libstdc++
cow_string.h
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1 // Definition of gcc4-compatible Copy-on-Write basic_string -*- C++ -*-
2 
3 // Copyright (C) 1997-2023 Free Software Foundation, Inc.
4 //
5 // This file is part of the GNU ISO C++ Library. This library is free
6 // software; you can redistribute it and/or modify it under the
7 // terms of the GNU General Public License as published by the
8 // Free Software Foundation; either version 3, or (at your option)
9 // any later version.
10 
11 // This library is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 // GNU General Public License for more details.
15 
16 // Under Section 7 of GPL version 3, you are granted additional
17 // permissions described in the GCC Runtime Library Exception, version
18 // 3.1, as published by the Free Software Foundation.
19 
20 // You should have received a copy of the GNU General Public License and
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22 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
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24 
25 /** @file bits/cow_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  * Defines the reference-counted COW string implementation.
30  */
31 
32 #ifndef _COW_STRING_H
33 #define _COW_STRING_H 1
34 
35 #if ! _GLIBCXX_USE_CXX11_ABI
36 
37 #include <ext/atomicity.h> // _Atomic_word, __is_single_threaded
38 
39 #ifdef __cpp_lib_is_constant_evaluated
40 // Support P1032R1 in C++20 (but not P0980R1 for COW strings).
41 # define __cpp_lib_constexpr_string 201811L
42 #elif __cplusplus >= 201703L && _GLIBCXX_HAVE_IS_CONSTANT_EVALUATED
43 // Support P0426R1 changes to char_traits in C++17.
44 # define __cpp_lib_constexpr_string 201611L
45 #endif
46 
47 namespace std _GLIBCXX_VISIBILITY(default)
48 {
49 _GLIBCXX_BEGIN_NAMESPACE_VERSION
50 
51  /**
52  * @class basic_string basic_string.h <string>
53  * @brief Managing sequences of characters and character-like objects.
54  *
55  * @ingroup strings
56  * @ingroup sequences
57  * @headerfile string
58  * @since C++98
59  *
60  * @tparam _CharT Type of character
61  * @tparam _Traits Traits for character type, defaults to
62  * char_traits<_CharT>.
63  * @tparam _Alloc Allocator type, defaults to allocator<_CharT>.
64  *
65  * Meets the requirements of a <a href="tables.html#65">container</a>, a
66  * <a href="tables.html#66">reversible container</a>, and a
67  * <a href="tables.html#67">sequence</a>. Of the
68  * <a href="tables.html#68">optional sequence requirements</a>, only
69  * @c push_back, @c at, and @c %array access are supported.
70  *
71  * @doctodo
72  *
73  *
74  * Documentation? What's that?
75  * Nathan Myers <ncm@cantrip.org>.
76  *
77  * A string looks like this:
78  *
79  * @code
80  * [_Rep]
81  * _M_length
82  * [basic_string<char_type>] _M_capacity
83  * _M_dataplus _M_refcount
84  * _M_p ----------------> unnamed array of char_type
85  * @endcode
86  *
87  * Where the _M_p points to the first character in the string, and
88  * you cast it to a pointer-to-_Rep and subtract 1 to get a
89  * pointer to the header.
90  *
91  * This approach has the enormous advantage that a string object
92  * requires only one allocation. All the ugliness is confined
93  * within a single %pair of inline functions, which each compile to
94  * a single @a add instruction: _Rep::_M_data(), and
95  * string::_M_rep(); and the allocation function which gets a
96  * block of raw bytes and with room enough and constructs a _Rep
97  * object at the front.
98  *
99  * The reason you want _M_data pointing to the character %array and
100  * not the _Rep is so that the debugger can see the string
101  * contents. (Probably we should add a non-inline member to get
102  * the _Rep for the debugger to use, so users can check the actual
103  * string length.)
104  *
105  * Note that the _Rep object is a POD so that you can have a
106  * static <em>empty string</em> _Rep object already @a constructed before
107  * static constructors have run. The reference-count encoding is
108  * chosen so that a 0 indicates one reference, so you never try to
109  * destroy the empty-string _Rep object.
110  *
111  * All but the last paragraph is considered pretty conventional
112  * for a Copy-On-Write C++ string implementation.
113  */
114  // 21.3 Template class basic_string
115  template<typename _CharT, typename _Traits, typename _Alloc>
117  {
119  rebind<_CharT>::other _CharT_alloc_type;
121 
122  // Types:
123  public:
124  typedef _Traits traits_type;
125  typedef typename _Traits::char_type value_type;
126  typedef _Alloc allocator_type;
127  typedef typename _CharT_alloc_traits::size_type size_type;
128  typedef typename _CharT_alloc_traits::difference_type difference_type;
129 #if __cplusplus < 201103L
130  typedef typename _CharT_alloc_type::reference reference;
131  typedef typename _CharT_alloc_type::const_reference const_reference;
132 #else
133  typedef value_type& reference;
134  typedef const value_type& const_reference;
135 #endif
136  typedef typename _CharT_alloc_traits::pointer pointer;
137  typedef typename _CharT_alloc_traits::const_pointer const_pointer;
138  typedef __gnu_cxx::__normal_iterator<pointer, basic_string> iterator;
139  typedef __gnu_cxx::__normal_iterator<const_pointer, basic_string>
140  const_iterator;
143 
144  protected:
145  // type used for positions in insert, erase etc.
146  typedef iterator __const_iterator;
147 
148  private:
149  // _Rep: string representation
150  // Invariants:
151  // 1. String really contains _M_length + 1 characters: due to 21.3.4
152  // must be kept null-terminated.
153  // 2. _M_capacity >= _M_length
154  // Allocated memory is always (_M_capacity + 1) * sizeof(_CharT).
155  // 3. _M_refcount has three states:
156  // -1: leaked, one reference, no ref-copies allowed, non-const.
157  // 0: one reference, non-const.
158  // n>0: n + 1 references, operations require a lock, const.
159  // 4. All fields==0 is an empty string, given the extra storage
160  // beyond-the-end for a null terminator; thus, the shared
161  // empty string representation needs no constructor.
162 
163  struct _Rep_base
164  {
165  size_type _M_length;
166  size_type _M_capacity;
167  _Atomic_word _M_refcount;
168  };
169 
170  struct _Rep : _Rep_base
171  {
172  // Types:
174  rebind<char>::other _Raw_bytes_alloc;
175 
176  // (Public) Data members:
177 
178  // The maximum number of individual char_type elements of an
179  // individual string is determined by _S_max_size. This is the
180  // value that will be returned by max_size(). (Whereas npos
181  // is the maximum number of bytes the allocator can allocate.)
182  // If one was to divvy up the theoretical largest size string,
183  // with a terminating character and m _CharT elements, it'd
184  // look like this:
185  // npos = sizeof(_Rep) + (m * sizeof(_CharT)) + sizeof(_CharT)
186  // Solving for m:
187  // m = ((npos - sizeof(_Rep))/sizeof(CharT)) - 1
188  // In addition, this implementation quarters this amount.
189  static const size_type _S_max_size;
190  static const _CharT _S_terminal;
191 
192  // The following storage is init'd to 0 by the linker, resulting
193  // (carefully) in an empty string with one reference.
194  static size_type _S_empty_rep_storage[];
195 
196  static _Rep&
197  _S_empty_rep() _GLIBCXX_NOEXCEPT
198  {
199  // NB: Mild hack to avoid strict-aliasing warnings. Note that
200  // _S_empty_rep_storage is never modified and the punning should
201  // be reasonably safe in this case.
202  void* __p = reinterpret_cast<void*>(&_S_empty_rep_storage);
203  return *reinterpret_cast<_Rep*>(__p);
204  }
205 
206  bool
207  _M_is_leaked() const _GLIBCXX_NOEXCEPT
208  {
209 #if defined(__GTHREADS)
210  // _M_refcount is mutated concurrently by _M_refcopy/_M_dispose,
211  // so we need to use an atomic load. However, _M_is_leaked
212  // predicate does not change concurrently (i.e. the string is either
213  // leaked or not), so a relaxed load is enough.
214  return __atomic_load_n(&this->_M_refcount, __ATOMIC_RELAXED) < 0;
215 #else
216  return this->_M_refcount < 0;
217 #endif
218  }
219 
220  bool
221  _M_is_shared() const _GLIBCXX_NOEXCEPT
222  {
223 #if defined(__GTHREADS)
224  // _M_refcount is mutated concurrently by _M_refcopy/_M_dispose,
225  // so we need to use an atomic load. Another thread can drop last
226  // but one reference concurrently with this check, so we need this
227  // load to be acquire to synchronize with release fetch_and_add in
228  // _M_dispose.
229  if (!__gnu_cxx::__is_single_threaded())
230  return __atomic_load_n(&this->_M_refcount, __ATOMIC_ACQUIRE) > 0;
231 #endif
232  return this->_M_refcount > 0;
233  }
234 
235  void
236  _M_set_leaked() _GLIBCXX_NOEXCEPT
237  { this->_M_refcount = -1; }
238 
239  void
240  _M_set_sharable() _GLIBCXX_NOEXCEPT
241  { this->_M_refcount = 0; }
242 
243  void
244  _M_set_length_and_sharable(size_type __n) _GLIBCXX_NOEXCEPT
245  {
246 #if _GLIBCXX_FULLY_DYNAMIC_STRING == 0
247  if (__builtin_expect(this != &_S_empty_rep(), false))
248 #endif
249  {
250  this->_M_set_sharable(); // One reference.
251  this->_M_length = __n;
252  traits_type::assign(this->_M_refdata()[__n], _S_terminal);
253  // grrr. (per 21.3.4)
254  // You cannot leave those LWG people alone for a second.
255  }
256  }
257 
258  _CharT*
259  _M_refdata() throw()
260  { return reinterpret_cast<_CharT*>(this + 1); }
261 
262  _CharT*
263  _M_grab(const _Alloc& __alloc1, const _Alloc& __alloc2)
264  {
265  return (!_M_is_leaked() && __alloc1 == __alloc2)
266  ? _M_refcopy() : _M_clone(__alloc1);
267  }
268 
269  // Create & Destroy
270  static _Rep*
271  _S_create(size_type, size_type, const _Alloc&);
272 
273  void
274  _M_dispose(const _Alloc& __a) _GLIBCXX_NOEXCEPT
275  {
276 #if _GLIBCXX_FULLY_DYNAMIC_STRING == 0
277  if (__builtin_expect(this != &_S_empty_rep(), false))
278 #endif
279  {
280  // Be race-detector-friendly. For more info see bits/c++config.
281  _GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&this->_M_refcount);
282  // Decrement of _M_refcount is acq_rel, because:
283  // - all but last decrements need to release to synchronize with
284  // the last decrement that will delete the object.
285  // - the last decrement needs to acquire to synchronize with
286  // all the previous decrements.
287  // - last but one decrement needs to release to synchronize with
288  // the acquire load in _M_is_shared that will conclude that
289  // the object is not shared anymore.
290  if (__gnu_cxx::__exchange_and_add_dispatch(&this->_M_refcount,
291  -1) <= 0)
292  {
293  _GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&this->_M_refcount);
294  _M_destroy(__a);
295  }
296  }
297  } // XXX MT
298 
299  void
300  _M_destroy(const _Alloc&) throw();
301 
302  _CharT*
303  _M_refcopy() throw()
304  {
305 #if _GLIBCXX_FULLY_DYNAMIC_STRING == 0
306  if (__builtin_expect(this != &_S_empty_rep(), false))
307 #endif
308  __gnu_cxx::__atomic_add_dispatch(&this->_M_refcount, 1);
309  return _M_refdata();
310  } // XXX MT
311 
312  _CharT*
313  _M_clone(const _Alloc&, size_type __res = 0);
314  };
315 
316  // Use empty-base optimization: http://www.cantrip.org/emptyopt.html
317  struct _Alloc_hider : _Alloc
318  {
319  _Alloc_hider(_CharT* __dat, const _Alloc& __a) _GLIBCXX_NOEXCEPT
320  : _Alloc(__a), _M_p(__dat) { }
321 
322  _CharT* _M_p; // The actual data.
323  };
324 
325  public:
326  // Data Members (public):
327  // NB: This is an unsigned type, and thus represents the maximum
328  // size that the allocator can hold.
329  /// Value returned by various member functions when they fail.
330  static const size_type npos = static_cast<size_type>(-1);
331 
332  private:
333  // Data Members (private):
334  mutable _Alloc_hider _M_dataplus;
335 
336  _CharT*
337  _M_data() const _GLIBCXX_NOEXCEPT
338  { return _M_dataplus._M_p; }
339 
340  _CharT*
341  _M_data(_CharT* __p) _GLIBCXX_NOEXCEPT
342  { return (_M_dataplus._M_p = __p); }
343 
344  _Rep*
345  _M_rep() const _GLIBCXX_NOEXCEPT
346  { return &((reinterpret_cast<_Rep*> (_M_data()))[-1]); }
347 
348  // For the internal use we have functions similar to `begin'/`end'
349  // but they do not call _M_leak.
350  iterator
351  _M_ibegin() const _GLIBCXX_NOEXCEPT
352  { return iterator(_M_data()); }
353 
354  iterator
355  _M_iend() const _GLIBCXX_NOEXCEPT
356  { return iterator(_M_data() + this->size()); }
357 
358  void
359  _M_leak() // for use in begin() & non-const op[]
360  {
361  if (!_M_rep()->_M_is_leaked())
362  _M_leak_hard();
363  }
364 
365  size_type
366  _M_check(size_type __pos, const char* __s) const
367  {
368  if (__pos > this->size())
369  __throw_out_of_range_fmt(__N("%s: __pos (which is %zu) > "
370  "this->size() (which is %zu)"),
371  __s, __pos, this->size());
372  return __pos;
373  }
374 
375  void
376  _M_check_length(size_type __n1, size_type __n2, const char* __s) const
377  {
378  if (this->max_size() - (this->size() - __n1) < __n2)
379  __throw_length_error(__N(__s));
380  }
381 
382  // NB: _M_limit doesn't check for a bad __pos value.
383  size_type
384  _M_limit(size_type __pos, size_type __off) const _GLIBCXX_NOEXCEPT
385  {
386  const bool __testoff = __off < this->size() - __pos;
387  return __testoff ? __off : this->size() - __pos;
388  }
389 
390  // True if _Rep and source do not overlap.
391  bool
392  _M_disjunct(const _CharT* __s) const _GLIBCXX_NOEXCEPT
393  {
394  return (less<const _CharT*>()(__s, _M_data())
395  || less<const _CharT*>()(_M_data() + this->size(), __s));
396  }
397 
398  // When __n = 1 way faster than the general multichar
399  // traits_type::copy/move/assign.
400  static void
401  _M_copy(_CharT* __d, const _CharT* __s, size_type __n) _GLIBCXX_NOEXCEPT
402  {
403  if (__n == 1)
404  traits_type::assign(*__d, *__s);
405  else
406  traits_type::copy(__d, __s, __n);
407  }
408 
409  static void
410  _M_move(_CharT* __d, const _CharT* __s, size_type __n) _GLIBCXX_NOEXCEPT
411  {
412  if (__n == 1)
413  traits_type::assign(*__d, *__s);
414  else
415  traits_type::move(__d, __s, __n);
416  }
417 
418  static void
419  _M_assign(_CharT* __d, size_type __n, _CharT __c) _GLIBCXX_NOEXCEPT
420  {
421  if (__n == 1)
422  traits_type::assign(*__d, __c);
423  else
424  traits_type::assign(__d, __n, __c);
425  }
426 
427  // _S_copy_chars is a separate template to permit specialization
428  // to optimize for the common case of pointers as iterators.
429  template<class _Iterator>
430  static void
431  _S_copy_chars(_CharT* __p, _Iterator __k1, _Iterator __k2)
432  {
433  for (; __k1 != __k2; ++__k1, (void)++__p)
434  traits_type::assign(*__p, *__k1); // These types are off.
435  }
436 
437  static void
438  _S_copy_chars(_CharT* __p, iterator __k1, iterator __k2) _GLIBCXX_NOEXCEPT
439  { _S_copy_chars(__p, __k1.base(), __k2.base()); }
440 
441  static void
442  _S_copy_chars(_CharT* __p, const_iterator __k1, const_iterator __k2)
443  _GLIBCXX_NOEXCEPT
444  { _S_copy_chars(__p, __k1.base(), __k2.base()); }
445 
446  static void
447  _S_copy_chars(_CharT* __p, _CharT* __k1, _CharT* __k2) _GLIBCXX_NOEXCEPT
448  { _M_copy(__p, __k1, __k2 - __k1); }
449 
450  static void
451  _S_copy_chars(_CharT* __p, const _CharT* __k1, const _CharT* __k2)
452  _GLIBCXX_NOEXCEPT
453  { _M_copy(__p, __k1, __k2 - __k1); }
454 
455  static int
456  _S_compare(size_type __n1, size_type __n2) _GLIBCXX_NOEXCEPT
457  {
458  const difference_type __d = difference_type(__n1 - __n2);
459 
460  if (__d > __gnu_cxx::__numeric_traits<int>::__max)
461  return __gnu_cxx::__numeric_traits<int>::__max;
462  else if (__d < __gnu_cxx::__numeric_traits<int>::__min)
463  return __gnu_cxx::__numeric_traits<int>::__min;
464  else
465  return int(__d);
466  }
467 
468  void
469  _M_mutate(size_type __pos, size_type __len1, size_type __len2);
470 
471  void
472  _M_leak_hard();
473 
474  static _Rep&
475  _S_empty_rep() _GLIBCXX_NOEXCEPT
476  { return _Rep::_S_empty_rep(); }
477 
478 #if __cplusplus >= 201703L
479  // A helper type for avoiding boiler-plate.
480  typedef basic_string_view<_CharT, _Traits> __sv_type;
481 
482  template<typename _Tp, typename _Res>
483  using _If_sv = enable_if_t<
484  __and_<is_convertible<const _Tp&, __sv_type>,
485  __not_<is_convertible<const _Tp*, const basic_string*>>,
486  __not_<is_convertible<const _Tp&, const _CharT*>>>::value,
487  _Res>;
488 
489  // Allows an implicit conversion to __sv_type.
490  static __sv_type
491  _S_to_string_view(__sv_type __svt) noexcept
492  { return __svt; }
493 
494  // Wraps a string_view by explicit conversion and thus
495  // allows to add an internal constructor that does not
496  // participate in overload resolution when a string_view
497  // is provided.
498  struct __sv_wrapper
499  {
500  explicit __sv_wrapper(__sv_type __sv) noexcept : _M_sv(__sv) { }
501  __sv_type _M_sv;
502  };
503 
504  /**
505  * @brief Only internally used: Construct string from a string view
506  * wrapper.
507  * @param __svw string view wrapper.
508  * @param __a Allocator to use.
509  */
510  explicit
511  basic_string(__sv_wrapper __svw, const _Alloc& __a)
512  : basic_string(__svw._M_sv.data(), __svw._M_sv.size(), __a) { }
513 #endif
514 
515  public:
516  // Construct/copy/destroy:
517  // NB: We overload ctors in some cases instead of using default
518  // arguments, per 17.4.4.4 para. 2 item 2.
519 
520  /**
521  * @brief Default constructor creates an empty string.
522  */
524 #if _GLIBCXX_FULLY_DYNAMIC_STRING == 0
525  _GLIBCXX_NOEXCEPT
526  : _M_dataplus(_S_empty_rep()._M_refdata(), _Alloc())
527 #else
528  : _M_dataplus(_S_construct(size_type(), _CharT(), _Alloc()), _Alloc())
529 #endif
530  { }
531 
532  /**
533  * @brief Construct an empty string using allocator @a a.
534  */
535  explicit
536  basic_string(const _Alloc& __a)
537  : _M_dataplus(_S_construct(size_type(), _CharT(), __a), __a)
538  { }
539 
540  // NB: per LWG issue 42, semantics different from IS:
541  /**
542  * @brief Construct string with copy of value of @a str.
