic_string::replace"),
5070  std::__sv_limit(__sv.size(), __pos2, __n2));
5071  }
5072 
5073  /**
5074  * @brief Replace range of characters with string_view.
5075  * @param __i1 An iterator referencing the start position
5076  to replace at.
5077  * @param __i2 An iterator referencing the end position
5078  for the replace.
5079  * @param __svt The object convertible to string_view to insert from.
5080  * @return Reference to this string.
5081  */
5082  template<typename _Tp>
5083  _If_sv<_Tp, basic_string&>
5084  replace(const_iterator __i1, const_iterator __i2, const _Tp& __svt)
5085  {
5086  __sv_type __sv = __svt;
5087  return this->replace(__i1 - begin(), __i2 - __i1, __sv);
5088  }
5089 #endif // C++17
5090 
5091  private:
5092  template<class _Integer>
5093  basic_string&
5094  _M_replace_dispatch(iterator __i1, iterator __i2, _Integer __n,
5095  _Integer __val, __true_type)
5096  { return _M_replace_aux(__i1 - _M_ibegin(), __i2 - __i1, __n, __val); }
5097 
5098  template<class _InputIterator>
5099  basic_string&
5100  _M_replace_dispatch(iterator __i1, iterator __i2, _InputIterator __k1,
5101  _InputIterator __k2, __false_type);
5102 
5103  basic_string&
5104  _M_replace_aux(size_type __pos1, size_type __n1, size_type __n2,
5105  _CharT __c);
5106 
5107  basic_string&
5108  _M_replace_safe(size_type __pos1, size_type __n1, const _CharT* __s,
5109  size_type __n2);
5110 
5111  // _S_construct_aux is used to implement the 21.3.1 para 15 which
5112  // requires special behaviour if _InIter is an integral type
5113  template<class _InIterator>
5114  static _CharT*
5115  _S_construct_aux(_InIterator __beg, _InIterator __end,
5116  const _Alloc& __a, __false_type)
5117  {
5118  typedef typename iterator_traits<_InIterator>::iterator_category _Tag;
5119  return _S_construct(__beg, __end, __a, _Tag());
5120  }
5121 
5122  // _GLIBCXX_RESOLVE_LIB_DEFECTS
5123  // 438. Ambiguity in the "do the right thing" clause
5124  template<class _Integer>
5125  static _CharT*
5126  _S_construct_aux(_Integer __beg, _Integer __end,
5127  const _Alloc& __a, __true_type)
5128  { return _S_construct_aux_2(static_cast<size_type>(__beg),
5129  __end, __a); }
5130 
5131  static _CharT*
5132  _S_construct_aux_2(size_type __req, _CharT __c, const _Alloc& __a)
5133  { return _S_construct(__req, __c, __a); }
5134 
5135  template<class _InIterator>
5136  static _CharT*
5137  _S_construct(_InIterator __beg, _InIterator __end, const _Alloc& __a)
5138  {
5139  typedef typename std::__is_integer<_InIterator>::__type _Integral;
5140  return _S_construct_aux(__beg, __end, __a, _Integral());
5141  }
5142 
5143  // For Input Iterators, used in istreambuf_iterators, etc.
5144  template<class _InIterator>
5145  static _CharT*
5146  _S_construct(_InIterator __beg, _InIterator __end, const _Alloc& __a,
5147  input_iterator_tag);
5148 
5149  // For forward_iterators up to random_access_iterators, used for
5150  // string::iterator, _CharT*, etc.
5151  template<class _FwdIterator>
5152  static _CharT*
5153  _S_construct(_FwdIterator __beg, _FwdIterator __end, const _Alloc& __a,
5154  forward_iterator_tag);
5155 
5156  static _CharT*
5157  _S_construct(size_type __req, _CharT __c, const _Alloc& __a);
5158 
5159  public:
5160 
5161  /**
5162  * @brief Copy substring into C string.
5163  * @param __s C string to copy value into.
5164  * @param __n Number of characters to copy.
5165  * @param __pos Index of first character to copy.
5166  * @return Number of characters actually copied
5167  * @throw std::out_of_range If __pos > size().
5168  *
5169  * Copies up to @a __n characters starting at @a __pos into the
5170  * C string @a __s. If @a __pos is %greater than size(),
5171  * out_of_range is thrown.
5172  */
5173  size_type
5174  copy(_CharT* __s, size_type __n, size_type __pos = 0) const;
5175 
5176  /**
5177  * @brief Swap contents with another string.
5178  * @param __s String to swap with.
5179  *
5180  * Exchanges the contents of this string with that of @a __s in constant
5181  * time.
5182  */
5183  void
5184  swap(basic_string& __s)
5185  _GLIBCXX_NOEXCEPT_IF(allocator_traits<_Alloc>::is_always_equal::value);
5186 
5187  // String operations:
5188  /**
5189  * @brief Return const pointer to null-terminated contents.
5190  *
5191  * This is a handle to internal data. Do not modify or dire things may
5192  * happen.
5193  */
5194  const _CharT*
5195  c_str() const _GLIBCXX_NOEXCEPT
5196  { return _M_data(); }
5197 
5198  /**
5199  * @brief Return const pointer to contents.
5200  *
5201  * This is a pointer to internal data. It is undefined to modify
5202  * the contents through the returned pointer. To get a pointer that
5203  * allows modifying the contents use @c &str[0] instead,
5204  * (or in C++17 the non-const @c str.data() overload).
5205  */
5206  const _CharT*
5207  data() const _GLIBCXX_NOEXCEPT
5208  { return _M_data(); }
5209 
5210 #if __cplusplus >= 201703L
5211  /**
5212  * @brief Return non-const pointer to contents.
5213  *
5214  * This is a pointer to the character sequence held by the string.
5215  * Modifying the characters in the sequence is allowed.
5216  */
5217  _CharT*
5218  data() noexcept
5219  {
5220  _M_leak();
5221  return _M_data();
5222  }
5223 #endif
5224 
5225  /**
5226  * @brief Return copy of allocator used to construct this string.
5227  */
5228  allocator_type
5229  get_allocator() const _GLIBCXX_NOEXCEPT
5230  { return _M_dataplus; }
5231 
5232  /**
5233  * @brief Find position of a C substring.
5234  * @param __s C string to locate.
5235  * @param __pos Index of character to search from.
5236  * @param __n Number of characters from @a s to search for.
5237  * @return Index of start of first occurrence.
5238  *
5239  * Starting from @a __pos, searches forward for the first @a
5240  * __n characters in @a __s within this string. If found,
5241  * returns the index where it begins. If not found, returns
5242  * npos.
5243  */
5244  size_type
5245  find(const _CharT* __s, size_type __pos, size_type __n) const
5246  _GLIBCXX_NOEXCEPT;
5247 
5248  /**
5249  * @brief Find position of a string.
5250  * @param __str String to locate.
5251  * @param __pos Index of character to search from (default 0).
5252  * @return Index of start of first occurrence.
5253  *
5254  * Starting from @a __pos, searches forward for value of @a __str within
5255  * this string. If found, returns the index where it begins. If not
5256  * found, returns npos.
5257  */
5258  size_type
5259  find(const basic_string& __str, size_type __pos = 0) const
5260  _GLIBCXX_NOEXCEPT
5261  { return this->find(__str.data(), __pos, __str.size()); }
5262 
5263  /**
5264  * @brief Find position of a C string.
5265  * @param __s C string to locate.
5266  * @param __pos Index of character to search from (default 0).
5267  * @return Index of start of first occurrence.
5268  *
5269  * Starting from @a __pos, searches forward for the value of @a
5270  * __s within this string. If found, returns the index where
5271  * it begins. If not found, returns npos.