543  * @param __str Source string.
544  */
546  : _M_dataplus(__str._M_rep()->_M_grab(_Alloc(__str.get_allocator()),
547  __str.get_allocator()),
548  __str.get_allocator())
549  { }
550 
551  // _GLIBCXX_RESOLVE_LIB_DEFECTS
552  // 2583. no way to supply an allocator for basic_string(str, pos)
553  /**
554  * @brief Construct string as copy of a substring.
555  * @param __str Source string.
556  * @param __pos Index of first character to copy from.
557  * @param __a Allocator to use.
558  */
559  basic_string(const basic_string& __str, size_type __pos,
560  const _Alloc& __a = _Alloc());
561 
562  /**
563  * @brief Construct string as copy of a substring.
564  * @param __str Source string.
565  * @param __pos Index of first character to copy from.
566  * @param __n Number of characters to copy.
567  */
568  basic_string(const basic_string& __str, size_type __pos,
569  size_type __n);
570  /**
571  * @brief Construct string as copy of a substring.
572  * @param __str Source string.
573  * @param __pos Index of first character to copy from.
574  * @param __n Number of characters to copy.
575  * @param __a Allocator to use.
576  */
577  basic_string(const basic_string& __str, size_type __pos,
578  size_type __n, const _Alloc& __a);
579 
580  /**
581  * @brief Construct string initialized by a character %array.
582  * @param __s Source character %array.
583  * @param __n Number of characters to copy.
584  * @param __a Allocator to use (default is default allocator).
585  *
586  * NB: @a __s must have at least @a __n characters, &apos;\\0&apos;
587  * has no special meaning.
588  */
589  basic_string(const _CharT* __s, size_type __n,
590  const _Alloc& __a = _Alloc())
591  : _M_dataplus(_S_construct(__s, __s + __n, __a), __a)
592  { }
593 
594  /**
595  * @brief Construct string as copy of a C string.
596  * @param __s Source C string.
597  * @param __a Allocator to use (default is default allocator).
598  */
599 #if __cpp_deduction_guides && ! defined _GLIBCXX_DEFINING_STRING_INSTANTIATIONS
600  // _GLIBCXX_RESOLVE_LIB_DEFECTS
601  // 3076. basic_string CTAD ambiguity
602  template<typename = _RequireAllocator<_Alloc>>
603 #endif
604  basic_string(const _CharT* __s, const _Alloc& __a = _Alloc())
605  : _M_dataplus(_S_construct(__s, __s ? __s + traits_type::length(__s) :
606  __s + npos, __a), __a)
607  { }
608 
609  /**
610  * @brief Construct string as multiple characters.
611  * @param __n Number of characters.
612  * @param __c Character to use.
613  * @param __a Allocator to use (default is default allocator).
614  */
615  basic_string(size_type __n, _CharT __c, const _Alloc& __a = _Alloc())
616  : _M_dataplus(_S_construct(__n, __c, __a), __a)
617  { }
618 
619 #if __cplusplus >= 201103L
620  /**
621  * @brief Move construct string.
622  * @param __str Source string.
623  *
624  * The newly-created string contains the exact contents of @a __str.
625  * @a __str is a valid, but unspecified string.
626  */
627  basic_string(basic_string&& __str) noexcept
628  : _M_dataplus(std::move(__str._M_dataplus))
629  {
630 #if _GLIBCXX_FULLY_DYNAMIC_STRING == 0
631  // Make __str use the shared empty string rep.
632  __str._M_data(_S_empty_rep()._M_refdata());
633 #else
634  // Rather than allocate an empty string for the rvalue string,
635  // just share ownership with it by incrementing the reference count.
636  // If the rvalue string was the unique owner then there are exactly
637  // two owners now.
638  if (_M_rep()->_M_is_shared())
639  __gnu_cxx::__atomic_add_dispatch(&_M_rep()->_M_refcount, 1);
640  else
641  _M_rep()->_M_refcount = 1;
642 #endif
643  }
644 
645  /**
646  * @brief Construct string from an initializer %list.
647  * @param __l std::initializer_list of characters.
648  * @param __a Allocator to use (default is default allocator).
649  */
650  basic_string(initializer_list<_CharT> __l, const _Alloc& __a = _Alloc())
651  : _M_dataplus(_S_construct(__l.begin(), __l.end(), __a), __a)
652  { }
653 
654  basic_string(const basic_string& __str, const _Alloc& __a)
655  : _M_dataplus(__str._M_rep()->_M_grab(__a, __str.get_allocator()), __a)
656  { }
657 
658  basic_string(basic_string&& __str, const _Alloc& __a)
659  : _M_dataplus(__str._M_data(), __a)
660  {
661  if (__a == __str.get_allocator())
662  {
663 #if _GLIBCXX_FULLY_DYNAMIC_STRING == 0
664  __str._M_data(_S_empty_rep()._M_refdata());
665 #else
666  __str._M_data(_S_construct(size_type(), _CharT(), __a));
667 #endif
668  }
669  else
670  _M_dataplus._M_p = _S_construct(__str.begin(), __str.end(), __a);
671  }
672 #endif // C++11
673 
674 #if __cplusplus >= 202100L
675  basic_string(nullptr_t) = delete;
676  basic_string& operator=(nullptr_t) = delete;
677 #endif // C++23
678 
679  /**
680  * @brief Construct string as copy of a range.
681  * @param __beg Start of range.
682  * @param __end End of range.
683  * @param __a Allocator to use (default is default allocator).
684  */
685  template<class _InputIterator>
686  basic_string(_InputIterator __beg, _InputIterator __end,
687  const _Alloc& __a = _Alloc())
688  : _M_dataplus(_S_construct(__beg, __end, __a), __a)
689  { }
690 
691 #if __cplusplus >= 201703L
692  /**
693  * @brief Construct string from a substring of a string_view.
694  * @param __t Source object convertible to string view.
695  * @param __pos The index of the first character to copy from __t.
696  * @param __n The number of characters to copy from __t.
697  * @param __a Allocator to use.
698  */
699  template<typename _Tp,
701  basic_string(const _Tp& __t, size_type __pos, size_type __n,
702  const _Alloc& __a = _Alloc())
703  : basic_string(_S_to_string_view(__t).substr(__pos, __n), __a) { }
704 
705  /**
706  * @brief Construct string from a string_view.
707  * @param __t Source object convertible to string view.
708  * @param __a Allocator to use (default is default allocator).
709  */
710  template<typename _Tp, typename = _If_sv<_Tp, void>>
711  explicit
712  basic_string(const _Tp& __t, const _Alloc& __a = _Alloc())
713  : basic_string(__sv_wrapper(_S_to_string_view(__t)), __a) { }
714 #endif // C++17
715 
716  /**
717  * @brief Destroy the string instance.
718  */
719  ~basic_string() _GLIBCXX_NOEXCEPT
720  { _M_rep()->_M_dispose(this->get_allocator()); }
721 
722  /**
723  * @brief Assign the value of @a str to this string.
724  * @param __str Source string.
725  */
726  basic_string&
727  operator=(const basic_string& __str)
728  { return this->assign(__str); }
729 
730  /**
731  * @brief Copy contents of @a s into this string.
732  * @param __s Source null-terminated string.
733  */
734  basic_string&
735  operator=(const _CharT* __s)
736  { return this->assign(__s); }
737 
738  /**
739  * @brief Set value to string of length 1.
740  * @param __c Source character.
741  *
742  * Assigning to a character makes this string length 1 and
743  * (*this)[0] == @a c.
744  */
745  basic_string&
746  operator=(_CharT __c)
747  {
748  this->assign(1, __c);
749  return *this;
750  }
751 
752 #if __cplusplus >= 201103L
753  /**
754  * @brief Move assign the value of @a str to this string.
755  * @param __str Source string.
756  *
757  * The contents of @a str are moved into this string (without copying).
758  * @a str is a valid, but unspecified string.
759  */
760  basic_string&
763  {
764  // NB: DR 1204.
765  this->swap(__str);
766  return *this;
767  }
768 
769  /**
770  * @brief Set value to string constructed from initializer %list.
771  * @param __l std::initializer_list.
772  */
773  basic_string&
775  {
776  this->assign(__l.begin(), __l.size());
777  return *this;
778  }
779 #endif // C++11
780 
781 #if __cplusplus >= 201703L
782  /**
783  * @brief Set value to string constructed from a string_view.
784  * @param __svt An object convertible to string_view.
785  */
786  template<typename _Tp>
787  _If_sv<_Tp, basic_string&>
788  operator=(const _Tp& __svt)
789  { return this->assign(__svt); }
790 
791  /**
792  * @brief Convert to a string_view.
793  * @return A string_view.
794  */
795  operator __sv_type() const noexcept
796  { return __sv_type(data(), size()); }
797 #endif // C++17
798 
799  // Iterators:
800  /**
801  * Returns a read/write iterator that points to the first character in
802  * the %string. Unshares the string.
803  */
804  iterator
805  begin() // FIXME C++11: should be noexcept.
806  {
807  _M_leak();
808  return iterator(_M_data());
809  }
810 
811  /**
812  * Returns a read-only (constant) iterator that points to the first
813  * character in the %string.
814  */
815  const_iterator
816  begin() const _GLIBCXX_NOEXCEPT
817  { return const_iterator(_M_data()); }
818 
819  /**
820  * Returns a read/write iterator that points one past the last
821  * character in the %string. Unshares the string.
822  */
823  iterator
824  end() // FIXME C++11: should be noexcept.
825  {
826  _M_leak();
827  return iterator(_M_data() + this->size());
828  }
829 
830  /**
831  * Returns a read-only (constant) iterator that points one past the
832  * last character in the %string.
833  */
834  const_iterator
835  end() const _GLIBCXX_NOEXCEPT
836  { return const_iterator(_M_data() + this->size()); }
837 
838  /**
839  * Returns a read/write reverse iterator that points to the last
840  * character in the %string. Iteration is done in reverse element
841  * order. Unshares the string.
842  */
843  reverse_iterator
844  rbegin() // FIXME C++11: should be noexcept.
845  { return reverse_iterator(this->end()); }
846 
847  /**
848  * Returns a read-only (constant) reverse iterator that points
849  * to the last character in the %string. Iteration is done in
850  * reverse element order.
851  */
852  const_reverse_iterator
853  rbegin() const _GLIBCXX_NOEXCEPT
854  { return const_reverse_iterator(this->end()); }
855 
856  /**
857  * Returns a read/write reverse iterator that points to one before the
858  * first character in the %string. Iteration is done in reverse
859  * element order. Unshares the string.
860  */
861  reverse_iterator
862  rend() // FIXME C++11: should be noexcept.
863  { return reverse_iterator(this->begin()); }
864 
865  /**
866  * Returns a read-only (constant) reverse iterator that points
867  * to one before the first character in the %string. Iteration
868  * is done in reverse element order.
869  */
870  const_reverse_iterator
871  rend() const _GLIBCXX_NOEXCEPT
872  { return const_reverse_iterator(this->begin()); }
873 
874 #if __cplusplus >= 201103L
875  /**
876  * Returns a read-only (constant) iterator that points to the first
877  * character in the %string.
878  */
879  const_iterator
880  cbegin() const noexcept
881  { return const_iterator(this->_M_data()); }
882 
883  /**
884  * Returns a read-only (constant) iterator that points one past the
885  * last character in the %string.
886  */
887  const_iterator
888  cend() const noexcept
889  { return const_iterator(this->_M_data() + this->size()); }
890 
891  /**
892  * Returns a read-only (constant) reverse iterator that points
893  * to the last character in the %string. Iteration is done in
894  * reverse element order.
895  */
896  const_reverse_iterator
897  crbegin() const noexcept
898  { return const_reverse_iterator(this->end()); }
899 
900  /**
901  * Returns a read-only (constant) reverse iterator that points
902  * to one before the first character in the %string. Iteration
903  * is done in reverse element order.
904  */
905  const_reverse_iterator
906  crend() const noexcept
907  { return const_reverse_iterator(this->begin()); }
908 #endif
909 
910  public:
911  // Capacity:
912 
913  /// Returns the number of characters in the string, not including any
914  /// null-termination.
915  size_type
916  size() const _GLIBCXX_NOEXCEPT
917  {
918 #if _GLIBCXX_FULLY_DYNAMIC_STRING == 0 && __OPTIMIZE__
919  if (_S_empty_rep()._M_length != 0)
920  __builtin_unreachable();
921 #endif
922  return _M_rep()->_M_length;
923  }
924 
925  /// Returns the number of characters in the string, not including any
926  /// null-termination.
927  size_type
928  length() const _GLIBCXX_NOEXCEPT
929  { return size(); }
930 
931  /// Returns the size() of the largest possible %string.
932  size_type
933  max_size() const _GLIBCXX_NOEXCEPT
934  { return _Rep::_S_max_size; }
935 
936  /**
937  * @brief Resizes the %string to the specified number of characters.
938  * @param __n Number of characters the %string should contain.
939  * @param __c Character to fill any new elements.
940  *
941  * This function will %resize the %string to the specified
942  * number of characters. If the number is smaller than the
943  * %string's current size the %string is truncated, otherwise
944  * the %string is extended and new elements are %set to @a __c.
945  */
946  void
947  resize(size_type __n, _CharT __c);
948 
949  /**
950  * @brief Resizes the %string to the specified number of characters.
951  * @param __n Number of characters the %string should contain.
952  *
953  * This function will resize the %string to the specified length. If
954  * the new size is smaller than the %string's current size the %string
955  * is truncated, otherwise the %string is extended and new characters
956  * are default-constructed. For basic types such as char, this means
957  * setting them to 0.
958  */
959  void
960  resize(size_type __n)
961  { this->resize(__n, _CharT()); }
962 
963 #if __cplusplus >= 201103L
964 #pragma GCC diagnostic push
965 #pragma GCC diagnostic ignored "-Wdeprecated-declarations"
966  /// A non-binding request to reduce capacity() to size().
967  void
968  shrink_to_fit() noexcept
969  { reserve(); }
970 #pragma GCC diagnostic pop
971 #endif
972 
973  /**
974  * Returns the total number of characters that the %string can hold
975  * before needing to allocate more memory.
976  */
977  size_type
978  capacity() const _GLIBCXX_NOEXCEPT
979  { return _M_rep()->_M_capacity; }
980 
981  /**
982  * @brief Attempt to preallocate enough memory for specified number of
983  * characters.
984  * @param __res_arg Number of characters required.
985  * @throw std::length_error If @a __res_arg exceeds @c max_size().
986  *
987  * This function attempts to reserve enough memory for the
988  * %string to hold the specified number of characters. If the
989  * number requested is more than max_size(), length_error is
990  * thrown.
991  *
992  * The advantage of this function is that if optimal code is a
993  * necessity and the user can determine the string length that will be
994  * required, the user can reserve the memory in %advance, and thus
995  * prevent a possible reallocation of memory and copying of %string
996  * data.
997  */
998  void
999  reserve(size_type __res_arg);
1000 
1001  /// Equivalent to shrink_to_fit().
1002 #if __cplusplus > 201703L
1003  [[deprecated("use shrink_to_fit() instead")]]
1004 #endif
1005  void
1007 
1008  /**
1009  * Erases the string, making it empty.
1010  */
1011 #if _GLIBCXX_FULLY_DYNAMIC_STRING == 0
1012  void
1013  clear() _GLIBCXX_NOEXCEPT
1014  {
1015  if (_M_rep()->_M_is_shared())
1016  {
1017  _M_rep()->_M_dispose(this->get_allocator());
1018  _M_data(_S_empty_rep()._M_refdata());
1019  }
1020  else
1021  _M_rep()->_M_set_length_and_sharable(0);
1022  }
1023 #else
1024  // PR 56166: this should not throw.
1025  void
1026  clear()
1027  { _M_mutate(0, this->size(), 0); }
1028 #endif
1029 
1030  /**
1031  * Returns true if the %string is empty. Equivalent to
1032  * <code>*this == ""</code>.
1033  */
1034  _GLIBCXX_NODISCARD bool
1035  empty() const _GLIBCXX_NOEXCEPT
1036  { return this->size() == 0; }
1037 
1038  // Element access:
1039  /**
1040  * @brief Subscript access to the data contained in the %string.
1041  * @param __pos The index of the character to access.
1042  * @return Read-only (constant) reference to the character.
1043  *
1044  * This operator allows for easy, array-style, data access.
1045  * Note that data access with this operator is unchecked and
1046  * out_of_range lookups are not defined. (For checked lookups
1047  * see at().)
1048  */
1049  const_reference
1050  operator[] (size_type __pos) const _GLIBCXX_NOEXCEPT
1051  {
1052  __glibcxx_assert(__pos <= size());
1053  return _M_data()[__pos];
1054  }
1055 
1056  /**
1057  * @brief Subscript access to the data contained in the %string.
1058  * @param __pos The index of the character to access.
1059  * @return Read/write reference to the character.
1060  *
1061  * This operator allows for easy, array-style, data access.
1062  * Note that data access with this operator is unchecked and
1063  * out_of_range lookups are not defined. (For checked lookups
1064  * see at().) Unshares the string.
1065  */
1066  reference
1067  operator[](size_type __pos)
1068  {
1069  // Allow pos == size() both in C++98 mode, as v3 extension,
1070  // and in C++11 mode.
1071  __glibcxx_assert(__pos <= size());
1072  // In pedantic mode be strict in C++98 mode.
1073  _GLIBCXX_DEBUG_PEDASSERT(__cplusplus >= 201103L || __pos < size());
1074  _M_leak();
1075  return _M_data()[__pos];
1076  }
1077 
1078  /**
1079  * @brief Provides access to the data contained in the %string.
1080  * @param __n The index of the character to access.
1081  * @return Read-only (const) reference to the character.
1082  * @throw std::out_of_range If @a n is an invalid index.
1083  *
1084  * This function provides for safer data access. The parameter is
1085  * first checked that it is in the range of the string. The function
1086  * throws out_of_range if the check fails.
1087  */
1088  const_reference
1089  at(size_type __n) const
1090  {
1091  if (__n >= this->size())
1092  __throw_out_of_range_fmt(__N("basic_string::at: __n "
1093  "(which is %zu) >= this->size() "
1094  "(which is %zu)"),
1095  __n, this->size());
1096  return _M_data()[__n];
1097  }
1098 
1099  /**
1100  * @brief Provides access to the data contained in the %string.
1101  * @param __n The index of the character to access.
1102  * @return Read/write reference to the character.
1103  * @throw std::out_of_range If @a n is an invalid index.
1104  *
1105  * This function provides for safer data access. The parameter is
1106  * first checked that it is in the range of the string. The function
1107  * throws out_of_range if the check fails. Success results in
1108  * unsharing the string.
1109  */
1110  reference
1111  at(size_type __n)
1112  {
1113  if (__n >= size())
1114  __throw_out_of_range_fmt(__N("basic_string::at: __n "
1115  "(which is %zu) >= this->size() "
1116  "(which is %zu)"),
1117  __n, this->size());
1118  _M_leak();
1119  return _M_data()[__n];
1120  }
1121 
1122 #if __cplusplus >= 201103L
1123  /**
1124  * Returns a read/write reference to the data at the first
1125  * element of the %string.
1126  */
1127  reference
1129  {
1130  __glibcxx_assert(!empty());
1131  return operator[](0);
1132  }
1133 
1134  /**
1135  * Returns a read-only (constant) reference to the data at the first
1136  * element of the %string.
1137  */
1138  const_reference
1139  front() const noexcept
1140  {
1141  __glibcxx_assert(!empty());
1142  return operator[](0);
1143  }
1144 
1145  /**
1146  * Returns a read/write reference to the data at the last
1147  * element of the %string.
1148  */
1149  reference
1151  {
1152  __glibcxx_assert(!empty());
1153  return operator[](this->size() - 1);
1154  }
1155 
1156  /**
1157  * Returns a read-only (constant) reference to the data at the
1158  * last element of the %string.
1159  */
1160  const_reference
1161  back() const noexcept
1162  {
1163  __glibcxx_assert(!empty());
1164  return operator[](this->size() - 1);
1165  }
1166 #endif
1167 
1168  // Modifiers:
1169  /**
1170  * @brief Append a string to this string.
1171  * @param __str The string to append.
1172  * @return Reference to this string.
1173  */
1174  basic_string&
1175  operator+=(const basic_string& __str)
1176  { return this->append(__str); }
1177 
1178  /**
1179  * @brief Append a C string.
1180  * @param __s The C string to append.
1181  * @return Reference to this string.
1182  */
1183  basic_string&
1184  operator+=(const _CharT* __s)
1185  { return this->append(__s); }
1186 
1187  /**
1188  * @brief Append a character.
1189  * @param __c The character to append.
1190  * @return Reference to this string.
1191  */
1192  basic_string&
1193  operator+=(_CharT __c)
1194  {
1195  this->push_back(__c);
1196  return *this;
1197  }
1198 
1199 #if __cplusplus >= 201103L
1200  /**
1201  * @brief Append an initializer_list of characters.
1202  * @param __l The initializer_list of characters to be appended.
1203  * @return Reference to this string.
1204  */
1205  basic_string&
1207  { return this->append(__l.begin(), __l.size()); }
1208 #endif // C++11
1209 
1210 #if __cplusplus >= 201703L
1211  /**
1212  * @brief Append a string_view.
1213  * @param __svt The object convertible to string_view to be appended.
1214  * @return Reference to this string.
1215  */
1216  template<typename _Tp>
1217  _If_sv<_Tp, basic_string&>
1218  operator+=(const _Tp& __svt)
1219  { return this->append(__svt); }
1220 #endif // C++17
1221 
1222  /**
1223  * @brief Append a string to this string.
1224  * @param __str The string to append.
1225  * @return Reference to this string.
1226  */
1227  basic_string&
1228  append(const basic_string& __str);
1229 
1230  /**
1231  * @brief Append a substring.
1232  * @param __str The string to append.
1233  * @param __pos Index of the first character of str to append.
1234  * @param __n The number of characters to append.
1235  * @return Reference to this string.
1236  * @throw std::out_of_range if @a __pos is not a valid index.
1237  *
1238  * This function appends @a __n characters from @a __str
1239  * starting at @a __pos to this string. If @a __n is is larger
1240  * than the number of available characters in @a __str, the
1241  * remainder of @a __str is appended.
1242  */
1243  basic_string&
1244  append(const basic_string& __str, size_type __pos, size_type __n = npos);
1245 
1246  /**
1247  * @brief Append a C substring.
1248  * @param __s The C string to append.
1249  * @param __n The number of characters to append.
1250  * @return Reference to this string.
1251  */
1252  basic_string&
1253  append(const _CharT* __s, size_type __n);
1254 
1255  /**
1256  * @brief Append a C string.
1257  * @param __s The C string to append.
1258  * @return Reference to this string.
1259  */
1260  basic_string&
1261  append(const _CharT* __s)
1262  {
1263  __glibcxx_requires_string(__s);
1264  return this->append(__s, traits_type::length(__s));
1265  }
1266 
1267  /**
1268  * @brief Append multiple characters.
1269  * @param __n The number of characters to append.
1270  * @param __c The character to use.
1271  * @return Reference to this string.
1272  *
1273  * Appends __n copies of __c to this string.
1274  */
1275  basic_string&
1276  append(size_type __n, _CharT __c);
1277 
1278 #if __cplusplus >= 201103L
1279  /**
1280  * @brief Append an initializer_list of characters.
1281  * @param __l The initializer_list of characters to append.
1282  * @return Reference to this string.
1283  */
1284  basic_string&
1286  { return this->append(__l.begin(), __l.size()); }
1287 #endif // C++11
1288 
1289  /**
1290  * @brief Append a range of characters.
1291  * @param __first Iterator referencing the first character to append.
1292  * @param __last Iterator marking the end of the range.
1293  * @return Reference to this string.
1294  *
1295  * Appends characters in the range [__first,__last) to this string.
1296  */
1297  template<class _InputIterator>
1298  basic_string&
1299  append(_InputIterator __first, _InputIterator __last)
1300  { return this->replace(_M_iend(), _M_iend(), __first, __last); }
1301 
1302 #if __cplusplus >= 201703L
1303  /**
1304  * @brief Append a string_view.
1305  * @param __svt The object convertible to string_view to be appended.
1306  * @return Reference to this string.
1307  */
1308  template<typename _Tp>
1309  _If_sv<_Tp, basic_string&>
1310  append(const _Tp& __svt)
1311  {
1312  __sv_type __sv = __svt;
1313  return this->append(__sv.data(), __sv.size());
1314  }
1315 
1316  /**
1317  * @brief Append a range of characters from a string_view.
1318  * @param __svt The object convertible to string_view to be appended
1319  * from.
1320  * @param __pos The position in the string_view to append from.
1321  * @param __n The number of characters to append from the string_view.
1322  * @return Reference to this string.
1323  */
1324  template<typename _Tp>
1325  _If_sv<_Tp, basic_string&>
1326  append(const _Tp& __svt, size_type __pos, size_type __n = npos)
1327  {
1328  __sv_type __sv = __svt;
1329  return append(__sv.data()
1330  + std::__sv_check(__sv.size(), __pos, "basic_string::append"),
1331  std::__sv_limit(__sv.size(), __pos, __n));
1332  }
1333 #endif // C++17
1334 
1335  /**
1336  * @brief Append a single character.
1337  * @param __c Character to append.
1338  */
1339  void
1340  push_back(_CharT __c)
1341  {
1342  const size_type __len = 1 + this->size();
1343  if (__len > this->capacity() || _M_rep()->_M_is_shared())
1344  this->reserve(__len);
1345  traits_type::assign(_M_data()[this->size()], __c);
1346  _M_rep()->_M_set_length_and_sharable(__len);
1347  }
1348 
1349  /**
1350  * @brief Set value to contents of another string.
1351  * @param __str Source string to use.
1352  * @return Reference to this string.
1353  */
1354  basic_string&
1355  assign(const basic_string& __str);
1356 
1357 #if __cplusplus >= 201103L
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  * This function sets this string to the exact contents of @a __str.
1364  * @a __str is a valid, but unspecified string.
1365  */
1366  basic_string&
1369  {
1370  this->swap(__str);
1371  return *this;
1372  }
1373 #endif // C++11
1374 
1375  /**
1376  * @brief Set value to a substring of a string.
1377  * @param __str The string to use.
1378  * @param __pos Index of the first character of str.
1379  * @param __n Number of characters to use.
1380  * @return Reference to this string.
1381  * @throw std::out_of_range if @a pos is not a valid index.
1382  *
1383  * This function sets this string to the substring of @a __str
1384  * consisting of @a __n characters at @a __pos. If @a __n is
1385  * is larger than the number of available characters in @a
1386  * __str, the remainder of @a __str is used.
1387  */
1388  basic_string&
1389  assign(const basic_string& __str, size_type __pos, size_type __n = npos)
1390  { return this->assign(__str._M_data()
1391  + __str._M_check(__pos, "basic_string::assign"),
1392  __str._M_limit(__pos, __n)); }
1393 
1394  /**
1395  * @brief Set value to a C substring.
1396  * @param __s The C string to use.
1397  * @param __n Number of characters to use.
1398  * @return Reference to this string.
1399  *
1400  * This function sets the value of this string to the first @a __n
1401  * characters of @a __s. If @a __n is is larger than the number of
1402  * available characters in @a __s, the remainder of @a __s is used.
1403  */
1404  basic_string&
1405  assign(const _CharT* __s, size_type __n);
1406 
1407  /**
1408  * @brief Set value to contents of a C string.
1409  * @param __s The C string to use.
1410  * @return Reference to this string.
1411  *
1412  * This function sets the value of this string to the value of @a __s.
1413  * The data is copied, so there is no dependence on @a __s once the
1414  * function returns.
1415  */
1416  basic_string&
1417  assign(const _CharT* __s)
1418  {
1419  __glibcxx_requires_string(__s);
1420  return this->assign(__s, traits_type::length(__s));
1421  }
1422 
1423  /**
1424  * @brief Set value to multiple characters.
1425  * @param __n Length of the resulting string.
1426  * @param __c The character to use.
1427  * @return Reference to this string.
1428  *
1429  * This function sets the value of this string to @a __n copies of
1430  * character @a __c.
1431  */
1432  basic_string&
1433  assign(size_type __n, _CharT __c)
1434  { return _M_replace_aux(size_type(0), this->size(), __n, __c); }
1435 
1436  /**
1437  * @brief Set value to a range of characters.
1438  * @param __first Iterator referencing the first character to append.
1439  * @param __last Iterator marking the end of the range.
1440  * @return Reference to this string.
1441  *
1442  * Sets value of string to characters in the range [__first,__last).
1443  */
1444  template<class _InputIterator>
1445  basic_string&
1446  assign(_InputIterator __first, _InputIterator __last)
1447  { return this->replace(_M_ibegin(), _M_iend(), __first, __last); }
1448 
1449 #if __cplusplus >= 201103L
1450  /**
1451  * @brief Set value to an initializer_list of characters.
1452  * @param __l The initializer_list of characters to assign.
1453  * @return Reference to this string.
1454  */
1455  basic_string&
1457  { return this->assign(__l.begin(), __l.size()); }
1458 #endif // C++11
1459 
1460 #if __cplusplus >= 201703L
1461  /**
1462  * @brief Set value from a string_view.
1463  * @param __svt The source object convertible to string_view.
1464  * @return Reference to this string.
1465  */
1466  template<typename _Tp>
1467  _If_sv<_Tp, basic_string&>
1468  assign(const _Tp& __svt)
1469  {
1470  __sv_type __sv = __svt;
1471  return this->assign(__sv.data(), __sv.size());
1472  }
1473 
1474  /**
1475  * @brief Set value from a range of characters in a string_view.
1476  * @param __svt The source object convertible to string_view.
1477  * @param __pos The position in the string_view to assign from.
1478  * @param __n The number of characters to assign.
1479  * @return Reference to this string.
1480  */
1481  template<typename _Tp>
1482  _If_sv<_Tp, basic_string&>
1483  assign(const _Tp& __svt, size_type __pos, size_type __n = npos)
1484  {
1485  __sv_type __sv = __svt;
1486  return assign(__sv.data()
1487  + std::__sv_check(__sv.size(), __pos, "basic_string::assign"),
1488  std::__sv_limit(__sv.size(), __pos, __n));
1489  }
1490 #endif // C++17
1491 
1492  /**
1493  * @brief Insert multiple characters.
1494  * @param __p Iterator referencing location in string to insert at.
1495  * @param __n Number of characters to insert
1496  * @param __c The character to insert.
1497  * @throw std::length_error If new length exceeds @c max_size().
1498  *
1499  * Inserts @a __n copies of character @a __c starting at the
1500  * position referenced by iterator @a __p. If adding
1501  * characters causes the length to exceed max_size(),
1502  * length_error is thrown. The value of the string doesn't
1503  * change if an error is thrown.
1504  */
1505  void
1506  insert(iterator __p, size_type __n, _CharT __c)
1507  { this->replace(__p, __p, __n, __c); }
1508 
1509  /**
1510  * @brief Insert a range of characters.
1511  * @param __p Iterator referencing location in string to insert at.
1512  * @param __beg Start of range.
1513  * @param __end End of range.
1514  * @throw std::length_error If new length exceeds @c max_size().
1515  *
1516  * Inserts characters in range [__beg,__end). If adding
1517  * characters causes the length to exceed max_size(),
1518  * length_error is thrown. The value of the string doesn't
1519  * change if an error is thrown.
1520  */
1521  template<class _InputIterator>
1522  void
1523  insert(iterator __p, _InputIterator __beg, _InputIterator __end)
1524  { this->replace(__p, __p, __beg, __end); }
1525 
1526 #if __cplusplus >= 201103L
1527  /**
1528  * @brief Insert an initializer_list of characters.
1529  * @param __p Iterator referencing location in string to insert at.
1530  * @param __l The initializer_list of characters to insert.
1531  * @throw std::length_error If new length exceeds @c max_size().
1532  */
1533  void
1535  {
1536  _GLIBCXX_DEBUG_PEDASSERT(__p >= _M_ibegin() && __p <= _M_iend());
1537  this->insert(__p - _M_ibegin(), __l.begin(), __l.size());
1538  }
1539 #endif // C++11
1540 
1541  /**
1542  * @brief Insert value of a string.
1543  * @param __pos1 Position in string to insert at.
1544  * @param __str The string to insert.
1545  * @return Reference to this string.
1546  * @throw std::length_error If new length exceeds @c max_size().
1547  *
1548  * Inserts value of @a __str starting at @a __pos1. If adding
1549  * characters causes the length to exceed max_size(),
1550  * length_error is thrown. The value of the string doesn't
1551  * change if an error is thrown.
1552  */
1553  basic_string&
1554  insert(size_type __pos1, const basic_string& __str)
1555  { return this->insert(__pos1, __str, size_type(0), __str.size()); }
1556 
1557  /**
1558  * @brief Insert a substring.
1559  * @param __pos1 Position in string to insert at.
1560  * @param __str The string to insert.
1561  * @param __pos2 Start of characters in str to insert.
1562  * @param __n Number of characters to insert.
1563  * @return Reference to this string.
1564  * @throw std::length_error If new length exceeds @c max_size().
1565  * @throw std::out_of_range If @a pos1 > size() or
1566  * @a __pos2 > @a str.size().
1567  *
1568  * Starting at @a pos1, insert @a __n character of @a __str
1569  * beginning with @a __pos2. If adding characters causes the
1570  * length to exceed max_size(), length_error is thrown. If @a
1571  * __pos1 is beyond the end of this string or @a __pos2 is
1572  * beyond the end of @a __str, out_of_range is thrown. The
1573  * value of the string doesn't change if an error is thrown.
1574  */
1575  basic_string&
1576  insert(size_type __pos1, const basic_string& __str,
1577  size_type __pos2, size_type __n = npos)
1578  { return this->insert(__pos1, __str._M_data()
1579  + __str._M_check(__pos2, "basic_string::insert"),
1580  __str._M_limit(__pos2, __n)); }
1581 
1582  /**
1583  * @brief Insert a C substring.
1584  * @param __pos Position in string to insert at.
1585  * @param __s The C string to insert.
1586  * @param __n The number of characters to insert.
1587  * @return Reference to this string.
1588  * @throw std::length_error If new length exceeds @c max_size().
1589  * @throw std::out_of_range If @a __pos is beyond the end of this
1590  * string.
1591  *
1592  * Inserts the first @a __n characters of @a __s starting at @a
1593  * __pos. If adding characters causes the length to exceed
1594  * max_size(), length_error is thrown. If @a __pos is beyond
1595  * end(), out_of_range is thrown. The value of the string
1596  * doesn't change if an error is thrown.
1597  */
1598  basic_string&
1599  insert(size_type __pos, const _CharT* __s, size_type __n);
1600 
1601  /**
1602  * @brief Insert a C string.
1603  * @param __pos Position in string to insert at.
1604  * @param __s The C string to insert.
1605  * @return Reference to this string.
1606  * @throw std::length_error If new length exceeds @c max_size().
1607  * @throw std::out_of_range If @a pos is beyond the end of this
1608  * string.
1609  *
1610  * Inserts the first @a n characters of @a __s starting at @a __pos. If
1611  * adding characters causes the length to exceed max_size(),
1612  * length_error is thrown. If @a __pos is beyond end(), out_of_range is
1613  * thrown. The value of the string doesn't change if an error is
1614  * thrown.
1615  */
1616  basic_string&
1617  insert(size_type __pos, const _CharT* __s)
1618  {
1619  __glibcxx_requires_string(__s);
1620  return this->insert(__pos, __s, traits_type::length(__s));
1621  }
1622 
1623  /**
1624  * @brief Insert multiple characters.
1625  * @param __pos Index in string to insert at.
1626  * @param __n Number of characters to insert
1627  * @param __c The character to insert.
1628  * @return Reference to this string.
1629  * @throw std::length_error If new length exceeds @c max_size().
1630  * @throw std::out_of_range If @a __pos is beyond the end of this
1631  * string.
1632  *
1633  * Inserts @a __n copies of character @a __c starting at index
1634  * @a __pos. If adding characters causes the length to exceed
1635  * max_size(), length_error is thrown. If @a __pos > length(),
1636  * out_of_range is thrown. The value of the string doesn't
1637  * change if an error is thrown.
1638  */
1639  basic_string&
1640  insert(size_type __pos, size_type __n, _CharT __c)
1641  { return _M_replace_aux(_M_check(__pos, "basic_string::insert"),
1642  size_type(0), __n, __c); }
1643 
1644  /**
1645  * @brief Insert one character.
1646  * @param __p Iterator referencing position in string to insert at.
1647  * @param __c The character to insert.
1648  * @return Iterator referencing newly inserted char.
1649  * @throw std::length_error If new length exceeds @c max_size().
1650  *
1651  * Inserts character @a __c at position referenced by @a __p.
1652  * If adding character causes the length to exceed max_size(),
1653  * length_error is thrown. If @a __p is beyond end of string,
1654  * out_of_range is thrown. The value of the string doesn't
1655  * change if an error is thrown.
1656  */
1657  iterator
1658  insert(iterator __p, _CharT __c)
1659  {
1660  _GLIBCXX_DEBUG_PEDASSERT(__p >= _M_ibegin() && __p <= _M_iend());
1661  const size_type __pos = __p - _M_ibegin();
1662  _M_replace_aux(__pos, size_type(0), size_type(1), __c);
1663  _M_rep()->_M_set_leaked();
1664  return iterator(_M_data() + __pos);
1665  }
1666 
1667 #if __cplusplus >= 201703L
1668  /**
1669  * @brief Insert a string_view.
1670  * @param __pos Position in string to insert at.
1671  * @param __svt The object convertible to string_view to insert.
1672  * @return Reference to this string.
1673  */
1674  template<typename _Tp>
1675  _If_sv<_Tp, basic_string&>
1676  insert(size_type __pos, const _Tp& __svt)
1677  {
1678  __sv_type __sv = __svt;
1679  return this->insert(__pos, __sv.data(), __sv.size());
1680  }
1681 
1682  /**
1683  * @brief Insert a string_view.
1684  * @param __pos1 Position in string to insert at.
1685  * @param __svt The object convertible to string_view to insert from.
1686  * @param __pos2 Position in string_view to insert from.
1687  * @param __n The number of characters to insert.
1688  * @return Reference to this string.
1689  */
1690  template<typename _Tp>
1691  _If_sv<_Tp, basic_string&>
1692  insert(size_type __pos1, const _Tp& __svt,
1693  size_type __pos2, size_type __n = npos)
1694  {
1695  __sv_type __sv = __svt;
1696  return this->replace(__pos1, size_type(0), __sv.data()
1697  + std::__sv_check(__sv.size(), __pos2, "basic_string::insert"),
1698  std::__sv_limit(__sv.size(), __pos2, __n));
1699  }
1700 #endif // C++17
1701 
1702  /**
1703  * @brief Remove characters.
1704  * @param __pos Index of first character to remove (default 0).
1705  * @param __n Number of characters to remove (default remainder).
1706  * @return Reference to this string.
1707  * @throw std::out_of_range If @a pos is beyond the end of this
1708  * string.
1709  *
1710  * Removes @a __n characters from this string starting at @a
1711  * __pos. The length of the string is reduced by @a __n. If
1712  * there are < @a __n characters to remove, the remainder of
1713  * the string is truncated. If @a __p is beyond end of string,
1714  * out_of_range is thrown. The value of the string doesn't
1715  * change if an error is thrown.