5272  */
5273  size_type
5274  find(const _CharT* __s, size_type __pos = 0) const _GLIBCXX_NOEXCEPT
5275  {
5276  __glibcxx_requires_string(__s);
5277  return this->find(__s, __pos, traits_type::length(__s));
5278  }
5279 
5280  /**
5281  * @brief Find position of a character.
5282  * @param __c Character to locate.
5283  * @param __pos Index of character to search from (default 0).
5284  * @return Index of first occurrence.
5285  *
5286  * Starting from @a __pos, searches forward for @a __c within
5287  * this string. If found, returns the index where it was
5288  * found. If not found, returns npos.
5289  */
5290  size_type
5291  find(_CharT __c, size_type __pos = 0) const _GLIBCXX_NOEXCEPT;
5292 
5293 #if __cplusplus >= 201703L
5294  /**
5295  * @brief Find position of a string_view.
5296  * @param __svt The object convertible to string_view to locate.
5297  * @param __pos Index of character to search from (default 0).
5298  * @return Index of start of first occurrence.
5299  */
5300  template<typename _Tp>
5301  _If_sv<_Tp, size_type>
5302  find(const _Tp& __svt, size_type __pos = 0) const
5303  noexcept(is_same<_Tp, __sv_type>::value)
5304  {
5305  __sv_type __sv = __svt;
5306  return this->find(__sv.data(), __pos, __sv.size());
5307  }
5308 #endif // C++17
5309 
5310  /**
5311  * @brief Find last position of a string.
5312  * @param __str String to locate.
5313  * @param __pos Index of character to search back from (default end).
5314  * @return Index of start of last occurrence.
5315  *
5316  * Starting from @a __pos, searches backward for value of @a
5317  * __str within this string. If found, returns the index where
5318  * it begins. If not found, returns npos.
5319  */
5320  size_type
5321  rfind(const basic_string& __str, size_type __pos = npos) const
5322  _GLIBCXX_NOEXCEPT
5323  { return this->rfind(__str.data(), __pos, __str.size()); }
5324 
5325  /**
5326  * @brief Find last position of a C substring.
5327  * @param __s C string to locate.
5328  * @param __pos Index of character to search back from.
5329  * @param __n Number of characters from s to search for.
5330  * @return Index of start of last occurrence.
5331  *
5332  * Starting from @a __pos, searches backward for the first @a
5333  * __n characters in @a __s within this string. If found,
5334  * returns the index where it begins. If not found, returns
5335  * npos.
5336  */
5337  size_type
5338  rfind(const _CharT* __s, size_type __pos, size_type __n) const
5339  _GLIBCXX_NOEXCEPT;
5340 
5341  /**
5342  * @brief Find last position of a C string.
5343  * @param __s C string to locate.
5344  * @param __pos Index of character to start search at (default end).
5345  * @return Index of start of last occurrence.
5346  *
5347  * Starting from @a __pos, searches backward for the value of
5348  * @a __s within this string. If found, returns the index
5349  * where it begins. If not found, returns npos.
5350  */
5351  size_type
5352  rfind(const _CharT* __s, size_type __pos = npos) const _GLIBCXX_NOEXCEPT
5353  {
5354  __glibcxx_requires_string(__s);
5355  return this->rfind(__s, __pos, traits_type::length(__s));
5356  }
5357 
5358  /**
5359  * @brief Find last position of a character.
5360  * @param __c Character to locate.
5361  * @param __pos Index of character to search back from (default end).
5362  * @return Index of last occurrence.
5363  *
5364  * Starting from @a __pos, searches backward for @a __c within
5365  * this string. If found, returns the index where it was
5366  * found. If not found, returns npos.
5367  */
5368  size_type
5369  rfind(_CharT __c, size_type __pos = npos) const _GLIBCXX_NOEXCEPT;
5370 
5371 #if __cplusplus >= 201703L
5372  /**
5373  * @brief Find last position of a string_view.
5374  * @param __svt The object convertible to string_view to locate.
5375  * @param __pos Index of character to search back from (default end).
5376  * @return Index of start of last occurrence.
5377  */
5378  template<typename _Tp>
5379  _If_sv<_Tp, size_type>
5380  rfind(const _Tp& __svt, size_type __pos = npos) const
5382  {
5383  __sv_type __sv = __svt;
5384  return this->rfind(__sv.data(), __pos, __sv.size());
5385  }
5386 #endif // C++17
5387 
5388  /**
5389  * @brief Find position of a character of string.
5390  * @param __str String containing characters to locate.
5391  * @param __pos Index of character to search from (default 0).
5392  * @return Index of first occurrence.
5393  *
5394  * Starting from @a __pos, searches forward for one of the
5395  * characters of @a __str within this string. If found,
5396  * returns the index where it was found. If not found, returns
5397  * npos.
5398  */
5399  size_type
5400  find_first_of(const basic_string& __str, size_type __pos = 0) const
5401  _GLIBCXX_NOEXCEPT
5402  { return this->find_first_of(__str.data(), __pos, __str.size()); }
5403 
5404  /**
5405  * @brief Find position of a character of C substring.
5406  * @param __s String containing characters to locate.
5407  * @param __pos Index of character to search from.
5408  * @param __n Number of characters from s to search for.
5409  * @return Index of first occurrence.
5410  *
5411  * Starting from @a __pos, searches forward for one of the
5412  * first @a __n characters of @a __s within this string. If
5413  * found, returns the index where it was found. If not found,
5414  * returns npos.
5415  */
5416  size_type
5417  find_first_of(const _CharT* __s, size_type __pos, size_type __n) const
5418  _GLIBCXX_NOEXCEPT;
5419 
5420  /**
5421  * @brief Find position of a character of C string.
5422  * @param __s String containing characters to locate.
5423  * @param __pos Index of character to search from (default 0).
5424  * @return Index of first occurrence.
5425  *
5426  * Starting from @a __pos, searches forward for one of the
5427  * characters of @a __s within this string. If found, returns
5428  * the index where it was found. If not found, returns npos.
5429  */
5430  size_type
5431  find_first_of(const _CharT* __s, size_type __pos = 0) const
5432  _GLIBCXX_NOEXCEPT
5433  {
5434  __glibcxx_requires_string(__s);
5435  return this->find_first_of(__s, __pos, traits_type::length(__s));
5436  }
5437 
5438  /**
5439  * @brief Find position of a character.
5440  * @param __c Character to locate.
5441  * @param __pos Index of character to search from (default 0).
5442  * @return Index of first occurrence.
5443  *
5444  * Starting from @a __pos, searches forward for the character
5445  * @a __c within this string. If found, returns the index
5446  * where it was found. If not found, returns npos.
5447  *
5448  * Note: equivalent to find(__c, __pos).
5449  */
5450  size_type
5451  find_first_of(_CharT __c, size_type __pos = 0) const _GLIBCXX_NOEXCEPT
5452  { return this->find(__c, __pos); }
5453 
5454 #if __cplusplus >= 201703L
5455  /**
5456  * @brief Find position of a character of a string_view.
5457  * @param __svt An object convertible to string_view containing
5458  * characters to locate.
5459  * @param __pos Index of character to search from (default 0).
5460  * @return Index of first occurrence.
5461  */
5462  template<typename _Tp>
5463  _If_sv<_Tp, size_type>
5464  find_first_of(const _Tp& __svt, size_type __pos = 0) const
5465  noexcept(is_same<_Tp, __sv_type>::value)
5466  {
5467  __sv_type __sv = __svt;
5468  return this->find_first_of(__sv.data(), __pos, __sv.size());
5469  }
5470 #endif // C++17
5471 
5472  /**
5473  * @brief Find last position of a character of string.
5474  * @param __str String containing characters to locate.
5475  * @param __pos Index of character to search back from (default end).
5476  * @return Index of last occurrence.