1716  */
1717  basic_string&
1718  erase(size_type __pos = 0, size_type __n = npos)
1719  {
1720  _M_mutate(_M_check(__pos, "basic_string::erase"),
1721  _M_limit(__pos, __n), size_type(0));
1722  return *this;
1723  }
1724 
1725  /**
1726  * @brief Remove one character.
1727  * @param __position Iterator referencing the character to remove.
1728  * @return iterator referencing same location after removal.
1729  *
1730  * Removes the character at @a __position from this string. The value
1731  * of the string doesn't change if an error is thrown.
1732  */
1733  iterator
1734  erase(iterator __position)
1735  {
1736  _GLIBCXX_DEBUG_PEDASSERT(__position >= _M_ibegin()
1737  && __position < _M_iend());
1738  const size_type __pos = __position - _M_ibegin();
1739  _M_mutate(__pos, size_type(1), size_type(0));
1740  _M_rep()->_M_set_leaked();
1741  return iterator(_M_data() + __pos);
1742  }
1743 
1744  /**
1745  * @brief Remove a range of characters.
1746  * @param __first Iterator referencing the first character to remove.
1747  * @param __last Iterator referencing the end of the range.
1748  * @return Iterator referencing location of first after removal.
1749  *
1750  * Removes the characters in the range [first,last) from this string.
1751  * The value of the string doesn't change if an error is thrown.
1752  */
1753  iterator
1754  erase(iterator __first, iterator __last);
1755 
1756 #if __cplusplus >= 201103L
1757  /**
1758  * @brief Remove the last character.
1759  *
1760  * The string must be non-empty.
1761  */
1762  void
1763  pop_back() // FIXME C++11: should be noexcept.
1764  {
1765  __glibcxx_assert(!empty());
1766  erase(size() - 1, 1);
1767  }
1768 #endif // C++11
1769 
1770  /**
1771  * @brief Replace characters with value from another string.
1772  * @param __pos Index of first character to replace.
1773  * @param __n Number of characters to be replaced.
1774  * @param __str String to insert.
1775  * @return Reference to this string.
1776  * @throw std::out_of_range If @a pos is beyond the end of this
1777  * string.
1778  * @throw std::length_error If new length exceeds @c max_size().
1779  *
1780  * Removes the characters in the range [__pos,__pos+__n) from
1781  * this string. In place, the value of @a __str is inserted.
1782  * If @a __pos is beyond end of string, out_of_range is thrown.
1783  * If the length of the result exceeds max_size(), length_error
1784  * is thrown. The value of the string doesn't change if an
1785  * error is thrown.
1786  */
1787  basic_string&
1788  replace(size_type __pos, size_type __n, const basic_string& __str)
1789  { return this->replace(__pos, __n, __str._M_data(), __str.size()); }
1790 
1791  /**
1792  * @brief Replace characters with value from another string.
1793  * @param __pos1 Index of first character to replace.
1794  * @param __n1 Number of characters to be replaced.
1795  * @param __str String to insert.
1796  * @param __pos2 Index of first character of str to use.
1797  * @param __n2 Number of characters from str to use.
1798  * @return Reference to this string.
1799  * @throw std::out_of_range If @a __pos1 > size() or @a __pos2 >
1800  * __str.size().
1801  * @throw std::length_error If new length exceeds @c max_size().
1802  *
1803  * Removes the characters in the range [__pos1,__pos1 + n) from this
1804  * string. In place, the value of @a __str is inserted. If @a __pos is
1805  * beyond end of string, out_of_range is thrown. If the length of the
1806  * result exceeds max_size(), length_error is thrown. The value of the
1807  * string doesn't change if an error is thrown.
1808  */
1809  basic_string&
1810  replace(size_type __pos1, size_type __n1, const basic_string& __str,
1811  size_type __pos2, size_type __n2 = npos)
1812  { return this->replace(__pos1, __n1, __str._M_data()
1813  + __str._M_check(__pos2, "basic_string::replace"),
1814  __str._M_limit(__pos2, __n2)); }
1815 
1816  /**
1817  * @brief Replace characters with value of a C substring.
1818  * @param __pos Index of first character to replace.
1819  * @param __n1 Number of characters to be replaced.
1820  * @param __s C string to insert.
1821  * @param __n2 Number of characters from @a s to use.
1822  * @return Reference to this string.
1823  * @throw std::out_of_range If @a pos1 > size().
1824  * @throw std::length_error If new length exceeds @c max_size().
1825  *
1826  * Removes the characters in the range [__pos,__pos + __n1)
1827  * from this string. In place, the first @a __n2 characters of
1828  * @a __s are inserted, or all of @a __s if @a __n2 is too large. If
1829  * @a __pos is beyond end of string, out_of_range is thrown. If
1830  * the length of result exceeds max_size(), length_error is
1831  * thrown. The value of the string doesn't change if an error
1832  * is thrown.
1833  */
1834  basic_string&
1835  replace(size_type __pos, size_type __n1, const _CharT* __s,
1836  size_type __n2);
1837 
1838  /**
1839  * @brief Replace characters with value of a C string.
1840  * @param __pos Index of first character to replace.
1841  * @param __n1 Number of characters to be replaced.
1842  * @param __s C string to insert.
1843  * @return Reference to this string.
1844  * @throw std::out_of_range If @a pos > size().
1845  * @throw std::length_error If new length exceeds @c max_size().
1846  *
1847  * Removes the characters in the range [__pos,__pos + __n1)
1848  * from this string. In place, the characters of @a __s are
1849  * inserted. If @a __pos is beyond end of string, out_of_range
1850  * is thrown. If the length of result exceeds max_size(),
1851  * length_error is thrown. The value of the string doesn't
1852  * change if an error is thrown.
1853  */
1854  basic_string&
1855  replace(size_type __pos, size_type __n1, const _CharT* __s)
1856  {
1857  __glibcxx_requires_string(__s);
1858  return this->replace(__pos, __n1, __s, traits_type::length(__s));
1859  }
1860 
1861  /**
1862  * @brief Replace characters with multiple characters.
1863  * @param __pos Index of first character to replace.
1864  * @param __n1 Number of characters to be replaced.
1865  * @param __n2 Number of characters to insert.
1866  * @param __c Character to insert.
1867  * @return Reference to this string.
1868  * @throw std::out_of_range If @a __pos > size().
1869  * @throw std::length_error If new length exceeds @c max_size().
1870  *
1871  * Removes the characters in the range [pos,pos + n1) from this
1872  * string. In place, @a __n2 copies of @a __c are inserted.
1873  * If @a __pos is beyond end of string, out_of_range is thrown.
1874  * If the length of result exceeds max_size(), length_error is
1875  * thrown. The value of the string doesn't change if an error
1876  * is thrown.
1877  */
1878  basic_string&
1879  replace(size_type __pos, size_type __n1, size_type __n2, _CharT __c)
1880  { return _M_replace_aux(_M_check(__pos, "basic_string::replace"),
1881  _M_limit(__pos, __n1), __n2, __c); }
1882 
1883  /**
1884  * @brief Replace range of characters with string.
1885  * @param __i1 Iterator referencing start of range to replace.
1886  * @param __i2 Iterator referencing end of range to replace.
1887  * @param __str String value to insert.
1888  * @return Reference to this string.
1889  * @throw std::length_error If new length exceeds @c max_size().
1890  *
1891  * Removes the characters in the range [__i1,__i2). In place,
1892  * the value of @a __str is inserted. If the length of result
1893  * exceeds max_size(), length_error is thrown. The value of
1894  * the string doesn't change if an error is thrown.
1895  */
1896  basic_string&
1897  replace(iterator __i1, iterator __i2, const basic_string& __str)
1898  { return this->replace(__i1, __i2, __str._M_data(), __str.size()); }
1899 
1900  /**
1901  * @brief Replace range of characters with C substring.
1902  * @param __i1 Iterator referencing start of range to replace.
1903  * @param __i2 Iterator referencing end of range to replace.
1904  * @param __s C string value to insert.
1905  * @param __n Number of characters from s to insert.
1906  * @return Reference to this string.
1907  * @throw std::length_error If new length exceeds @c max_size().
1908  *
1909  * Removes the characters in the range [__i1,__i2). In place,
1910  * the first @a __n characters of @a __s are inserted. If the
1911  * length of result exceeds max_size(), length_error is thrown.
1912  * The value of the string doesn't change if an error is
1913  * thrown.
1914  */
1915  basic_string&
1916  replace(iterator __i1, iterator __i2, const _CharT* __s, size_type __n)
1917  {
1918  _GLIBCXX_DEBUG_PEDASSERT(_M_ibegin() <= __i1 && __i1 <= __i2
1919  && __i2 <= _M_iend());
1920  return this->replace(__i1 - _M_ibegin(), __i2 - __i1, __s, __n);
1921  }
1922 
1923  /**
1924  * @brief Replace range of characters with C string.
1925  * @param __i1 Iterator referencing start of range to replace.
1926  * @param __i2 Iterator referencing end of range to replace.
1927  * @param __s C string value to insert.
1928  * @return Reference to this string.
1929  * @throw std::length_error If new length exceeds @c max_size().
1930  *
1931  * Removes the characters in the range [__i1,__i2). In place,
1932  * the characters of @a __s are inserted. If the length of
1933  * result exceeds max_size(), length_error is thrown. The
1934  * value of the string doesn't change if an error is thrown.
1935  */
1936  basic_string&
1937  replace(iterator __i1, iterator __i2, const _CharT* __s)
1938  {
1939  __glibcxx_requires_string(__s);
1940  return this->replace(__i1, __i2, __s, traits_type::length(__s));
1941  }
1942 
1943  /**
1944  * @brief Replace range of characters with multiple characters
1945  * @param __i1 Iterator referencing start of range to replace.
1946  * @param __i2 Iterator referencing end of range to replace.
1947  * @param __n Number of characters to insert.
1948  * @param __c Character to insert.
1949  * @return Reference to this string.
1950  * @throw std::length_error If new length exceeds @c max_size().
1951  *
1952  * Removes the characters in the range [__i1,__i2). In place,
1953  * @a __n copies of @a __c are inserted. If the length of
1954  * result exceeds max_size(), length_error is thrown. The
1955  * value of the string doesn't change if an error is thrown.
1956  */
1957  basic_string&
1958  replace(iterator __i1, iterator __i2, size_type __n, _CharT __c)
1959  {
1960  _GLIBCXX_DEBUG_PEDASSERT(_M_ibegin() <= __i1 && __i1 <= __i2
1961  && __i2 <= _M_iend());
1962  return _M_replace_aux(__i1 - _M_ibegin(), __i2 - __i1, __n, __c);
1963  }
1964 
1965  /**
1966  * @brief Replace range of characters with range.
1967  * @param __i1 Iterator referencing start of range to replace.
1968  * @param __i2 Iterator referencing end of range to replace.
1969  * @param __k1 Iterator referencing start of range to insert.
1970  * @param __k2 Iterator referencing end of range to insert.
1971  * @return Reference to this string.
1972  * @throw std::length_error If new length exceeds @c max_size().
1973  *
1974  * Removes the characters in the range [__i1,__i2). In place,
1975  * characters in the range [__k1,__k2) are inserted. If the
1976  * length of result exceeds max_size(), length_error is thrown.
1977  * The value of the string doesn't change if an error is
1978  * thrown.
1979  */
1980  template<class _InputIterator>
1981  basic_string&
1982  replace(iterator __i1, iterator __i2,
1983  _InputIterator __k1, _InputIterator __k2)
1984  {
1985  _GLIBCXX_DEBUG_PEDASSERT(_M_ibegin() <= __i1 && __i1 <= __i2
1986  && __i2 <= _M_iend());
1987  __glibcxx_requires_valid_range(__k1, __k2);
1988  typedef typename std::__is_integer<_InputIterator>::__type _Integral;
1989  return _M_replace_dispatch(__i1, __i2, __k1, __k2, _Integral());
1990  }
1991 
1992  // Specializations for the common case of pointer and iterator:
1993  // useful to avoid the overhead of temporary buffering in _M_replace.
1994  basic_string&
1995  replace(iterator __i1, iterator __i2, _CharT* __k1, _CharT* __k2)
1996  {
1997  _GLIBCXX_DEBUG_PEDASSERT(_M_ibegin() <= __i1 && __i1 <= __i2
1998  && __i2 <= _M_iend());
1999  __glibcxx_requires_valid_range(__k1, __k2);
2000  return this->replace(__i1 - _M_ibegin(), __i2 - __i1,
2001  __k1, __k2 - __k1);
2002  }
2003 
2004  basic_string&
2005  replace(iterator __i1, iterator __i2,
2006  const _CharT* __k1, const _CharT* __k2)
2007  {
2008  _GLIBCXX_DEBUG_PEDASSERT(_M_ibegin() <= __i1 && __i1 <= __i2
2009  && __i2 <= _M_iend());
2010  __glibcxx_requires_valid_range(__k1, __k2);
2011  return this->replace(__i1 - _M_ibegin(), __i2 - __i1,
2012  __k1, __k2 - __k1);
2013  }
2014 
2015  basic_string&
2016  replace(iterator __i1, iterator __i2, iterator __k1, iterator __k2)
2017  {
2018  _GLIBCXX_DEBUG_PEDASSERT(_M_ibegin() <= __i1 && __i1 <= __i2
2019  && __i2 <= _M_iend());
2020  __glibcxx_requires_valid_range(__k1, __k2);
2021  return this->replace(__i1 - _M_ibegin(), __i2 - __i1,
2022  __k1.base(), __k2 - __k1);
2023  }
2024 
2025  basic_string&
2026  replace(iterator __i1, iterator __i2,
2027  const_iterator __k1, const_iterator __k2)
2028  {
2029  _GLIBCXX_DEBUG_PEDASSERT(_M_ibegin() <= __i1 && __i1 <= __i2
2030  && __i2 <= _M_iend());
2031  __glibcxx_requires_valid_range(__k1, __k2);
2032  return this->replace(__i1 - _M_ibegin(), __i2 - __i1,
2033  __k1.base(), __k2 - __k1);
2034  }
2035 
2036 #if __cplusplus >= 201103L
2037  /**
2038  * @brief Replace range of characters with initializer_list.
2039  * @param __i1 Iterator referencing start of range to replace.
2040  * @param __i2 Iterator referencing end of range to replace.
2041  * @param __l The initializer_list of characters to insert.
2042  * @return Reference to this string.
2043  * @throw std::length_error If new length exceeds @c max_size().
2044  *
2045  * Removes the characters in the range [__i1,__i2). In place,
2046  * characters in the range [__k1,__k2) are inserted. If the
2047  * length of result exceeds max_size(), length_error is thrown.
2048  * The value of the string doesn't change if an error is
2049  * thrown.
2050  */
2051  basic_string& replace(iterator __i1, iterator __i2,
2053  { return this->replace(__i1, __i2, __l.begin(), __l.end()); }
2054 #endif // C++11
2055 
2056 #if __cplusplus >= 201703L
2057  /**
2058  * @brief Replace range of characters with string_view.
2059  * @param __pos The position to replace at.
2060  * @param __n The number of characters to replace.
2061  * @param __svt The object convertible to string_view to insert.
2062  * @return Reference to this string.
2063  */
2064  template<typename _Tp>
2065  _If_sv<_Tp, basic_string&>
2066  replace(size_type __pos, size_type __n, const _Tp& __svt)
2067  {
2068  __sv_type __sv = __svt;
2069  return this->replace(__pos, __n, __sv.data(), __sv.size());
2070  }
2071 
2072  /**
2073  * @brief Replace range of characters with string_view.
2074  * @param __pos1 The position to replace at.
2075  * @param __n1 The number of characters to replace.
2076  * @param __svt The object convertible to string_view to insert from.
2077  * @param __pos2 The position in the string_view to insert from.
2078  * @param __n2 The number of characters to insert.
2079  * @return Reference to this string.
2080  */
2081  template<typename _Tp>
2082  _If_sv<_Tp, basic_string&>
2083  replace(size_type __pos1, size_type __n1, const _Tp& __svt,
2084  size_type __pos2, size_type __n2 = npos)
2085  {
2086  __sv_type __sv = __svt;
2087  return this->replace(__pos1, __n1,
2088  __sv.data()
2089  + std::__sv_check(__sv.size(), __pos2, "basic_string::replace"),
2090  std::__sv_limit(__sv.size(), __pos2, __n2));
2091  }
2092 
2093  /**
2094  * @brief Replace range of characters with string_view.
2095  * @param __i1 An iterator referencing the start position
2096  * to replace at.
2097  * @param __i2 An iterator referencing the end position
2098  * for the replace.
2099  * @param __svt The object convertible to string_view to insert from.
2100  * @return Reference to this string.
2101  */
2102  template<typename _Tp>
2103  _If_sv<_Tp, basic_string&>
2104  replace(const_iterator __i1, const_iterator __i2, const _Tp& __svt)
2105  {
2106  __sv_type __sv = __svt;
2107  return this->replace(__i1 - begin(), __i2 - __i1, __sv);
2108  }
2109 #endif // C++17
2110 
2111  private:
2112  template<class _Integer>
2113  basic_string&
2114  _M_replace_dispatch(iterator __i1, iterator __i2, _Integer __n,
2115  _Integer __val, __true_type)
2116  { return _M_replace_aux(__i1 - _M_ibegin(), __i2 - __i1, __n, __val); }
2117 
2118  template<class _InputIterator>
2119  basic_string&
2120  _M_replace_dispatch(iterator __i1, iterator __i2, _InputIterator __k1,
2121  _InputIterator __k2, __false_type);
2122 
2123  basic_string&
2124  _M_replace_aux(size_type __pos1, size_type __n1, size_type __n2,
2125  _CharT __c);
2126 
2127  basic_string&
2128  _M_replace_safe(size_type __pos1, size_type __n1, const _CharT* __s,
2129  size_type __n2);
2130 
2131  // _S_construct_aux is used to implement the 21.3.1 para 15 which
2132  // requires special behaviour if _InIter is an integral type
2133  template<class _InIterator>
2134  static _CharT*
2135  _S_construct_aux(_InIterator __beg, _InIterator __end,
2136  const _Alloc& __a, __false_type)
2137  {
2138  typedef typename iterator_traits<_InIterator>::iterator_category _Tag;
2139  return _S_construct(__beg, __end, __a, _Tag());
2140  }
2141 
2142  // _GLIBCXX_RESOLVE_LIB_DEFECTS
2143  // 438. Ambiguity in the "do the right thing" clause
2144  template<class _Integer>
2145  static _CharT*
2146  _S_construct_aux(_Integer __beg, _Integer __end,
2147  const _Alloc& __a, __true_type)
2148  { return _S_construct_aux_2(static_cast<size_type>(__beg),
2149  __end, __a); }
2150 
2151  static _CharT*
2152  _S_construct_aux_2(size_type __req, _CharT __c, const _Alloc& __a)
2153  { return _S_construct(__req, __c, __a); }
2154 
2155  template<class _InIterator>
2156  static _CharT*
2157  _S_construct(_InIterator __beg, _InIterator __end, const _Alloc& __a)
2158  {
2159  typedef typename std::__is_integer<_InIterator>::__type _Integral;
2160  return _S_construct_aux(__beg, __end, __a, _Integral());
2161  }
2162 
2163  // For Input Iterators, used in istreambuf_iterators, etc.
2164  template<class _InIterator>
2165  static _CharT*
2166  _S_construct(_InIterator __beg, _InIterator __end, const _Alloc& __a,
2167  input_iterator_tag);
2168 
2169  // For forward_iterators up to random_access_iterators, used for
2170  // string::iterator, _CharT*, etc.
2171  template<class _FwdIterator>
2172  static _CharT*
2173  _S_construct(_FwdIterator __beg, _FwdIterator __end, const _Alloc& __a,
2174  forward_iterator_tag);
2175 
2176  static _CharT*
2177  _S_construct(size_type __req, _CharT __c, const _Alloc& __a);
2178 
2179  public:
2180 
2181  /**
2182  * @brief Copy substring into C string.
2183  * @param __s C string to copy value into.
2184  * @param __n Number of characters to copy.
2185  * @param __pos Index of first character to copy.
2186  * @return Number of characters actually copied
2187  * @throw std::out_of_range If __pos > size().
2188  *
2189  * Copies up to @a __n characters starting at @a __pos into the
2190  * C string @a __s. If @a __pos is %greater than size(),
2191  * out_of_range is thrown.
2192  */
2193  size_type
2194  copy(_CharT* __s, size_type __n, size_type __pos = 0) const;
2195 
2196  /**
2197  * @brief Swap contents with another string.
2198  * @param __s String to swap with.
2199  *
2200  * Exchanges the contents of this string with that of @a __s in constant
2201  * time.
2202  */
2203  void
2206 
2207  // String operations:
2208  /**
2209  * @brief Return const pointer to null-terminated contents.
2210  *
2211  * This is a handle to internal data. Do not modify or dire things may
2212  * happen.
2213  */
2214  const _CharT*
2215  c_str() const _GLIBCXX_NOEXCEPT
2216  { return _M_data(); }
2217 
2218  /**
2219  * @brief Return const pointer to contents.
2220  *
2221  * This is a pointer to internal data. It is undefined to modify
2222  * the contents through the returned pointer. To get a pointer that
2223  * allows modifying the contents use @c &str[0] instead,
2224  * (or in C++17 the non-const @c str.data() overload).
2225  */
2226  const _CharT*
2227  data() const _GLIBCXX_NOEXCEPT
2228  { return _M_data(); }
2229 
2230 #if __cplusplus >= 201703L
2231  /**
2232  * @brief Return non-const pointer to contents.
2233  *
2234  * This is a pointer to the character sequence held by the string.
2235  * Modifying the characters in the sequence is allowed.
2236  */
2237  _CharT*
2238  data() noexcept
2239  {
2240  _M_leak();
2241  return _M_data();
2242  }
2243 #endif
2244 
2245  /**
2246  * @brief Return copy of allocator used to construct this string.
2247  */
2248  allocator_type
2249  get_allocator() const _GLIBCXX_NOEXCEPT
2250  { return _M_dataplus; }
2251 
2252  /**
2253  * @brief Find position of a C substring.
2254  * @param __s C string to locate.
2255  * @param __pos Index of character to search from.
2256  * @param __n Number of characters from @a s to search for.
2257  * @return Index of start of first occurrence.
2258  *
2259  * Starting from @a __pos, searches forward for the first @a
2260  * __n characters in @a __s within this string. If found,
2261  * returns the index where it begins. If not found, returns
2262  * npos.
2263  */
2264  size_type
2265  find(const _CharT* __s, size_type __pos, size_type __n) const
2266  _GLIBCXX_NOEXCEPT;
2267 
2268  /**
2269  * @brief Find position of a string.
2270  * @param __str String to locate.
2271  * @param __pos Index of character to search from (default 0).
2272  * @return Index of start of first occurrence.
2273  *
2274  * Starting from @a __pos, searches forward for value of @a __str within
2275  * this string. If found, returns the index where it begins. If not
2276  * found, returns npos.
2277  */
2278  size_type
2279  find(const basic_string& __str, size_type __pos = 0) const
2280  _GLIBCXX_NOEXCEPT
2281  { return this->find(__str.data(), __pos, __str.size()); }
2282 
2283  /**
2284  * @brief Find position of a C string.
2285  * @param __s C string to locate.
2286  * @param __pos Index of character to search from (default 0).
2287  * @return Index of start of first occurrence.
2288  *
2289  * Starting from @a __pos, searches forward for the value of @a
2290  * __s within this string. If found, returns the index where
2291  * it begins. If not found, returns npos.
2292  */
2293  size_type
2294  find(const _CharT* __s, size_type __pos = 0) const _GLIBCXX_NOEXCEPT
2295  {
2296  __glibcxx_requires_string(__s);
2297  return this->find(__s, __pos, traits_type::length(__s));
2298  }
2299 
2300  /**
2301  * @brief Find position of a character.
2302  * @param __c Character to locate.
2303  * @param __pos Index of character to search from (default 0).
2304  * @return Index of first occurrence.
2305  *
2306  * Starting from @a __pos, searches forward for @a __c within
2307  * this string. If found, returns the index where it was
2308  * found. If not found, returns npos.
2309  */
2310  size_type
2311  find(_CharT __c, size_type __pos = 0) const _GLIBCXX_NOEXCEPT;
2312 
2313 #if __cplusplus >= 201703L
2314  /**
2315  * @brief Find position of a string_view.
2316  * @param __svt The object convertible to string_view to locate.
2317  * @param __pos Index of character to search from (default 0).
2318  * @return Index of start of first occurrence.
2319  */
2320  template<typename _Tp>
2321  _If_sv<_Tp, size_type>
2322  find(const _Tp& __svt, size_type __pos = 0) const
2323  noexcept(is_same<_Tp, __sv_type>::value)
2324  {
2325  __sv_type __sv = __svt;
2326  return this->find(__sv.data(), __pos, __sv.size());
2327  }
2328 #endif // C++17
2329 
2330  /**
2331  * @brief Find last position of a string.
2332  * @param __str String to locate.
2333  * @param __pos Index of character to search back from (default end).
2334  * @return Index of start of last occurrence.
2335  *
2336  * Starting from @a __pos, searches backward for value of @a
2337  * __str within this string. If found, returns the index where
2338  * it begins. If not found, returns npos.
2339  */
2340  size_type
2341  rfind(const basic_string& __str, size_type __pos = npos) const
2342  _GLIBCXX_NOEXCEPT
2343  { return this->rfind(__str.data(), __pos, __str.size()); }
2344 
2345  /**
2346  * @brief Find last position of a C substring.
2347  * @param __s C string to locate.
2348  * @param __pos Index of character to search back from.
2349  * @param __n Number of characters from s to search for.
2350  * @return Index of start of last occurrence.
2351  *
2352  * Starting from @a __pos, searches backward for the first @a
2353  * __n characters in @a __s within this string. If found,
2354  * returns the index where it begins. If not found, returns
2355  * npos.
2356  */
2357  size_type
2358  rfind(const _CharT* __s, size_type __pos, size_type __n) const
2359  _GLIBCXX_NOEXCEPT;
2360 
2361  /**
2362  * @brief Find last position of a C string.
2363  * @param __s C string to locate.
2364  * @param __pos Index of character to start search at (default end).
2365  * @return Index of start of last occurrence.
2366  *
2367  * Starting from @a __pos, searches backward for the value of
2368  * @a __s within this string. If found, returns the index
2369  * where it begins. If not found, returns npos.
2370  */
2371  size_type
2372  rfind(const _CharT* __s, size_type __pos = npos) const _GLIBCXX_NOEXCEPT
2373  {
2374  __glibcxx_requires_string(__s);
2375  return this->rfind(__s, __pos, traits_type::length(__s));
2376  }
2377 
2378  /**
2379  * @brief Find last position of a character.
2380  * @param __c Character to locate.
2381  * @param __pos Index of character to search back from (default end).
2382  * @return Index of last occurrence.
2383  *
2384  * Starting from @a __pos, searches backward for @a __c within
2385  * this string. If found, returns the index where it was
2386  * found. If not found, returns npos.
2387  */
2388  size_type
2389  rfind(_CharT __c, size_type __pos = npos) const _GLIBCXX_NOEXCEPT;
2390 
2391 #if __cplusplus >= 201703L
2392  /**
2393  * @brief Find last position of a string_view.
2394  * @param __svt The object convertible to string_view to locate.
2395  * @param __pos Index of character to search back from (default end).
2396  * @return Index of start of last occurrence.
2397  */
2398  template<typename _Tp>
2399  _If_sv<_Tp, size_type>
2400  rfind(const _Tp& __svt, size_type __pos = npos) const
2402  {
2403  __sv_type __sv = __svt;
2404  return this->rfind(__sv.data(), __pos, __sv.size());
2405  }
2406 #endif // C++17
2407 
2408  /**
2409  * @brief Find position of a character of string.
2410  * @param __str String containing characters to locate.
2411  * @param __pos Index of character to search from (default 0).
2412  * @return Index of first occurrence.
2413  *
2414  * Starting from @a __pos, searches forward for one of the
2415  * characters of @a __str within this string. If found,
2416  * returns the index where it was found. If not found, returns
2417  * npos.
2418  */
2419  size_type
2420  find_first_of(const basic_string& __str, size_type __pos = 0) const
2421  _GLIBCXX_NOEXCEPT
2422  { return this->find_first_of(__str.data(), __pos, __str.size()); }
2423 
2424  /**
2425  * @brief Find position of a character of C substring.
2426  * @param __s String containing characters to locate.
2427  * @param __pos Index of character to search from.
2428  * @param __n Number of characters from s to search for.
2429  * @return Index of first occurrence.
2430  *
2431  * Starting from @a __pos, searches forward for one of the
2432  * first @a __n characters of @a __s within this string. If
2433  * found, returns the index where it was found. If not found,
2434  * returns npos.
2435  */
2436  size_type
2437  find_first_of(const _CharT* __s, size_type __pos, size_type __n) const
2438  _GLIBCXX_NOEXCEPT;
2439 
2440  /**
2441  * @brief Find position of a character of C string.
2442  * @param __s String containing characters to locate.
2443  * @param __pos Index of character to search from (default 0).
2444  * @return Index of first occurrence.
2445  *
2446  * Starting from @a __pos, searches forward for one of the
2447  * characters of @a __s within this string. If found, returns
2448  * the index where it was found. If not found, returns npos.
2449  */
2450  size_type
2451  find_first_of(const _CharT* __s, size_type __pos = 0) const
2452  _GLIBCXX_NOEXCEPT
2453  {
2454  __glibcxx_requires_string(__s);
2455  return this->find_first_of(__s, __pos, traits_type::length(__s));
2456  }
2457 
2458  /**
2459  * @brief Find position of a character.
2460  * @param __c Character to locate.
2461  * @param __pos Index of character to search from (default 0).
2462  * @return Index of first occurrence.
2463  *
2464  * Starting from @a __pos, searches forward for the character
2465  * @a __c within this string. If found, returns the index
2466  * where it was found. If not found, returns npos.
2467  *
2468  * Note: equivalent to find(__c, __pos).
2469  */
2470  size_type
2471  find_first_of(_CharT __c, size_type __pos = 0) const _GLIBCXX_NOEXCEPT
2472  { return this->find(__c, __pos); }
2473 
2474 #if __cplusplus >= 201703L
2475  /**
2476  * @brief Find position of a character of a string_view.
2477  * @param __svt An object convertible to string_view containing
2478  * characters to locate.
2479  * @param __pos Index of character to search from (default 0).
2480  * @return Index of first occurrence.
2481  */
2482  template<typename _Tp>
2483  _If_sv<_Tp, size_type>
2484  find_first_of(const _Tp& __svt, size_type __pos = 0) const
2485  noexcept(is_same<_Tp, __sv_type>::value)
2486  {
2487  __sv_type __sv = __svt;
2488  return this->find_first_of(__sv.data(), __pos, __sv.size());
2489  }
2490 #endif // C++17
2491 
2492  /**
2493  * @brief Find last position of a character of string.
2494  * @param __str String containing characters to locate.
2495  * @param __pos Index of character to search back from (default end).
2496  * @return Index of last occurrence.
2497  *
2498  * Starting from @a __pos, searches backward for one of the
2499  * characters of @a __str within this string. If found,
2500  * returns the index where it was found. If not found, returns
2501  * npos.
2502  */
2503  size_type
2504  find_last_of(const basic_string& __str, size_type __pos = npos) const
2505  _GLIBCXX_NOEXCEPT
2506  { return this->find_last_of(__str.data(), __pos, __str.size()); }
2507 
2508  /**
2509  * @brief Find last position of a character of C substring.
2510  * @param __s C string containing characters to locate.
2511  * @param __pos Index of character to search back from.
2512  * @param __n Number of characters from s to search for.
2513  * @return Index of last occurrence.
2514  *
2515  * Starting from @a __pos, searches backward for one of the
2516  * first @a __n characters of @a __s within this string. If
2517  * found, returns the index where it was found. If not found,
2518  * returns npos.
2519  */
2520  size_type
2521  find_last_of(const _CharT* __s, size_type __pos, size_type __n) const
2522  _GLIBCXX_NOEXCEPT;
2523 
2524  /**
2525  * @brief Find last position of a character of C string.
2526  * @param __s C string containing characters to locate.
2527  * @param __pos Index of character to search back from (default end).
2528  * @return Index of last occurrence.
2529  *
2530  * Starting from @a __pos, searches backward for one of the
2531  * characters of @a __s within this string. If found, returns
2532  * the index where it was found. If not found, returns npos.
2533  */
2534  size_type
2535  find_last_of(const _CharT* __s, size_type __pos = npos) const
2536  _GLIBCXX_NOEXCEPT
2537  {
2538  __glibcxx_requires_string(__s);
2539  return this->find_last_of(__s, __pos, traits_type::length(__s));
2540  }
2541 
2542  /**
2543  * @brief Find last position of a character.
2544  * @param __c Character to locate.
2545  * @param __pos Index of character to search back from (default end).
2546  * @return Index of last occurrence.
2547  *
2548  * Starting from @a __pos, searches backward for @a __c within
2549  * this string. If found, returns the index where it was
2550  * found. If not found, returns npos.
2551  *
2552  * Note: equivalent to rfind(__c, __pos).
2553  */
2554  size_type
2555  find_last_of(_CharT __c, size_type __pos = npos) const _GLIBCXX_NOEXCEPT
2556  { return this->rfind(__c, __pos); }
2557 
2558 #if __cplusplus >= 201703L
2559  /**
2560  * @brief Find last position of a character of string.
2561  * @param __svt An object convertible to string_view containing
2562  * characters to locate.
2563  * @param __pos Index of character to search back from (default end).
2564  * @return Index of last occurrence.
2565  */
2566  template<typename _Tp>
2567  _If_sv<_Tp, size_type>
2568  find_last_of(const _Tp& __svt, size_type __pos = npos) const
2570  {
2571  __sv_type __sv = __svt;
2572  return this->find_last_of(__sv.data(), __pos, __sv.size());
2573  }
2574 #endif // C++17
2575 
2576  /**
2577  * @brief Find position of a character not in string.
2578  * @param __str String containing characters to avoid.
2579  * @param __pos Index of character to search from (default 0).
2580  * @return Index of first occurrence.
2581  *
2582  * Starting from @a __pos, searches forward for a character not contained
2583  * in @a __str within this string. If found, returns the index where it
2584  * was found. If not found, returns npos.
2585  */
2586  size_type
2587  find_first_not_of(const basic_string& __str, size_type __pos = 0) const
2588  _GLIBCXX_NOEXCEPT
2589  { return this->find_first_not_of(__str.data(), __pos, __str.size()); }
2590 
2591  /**
2592  * @brief Find position of a character not in C substring.
2593  * @param __s C string containing characters to avoid.
2594  * @param __pos Index of character to search from.
2595  * @param __n Number of characters from __s to consider.
2596  * @return Index of first occurrence.
2597  *
2598  * Starting from @a __pos, searches forward for a character not
2599  * contained in the first @a __n characters of @a __s within
2600  * this string. If found, returns the index where it was
2601  * found. If not found, returns npos.
2602  */
2603  size_type
2604  find_first_not_of(const _CharT* __s, size_type __pos,
2605  size_type __n) const _GLIBCXX_NOEXCEPT;
2606 
2607  /**
2608  * @brief Find position of a character not in C string.
2609  * @param __s C string containing characters to avoid.
2610  * @param __pos Index of character to search from (default 0).
2611  * @return Index of first occurrence.
2612  *
2613  * Starting from @a __pos, searches forward for a character not
2614  * contained in @a __s within this string. If found, returns
2615  * the index where it was found. If not found, returns npos.
2616  */
2617  size_type
2618  find_first_not_of(const _CharT* __s, size_type __pos = 0) const
2619  _GLIBCXX_NOEXCEPT
2620  {
2621  __glibcxx_requires_string(__s);
2622  return this->find_first_not_of(__s, __pos, traits_type::length(__s));
2623  }
2624 
2625  /**
2626  * @brief Find position of a different character.
2627  * @param __c Character to avoid.
2628  * @param __pos Index of character to search from (default 0).
2629  * @return Index of first occurrence.
2630  *
2631  * Starting from @a __pos, searches forward for a character
2632  * other than @a __c within this string. If found, returns the
2633  * index where it was found. If not found, returns npos.
2634  */
2635  size_type
2636  find_first_not_of(_CharT __c, size_type __pos = 0) const
2637  _GLIBCXX_NOEXCEPT;
2638 
2639 #if __cplusplus >= 201703L
2640  /**
2641  * @brief Find position of a character not in a string_view.
2642  * @param __svt An object convertible to string_view containing
2643  * characters to avoid.
2644  * @param __pos Index of character to search from (default 0).
2645  * @return Index of first occurrence.
2646  */
2647  template<typename _Tp>
2648  _If_sv<_Tp, size_type>
2649  find_first_not_of(const _Tp& __svt, size_type __pos = 0) const
2650  noexcept(is_same<_Tp, __sv_type>::value)
2651  {
2652  __sv_type __sv = __svt;
2653  return this->find_first_not_of(__sv.data(), __pos, __sv.size());
2654  }
2655 #endif // C++17
2656 
2657  /**
2658  * @brief Find last position of a character not in string.
2659  * @param __str String containing characters to avoid.
2660  * @param __pos Index of character to search back from (default end).
2661  * @return Index of last occurrence.
2662  *
2663  * Starting from @a __pos, searches backward for a character
2664  * not contained in @a __str within this string. If found,
2665  * returns the index where it was found. If not found, returns
2666  * npos.
2667  */
2668  size_type
2669  find_last_not_of(const basic_string& __str, size_type __pos = npos) const
2670  _GLIBCXX_NOEXCEPT
2671  { return this->find_last_not_of(__str.data(), __pos, __str.size()); }
2672 
2673  /**
2674  * @brief Find last position of a character not in C substring.
2675  * @param __s C string containing characters to avoid.
2676  * @param __pos Index of character to search back from.
2677  * @param __n Number of characters from s to consider.
2678  * @return Index of last occurrence.
2679  *
2680  * Starting from @a __pos, searches backward for a character not
2681  * contained in the first @a __n characters of @a __s within this string.
2682  * If found, returns the index where it was found. If not found,
2683  * returns npos.
2684  */
2685  size_type
2686  find_last_not_of(const _CharT* __s, size_type __pos,
2687  size_type __n) const _GLIBCXX_NOEXCEPT;
2688  /**
2689  * @brief Find last position of a character not in C string.
2690  * @param __s C string containing characters to avoid.
2691  * @param __pos Index of character to search back from (default end).
2692  * @return Index of last occurrence.
2693  *
2694  * Starting from @a __pos, searches backward for a character
2695  * not contained in @a __s within this string. If found,
2696  * returns the index where it was found. If not found, returns
2697  * npos.
2698  */
2699  size_type
2700  find_last_not_of(const _CharT* __s, size_type __pos = npos) const
2701  _GLIBCXX_NOEXCEPT
2702  {
2703  __glibcxx_requires_string(__s);
2704  return this->find_last_not_of(__s, __pos, traits_type::length(__s));
2705  }
2706 
2707  /**
2708  * @brief Find last position of a different character.
2709  * @param __c Character to avoid.
2710  * @param __pos Index of character to search back from (default end).
2711  * @return Index of last occurrence.
2712  *
2713  * Starting from @a __pos, searches backward for a character other than
2714  * @a __c within this string. If found, returns the index where it was
2715  * found. If not found, returns npos.