5477  *
5478  * Starting from @a __pos, searches backward for one of the
5479  * characters of @a __str within this string. If found,
5480  * returns the index where it was found. If not found, returns
5481  * npos.
5482  */
5483  size_type
5484  find_last_of(const basic_string& __str, size_type __pos = npos) const
5485  _GLIBCXX_NOEXCEPT
5486  { return this->find_last_of(__str.data(), __pos, __str.size()); }
5487 
5488  /**
5489  * @brief Find last position of a character of C substring.
5490  * @param __s C string containing characters to locate.
5491  * @param __pos Index of character to search back from.
5492  * @param __n Number of characters from s to search for.
5493  * @return Index of last occurrence.
5494  *
5495  * Starting from @a __pos, searches backward for one of the
5496  * first @a __n characters of @a __s within this string. If
5497  * found, returns the index where it was found. If not found,
5498  * returns npos.
5499  */
5500  size_type
5501  find_last_of(const _CharT* __s, size_type __pos, size_type __n) const
5502  _GLIBCXX_NOEXCEPT;
5503 
5504  /**
5505  * @brief Find last position of a character of C string.
5506  * @param __s C string containing characters to locate.
5507  * @param __pos Index of character to search back from (default end).
5508  * @return Index of last occurrence.
5509  *
5510  * Starting from @a __pos, searches backward for one of the
5511  * characters of @a __s within this string. If found, returns
5512  * the index where it was found. If not found, returns npos.
5513  */
5514  size_type
5515  find_last_of(const _CharT* __s, size_type __pos = npos) const
5516  _GLIBCXX_NOEXCEPT
5517  {
5518  __glibcxx_requires_string(__s);
5519  return this->find_last_of(__s, __pos, traits_type::length(__s));
5520  }
5521 
5522  /**
5523  * @brief Find last position of a character.
5524  * @param __c Character to locate.
5525  * @param __pos Index of character to search back from (default end).
5526  * @return Index of last occurrence.
5527  *
5528  * Starting from @a __pos, searches backward for @a __c within
5529  * this string. If found, returns the index where it was
5530  * found. If not found, returns npos.
5531  *
5532  * Note: equivalent to rfind(__c, __pos).
5533  */
5534  size_type
5535  find_last_of(_CharT __c, size_type __pos = npos) const _GLIBCXX_NOEXCEPT
5536  { return this->rfind(__c, __pos); }
5537 
5538 #if __cplusplus >= 201703L
5539  /**
5540  * @brief Find last position of a character of string.
5541  * @param __svt An object convertible to string_view containing
5542  * characters to locate.
5543  * @param __pos Index of character to search back from (default end).
5544  * @return Index of last occurrence.
5545  */
5546  template<typename _Tp>
5547  _If_sv<_Tp, size_type>
5548  find_last_of(const _Tp& __svt, size_type __pos = npos) const
5550  {
5551  __sv_type __sv = __svt;
5552  return this->find_last_of(__sv.data(), __pos, __sv.size());
5553  }
5554 #endif // C++17
5555 
5556  /**
5557  * @brief Find position of a character not in string.
5558  * @param __str String containing characters to avoid.
5559  * @param __pos Index of character to search from (default 0).
5560  * @return Index of first occurrence.
5561  *
5562  * Starting from @a __pos, searches forward for a character not contained
5563  * in @a __str within this string. If found, returns the index where it
5564  * was found. If not found, returns npos.
5565  */
5566  size_type
5567  find_first_not_of(const basic_string& __str, size_type __pos = 0) const
5568  _GLIBCXX_NOEXCEPT
5569  { return this->find_first_not_of(__str.data(), __pos, __str.size()); }
5570 
5571  /**
5572  * @brief Find position of a character not in C substring.
5573  * @param __s C string containing characters to avoid.
5574  * @param __pos Index of character to search from.
5575  * @param __n Number of characters from __s to consider.
5576  * @return Index of first occurrence.
5577  *
5578  * Starting from @a __pos, searches forward for a character not
5579  * contained in the first @a __n characters of @a __s within
5580  * this string. If found, returns the index where it was
5581  * found. If not found, returns npos.
5582  */
5583  size_type
5584  find_first_not_of(const _CharT* __s, size_type __pos,
5585  size_type __n) const _GLIBCXX_NOEXCEPT;
5586 
5587  /**
5588  * @brief Find position of a character not in C string.
5589  * @param __s C string containing characters to avoid.
5590  * @param __pos Index of character to search from (default 0).
5591  * @return Index of first occurrence.
5592  *
5593  * Starting from @a __pos, searches forward for a character not
5594  * contained in @a __s within this string. If found, returns
5595  * the index where it was found. If not found, returns npos.
5596  */
5597  size_type
5598  find_first_not_of(const _CharT* __s, size_type __pos = 0) const
5599  _GLIBCXX_NOEXCEPT
5600  {
5601  __glibcxx_requires_string(__s);
5602  return this->find_first_not_of(__s, __pos, traits_type::length(__s));
5603  }
5604 
5605  /**
5606  * @brief Find position of a different character.
5607  * @param __c Character to avoid.
5608  * @param __pos Index of character to search from (default 0).
5609  * @return Index of first occurrence.
5610  *
5611  * Starting from @a __pos, searches forward for a character
5612  * other than @a __c within this string. If found, returns the
5613  * index where it was found. If not found, returns npos.
5614  */
5615  size_type
5616  find_first_not_of(_CharT __c, size_type __pos = 0) const
5617  _GLIBCXX_NOEXCEPT;
5618 
5619 #if __cplusplus >= 201703L
5620  /**
5621  * @brief Find position of a character not in a string_view.
5622  * @param __svt An object convertible to string_view containing
5623  * characters to avoid.
5624  * @param __pos Index of character to search from (default 0).
5625  * @return Index of first occurrence.
5626  */
5627  template<typename _Tp>
5628  _If_sv<_Tp, size_type>
5629  find_first_not_of(const _Tp& __svt, size_type __pos = 0) const
5630  noexcept(is_same<_Tp, __sv_type>::value)
5631  {
5632  __sv_type __sv = __svt;
5633  return this->find_first_not_of(__sv.data(), __pos, __sv.size());
5634  }
5635 #endif // C++17
5636 
5637  /**
5638  * @brief Find last position of a character not in string.
5639  * @param __str String containing characters to avoid.
5640  * @param __pos Index of character to search back from (default end).
5641  * @return Index of last occurrence.
5642  *
5643  * Starting from @a __pos, searches backward for a character
5644  * not contained in @a __str within this string. If found,
5645  * returns the index where it was found. If not found, returns
5646  * npos.
5647  */
5648  size_type
5649  find_last_not_of(const basic_string& __str, size_type __pos = npos) const
5650  _GLIBCXX_NOEXCEPT
5651  { return this->find_last_not_of(__str.data(), __pos, __str.size()); }
5652 
5653  /**
5654  * @brief Find last position of a character not in C substring.
5655  * @param __s C string containing characters to avoid.
5656  * @param __pos Index of character to search back from.
5657  * @param __n Number of characters from s to consider.
5658  * @return Index of last occurrence.
5659  *
5660  * Starting from @a __pos, searches backward for a character not
5661  * contained in the first @a __n characters of @a __s within this string.
5662  * If found, returns the index where it was found. If not found,
5663  * returns npos.
5664  */
5665  size_type
5666  find_last_not_of(const _CharT* __s, size_type __pos,
5667  size_type __n) const _GLIBCXX_NOEXCEPT;
5668  /**
5669  * @brief Find last position of a character not in C string.
5670  * @param __s C string containing characters to avoid.
5671  * @param __pos Index of character to search back from (default end).
5672  * @return Index of last occurrence.
5673  *
5674  * Starting from @a __pos, searches backward for a character
5675  * not contained in @a __s within this string. If found,
5676  * returns the index where it was found. If not found, returns
5677  * npos.
5678  */
5679  size_type
5680  find_last_not_of(const _CharT* __s, size_type __pos = npos) const
5681  _GLIBCXX_NOEXCEPT
5682  {
5683  __glibcxx_requires_string(__s);
5684  return this->find_last_not_of(__s, __pos, traits_type::length(__s));
5685  }
5686 
5687  /**
5688  * @brief Find last position of a different character.
5689  * @param __c Character to avoid.
5690  * @param __pos Index of character to search back from (default end).
5691  * @return Index of last occurrence.
5692  *
5693  * Starting from @a __pos, searches backward for a character other than
5694  * @a __c within this string. If found, returns the index where it was
5695  * found. If not found, returns npos.
5696  */
5697  size_type
5698  find_last_not_of(_CharT __c, size_type __pos = npos) const
5699  _GLIBCXX_NOEXCEPT;
5700 
5701 #if __cplusplus >= 201703L
5702  /**
5703  * @brief Find last position of a character not in a string_view.
5704  * @param __svt An object convertible to string_view containing
5705  * characters to avoid.
5706  * @param __pos Index of character to search back from (default end).
5707  * @return Index of last occurrence.
5708  */
5709  template<typename _Tp>
5710  _If_sv<_Tp, size_type>
5711  find_last_not_of(const _Tp& __svt, size_type __pos = npos) const
5713  {
5714  __sv_type __sv = __svt;
5715  return this->find_last_not_of(__sv.data(), __pos, __sv.size());
5716  }
5717 #endif // C++17
5718 
5719  /**
5720  * @brief Get a substring.
5721  * @param __pos Index of first character (default 0).
5722  * @param __n Number of characters in substring (default remainder).
5723  * @return The new string.
5724  * @throw std::out_of_range If __pos > size().
5725  *
5726  * Construct and return a new string using the @a __n
5727  * characters starting at @a __pos. If the string is too
5728  * short, use the remainder of the characters. If @a __pos is
5729  * beyond the end of the string, out_of_range is thrown.
5730  */
5731  basic_string
5732  substr(size_type __pos = 0, size_type __n = npos) const
5733  { return basic_string(*this,
5734  _M_check(__pos, "basic_string::substr"), __n); }
5735 
5736  /**
5737  * @brief Compare to a string.
5738  * @param __str String to compare against.
5739  * @return Integer < 0, 0, or > 0.
5740  *
5741  * Returns an integer < 0 if this string is ordered before @a
5742  * __str, 0 if their values are equivalent, or > 0 if this
5743  * string is ordered after @a __str. Determines the effective
5744  * length rlen of the strings to compare as the smallest of
5745  * size() and str.size(). The function then compares the two
5746  * strings by calling traits::compare(data(), str.data(),rlen).
5747  * If the result of the comparison is nonzero returns it,
5748  * otherwise the shorter one is ordered first.
5749  */
5750  int
5751  compare(const basic_string& __str) const
5752  {
5753  const size_type __size = this->size();
5754  const size_type __osize = __str.size();
5755  const size_type __len = std::min(__size, __osize);
5756 
5757  int __r = traits_type::compare(_M_data(), __str.data(), __len);
5758  if (!__r)
5759  __r = _S_compare(__size, __osize);
5760  return __r;
5761  }
5762 
5763 #if __cplusplus >= 201703L
5764  /**
5765  * @brief Compare to a string_view.
5766  * @param __svt An object convertible to string_view to compare against.
5767  * @return Integer < 0, 0, or > 0.
5768  */
5769  template<typename _Tp>
5770  _If_sv<_Tp, int>
5771  compare(const _Tp& __svt) const
5773  {
5774  __sv_type __sv = __svt;
5775  const size_type __size = this->size();
5776  const size_type __osize = __sv.size();
5777  const size_type __len = std::min(__size, __osize);
5778 
5779  int __r = traits_type::compare(_M_data(), __sv.data(), __len);
5780  if (!__r)
5781  __r = _S_compare(__size, __osize);
5782  return __r;
5783  }
5784 
5785  /**
5786  * @brief Compare to a string_view.
5787  * @param __pos A position in the string to start comparing from.
5788  * @param __n The number of characters to compare.
5789  * @param __svt An object convertible to string_view to compare
5790  * against.
5791  * @return Integer < 0, 0, or > 0.
5792  */
5793  template<typename _Tp>
5794  _If_sv<_Tp, int>
5795  compare(size_type __pos, size_type __n, const _Tp& __svt) const
5796  noexcept(is_same<_Tp, __sv_type>::value)
5797  {
5798  __sv_type __sv = __svt;
5799  return __sv_type(*this).substr(__pos, __n).compare(__sv);
5800  }
5801 
5802  /**
5803  * @brief Compare to a string_view.
5804  * @param __pos1 A position in the string to start comparing from.
5805  * @param __n1 The number of characters to compare.
5806  * @param __svt An object convertible to string_view to compare
5807  * against.
5808  * @param __pos2 A position in the string_view to start comparing from.
5809  * @param __n2 The number of characters to compare.
5810  * @return Integer < 0, 0, or > 0.
5811  */
5812  template<typename _Tp>
5813  _If_sv<_Tp, int>
5814  compare(size_type __pos1, size_type __n1, const _Tp& __svt,
5815  size_type __pos2, size_type __n2 = npos) const
5816  noexcept(is_same<_Tp, __sv_type>::value)
5817  {
5818  __sv_type __sv = __svt;
5819  return __sv_type(*this)
5820  .substr(__pos1, __n1).compare(__sv.substr(__pos2, __n2));
5821  }
5822 #endif // C++17
5823 
5824  /**
5825  * @brief Compare substring to a string.
5826  * @param __pos Index of first character of substring.
5827  * @param __n Number of characters in substring.
5828  * @param __str String to compare against.
5829  * @return Integer < 0, 0, or > 0.
5830  *
5831  * Form the substring of this string from the @a __n characters
5832  * starting at @a __pos. Returns an integer < 0 if the
5833  * substring is ordered before @a __str, 0 if their values are
5834  * equivalent, or > 0 if the substring is ordered after @a
5835  * __str. Determines the effective length rlen of the strings
5836  * to compare as the smallest of the length of the substring
5837  * and @a __str.size(). The function then compares the two
5838  * strings by calling
5839  * traits::compare(substring.data(),str.data(),rlen). If the
5840  * result of the comparison is nonzero returns it, otherwise
5841  * the shorter one is ordered first.
5842  */
5843  int
5844  compare(size_type __pos, size_type __n, const basic_string& __str) const;
5845 
5846  /**
5847  * @brief Compare substring to a substring.
5848  * @param __pos1 Index of first character of substring.
5849  * @param __n1 Number of characters in substring.
5850  * @param __str String to compare against.
5851  * @param __pos2 Index of first character of substring of str.
5852  * @param __n2 Number of characters in substring of str.
5853  * @return Integer < 0, 0, or > 0.
5854  *
5855  * Form the substring of this string from the @a __n1
5856  * characters starting at @a __pos1. Form the substring of @a
5857  * __str from the @a __n2 characters starting at @a __pos2.
5858  * Returns an integer < 0 if this substring is ordered before
5859  * the substring of @a __str, 0 if their values are equivalent,
5860  * or > 0 if this substring is ordered after the substring of
5861  * @a __str. Determines the effective length rlen of the
5862  * strings to compare as the smallest of the lengths of the
5863  * substrings. The function then compares the two strings by
5864  * calling
5865  * traits::compare(substring.data(),str.substr(pos2,n2).data(),rlen).
5866  * If the result of the comparison is nonzero returns it,
5867  * otherwise the shorter one is ordered first.