2716  */
2717  size_type
2718  find_last_not_of(_CharT __c, size_type __pos = npos) const
2719  _GLIBCXX_NOEXCEPT;
2720 
2721 #if __cplusplus >= 201703L
2722  /**
2723  * @brief Find last position of a character not in a string_view.
2724  * @param __svt An object convertible to string_view containing
2725  * characters to avoid.
2726  * @param __pos Index of character to search back from (default end).
2727  * @return Index of last occurrence.
2728  */
2729  template<typename _Tp>
2730  _If_sv<_Tp, size_type>
2731  find_last_not_of(const _Tp& __svt, size_type __pos = npos) const
2733  {
2734  __sv_type __sv = __svt;
2735  return this->find_last_not_of(__sv.data(), __pos, __sv.size());
2736  }
2737 #endif // C++17
2738 
2739  /**
2740  * @brief Get a substring.
2741  * @param __pos Index of first character (default 0).
2742  * @param __n Number of characters in substring (default remainder).
2743  * @return The new string.
2744  * @throw std::out_of_range If __pos > size().
2745  *
2746  * Construct and return a new string using the @a __n
2747  * characters starting at @a __pos. If the string is too
2748  * short, use the remainder of the characters. If @a __pos is
2749  * beyond the end of the string, out_of_range is thrown.
2750  */
2751  basic_string
2752  substr(size_type __pos = 0, size_type __n = npos) const
2753  { return basic_string(*this,
2754  _M_check(__pos, "basic_string::substr"), __n); }
2755 
2756  /**
2757  * @brief Compare to a string.
2758  * @param __str String to compare against.
2759  * @return Integer < 0, 0, or > 0.
2760  *
2761  * Returns an integer < 0 if this string is ordered before @a
2762  * __str, 0 if their values are equivalent, or > 0 if this
2763  * string is ordered after @a __str. Determines the effective
2764  * length rlen of the strings to compare as the smallest of
2765  * size() and str.size(). The function then compares the two
2766  * strings by calling traits::compare(data(), str.data(),rlen).
2767  * If the result of the comparison is nonzero returns it,
2768  * otherwise the shorter one is ordered first.
2769  */
2770  int
2771  compare(const basic_string& __str) const
2772  {
2773  const size_type __size = this->size();
2774  const size_type __osize = __str.size();
2775  const size_type __len = std::min(__size, __osize);
2776 
2777  int __r = traits_type::compare(_M_data(), __str.data(), __len);
2778  if (!__r)
2779  __r = _S_compare(__size, __osize);
2780  return __r;
2781  }
2782 
2783 #if __cplusplus >= 201703L
2784  /**
2785  * @brief Compare to a string_view.
2786  * @param __svt An object convertible to string_view to compare against.
2787  * @return Integer < 0, 0, or > 0.
2788  */
2789  template<typename _Tp>
2790  _If_sv<_Tp, int>
2791  compare(const _Tp& __svt) const
2793  {
2794  __sv_type __sv = __svt;
2795  const size_type __size = this->size();
2796  const size_type __osize = __sv.size();
2797  const size_type __len = std::min(__size, __osize);
2798 
2799  int __r = traits_type::compare(_M_data(), __sv.data(), __len);
2800  if (!__r)
2801  __r = _S_compare(__size, __osize);
2802  return __r;
2803  }
2804 
2805  /**
2806  * @brief Compare to a string_view.
2807  * @param __pos A position in the string to start comparing from.
2808  * @param __n The number of characters to compare.
2809  * @param __svt An object convertible to string_view to compare
2810  * against.
2811  * @return Integer < 0, 0, or > 0.
2812  */
2813  template<typename _Tp>
2814  _If_sv<_Tp, int>
2815  compare(size_type __pos, size_type __n, const _Tp& __svt) const
2817  {
2818  __sv_type __sv = __svt;
2819  return __sv_type(*this).substr(__pos, __n).compare(__sv);
2820  }
2821 
2822  /**
2823  * @brief Compare to a string_view.
2824  * @param __pos1 A position in the string to start comparing from.
2825  * @param __n1 The number of characters to compare.
2826  * @param __svt An object convertible to string_view to compare
2827  * against.
2828  * @param __pos2 A position in the string_view to start comparing from.
2829  * @param __n2 The number of characters to compare.
2830  * @return Integer < 0, 0, or > 0.
2831  */
2832  template<typename _Tp>
2833  _If_sv<_Tp, int>
2834  compare(size_type __pos1, size_type __n1, const _Tp& __svt,
2835  size_type __pos2, size_type __n2 = npos) const
2837  {
2838  __sv_type __sv = __svt;
2839  return __sv_type(*this)
2840  .substr(__pos1, __n1).compare(__sv.substr(__pos2, __n2));
2841  }
2842 #endif // C++17
2843 
2844  /**
2845  * @brief Compare substring to a string.
2846  * @param __pos Index of first character of substring.
2847  * @param __n Number of characters in substring.
2848  * @param __str String to compare against.
2849  * @return Integer < 0, 0, or > 0.
2850  *
2851  * Form the substring of this string from the @a __n characters
2852  * starting at @a __pos. Returns an integer < 0 if the
2853  * substring is ordered before @a __str, 0 if their values are
2854  * equivalent, or > 0 if the substring is ordered after @a
2855  * __str. Determines the effective length rlen of the strings
2856  * to compare as the smallest of the length of the substring
2857  * and @a __str.size(). The function then compares the two
2858  * strings by calling
2859  * traits::compare(substring.data(),str.data(),rlen). If the
2860  * result of the comparison is nonzero returns it, otherwise
2861  * the shorter one is ordered first.
2862  */
2863  int
2864  compare(size_type __pos, size_type __n, const basic_string& __str) const
2865  {
2866  _M_check(__pos, "basic_string::compare");
2867  __n = _M_limit(__pos, __n);
2868  const size_type __osize = __str.size();
2869  const size_type __len = std::min(__n, __osize);
2870  int __r = traits_type::compare(_M_data() + __pos, __str.data(), __len);
2871  if (!__r)
2872  __r = _S_compare(__n, __osize);
2873  return __r;
2874  }
2875 
2876  /**
2877  * @brief Compare substring to a substring.
2878  * @param __pos1 Index of first character of substring.
2879  * @param __n1 Number of characters in substring.
2880  * @param __str String to compare against.
2881  * @param __pos2 Index of first character of substring of str.
2882  * @param __n2 Number of characters in substring of str.
2883  * @return Integer < 0, 0, or > 0.
2884  *
2885  * Form the substring of this string from the @a __n1
2886  * characters starting at @a __pos1. Form the substring of @a
2887  * __str from the @a __n2 characters starting at @a __pos2.
2888  * Returns an integer < 0 if this substring is ordered before
2889  * the substring of @a __str, 0 if their values are equivalent,
2890  * or > 0 if this substring is ordered after the substring of
2891  * @a __str. Determines the effective length rlen of the
2892  * strings to compare as the smallest of the lengths of the
2893  * substrings. The function then compares the two strings by
2894  * calling
2895  * traits::compare(substring.data(),str.substr(pos2,n2).data(),rlen).
2896  * If the result of the comparison is nonzero returns it,
2897  * otherwise the shorter one is ordered first.
2898  */
2899  int
2900  compare(size_type __pos1, size_type __n1, const basic_string& __str,
2901  size_type __pos2, size_type __n2 = npos) const
2902  {
2903  _M_check(__pos1, "basic_string::compare");
2904  __str._M_check(__pos2, "basic_string::compare");
2905  __n1 = _M_limit(__pos1, __n1);
2906  __n2 = __str._M_limit(__pos2, __n2);
2907  const size_type __len = std::min(__n1, __n2);
2908  int __r = traits_type::compare(_M_data() + __pos1,
2909  __str.data() + __pos2, __len);
2910  if (!__r)
2911  __r = _S_compare(__n1, __n2);
2912  return __r;
2913  }
2914 
2915  /**
2916  * @brief Compare to a C string.
2917  * @param __s C string to compare against.
2918  * @return Integer < 0, 0, or > 0.
2919  *
2920  * Returns an integer < 0 if this string is ordered before @a __s, 0 if
2921  * their values are equivalent, or > 0 if this string is ordered after
2922  * @a __s. Determines the effective length rlen of the strings to
2923  * compare as the smallest of size() and the length of a string
2924  * constructed from @a __s. The function then compares the two strings
2925  * by calling traits::compare(data(),s,rlen). If the result of the
2926  * comparison is nonzero returns it, otherwise the shorter one is
2927  * ordered first.
2928  */
2929  int
2930  compare(const _CharT* __s) const _GLIBCXX_NOEXCEPT
2931  {
2932  __glibcxx_requires_string(__s);
2933  const size_type __size = this->size();
2934  const size_type __osize = traits_type::length(__s);
2935  const size_type __len = std::min(__size, __osize);
2936  int __r = traits_type::compare(_M_data(), __s, __len);
2937  if (!__r)
2938  __r = _S_compare(__size, __osize);
2939  return __r;
2940  }
2941 
2942  // _GLIBCXX_RESOLVE_LIB_DEFECTS
2943  // 5 String::compare specification questionable
2944  /**
2945  * @brief Compare substring to a C string.
2946  * @param __pos Index of first character of substring.
2947  * @param __n1 Number of characters in substring.
2948  * @param __s C string to compare against.
2949  * @return Integer < 0, 0, or > 0.
2950  *
2951  * Form the substring of this string from the @a __n1
2952  * characters starting at @a pos. Returns an integer < 0 if
2953  * the substring is ordered before @a __s, 0 if their values
2954  * are equivalent, or > 0 if the substring is ordered after @a
2955  * __s. Determines the effective length rlen of the strings to
2956  * compare as the smallest of the length of the substring and
2957  * the length of a string constructed from @a __s. The
2958  * function then compares the two string by calling
2959  * traits::compare(substring.data(),__s,rlen). If the result of
2960  * the comparison is nonzero returns it, otherwise the shorter
2961  * one is ordered first.
2962  */
2963  int
2964  compare(size_type __pos, size_type __n1, const _CharT* __s) const
2965  {
2966  __glibcxx_requires_string(__s);
2967  _M_check(__pos, "basic_string::compare");
2968  __n1 = _M_limit(__pos, __n1);
2969  const size_type __osize = traits_type::length(__s);
2970  const size_type __len = std::min(__n1, __osize);
2971  int __r = traits_type::compare(_M_data() + __pos, __s, __len);
2972  if (!__r)
2973  __r = _S_compare(__n1, __osize);
2974  return __r;
2975  }
2976 
2977  /**
2978  * @brief Compare substring against a character %array.
2979  * @param __pos Index of first character of substring.
2980  * @param __n1 Number of characters in substring.
2981  * @param __s character %array to compare against.
2982  * @param __n2 Number of characters of s.
2983  * @return Integer < 0, 0, or > 0.
2984  *
2985  * Form the substring of this string from the @a __n1
2986  * characters starting at @a __pos. Form a string from the
2987  * first @a __n2 characters of @a __s. Returns an integer < 0
2988  * if this substring is ordered before the string from @a __s,
2989  * 0 if their values are equivalent, or > 0 if this substring
2990  * is ordered after the string from @a __s. Determines the
2991  * effective length rlen of the strings to compare as the
2992  * smallest of the length of the substring and @a __n2. The
2993  * function then compares the two strings by calling
2994  * traits::compare(substring.data(),s,rlen). If the result of
2995  * the comparison is nonzero returns it, otherwise the shorter
2996  * one is ordered first.
2997  *
2998  * NB: s must have at least n2 characters, &apos;\\0&apos; has
2999  * no special meaning.
3000  */
3001  int
3002  compare(size_type __pos, size_type __n1, const _CharT* __s,
3003  size_type __n2) const
3004  {
3005  __glibcxx_requires_string_len(__s, __n2);
3006  _M_check(__pos, "basic_string::compare");
3007  __n1 = _M_limit(__pos, __n1);
3008  const size_type __len = std::min(__n1, __n2);
3009  int __r = traits_type::compare(_M_data() + __pos, __s, __len);
3010  if (!__r)
3011  __r = _S_compare(__n1, __n2);
3012  return __r;
3013  }
3014 
3015 #if __cplusplus > 201703L
3016  bool
3017  starts_with(basic_string_view<_CharT, _Traits> __x) const noexcept
3018  { return __sv_type(this->data(), this->size()).starts_with(__x); }
3019 
3020  bool
3021  starts_with(_CharT __x) const noexcept
3022  { return __sv_type(this->data(), this->size()).starts_with(__x); }
3023 
3024  [[__gnu__::__nonnull__]]
3025  bool
3026  starts_with(const _CharT* __x) const noexcept
3027  { return __sv_type(this->data(), this->size()).starts_with(__x); }
3028 
3029  bool
3030  ends_with(basic_string_view<_CharT, _Traits> __x) const noexcept
3031  { return __sv_type(this->data(), this->size()).ends_with(__x); }
3032 
3033  bool
3034  ends_with(_CharT __x) const noexcept
3035  { return __sv_type(this->data(), this->size()).ends_with(__x); }
3036 
3037  [[__gnu__::__nonnull__]]
3038  bool
3039  ends_with(const _CharT* __x) const noexcept
3040  { return __sv_type(this->data(), this->size()).ends_with(__x); }
3041 #endif // C++20
3042 
3043 #if __cplusplus > 202011L
3044  bool
3045  contains(basic_string_view<_CharT, _Traits> __x) const noexcept
3046  { return __sv_type(this->data(), this->size()).contains(__x); }
3047 
3048  bool
3049  contains(_CharT __x) const noexcept
3050  { return __sv_type(this->data(), this->size()).contains(__x); }
3051 
3052  [[__gnu__::__nonnull__]]
3053  bool
3054  contains(const _CharT* __x) const noexcept
3055  { return __sv_type(this->data(), this->size()).contains(__x); }
3056 #endif // C++23
3057 
3058 # ifdef _GLIBCXX_TM_TS_INTERNAL
3059  friend void
3060  ::_txnal_cow_string_C1_for_exceptions(void* that, const char* s,
3061  void* exc);
3062  friend const char*
3063  ::_txnal_cow_string_c_str(const void *that);
3064  friend void
3065  ::_txnal_cow_string_D1(void *that);
3066  friend void
3067  ::_txnal_cow_string_D1_commit(void *that);
3068 # endif
3069  };
3070 
3071  template<typename _CharT, typename _Traits, typename _Alloc>
3072  const typename basic_string<_CharT, _Traits, _Alloc>::size_type
3073  basic_string<_CharT, _Traits, _Alloc>::
3074  _Rep::_S_max_size = (((npos - sizeof(_Rep_base))/sizeof(_CharT)) - 1) / 4;
3075 
3076  template<typename _CharT, typename _Traits, typename _Alloc>
3077  const _CharT
3078  basic_string<_CharT, _Traits, _Alloc>::
3079  _Rep::_S_terminal = _CharT();
3080 
3081  template<typename _CharT, typename _Traits, typename _Alloc>
3082  const typename basic_string<_CharT, _Traits, _Alloc>::size_type
3084 
3085  // Linker sets _S_empty_rep_storage to all 0s (one reference, empty string)
3086  // at static init time (before static ctors are run).
3087  template<typename _CharT, typename _Traits, typename _Alloc>
3088  typename basic_string<_CharT, _Traits, _Alloc>::size_type
3089  basic_string<_CharT, _Traits, _Alloc>::_Rep::_S_empty_rep_storage[
3090  (sizeof(_Rep_base) + sizeof(_CharT) + sizeof(size_type) - 1) /
3091  sizeof(size_type)];
3092 
3093  // NB: This is the special case for Input Iterators, used in
3094  // istreambuf_iterators, etc.
3095  // Input Iterators have a cost structure very different from
3096  // pointers, calling for a different coding style.
3097  template<typename _CharT, typename _Traits, typename _Alloc>
3098  template<typename _InIterator>
3099  _CharT*
3100  basic_string<_CharT, _Traits, _Alloc>::
3101  _S_construct(_InIterator __beg, _InIterator __end, const _Alloc& __a,
3102  input_iterator_tag)
3103  {
3104 #if _GLIBCXX_FULLY_DYNAMIC_STRING == 0
3105  if (__beg == __end && __a == _Alloc())
3106  return _S_empty_rep()._M_refdata();
3107 #endif
3108  // Avoid reallocation for common case.
3109  _CharT __buf[128];
3110  size_type __len = 0;
3111  while (__beg != __end && __len < sizeof(__buf) / sizeof(_CharT))
3112  {
3113  __buf[__len++] = *__beg;
3114  ++__beg;
3115  }
3116  _Rep* __r = _Rep::_S_create(__len, size_type(0), __a);
3117  _M_copy(__r->_M_refdata(), __buf, __len);
3118  __try
3119  {
3120  while (__beg != __end)
3121  {
3122  if (__len == __r->_M_capacity)
3123  {
3124  // Allocate more space.
3125  _Rep* __another = _Rep::_S_create(__len + 1, __len, __a);
3126  _M_copy(__another->_M_refdata(), __r->_M_refdata(), __len);
3127  __r->_M_destroy(__a);
3128  __r = __another;
3129  }
3130  __r->_M_refdata()[__len++] = *__beg;
3131  ++__beg;
3132  }
3133  }
3134  __catch(...)
3135  {
3136  __r->_M_destroy(__a);
3137  __throw_exception_again;
3138  }
3139  __r->_M_set_length_and_sharable(__len);
3140  return __r->_M_refdata();
3141  }
3142 
3143  template<typename _CharT, typename _Traits, typename _Alloc>
3144  template <typename _InIterator>
3145  _CharT*
3146  basic_string<_CharT, _Traits, _Alloc>::
3147  _S_construct(_InIterator __beg, _InIterator __end, const _Alloc& __a,
3148  forward_iterator_tag)
3149  {
3150 #if _GLIBCXX_FULLY_DYNAMIC_STRING == 0
3151  if (__beg == __end && __a == _Alloc())
3152  return _S_empty_rep()._M_refdata();
3153 #endif
3154  // NB: Not required, but considered best practice.
3155  if (__gnu_cxx::__is_null_pointer(__beg) && __beg != __end)
3156  __throw_logic_error(__N("basic_string::_S_construct null not valid"));
3157 
3158  const size_type __dnew = static_cast<size_type>(std::distance(__beg,
3159  __end));
3160  // Check for out_of_range and length_error exceptions.
3161  _Rep* __r = _Rep::_S_create(__dnew, size_type(0), __a);
3162  __try
3163  { _S_copy_chars(__r->_M_refdata(), __beg, __end); }
3164  __catch(...)
3165  {
3166  __r->_M_destroy(__a);
3167  __throw_exception_again;
3168  }
3169  __r->_M_set_length_and_sharable(__dnew);
3170  return __r->_M_refdata();
3171  }
3172 
3173  template<typename _CharT, typename _Traits, typename _Alloc>
3174  _CharT*
3175  basic_string<_CharT, _Traits, _Alloc>::
3176  _S_construct(size_type __n, _CharT __c, const _Alloc& __a)
3177  {
3178 #if _GLIBCXX_FULLY_DYNAMIC_STRING == 0
3179  if (__n == 0 && __a == _Alloc())
3180  return _S_empty_rep()._M_refdata();
3181 #endif
3182  // Check for out_of_range and length_error exceptions.