5868  */
5869  int
5870  compare(size_type __pos1, size_type __n1, const basic_string& __str,
5871  size_type __pos2, size_type __n2 = npos) const;
5872 
5873  /**
5874  * @brief Compare to a C string.
5875  * @param __s C string to compare against.
5876  * @return Integer < 0, 0, or > 0.
5877  *
5878  * Returns an integer < 0 if this string is ordered before @a __s, 0 if
5879  * their values are equivalent, or > 0 if this string is ordered after
5880  * @a __s. Determines the effective length rlen of the strings to
5881  * compare as the smallest of size() and the length of a string
5882  * constructed from @a __s. The function then compares the two strings
5883  * by calling traits::compare(data(),s,rlen). If the result of the
5884  * comparison is nonzero returns it, otherwise the shorter one is
5885  * ordered first.
5886  */
5887  int
5888  compare(const _CharT* __s) const _GLIBCXX_NOEXCEPT;
5889 
5890  // _GLIBCXX_RESOLVE_LIB_DEFECTS
5891  // 5 String::compare specification questionable
5892  /**
5893  * @brief Compare substring to a C string.
5894  * @param __pos Index of first character of substring.
5895  * @param __n1 Number of characters in substring.
5896  * @param __s C string to compare against.
5897  * @return Integer < 0, 0, or > 0.
5898  *
5899  * Form the substring of this string from the @a __n1
5900  * characters starting at @a pos. Returns an integer < 0 if
5901  * the substring is ordered before @a __s, 0 if their values
5902  * are equivalent, or > 0 if the substring is ordered after @a
5903  * __s. Determines the effective length rlen of the strings to
5904  * compare as the smallest of the length of the substring and
5905  * the length of a string constructed from @a __s. The
5906  * function then compares the two string by calling
5907  * traits::compare(substring.data(),__s,rlen). If the result of
5908  * the comparison is nonzero returns it, otherwise the shorter
5909  * one is ordered first.
5910  */
5911  int
5912  compare(size_type __pos, size_type __n1, const _CharT* __s) const;
5913 
5914  /**
5915  * @brief Compare substring against a character %array.
5916  * @param __pos Index of first character of substring.
5917  * @param __n1 Number of characters in substring.
5918  * @param __s character %array to compare against.
5919  * @param __n2 Number of characters of s.
5920  * @return Integer < 0, 0, or > 0.
5921  *
5922  * Form the substring of this string from the @a __n1
5923  * characters starting at @a __pos. Form a string from the
5924  * first @a __n2 characters of @a __s. Returns an integer < 0
5925  * if this substring is ordered before the string from @a __s,
5926  * 0 if their values are equivalent, or > 0 if this substring
5927  * is ordered after the string from @a __s. Determines the
5928  * effective length rlen of the strings to compare as the
5929  * smallest of the length of the substring and @a __n2. The
5930  * function then compares the two strings by calling
5931  * traits::compare(substring.data(),s,rlen). If the result of
5932  * the comparison is nonzero returns it, otherwise the shorter
5933  * one is ordered first.
5934  *
5935  * NB: s must have at least n2 characters, &apos;\\0&apos; has
5936  * no special meaning.
5937  */
5938  int
5939  compare(size_type __pos, size_type __n1, const _CharT* __s,
5940  size_type __n2) const;
5941 
5942 #if __cplusplus > 201703L
5943  bool
5944  starts_with(basic_string_view<_CharT, _Traits> __x) const noexcept
5945  { return __sv_type(this->data(), this->size()).starts_with(__x); }
5946 
5947  bool
5948  starts_with(_CharT __x) const noexcept
5949  { return __sv_type(this->data(), this->size()).starts_with(__x); }
5950 
5951  bool
5952  starts_with(const _CharT* __x) const noexcept
5953  { return __sv_type(this->data(), this->size()).starts_with(__x); }
5954 
5955  bool
5956  ends_with(basic_string_view<_CharT, _Traits> __x) const noexcept
5957  { return __sv_type(this->data(), this->size()).ends_with(__x); }
5958 
5959  bool
5960  ends_with(_CharT __x) const noexcept
5961  { return __sv_type(this->data(), this->size()).ends_with(__x); }
5962 
5963  bool
5964  ends_with(const _CharT* __x) const noexcept
5965  { return __sv_type(this->data(), this->size()).ends_with(__x); }
5966 #endif // C++20
5967 
5968 # ifdef _GLIBCXX_TM_TS_INTERNAL
5969  friend void
5970  ::_txnal_cow_string_C1_for_exceptions(void* that, const char* s,
5971  void* exc);
5972  friend const char*
5973  ::_txnal_cow_string_c_str(const void *that);
5974  friend void
5975  ::_txnal_cow_string_D1(void *that);
5976  friend void
5977  ::_txnal_cow_string_D1_commit(void *that);
5978 # endif
5979  };
5980 #endif // !_GLIBCXX_USE_CXX11_ABI
5981 
5982 #if __cpp_deduction_guides >= 201606
5983 _GLIBCXX_BEGIN_NAMESPACE_CXX11
5984  template<typename _InputIterator, typename _CharT
5985  = typename iterator_traits<_InputIterator>::value_type,
5986  typename _Allocator = allocator<_CharT>,
5987  typename = _RequireInputIter<_InputIterator>,
5988  typename = _RequireAllocator<_Allocator>>
5989  basic_string(_InputIterator, _InputIterator, _Allocator = _Allocator())
5990  -> basic_string<_CharT, char_traits<_CharT>, _Allocator>;
5991 
5992  // _GLIBCXX_RESOLVE_LIB_DEFECTS
5993  // 3075. basic_string needs deduction guides from basic_string_view
5994  template<typename _CharT, typename _Traits,
5995  typename _Allocator = allocator<_CharT>,
5996  typename = _RequireAllocator<_Allocator>>
5997  basic_string(basic_string_view<_CharT, _Traits>, const _Allocator& = _Allocator())
5998  -> basic_string<_CharT, _Traits, _Allocator>;
5999 
6000  template<typename _CharT, typename _Traits,
6001  typename _Allocator = allocator<_CharT>,
6002  typename = _RequireAllocator<_Allocator>>
6003  basic_string(basic_string_view<_CharT, _Traits>,
6004  typename basic_string<_CharT, _Traits, _Allocator>::size_type,
6005  typename basic_string<_CharT, _Traits, _Allocator>::size_type,
6006  const _Allocator& = _Allocator())
6007  -> basic_string<_CharT, _Traits, _Allocator>;
6008 _GLIBCXX_END_NAMESPACE_CXX11
6009 #endif
6010 
6011  // operator+
6012  /**
6013  * @brief Concatenate two strings.
6014  * @param __lhs First string.
6015  * @param __rhs Last string.
6016  * @return New string with value of @a __lhs followed by @a __rhs.
6017  */
6018  template<typename _CharT, typename _Traits, typename _Alloc>
6019  basic_string<_CharT, _Traits, _Alloc>
6022  {
6024  __str.append(__rhs);
6025  return __str;
6026  }
6027 
6028  /**
6029  * @brief Concatenate C string and string.
6030  * @param __lhs First string.
6031  * @param __rhs Last string.
6032  * @return New string with value of @a __lhs followed by @a __rhs.
6033  */
6034  template<typename _CharT, typename _Traits, typename _Alloc>
6035  basic_string<_CharT,_Traits,_Alloc>
6036  operator+(const _CharT* __lhs,
6037  const basic_string<_CharT,_Traits,_Alloc>& __rhs);
6038 
6039  /**
6040  * @brief Concatenate character and string.
6041  * @param __lhs First string.
6042  * @param __rhs Last string.
6043  * @return New string with @a __lhs followed by @a __rhs.
6044  */
6045  template<typename _CharT, typename _Traits, typename _Alloc>
6046  basic_string<_CharT,_Traits,_Alloc>
6047  operator+(_CharT __lhs, const basic_string<_CharT,_Traits,_Alloc>& __rhs);
6048 
6049  /**
6050  * @brief Concatenate string and C string.
6051  * @param __lhs First string.
6052  * @param __rhs Last string.
6053  * @return New string with @a __lhs followed by @a __rhs.
6054  */
6055  template<typename _CharT, typename _Traits, typename _Alloc>
6056  inline basic_string<_CharT, _Traits, _Alloc>
6058  const _CharT* __rhs)
6059  {
6061  __str.append(__rhs);
6062  return __str;
6063  }
6064 
6065  /**
6066  * @brief Concatenate string and character.
6067  * @param __lhs First string.
6068  * @param __rhs Last string.
6069  * @return New string with @a __lhs followed by @a __rhs.
6070  */
6071  template<typename _CharT, typename _Traits, typename _Alloc>
6072  inline basic_string<_CharT, _Traits, _Alloc>
6074  {
6075  typedef basic_string<_CharT, _Traits, _Alloc> __string_type;
6076  typedef typename __string_type::size_type __size_type;
6077  __string_type __str(__lhs);
6078  __str.append(__size_type(1), __rhs);
6079  return __str;
6080  }
6081 
6082 #if __cplusplus >= 201103L
6083  template<typename _CharT, typename _Traits, typename _Alloc>
6084  inline basic_string<_CharT, _Traits, _Alloc>
6085  operator+(basic_string<_CharT, _Traits, _Alloc>&& __lhs,
6086  const basic_string<_CharT, _Traits, _Alloc>& __rhs)
6087  { return std::move(__lhs.append(__rhs)); }
6088 
6089  template<typename _CharT, typename _Traits, typename _Alloc>
6090  inline basic_string<_CharT, _Traits, _Alloc>
6091  operator+(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
6092  basic_string<_CharT, _Traits, _Alloc>&& __rhs)
6093  { return std::move(__rhs.insert(0, __lhs)); }
6094 
6095  template<typename _CharT, typename _Traits, typename _Alloc>
6096  inline basic_string<_CharT, _Traits, _Alloc>
6097  operator+(basic_string<_CharT, _Traits, _Alloc>&& __lhs,
6098  basic_string<_CharT, _Traits, _Alloc>&& __rhs)
6099  {
6100  const auto __size = __lhs.size() + __rhs.size();
6101  const bool __cond = (__size > __lhs.capacity()
6102  && __size <= __rhs.capacity());
6103  return __cond ? std::move(__rhs.insert(0, __lhs))
6104  : std::move(__lhs.append(__rhs));
6105  }
6106 
6107  template<typename _CharT, typename _Traits, typename _Alloc>
6108  inline basic_string<_CharT, _Traits, _Alloc>
6109  operator+(const _CharT* __lhs,
6110  basic_string<_CharT, _Traits, _Alloc>&& __rhs)
6111  { return std::move(__rhs.insert(0, __lhs)); }
6112 
6113  template<typename _CharT, typename _Traits, typename _Alloc>
6114  inline basic_string<_CharT, _Traits, _Alloc>
6115  operator+(_CharT __lhs,
6116  basic_string<_CharT, _Traits, _Alloc>&& __rhs)
6117  { return std::move(__rhs.insert(0, 1, __lhs)); }
6118 
6119  template<typename _CharT, typename _Traits, typename _Alloc>
6120  inline basic_string<_CharT, _Traits, _Alloc>
6121  operator+(basic_string<_CharT, _Traits, _Alloc>&& __lhs,
6122  const _CharT* __rhs)
6123  { return std::move(__lhs.append(__rhs)); }
6124 
6125  template<typename _CharT, typename _Traits, typename _Alloc>
6126  inline basic_string<_CharT, _Traits, _Alloc>
6127  operator+(basic_string<_CharT, _Traits, _Alloc>&& __lhs,
6128  _CharT __rhs)
6129  { return std::move(__lhs.append(1, __rhs)); }
6130 #endif
6131 
6132  // operator ==
6133  /**
6134  * @brief Test equivalence of two strings.
6135  * @param __lhs First string.
6136  * @param __rhs Second string.
6137  * @return True if @a __lhs.compare(@a __rhs) == 0. False otherwise.
6138  */
6139  template<typename _CharT, typename _Traits, typename _Alloc>
6140  inline bool
6141  operator==(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
6143  _GLIBCXX_NOEXCEPT
6144  { return __lhs.compare(__rhs) == 0; }
6145 
6146  template<typename _CharT>
6147  inline
6148  typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value, bool>::__type
6149  operator==(const basic_string<_CharT>& __lhs,
6150  const basic_string<_CharT>& __rhs) _GLIBCXX_NOEXCEPT
6151  { return (__lhs.size() == __rhs.size()
6152  && !std::char_traits<_CharT>::compare(__lhs.data(), __rhs.data(),
6153  __lhs.size())); }
6154 
6155  /**
6156  * @brief Test equivalence of C string and string.
6157  * @param __lhs C string.
6158  * @param __rhs String.
6159  * @return True if @a __rhs.compare(@a __lhs) == 0. False otherwise.
6160  */
6161  template<typename _CharT, typename _Traits, typename _Alloc>
6162  inline bool
6163  operator==(const _CharT* __lhs,
6165  { return __rhs.compare(__lhs) == 0; }
6166 
6167  /**
6168  * @brief Test equivalence of string and C string.
6169  * @param __lhs String.
6170  * @param __rhs C string.
6171  * @return True if @a __lhs.compare(@a __rhs) == 0. False otherwise.
6172  */
6173  template<typename _CharT, typename _Traits, typename _Alloc>
6174  inline bool
6175  operator==(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
6176  const _CharT* __rhs)
6177  { return __lhs.compare(__rhs) == 0; }
6178 
6179  // operator !=
6180  /**
6181  * @brief Test difference of two strings.
6182  * @param __lhs First string.
6183  * @param __rhs Second string.
6184  * @return True if @a __lhs.compare(@a __rhs) != 0. False otherwise.
6185  */
6186  template<typename _CharT, typename _Traits, typename _Alloc>
6187  inline bool
6188  operator!=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
6190  _GLIBCXX_NOEXCEPT
6191  { return !(__lhs == __rhs); }
6192 
6193  /**
6194  * @brief Test difference of C string and string.
6195  * @param __lhs C string.
6196  * @param __rhs String.
6197  * @return True if @a __rhs.compare(@a __lhs) != 0. False otherwise.
6198  */
6199  template<typename _CharT, typename _Traits, typename _Alloc>
6200  inline bool
6201  operator!=(const _CharT* __lhs,
6203  { return !(__lhs == __rhs); }
6204 
6205  /**
6206  * @brief Test difference of string and C string.
6207  * @param __lhs String.
6208  * @param __rhs C string.
6209  * @return True if @a __lhs.compare(@a __rhs) != 0. False otherwise.
6210  */
6211  template<typename _CharT, typename _Traits, typename _Alloc>
6212  inline bool
6213  operator!=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
6214  const _CharT* __rhs)
6215  { return !(__lhs == __rhs); }
6216 
6217  // operator <
6218  /**
6219  * @brief Test if string precedes string.
6220  * @param __lhs First string.
6221  * @param __rhs Second string.
6222  * @return True if @a __lhs precedes @a __rhs. False otherwise.
6223  */
6224  template<typename _CharT, typename _Traits, typename _Alloc>
6225  inline bool
6226  operator<(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
6228  _GLIBCXX_NOEXCEPT
6229  { return __lhs.compare(__rhs) < 0; }
6230 
6231  /**
6232  * @brief Test if string precedes C string.
6233  * @param __lhs String.
6234  * @param __rhs C string.