3183  _Rep* __r = _Rep::_S_create(__n, size_type(0), __a);
3184  if (__n)
3185  _M_assign(__r->_M_refdata(), __n, __c);
3186 
3187  __r->_M_set_length_and_sharable(__n);
3188  return __r->_M_refdata();
3189  }
3190 
3191  template<typename _CharT, typename _Traits, typename _Alloc>
3193  basic_string(const basic_string& __str, size_type __pos, const _Alloc& __a)
3194  : _M_dataplus(_S_construct(__str._M_data()
3195  + __str._M_check(__pos,
3196  "basic_string::basic_string"),
3197  __str._M_data() + __str._M_limit(__pos, npos)
3198  + __pos, __a), __a)
3199  { }
3200 
3201  template<typename _CharT, typename _Traits, typename _Alloc>
3203  basic_string(const basic_string& __str, size_type __pos, size_type __n)
3204  : _M_dataplus(_S_construct(__str._M_data()
3205  + __str._M_check(__pos,
3206  "basic_string::basic_string"),
3207  __str._M_data() + __str._M_limit(__pos, __n)
3208  + __pos, _Alloc()), _Alloc())
3209  { }
3210 
3211  template<typename _CharT, typename _Traits, typename _Alloc>
3213  basic_string(const basic_string& __str, size_type __pos,
3214  size_type __n, const _Alloc& __a)
3215  : _M_dataplus(_S_construct(__str._M_data()
3216  + __str._M_check(__pos,
3217  "basic_string::basic_string"),
3218  __str._M_data() + __str._M_limit(__pos, __n)
3219  + __pos, __a), __a)
3220  { }
3221 
3222  template<typename _CharT, typename _Traits, typename _Alloc>
3225  assign(const basic_string& __str)
3226  {
3227  if (_M_rep() != __str._M_rep())
3228  {
3229  // XXX MT
3230  const allocator_type __a = this->get_allocator();
3231  _CharT* __tmp = __str._M_rep()->_M_grab(__a, __str.get_allocator());
3232  _M_rep()->_M_dispose(__a);
3233  _M_data(__tmp);
3234  }
3235  return *this;
3236  }
3237 
3238  template<typename _CharT, typename _Traits, typename _Alloc>
3241  assign(const _CharT* __s, size_type __n)
3242  {
3243  __glibcxx_requires_string_len(__s, __n);
3244  _M_check_length(this->size(), __n, "basic_string::assign");
3245  if (_M_disjunct(__s) || _M_rep()->_M_is_shared())
3246  return _M_replace_safe(size_type(0), this->size(), __s, __n);
3247  else
3248  {
3249  // Work in-place.
3250  const size_type __pos = __s - _M_data();
3251  if (__pos >= __n)
3252  _M_copy(_M_data(), __s, __n);
3253  else if (__pos)
3254  _M_move(_M_data(), __s, __n);
3255  _M_rep()->_M_set_length_and_sharable(__n);
3256  return *this;
3257  }
3258  }
3259 
3260  template<typename _CharT, typename _Traits, typename _Alloc>
3263  append(size_type __n, _CharT __c)
3264  {
3265  if (__n)
3266  {
3267  _M_check_length(size_type(0), __n, "basic_string::append");
3268  const size_type __len = __n + this->size();
3269  if (__len > this->capacity() || _M_rep()->_M_is_shared())
3270  this->reserve(__len);
3271  _M_assign(_M_data() + this->size(), __n, __c);
3272  _M_rep()->_M_set_length_and_sharable(__len);
3273  }
3274  return *this;
3275  }
3276 
3277  template<typename _CharT, typename _Traits, typename _Alloc>
3280  append(const _CharT* __s, size_type __n)
3281  {
3282  __glibcxx_requires_string_len(__s, __n);
3283  if (__n)
3284  {
3285  _M_check_length(size_type(0), __n, "basic_string::append");
3286  const size_type __len = __n + this->size();
3287  if (__len > this->capacity() || _M_rep()->_M_is_shared())
3288  {
3289  if (_M_disjunct(__s))
3290  this->reserve(__len);
3291  else
3292  {
3293  const size_type __off = __s - _M_data();
3294  this->reserve(__len);
3295  __s = _M_data() + __off;
3296  }
3297  }
3298  _M_copy(_M_data() + this->size(), __s, __n);
3299  _M_rep()->_M_set_length_and_sharable(__len);
3300  }
3301  return *this;
3302  }
3303 
3304  template<typename _CharT, typename _Traits, typename _Alloc>
3307  append(const basic_string& __str)
3308  {
3309  const size_type __size = __str.size();
3310  if (__size)
3311  {
3312  const size_type __len = __size + this->size();
3313  if (__len > this->capacity() || _M_rep()->_M_is_shared())
3314  this->reserve(__len);
3315  _M_copy(_M_data() + this->size(), __str._M_data(), __size);
3316  _M_rep()->_M_set_length_and_sharable(__len);
3317  }
3318  return *this;
3319  }
3320 
3321  template<typename _CharT, typename _Traits, typename _Alloc>
3324  append(const basic_string& __str, size_type __pos, size_type __n)
3325  {
3326  __str._M_check(__pos, "basic_string::append");
3327  __n = __str._M_limit(__pos, __n);
3328  if (__n)
3329  {
3330  const size_type __len = __n + this->size();
3331  if (__len > this->capacity() || _M_rep()->_M_is_shared())
3332  this->reserve(__len);
3333  _M_copy(_M_data() + this->size(), __str._M_data() + __pos, __n);
3334  _M_rep()->_M_set_length_and_sharable(__len);
3335  }
3336  return *this;
3337  }
3338 
3339  template<typename _CharT, typename _Traits, typename _Alloc>
3342  insert(size_type __pos, const _CharT* __s, size_type __n)
3343  {
3344  __glibcxx_requires_string_len(__s, __n);
3345  _M_check(__pos, "basic_string::insert");
3346  _M_check_length(size_type(0), __n, "basic_string::insert");
3347  if (_M_disjunct(__s) || _M_rep()->_M_is_shared())
3348  return _M_replace_safe(__pos, size_type(0), __s, __n);
3349  else
3350  {
3351  // Work in-place.
3352  const size_type __off = __s - _M_data();
3353  _M_mutate(__pos, 0, __n);
3354  __s = _M_data() + __off;
3355  _CharT* __p = _M_data() + __pos;
3356  if (__s + __n <= __p)
3357  _M_copy(__p, __s, __n);
3358  else if (__s >= __p)
3359  _M_copy(__p, __s + __n, __n);
3360  else
3361  {
3362  const size_type __nleft = __p - __s;
3363  _M_copy(__p, __s, __nleft);
3364  _M_copy(__p + __nleft, __p + __n, __n - __nleft);
3365  }
3366  return *this;
3367  }
3368  }
3369 
3370  template<typename _CharT, typename _Traits, typename _Alloc>
3371  typename basic_string<_CharT, _Traits, _Alloc>::iterator
3373  erase(iterator __first, iterator __last)
3374  {
3375  _GLIBCXX_DEBUG_PEDASSERT(__first >= _M_ibegin() && __first <= __last
3376  && __last <= _M_iend());
3377 
3378  // NB: This isn't just an optimization (bail out early when
3379  // there is nothing to do, really), it's also a correctness
3380  // issue vs MT, see libstdc++/40518.
3381  const size_type __size = __last - __first;
3382  if (__size)
3383  {
3384  const size_type __pos = __first - _M_ibegin();
3385  _M_mutate(__pos, __size, size_type(0));
3386  _M_rep()->_M_set_leaked();
3387  return iterator(_M_data() + __pos);
3388  }
3389  else
3390  return __first;
3391  }
3392 
3393  template<typename _CharT, typename _Traits, typename _Alloc>
3396  replace(size_type __pos, size_type __n1, const _CharT* __s,
3397  size_type __n2)
3398  {
3399  __glibcxx_requires_string_len(__s, __n2);
3400  _M_check(__pos, "basic_string::replace");
3401  __n1 = _M_limit(__pos, __n1);
3402  _M_check_length(__n1, __n2, "basic_string::replace");
3403  bool __left;
3404  if (_M_disjunct(__s) || _M_rep()->_M_is_shared())
3405  return _M_replace_safe(__pos, __n1, __s, __n2);
3406  else if ((__left = __s + __n2 <= _M_data() + __pos)
3407  || _M_data() + __pos + __n1 <= __s)
3408  {
3409  // Work in-place: non-overlapping case.
3410  size_type __off = __s - _M_data();
3411  __left ? __off : (__off += __n2 - __n1);
3412  _M_mutate(__pos, __n1, __n2);
3413  _M_copy(_M_data() + __pos, _M_data() + __off, __n2);
3414  return *this;
3415  }
3416  else
3417  {
3418  // TODO: overlapping case.
3419  const basic_string __tmp(__s, __n2);
3420  return _M_replace_safe(__pos, __n1, __tmp._M_data(), __n2);
3421  }
3422  }
3423 
3424  template<typename _CharT, typename _Traits, typename _Alloc>
3425  void
3427  _M_destroy(const _Alloc& __a) throw ()
3428  {
3429  const size_type __size = sizeof(_Rep_base)
3430  + (this->_M_capacity + 1) * sizeof(_CharT);
3431  _Raw_bytes_alloc(__a).deallocate(reinterpret_cast<char*>(this), __size);
3432  }
3433 
3434  template<typename _CharT, typename _Traits, typename _Alloc>
3435  void
3436  basic_string<_CharT, _Traits, _Alloc>::
3437  _M_leak_hard()
3438  {
3439  // No need to create a new copy of an empty string when a non-const
3440  // reference/pointer/iterator into it is obtained. Modifying the
3441  // trailing null character is undefined, so the ref/pointer/iterator
3442  // is effectively const anyway.
3443  if (this->empty())
3444  return;
3445 
3446  if (_M_rep()->_M_is_shared())
3447  _M_mutate(0, 0, 0);
3448  _M_rep()->_M_set_leaked();
3449  }
3450 
3451  template<typename _CharT, typename _Traits, typename _Alloc>
3452  void
3453  basic_string<_CharT, _Traits, _Alloc>::
3454  _M_mutate(size_type __pos, size_type __len1, size_type __len2)
3455  {
3456  const size_type __old_size = this->size();
3457  const size_type __new_size = __old_size + __len2 - __len1;
3458  const size_type __how_much = __old_size - __pos - __len1;
3459 
3460  if (__new_size > this->capacity() || _M_rep()->_M_is_shared())
3461  {
3462  // Must reallocate.
3463  const allocator_type __a = get_allocator();
3464  _Rep* __r = _Rep::_S_create(__new_size, this->capacity(), __a);
3465 
3466  if (__pos)
3467  _M_copy(__r->_M_refdata(), _M_data(), __pos);
3468  if (__how_much)
3469  _M_copy(__r->_M_refdata() + __pos + __len2,
3470  _M_data() + __pos + __len1, __how_much);
3471 
3472  _M_rep()->_M_dispose(__a);
3473  _M_data(__r->_M_refdata());
3474  }
3475  else if (__how_much && __len1 != __len2)
3476  {
3477  // Work in-place.
3478  _M_move(_M_data() + __pos + __len2,
3479  _M_data() + __pos + __len1, __how_much);
3480  }
3481  _M_rep()->_M_set_length_and_sharable(__new_size);
3482  }
3483 
3484  template<typename _CharT, typename _Traits, typename _Alloc>
3485  void
3487  reserve(size_type __res)
3488  {
3489  const size_type __capacity = capacity();
3490 
3491  // _GLIBCXX_RESOLVE_LIB_DEFECTS
3492  // 2968. Inconsistencies between basic_string reserve and
3493  // vector/unordered_map/unordered_set reserve functions
3494  // P0966 reserve should not shrink
3495  if (__res <= __capacity)
3496  {
3497  if (!_M_rep()->_M_is_shared())
3498  return;
3499 
3500  // unshare, but keep same capacity
3501  __res = __capacity;
3502  }
3503 
3504  const allocator_type __a = get_allocator();
3505  _CharT* __tmp = _M_rep()->_M_clone(__a, __res - this->size());
3506  _M_rep()->_M_dispose(__a);
3507  _M_data(__tmp);
3508  }
3509 
3510  template<typename _CharT, typename _Traits, typename _Alloc>
3511  void
3513  swap(basic_string& __s)
3515  {
3516  if (_M_rep()->_M_is_leaked())
3517  _M_rep()->_M_set_sharable();
3518  if (__s._M_rep()->_M_is_leaked())
3519  __s._M_rep()->_M_set_sharable();
3520  if (this->get_allocator() == __s.get_allocator())
3521  {
3522  _CharT* __tmp = _M_data();
3523  _M_data(__s._M_data());
3524  __s._M_data(__tmp);
3525  }
3526  // The code below can usually be optimized away.
3527  else
3528  {
3529  const basic_string __tmp1(_M_ibegin(), _M_iend(),
3530  __s.get_allocator());
3531  const basic_string __tmp2(__s._M_ibegin(), __s._M_iend(),
3532  this->get_allocator());
3533  *this = __tmp2;
3534  __s = __tmp1;
3535  }
3536  }
3537 
3538  template<typename _CharT, typename _Traits, typename _Alloc>
3541  _S_create(size_type __capacity, size_type __old_capacity,
3542  const _Alloc& __alloc)
3543  {
3544  // _GLIBCXX_RESOLVE_LIB_DEFECTS
3545  // 83. String::npos vs. string::max_size()
3546  if (__capacity > _S_max_size)
3547  __throw_length_error(__N("basic_string::_S_create"));
3548 
3549  // The standard places no restriction on allocating more memory
3550  // than is strictly needed within this layer at the moment or as
3551  // requested by an explicit application call to reserve(n).
3552 
3553  // Many malloc implementations perform quite poorly when an
3554  // application attempts to allocate memory in a stepwise fashion
3555  // growing each allocation size by only 1 char. Additionally,
3556  // it makes little sense to allocate less linear memory than the
3557  // natural blocking size of the malloc implementation.
3558  // Unfortunately, we would need a somewhat low-level calculation
3559  // with tuned parameters to get this perfect for any particular
3560  // malloc implementation. Fortunately, generalizations about
3561  // common features seen among implementations seems to suffice.
3562 
3563  // __pagesize need not match the actual VM page size for good
3564  // results in practice, thus we pick a common value on the low
3565  // side. __malloc_header_size is an estimate of the amount of
3566  // overhead per memory allocation (in practice seen N * sizeof
3567  // (void*) where N is 0, 2 or 4). According to folklore,
3568  // picking this value on the high side is better than
3569  // low-balling it (especially when this algorithm is used with
3570  // malloc implementations that allocate memory blocks rounded up
3571  // to a size which is a power of 2).
3572  const size_type __pagesize = 4096;
3573  const size_type __malloc_header_size = 4 * sizeof(void*);
3574 
3575  // The below implements an exponential growth policy, necessary to
3576  // meet amortized linear time requirements of the library: see
3577  // http://gcc.gnu.org/ml/libstdc++/2001-07/msg00085.html.
3578  // It's active for allocations requiring an amount of memory above
3579  // system pagesize. This is consistent with the requirements of the
3580  // standard: http://gcc.gnu.org/ml/libstdc++/2001-07/msg00130.html
3581  if (__capacity > __old_capacity && __capacity < 2 * __old_capacity)
3582  __capacity = 2 * __old_capacity;
3583 
3584  // NB: Need an array of char_type[__capacity], plus a terminating
3585  // null char_type() element, plus enough for the _Rep data structure.
3586  // Whew. Seemingly so needy, yet so elemental.
3587  size_type __size = (__capacity + 1) * sizeof(_CharT) + sizeof(_Rep);
3588 
3589  const size_type __adj_size = __size + __malloc_header_size;
3590  if (__adj_size > __pagesize && __capacity > __old_capacity)
3591  {
3592  const size_type __extra = __pagesize - __adj_size % __pagesize;
3593  __capacity += __extra / sizeof(_CharT);
3594  // Never allocate a string bigger than _S_max_size.
3595  if (__capacity > _S_max_size)
3596  __capacity = _S_max_size;
3597  __size = (__capacity + 1) * sizeof(_CharT) + sizeof(_Rep);
3598  }
3599 
3600  // NB: Might throw, but no worries about a leak, mate: _Rep()
3601  // does not throw.
3602  void* __place = _Raw_bytes_alloc(__alloc).allocate(__size);
3603  _Rep *__p = new (__place) _Rep;
3604  __p->_M_capacity = __capacity;
3605  // ABI compatibility - 3.4.x set in _S_create both
3606  // _M_refcount and _M_length. All callers of _S_create
3607  // in basic_string.tcc then set just _M_length.
3608  // In 4.0.x and later both _M_refcount and _M_length
3609  // are initialized in the callers, unfortunately we can
3610  // have 3.4.x compiled code with _S_create callers inlined
3611  // calling 4.0.x+ _S_create.
3612  __p->_M_set_sharable();
3613  return __p;
3614  }
3615 
3616  template<typename _CharT, typename _Traits, typename _Alloc>
3617  _CharT*
3618  basic_string<_CharT, _Traits, _Alloc>::_Rep::
3619  _M_clone(const _Alloc& __alloc, size_type __res)
3620  {
3621  // Requested capacity of the clone.
3622  const size_type __requested_cap = this->_M_length + __res;
3623  _Rep* __r = _Rep::_S_create(__requested_cap, this->_M_capacity,
3624  __alloc);
3625  if (this->_M_length)
3626  _M_copy(__r->_M_refdata(), _M_refdata(), this->_M_length);
3627 
3628  __r->_M_set_length_and_sharable(this->_M_length);
3629  return __r->_M_refdata();
3630  }
3631 
3632  template<typename _CharT, typename _Traits, typename _Alloc>
3633  void
3635  resize(size_type __n, _CharT __c)
3636  {
3637  const size_type __size = this->size();
3638  _M_check_length(__size, __n, "basic_string::resize");
3639  if (__size < __n)
3640  this->append(__n - __size, __c);
3641  else if (__n < __size)
3642  this->erase(__n);
3643  // else nothing (in particular, avoid calling _M_mutate() unnecessarily.)
3644  }
3645 
3646  template<typename _CharT, typename _Traits, typename _Alloc>
3647  template<typename _InputIterator>
3650  _M_replace_dispatch(iterator __i1, iterator __i2, _InputIterator __k1,
3651  _InputIterator __k2, __false_type)
3652  {
3653  const basic_string __s(__k1, __k2);
3654  const size_type __n1 = __i2 - __i1;
3655  _M_check_length(__n1, __s.size(), "basic_string::_M_replace_dispatch");
3656  return _M_replace_safe(__i1 - _M_ibegin(), __n1, __s._M_data(),
3657  __s.size());
3658  }
3659 
3660  template<typename _CharT, typename _Traits, typename _Alloc>
3661  basic_string<_CharT, _Traits, _Alloc>&
3662  basic_string<_CharT, _Traits, _Alloc>::
3663  _M_replace_aux(size_type __pos1, size_type __n1, size_type __n2,
3664  _CharT __c)
3665  {
3666  _M_check_length(__n1, __n2, "basic_string::_M_replace_aux");
3667  _M_mutate(__pos1, __n1, __n2);
3668  if (__n2)
3669  _M_assign(_M_data() + __pos1, __n2, __c);
3670  return *this;
3671  }
3672 
3673  template<typename _CharT, typename _Traits, typename _Alloc>
3674  basic_string<_CharT, _Traits, _Alloc>&
3675  basic_string<_CharT, _Traits, _Alloc>::
3676  _M_replace_safe(size_type __pos1, size_type __n1, const _CharT* __s,
3677  size_type __n2)
3678  {
3679  _M_mutate(__pos1, __n1, __n2);
3680  if (__n2)
3681  _M_copy(_M_data() + __pos1, __s, __n2);
3682  return *this;
3683  }
3684 
3685  template<typename _CharT, typename _Traits, typename _Alloc>
3686  void
3688  reserve()
3689  {
3690 #if __cpp_exceptions
3691  if (length() < capacity() || _M_rep()->_M_is_shared())
3692  try
3693  {
3694  const allocator_type __a = get_allocator();
3695  _CharT* __tmp = _M_rep()->_M_clone(__a);
3696  _M_rep()->_M_dispose(__a);
3697  _M_data(__tmp);
3698  }
3699  catch (const __cxxabiv1::__forced_unwind&)
3700  { throw; }
3701  catch (...)