6235  * @return True if @a __lhs precedes @a __rhs. False otherwise.
6236  */
6237  template<typename _CharT, typename _Traits, typename _Alloc>
6238  inline bool
6239  operator<(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
6240  const _CharT* __rhs)
6241  { return __lhs.compare(__rhs) < 0; }
6242 
6243  /**
6244  * @brief Test if C string precedes string.
6245  * @param __lhs C string.
6246  * @param __rhs String.
6247  * @return True if @a __lhs precedes @a __rhs. False otherwise.
6248  */
6249  template<typename _CharT, typename _Traits, typename _Alloc>
6250  inline bool
6251  operator<(const _CharT* __lhs,
6253  { return __rhs.compare(__lhs) > 0; }
6254 
6255  // operator >
6256  /**
6257  * @brief Test if string follows string.
6258  * @param __lhs First string.
6259  * @param __rhs Second string.
6260  * @return True if @a __lhs follows @a __rhs. False otherwise.
6261  */
6262  template<typename _CharT, typename _Traits, typename _Alloc>
6263  inline bool
6266  _GLIBCXX_NOEXCEPT
6267  { return __lhs.compare(__rhs) > 0; }
6268 
6269  /**
6270  * @brief Test if string follows C string.
6271  * @param __lhs String.
6272  * @param __rhs C string.
6273  * @return True if @a __lhs follows @a __rhs. False otherwise.
6274  */
6275  template<typename _CharT, typename _Traits, typename _Alloc>
6276  inline bool
6278  const _CharT* __rhs)
6279  { return __lhs.compare(__rhs) > 0; }
6280 
6281  /**
6282  * @brief Test if C string follows string.
6283  * @param __lhs C string.
6284  * @param __rhs String.
6285  * @return True if @a __lhs follows @a __rhs. False otherwise.
6286  */
6287  template<typename _CharT, typename _Traits, typename _Alloc>
6288  inline bool
6289  operator>(const _CharT* __lhs,
6291  { return __rhs.compare(__lhs) < 0; }
6292 
6293  // operator <=
6294  /**
6295  * @brief Test if string doesn't follow string.
6296  * @param __lhs First string.
6297  * @param __rhs Second string.
6298  * @return True if @a __lhs doesn't follow @a __rhs. False otherwise.
6299  */
6300  template<typename _CharT, typename _Traits, typename _Alloc>
6301  inline bool
6302  operator<=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
6304  _GLIBCXX_NOEXCEPT
6305  { return __lhs.compare(__rhs) <= 0; }
6306 
6307  /**
6308  * @brief Test if string doesn't follow C string.
6309  * @param __lhs String.
6310  * @param __rhs C string.
6311  * @return True if @a __lhs doesn't follow @a __rhs. False otherwise.
6312  */
6313  template<typename _CharT, typename _Traits, typename _Alloc>
6314  inline bool
6315  operator<=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
6316  const _CharT* __rhs)
6317  { return __lhs.compare(__rhs) <= 0; }
6318 
6319  /**
6320  * @brief Test if C string doesn't follow string.
6321  * @param __lhs C string.
6322  * @param __rhs String.
6323  * @return True if @a __lhs doesn't follow @a __rhs. False otherwise.
6324  */
6325  template<typename _CharT, typename _Traits, typename _Alloc>
6326  inline bool
6327  operator<=(const _CharT* __lhs,
6329  { return __rhs.compare(__lhs) >= 0; }
6330 
6331  // operator >=
6332  /**
6333  * @brief Test if string doesn't precede string.
6334  * @param __lhs First string.
6335  * @param __rhs Second string.
6336  * @return True if @a __lhs doesn't precede @a __rhs. False otherwise.
6337  */
6338  template<typename _CharT, typename _Traits, typename _Alloc>
6339  inline bool
6340  operator>=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
6342  _GLIBCXX_NOEXCEPT
6343  { return __lhs.compare(__rhs) >= 0; }
6344 
6345  /**
6346  * @brief Test if string doesn't precede C string.
6347  * @param __lhs String.
6348  * @param __rhs C string.
6349  * @return True if @a __lhs doesn't precede @a __rhs. False otherwise.
6350  */
6351  template<typename _CharT, typename _Traits, typename _Alloc>
6352  inline bool
6353  operator>=(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
6354  const _CharT* __rhs)
6355  { return __lhs.compare(__rhs) >= 0; }
6356 
6357  /**
6358  * @brief Test if C string doesn't precede string.
6359  * @param __lhs C string.
6360  * @param __rhs String.
6361  * @return True if @a __lhs doesn't precede @a __rhs. False otherwise.
6362  */
6363  template<typename _CharT, typename _Traits, typename _Alloc>
6364  inline bool
6365  operator>=(const _CharT* __lhs,
6367  { return __rhs.compare(__lhs) <= 0; }
6368 
6369  /**
6370  * @brief Swap contents of two strings.
6371  * @param __lhs First string.
6372  * @param __rhs Second string.
6373  *
6374  * Exchanges the contents of @a __lhs and @a __rhs in constant time.
6375  */
6376  template<typename _CharT, typename _Traits, typename _Alloc>
6377  inline void
6380  _GLIBCXX_NOEXCEPT_IF(noexcept(__lhs.swap(__rhs)))
6381  { __lhs.swap(__rhs); }
6382 
6383 
6384  /**
6385  * @brief Read stream into a string.
6386  * @param __is Input stream.
6387  * @param __str Buffer to store into.
6388  * @return Reference to the input stream.
6389  *
6390  * Stores characters from @a __is into @a __str until whitespace is
6391  * found, the end of the stream is encountered, or str.max_size()
6392  * is reached. If is.width() is non-zero, that is the limit on the
6393  * number of characters stored into @a __str. Any previous
6394  * contents of @a __str are erased.
6395  */
6396  template<typename _CharT, typename _Traits, typename _Alloc>
6397  basic_istream<_CharT, _Traits>&
6398  operator>>(basic_istream<_CharT, _Traits>& __is,
6399  basic_string<_CharT, _Traits, _Alloc>& __str);
6400 
6401  template<>
6402  basic_istream<char>&
6403  operator>>(basic_istream<char>& __is, basic_string<char>& __str);
6404 
6405  /**
6406  * @brief Write string to a stream.
6407  * @param __os Output stream.
6408  * @param __str String to write out.
6409  * @return Reference to the output stream.
6410  *
6411  * Output characters of @a __str into os following the same rules as for
6412  * writing a C string.
6413  */
6414  template<typename _CharT, typename _Traits, typename _Alloc>
6415  inline basic_ostream<_CharT, _Traits>&
6416  operator<<(basic_ostream<_CharT, _Traits>& __os,
6418  {
6419  // _GLIBCXX_RESOLVE_LIB_DEFECTS
6420  // 586. string inserter not a formatted function
6421  return __ostream_insert(__os, __str.data(), __str.size());
6422  }
6423 
6424  /**
6425  * @brief Read a line from stream into a string.
6426  * @param __is Input stream.
6427  * @param __str Buffer to store into.
6428  * @param __delim Character marking end of line.
6429  * @return Reference to the input stream.
6430  *
6431  * Stores characters from @a __is into @a __str until @a __delim is
6432  * found, the end of the stream is encountered, or str.max_size()
6433  * is reached. Any previous contents of @a __str are erased. If
6434  * @a __delim is encountered, it is extracted but not stored into
6435  * @a __str.
6436  */
6437  template<typename _CharT, typename _Traits, typename _Alloc>
6438  basic_istream<_CharT, _Traits>&
6439  getline(basic_istream<_CharT, _Traits>& __is,
6440  basic_string<_CharT, _Traits, _Alloc>& __str, _CharT __delim);
6441 
6442  /**
6443  * @brief Read a line from stream into a string.
6444  * @param __is Input stream.
6445  * @param __str Buffer to store into.
6446  * @return Reference to the input stream.
6447  *
6448  * Stores characters from is into @a __str until &apos;\n&apos; is
6449  * found, the end of the stream is encountered, or str.max_size()
6450  * is reached. Any previous contents of @a __str are erased. If
6451  * end of line is encountered, it is extracted but not stored into
6452  * @a __str.
6453  */
6454  template<typename _CharT, typename _Traits, typename _Alloc>
6455  inline basic_istream<_CharT, _Traits>&
6458  { return std::getline(__is, __str, __is.widen('\n')); }
6459 
6460 #if __cplusplus >= 201103L
6461  /// Read a line from an rvalue stream into a string.
6462  template<typename _CharT, typename _Traits, typename _Alloc>
6463  inline basic_istream<_CharT, _Traits>&
6465  basic_string<_CharT, _Traits, _Alloc>& __str, _CharT __delim)
6466  { return std::getline(__is, __str, __delim); }
6467 
6468  /// Read a line from an rvalue stream into a string.
6469  template<typename _CharT, typename _Traits, typename _Alloc>
6470  inline basic_istream<_CharT, _Traits>&
6473  { return std::getline(__is, __str); }
6474 #endif
6475 
6476  template<>
6477  basic_istream<char>&
6478  getline(basic_istream<char>& __in, basic_string<char>& __str,
6479  char __delim);
6480 
6481 #ifdef _GLIBCXX_USE_WCHAR_T
6482  template<>
6483  basic_istream<wchar_t>&
6484  getline(basic_istream<wchar_t>& __in, basic_string<wchar_t>& __str,
6485  wchar_t __delim);
6486 #endif
6487 
6488 _GLIBCXX_END_NAMESPACE_VERSION
6489 } // namespace
6490 
6491 #if __cplusplus >= 201103L
6492 
6493 #include <ext/string_conversions.h>
6494 
6495 namespace std _GLIBCXX_VISIBILITY(default)
6496 {
6497 _GLIBCXX_BEGIN_NAMESPACE_VERSION
6498 _GLIBCXX_BEGIN_NAMESPACE_CXX11
6499 
6500 #if _GLIBCXX_USE_C99_STDLIB
6501  // 21.4 Numeric Conversions [string.conversions].
6502  inline int
6503  stoi(const string& __str, size_t* __idx = 0, int __base = 10)
6504  { return __gnu_cxx::__stoa<long, int>(&std::strtol, "stoi", __str.c_str(),
6505  __idx, __base); }
6506 
6507  inline long
6508  stol(const string& __str, size_t* __idx = 0, int __base = 10)
6509  { return __gnu_cxx::__stoa(&std::strtol, "stol", __str.c_str(),
6510  __idx, __base); }
6511 
6512  inline unsigned long
6513  stoul(const string& __str, size_t* __idx = 0, int __base = 10)
6514  { return __gnu_cxx::__stoa(&std::strtoul, "stoul", __str.c_str(),
6515  __idx, __base); }
6516 
6517  inline long long
6518  stoll(const string& __str, size_t* __idx = 0, int __base = 10)
6519  { return __gnu_cxx::__stoa(&std::strtoll, "stoll", __str.c_str(),
6520  __idx, __base); }
6521 
6522  inline unsigned long long
6523  stoull(const string& __str, size_t* __idx = 0, int __base = 10)
6524  { return __gnu_cxx::__stoa(&std::strtoull, "stoull", __str.c_str(),
6525  __idx, __base); }
6526 
6527  // NB: strtof vs strtod.
6528  inline float
6529  stof(const string& __str, size_t* __idx = 0)
6530  { return __gnu_cxx::__stoa(&std::strtof, "stof", __str.c_str(), __idx); }
6531 
6532  inline double
6533  stod(const string& __str, size_t* __idx = 0)
6534  { return __gnu_cxx::__stoa(&std::strtod, "stod", __str.c_str(), __idx); }
6535 
6536  inline long double
6537  stold(const string& __str, size_t* __idx = 0)
6538  { return __gnu_cxx::__stoa(&std::strtold, "stold", __str.c_str(), __idx); }
6539 #endif // _GLIBCXX_USE_C99_STDLIB
6540 
6541 #if _GLIBCXX_USE_C99_STDIO
6542  // NB: (v)snprintf vs sprintf.
6543 
6544  // DR 1261.
6545  inline string
6546  to_string(int __val)
6547  { return __gnu_cxx::__to_xstring<string>(&std::vsnprintf, 4 * sizeof(int),
6548  "%d", __val); }
6549 
6550  inline string
6551  to_string(unsigned __val)
6552  { return __gnu_cxx::__to_xstring<string>(&std::vsnprintf,
6553  4 * sizeof(unsigned),
6554  "%u", __val); }
6555 
6556  inline string
6557  to_string(long __val)
6558  { return __gnu_cxx::__to_xstring<string>(&std::vsnprintf, 4 * sizeof(long),
6559  "%ld", __val); }
6560 
6561  inline string
6562  to_string(unsigned long __val)
6563  { return __gnu_cxx::__to_xstring<string>(&std::vsnprintf,
6564  4 * sizeof(unsigned long),
6565  "%lu", __val); }
6566 
6567  inline string
6568  to_string(long long __val)
6569  { return __gnu_cxx::__to_xstring<string>(&std::vsnprintf,
6570  4 * sizeof(long long),
6571  "%lld", __val); }
6572 
6573  inline string
6574  to_string(unsigned long long __val)
6575  { return __gnu_cxx::__to_xstring<string>(&std::vsnprintf,
6576  4 * sizeof(unsigned long long),
6577  "%llu", __val); }
6578 
6579  inline string
6580  to_string(float __val)
6581  {
6582  const int __n =
6583  __gnu_cxx::__numeric_traits<float>::__max_exponent10 + 20;
6584  return __gnu_cxx::__to_xstring<string>(&std::vsnprintf, __n,
6585  "%f", __val);
6586  }
6587 
6588  inline string
6589  to_string(double __val)
6590  {
6591  const int __n =
6592  __gnu_cxx::__numeric_traits<double>::__max_exponent10 + 20;
6593  return __gnu_cxx::__to_xstring<string>(&std::vsnprintf, __n,
6594  "%f", __val);
6595  }
6596 
6597  inline string
6598  to_string(long double __val)
6599  {
6600  const int __n =
6601  __gnu_cxx::__numeric_traits<long double>::__max_exponent10 + 20;
6602  return __gnu_cxx::__to_xstring<string>(&std::vsnprintf, __n,
6603  "%Lf", __val);
6604  }
6605 #endif // _GLIBCXX_USE_C99_STDIO
6606 
6607 #if defined(_GLIBCXX_USE_WCHAR_T) && _GLIBCXX_USE_C99_WCHAR
6608  inline int
6609  stoi(const wstring& __str, size_t* __idx = 0, int __base = 10)
6610  { return __gnu_cxx::__stoa<long, int>(&std::wcstol, "stoi", __str.c_str(),
6611  __idx, __base); }
6612 
6613  inline long
6614  stol(const wstring& __str, size_t* __idx = 0, int __base = 10)
6615  { return __gnu_cxx::__stoa(&std::wcstol, "stol", __str.c_str(),
6616  __idx, __base); }
6617 
6618  inline unsigned long
6619  stoul(const wstring& __str, size_t* __idx = 0, int __base = 10)
6620  { return __gnu_cxx::__stoa(&std::wcstoul, "stoul", __str.c_str(),
6621  __idx, __base); }
6622 
6623  inline long long
6624  stoll(const wstring& __str, size_t* __idx = 0, int __base = 10)
6625  { return __gnu_cxx::__stoa(&std::wcstoll, &