3702  { /* swallow the exception */ }
3703 #endif
3704  }
3705 
3706  template<typename _CharT, typename _Traits, typename _Alloc>
3707  typename basic_string<_CharT, _Traits, _Alloc>::size_type
3709  copy(_CharT* __s, size_type __n, size_type __pos) const
3710  {
3711  _M_check(__pos, "basic_string::copy");
3712  __n = _M_limit(__pos, __n);
3713  __glibcxx_requires_string_len(__s, __n);
3714  if (__n)
3715  _M_copy(__s, _M_data() + __pos, __n);
3716  // 21.3.5.7 par 3: do not append null. (good.)
3717  return __n;
3718  }
3719 _GLIBCXX_END_NAMESPACE_VERSION
3720 } // namespace std
3721 #endif // ! _GLIBCXX_USE_CXX11_ABI
3722 #endif // _COW_STRING_H
typename enable_if< _Cond, _Tp >::type enable_if_t
Alias template for enable_if.
Definition: type_traits:2610
constexpr std::remove_reference< _Tp >::type && move(_Tp &&__t) noexcept
Convert a value to an rvalue.
Definition: move.h:97
constexpr const _Tp & min(const _Tp &, const _Tp &)
This does what you think it does.
Definition: stl_algobase.h:233
ISO C++ entities toplevel namespace is std.
constexpr iterator_traits< _InputIterator >::difference_type distance(_InputIterator __first, _InputIterator __last)
A generalization of pointer arithmetic.
constexpr auto empty(const _Container &__cont) noexcept(noexcept(__cont.empty())) -> decltype(__cont.empty())
Return whether a container is empty.
Definition: range_access.h:284
constexpr auto size(const _Container &__cont) noexcept(noexcept(__cont.size())) -> decltype(__cont.size())
Return the size of a container.
Definition: range_access.h:264
initializer_list
is_same
Definition: type_traits:1399
Uniform interface to all allocator types.
Managing sequences of characters and character-like objects.
Definition: cow_string.h:117
int compare(size_type __pos1, size_type __n1, const basic_string &__str, size_type __pos2, size_type __n2=npos) const
Compare substring to a substring.
Definition: cow_string.h:2900
const_reverse_iterator crbegin() const noexcept
Definition: cow_string.h:897
void swap(basic_string &__s) noexcept(/*conditional */)
Swap contents with another string.
Definition: cow_string.h:3513
basic_string & assign(size_type __n, _CharT __c)
Set value to multiple characters.
Definition: cow_string.h:1433
_If_sv< _Tp, basic_string & > append(const _Tp &__svt)
Append a string_view.
Definition: cow_string.h:1310
basic_string & append(const basic_string &__str, size_type __pos, size_type __n=npos)
Append a substring.
Definition: cow_string.h:3324
void push_back(_CharT __c)
Append a single character.
Definition: cow_string.h:1340
const_iterator cend() const noexcept
Definition: cow_string.h:888
size_type find(const _CharT *__s, size_type __pos=0) const noexcept
Find position of a C string.
Definition: cow_string.h:2294
basic_string(_InputIterator __beg, _InputIterator __end, const _Alloc &__a=_Alloc())
Construct string as copy of a range.
Definition: cow_string.h:686
basic_string & replace(size_type __pos, size_type __n1, size_type __n2, _CharT __c)
Replace characters with multiple characters.
Definition: cow_string.h:1879
basic_string & replace(iterator __i1, iterator __i2, const _CharT *__s)
Replace range of characters with C string.
Definition: cow_string.h:1937
_If_sv< _Tp, size_type > find_last_of(const _Tp &__svt, size_type __pos=npos) const noexcept(is_same< _Tp, __sv_type >::value)
Find last position of a character of string.
Definition: cow_string.h:2568
size_type find_first_of(const basic_string &__str, size_type __pos=0) const noexcept
Find position of a character of string.
Definition: cow_string.h:2420
basic_string & append(_InputIterator __first, _InputIterator __last)
Append a range of characters.
Definition: cow_string.h:1299
basic_string & operator=(initializer_list< _CharT > __l)
Set value to string constructed from initializer list.
Definition: cow_string.h:774
iterator erase(iterator __first, iterator __last)
Remove a range of characters.
Definition: cow_string.h:3373
_If_sv< _Tp, size_type > find(const _Tp &__svt, size_type __pos=0) const noexcept(is_same< _Tp, __sv_type >::value)
Find position of a string_view.
Definition: cow_string.h:2322
basic_string(const _Alloc &__a)
Construct an empty string using allocator a.
Definition: cow_string.h:536
const _CharT * c_str() const noexcept
Return const pointer to null-terminated contents.
Definition: cow_string.h:2215
basic_string & assign(const _CharT *__s)
Set value to contents of a C string.
Definition: cow_string.h:1417
size_type find_last_of(const _CharT *__s, size_type __pos=npos) const noexcept
Find last position of a character of C string.
Definition: cow_string.h:2535
_If_sv< _Tp, basic_string & > append(const _Tp &__svt, size_type __pos, size_type __n=npos)
Append a range of characters from a string_view.
Definition: cow_string.h:1326
int compare(const _CharT *__s) const noexcept
Compare to a C string.
Definition: cow_string.h:2930
void insert(iterator __p, initializer_list< _CharT > __l)
Insert an initializer_list of characters.
Definition: cow_string.h:1534
size_type rfind(const _CharT *__s, size_type __pos=npos) const noexcept
Find last position of a C string.
Definition: cow_string.h:2372
basic_string substr(size_type __pos=0, size_type __n=npos) const
Get a substring.
Definition: cow_string.h:2752
iterator erase(iterator __position)
Remove one character.
Definition: cow_string.h:1734
size_type find(const _CharT *__s, size_type __pos, size_type __n) const noexcept
Find position of a C substring.
size_type find(const basic_string &__str, size_type __pos=0) const noexcept
Find position of a string.
Definition: cow_string.h:2279
basic_string & assign(const _CharT *__s, size_type __n)
Set value to a C substring.
Definition: cow_string.h:3241
size_type find_last_not_of(const basic_string &__str, size_type __pos=npos) const noexcept
Find last position of a character not in string.
Definition: cow_string.h:2669
int compare(size_type __pos, size_type __n, const basic_string &__str) const
Compare substring to a string.
Definition: cow_string.h:2864
_If_sv< _Tp, basic_string & > operator=(const _Tp &__svt)
Set value to string constructed from a string_view.
Definition: cow_string.h:788
basic_string(const basic_string &__str)
Construct string with copy of value of str.
Definition: cow_string.h:545
basic_string & replace(iterator __i1, iterator __i2, size_type __n, _CharT __c)
Replace range of characters with multiple characters.
Definition: cow_string.h:1958
int compare(const basic_string &__str) const
Compare to a string.
Definition: cow_string.h:2771
int compare(size_type __pos, size_type __n1, const _CharT *__s) const
Compare substring to a C string.
Definition: cow_string.h:2964
int compare(size_type __pos, size_type __n1, const _CharT *__s, size_type __n2) const
Compare substring against a character array.
Definition: cow_string.h:3002
reverse_iterator rend()
Definition: cow_string.h:862
_If_sv< _Tp, basic_string & > replace(const_iterator __i1, const_iterator __i2, const _Tp &__svt)
Replace range of characters with string_view.
Definition: cow_string.h:2104
basic_string & operator=(const _CharT *__s)
Copy contents of s into this string.
Definition: cow_string.h:735
basic_string(const basic_string &__str, size_type __pos, const _Alloc &__a=_Alloc())
Construct string as copy of a substring.
Definition: cow_string.h:3193
basic_string(const basic_string &__str, size_type __pos, size_type __n)
Construct string as copy of a substring.
Definition: cow_string.h:3203
size_type find_first_not_of(const basic_string &__str, size_type __pos=0) const noexcept
Find position of a character not in string.
Definition: cow_string.h:2587
_If_sv< _Tp, basic_string & > insert(size_type __pos, const _Tp &__svt)
Insert a string_view.
Definition: cow_string.h:1676
basic_string & replace(size_type __pos, size_type __n1, const _CharT *__s)
Replace characters with value of a C string.
Definition: cow_string.h:1855
const_reference front() const noexcept
Definition: cow_string.h:1139
size_type find_last_not_of(const _CharT *__s, size_type __pos=npos) const noexcept
Find last position of a character not in C string.
Definition: cow_string.h:2700
void insert(iterator __p, size_type __n, _CharT __c)
Insert multiple characters.
Definition: cow_string.h:1506
basic_string & operator+=(const basic_string &__str)
Append a string to this string.
Definition: cow_string.h:1175
basic_string & assign(const basic_string &__str)
Set value to contents of another string.
Definition: cow_string.h:3225
basic_string & append(size_type __n, _CharT __c)
Append multiple characters.
Definition: cow_string.h:3263
basic_string(const _Tp &__t, size_type __pos, size_type __n, const _Alloc &__a=_Alloc())
Construct string from a substring of a string_view.
Definition: cow_string.h:701
reverse_iterator rbegin()
Definition: cow_string.h:844
basic_string & operator+=(initializer_list< _CharT > __l)
Append an initializer_list of characters.
Definition: cow_string.h:1206
_If_sv< _Tp, basic_string & > operator+=(const _Tp &__svt)
Append a string_view.
Definition: cow_string.h:1218
basic_string(initializer_list< _CharT > __l, const _Alloc &__a=_Alloc())
Construct string from an initializer list.
Definition: cow_string.h:650
basic_string & replace(size_type __pos, size_type __n, const basic_string &__str)
Replace characters with value from another string.
Definition: cow_string.h:1788
reference front()
Definition: cow_string.h:1128
basic_string(const basic_string &__str, size_type __pos, size_type __n, const _Alloc &__a)
Construct string as copy of a substring.
Definition: cow_string.h:3213
basic_string(const _Tp &__t, const _Alloc &__a=_Alloc())
Construct string from a string_view.
Definition: cow_string.h:712
basic_string & replace(size_type __pos, size_type __n1, const _CharT *__s, size_type __n2)
Replace characters with value of a C substring.
Definition: cow_string.h:3396
_If_sv< _Tp, basic_string & > replace(size_type __pos, size_type __n, const _Tp &__svt)
Replace range of characters with string_view.
Definition: cow_string.h:2066
basic_string & assign(_InputIterator __first, _InputIterator __last)
Set value to a range of characters.
Definition: cow_string.h:1446
void pop_back()
Remove the last character.
Definition: cow_string.h:1763
basic_string & insert(size_type __pos1, const basic_string &__str)
Insert value of a string.
Definition: cow_string.h:1554
_If_sv< _Tp, basic_string & > assign(const _Tp &__svt)
Set value from a string_view.
Definition: cow_string.h:1468
basic_string(basic_string &&__str) noexcept
Move construct string.
Definition: cow_string.h:627
size_type copy(_CharT *__s, size_type __n, size_type __pos=0) const
Copy substring into C string.
Definition: cow_string.h:3709
size_type length() const noexcept
Returns the number of characters in the string, not including any null-termination.
Definition: cow_string.h:928
size_type find_last_of(const basic_string &__str, size_type __pos=npos) const noexcept
Find last position of a character of string.
Definition: cow_string.h:2504
basic_string & replace(iterator __i1, iterator __i2, initializer_list< _CharT > __l)
Replace range of characters with initializer_list.
Definition: cow_string.h:2051
basic_string & insert(size_type __pos, const _CharT *__s, size_type __n)
Insert a C substring.
Definition: cow_string.h:3342
basic_string & insert(size_type __pos1, const basic_string &__str, size_type __pos2, size_type __n=npos)
Insert a substring.
Definition: cow_string.h:1576
_If_sv< _Tp, int > compare(const _Tp &__svt) const noexcept(is_same< _Tp, __sv_type >::value)
Compare to a string_view.
Definition: cow_string.h:2791
_If_sv< _Tp, size_type > rfind(const _Tp &__svt, size_type __pos=npos) const noexcept(is_same< _Tp, __sv_type >::value)
Find last position of a string_view.
Definition: cow_string.h:2400
size_type size() const noexcept
Returns the number of characters in the string, not including any null-termination.
Definition: cow_string.h:916
size_type rfind(const basic_string &__str, size_type __pos=npos) const noexcept
Find last position of a string.
Definition: cow_string.h:2341
basic_string & assign(initializer_list< _CharT > __l)
Set value to an initializer_list of characters.
Definition: cow_string.h:1456
basic_string(size_type __n, _CharT __c, const _Alloc &__a=_Alloc())
Construct string as multiple characters.
Definition: cow_string.h:615
_If_sv< _Tp, basic_string & > assign(const _Tp &__svt, size_type __pos, size_type __n=npos)
Set value from a range of characters in a string_view.
Definition: cow_string.h:1483
void shrink_to_fit() noexcept
A non-binding request to reduce capacity() to size().
Definition: cow_string.h:968
basic_string & replace(iterator __i1, iterator __i2, const _CharT *__s, size_type __n)
Replace range of characters with C substring.
Definition: cow_string.h:1916
basic_string & assign(basic_string &&__str) noexcept(allocator_traits< _Alloc >::is_always_equal::value)
Set value to contents of another string.
Definition: cow_string.h:1367
void resize(size_type __n, _CharT __c)
Resizes the string to the specified number of characters.
Definition: cow_string.h:3635
void reserve()
Equivalent to shrink_to_fit().
Definition: cow_string.h:3688
const _CharT * data() const noexcept
Return const pointer to contents.
Definition: cow_string.h:2227
basic_string & operator=(_CharT __c)
Set value to string of length 1.
Definition: cow_string.h:746
const_reference at(size_type __n) const
Provides access to the data contained in the string.
Definition: cow_string.h:1089
const_reference back() const noexcept
Definition: cow_string.h:1161
const_reverse_iterator rend() const noexcept
Definition: cow_string.h:871
_If_sv< _Tp, basic_string & > insert(size_type __pos1, const _Tp &__svt, size_type __pos2, size_type __n=npos)
Insert a string_view.
Definition: cow_string.h:1692
const_iterator end() const noexcept
Definition: cow_string.h:835
basic_string & operator+=(_CharT __c)
Append a character.
Definition: cow_string.h:1193
size_type find_last_of(_CharT __c, size_type __pos=npos) const noexcept
Find last position of a character.
Definition: cow_string.h:2555
_If_sv< _Tp, size_type > find_first_not_of(const _Tp &__svt, size_type __pos=0) const noexcept(is_same< _Tp, __sv_type >::value)
Find position of a character not in a string_view.
Definition: cow_string.h:2649
iterator begin()
Definition: cow_string.h:805
basic_string & append(const basic_string &__str)
Append a string to this string.
Definition: cow_string.h:3307
_CharT * data() noexcept
Return non-const pointer to contents.
Definition: cow_string.h:2238
const_iterator begin() const noexcept
Definition: cow_string.h:816
_If_sv< _Tp, int > compare(size_type __pos1, size_type __n1, const _Tp &__svt, size_type __pos2, size_type __n2=npos) const noexcept(is_same< _Tp, __sv_type >::value)
Compare to a string_view.
Definition: cow_string.h:2834
const_reverse_iterator crend() const noexcept
Definition: cow_string.h:906
void resize(size_type __n)
Resizes the string to the specified number of characters.
Definition: cow_string.h:960
const_reverse_iterator rbegin() const noexcept
Definition: cow_string.h:853
_If_sv< _Tp, basic_string & > replace(size_type __pos1, size_type __n1, const _Tp &__svt, size_type __pos2, size_type __n2=npos)
Replace range of characters with string_view.
Definition: cow_string.h:2083
iterator end()
Definition: cow_string.h:824
_If_sv< _Tp, int > compare(size_type __pos, size_type __n, const _Tp &__svt) const noexcept(is_same< _Tp, __sv_type >::value)
Compare to a string_view.
Definition: cow_string.h:2815
basic_string & operator=(const basic_string &__str)
Assign the value of str to this string.
Definition: cow_string.h:727
const_reference operator[](size_type __pos) const noexcept
Subscript access to the data contained in the string.
Definition: cow_string.h:1050
basic_string(const _CharT *__s, const _Alloc &__a=_Alloc())
Construct string as copy of a C string.
Definition: cow_string.h:604
basic_string & operator=(basic_string &&__str) noexcept(/*conditional */)
Move assign the value of str to this string.
Definition: cow_string.h:761
void clear() noexcept
Definition: cow_string.h:1013
size_type find_first_of(_CharT __c, size_type __pos=0) const noexcept
Find position of a character.
Definition: cow_string.h:2471
basic_string & replace(iterator __i1, iterator __i2, _InputIterator __k1, _InputIterator __k2)
Replace range of characters with range.
Definition: cow_string.h:1982
bool empty() const noexcept
Definition: cow_string.h:1035
basic_string & append(initializer_list< _CharT > __l)
Append an initializer_list of characters.
Definition: cow_string.h:1285
reference back()
Definition: cow_string.h:1150
static const size_type npos
Value returned by various member functions when they fail.
Definition: cow_string.h:330
allocator_type get_allocator() const noexcept
Return copy of allocator used to construct this string.
Definition: cow_string.h:2249
basic_string & insert(size_type __pos, const _CharT *__s)
Insert a C string.
Definition: cow_string.h:1617
const_iterator cbegin() const noexcept
Definition: cow_string.h:880
basic_string & erase(size_type __pos=0, size_type __n=npos)
Remove characters.
Definition: cow_string.h:1718
basic_string & replace(iterator __i1, iterator __i2, const basic_string &__str)
Replace range of characters with string.
Definition: cow_string.h:1897
~basic_string() noexcept
Destroy the string instance.
Definition: cow_string.h:719
size_type capacity() const noexcept
Definition: cow_string.h:978
basic_string & operator+=(const _CharT *__s)
Append a C string.
Definition: cow_string.h:1184
basic_string() noexcept
Default constructor creates an empty string.
Definition: cow_string.h:523
void insert(iterator __p, _InputIterator __beg, _InputIterator __end)
Insert a range of characters.
Definition: cow_string.h:1523
size_type find_first_of(const _CharT *__s, size_type __pos=0) const noexcept
Find position of a character of C string.
Definition: cow_string.h:2451
basic_string & replace(size_type __pos1, size_type __n1, const basic_string &__str, size_type __pos2, size_type __n2=npos)
Replace characters with value from another string.
Definition: cow_string.h:1810
size_type max_size() const noexcept
Returns the size() of the largest possible string.
Definition: cow_string.h:933
reference operator[](size_type __pos)
Subscript access to the data contained in the string.
Definition: cow_string.h:1067
basic_string & insert(size_type __pos, size_type __n, _CharT __c)
Insert multiple characters.
Definition: cow_string.h:1640
basic_string & append(const _CharT *__s, size_type __n)
Append a C substring.
Definition: cow_string.h:3280
_If_sv< _Tp, size_type > find_last_not_of(const _Tp &__svt, size_type __pos=npos) const noexcept(is_same< _Tp, __sv_type >::value)
Find last position of a character not in a string_view.
Definition: cow_string.h:2731
basic_string(const _CharT *__s, size_type __n, const _Alloc &__a=_Alloc())
Construct string initialized by a character array.
Definition: cow_string.h:589
basic_string & assign(const basic_string &__str, size_type __pos, size_type __n=npos)
Set value to a substring of a string.
Definition: cow_string.h:1389
basic_string & append(const _CharT *__s)
Append a C string.
Definition: cow_string.h:1261
size_type find_first_not_of(const _CharT *__s, size_type __pos=0) const noexcept
Find position of a character not in C string.
Definition: cow_string.h:2618
reference at(size_type __n)
Provides access to the data contained in the string.
Definition: cow_string.h:1111
_If_sv< _Tp, size_type > find_first_of(const _Tp &__svt, size_type __pos=0) const noexcept(is_same< _Tp, __sv_type >::value)
Find position of a character of a string_view.
Definition: cow_string.h:2484
iterator insert(iterator __p, _CharT __c)
Insert one character.
Definition: cow_string.h:1658
Thrown as part of forced unwinding.
Definition: cxxabi_forced.h:49
Common iterator class.
Uniform interface to C++98 and C++11 allocators.