1// -*- C++ -*-
2//===----------------------------------------------------------------------===//
3//
4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5// See https://llvm.org/LICENSE.txt for license information.
6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7//
8//===----------------------------------------------------------------------===//
9
10#ifndef _LIBCPP_STRING
11#define _LIBCPP_STRING
12
13// clang-format off
14
15/*
16 string synopsis
17
18#include <compare>
19#include <initializer_list>
20
21namespace std
22{
23
24template <class stateT>
25class fpos
26{
27private:
28 stateT st;
29public:
30 fpos(streamoff = streamoff());
31
32 operator streamoff() const;
33
34 stateT state() const;
35 void state(stateT);
36
37 fpos& operator+=(streamoff);
38 fpos operator+ (streamoff) const;
39 fpos& operator-=(streamoff);
40 fpos operator- (streamoff) const;
41};
42
43template <class stateT> streamoff operator-(const fpos<stateT>& x, const fpos<stateT>& y);
44
45template <class stateT> bool operator==(const fpos<stateT>& x, const fpos<stateT>& y);
46template <class stateT> bool operator!=(const fpos<stateT>& x, const fpos<stateT>& y);
47
48template <class charT>
49struct char_traits
50{
51 using char_type = charT;
52 using int_type = ...;
53 using off_type = streamoff;
54 using pos_type = streampos;
55 using state_type = mbstate_t;
56 using comparison_category = strong_ordering; // Since C++20 only for the specializations
57 // char, wchar_t, char8_t, char16_t, and char32_t.
58
59 static void assign(char_type& c1, const char_type& c2) noexcept;
60 static constexpr bool eq(char_type c1, char_type c2) noexcept;
61 static constexpr bool lt(char_type c1, char_type c2) noexcept;
62
63 static int compare(const char_type* s1, const char_type* s2, size_t n);
64 static size_t length(const char_type* s);
65 static const char_type* find(const char_type* s, size_t n, const char_type& a);
66 static char_type* move(char_type* s1, const char_type* s2, size_t n);
67 static char_type* copy(char_type* s1, const char_type* s2, size_t n);
68 static char_type* assign(char_type* s, size_t n, char_type a);
69
70 static constexpr int_type not_eof(int_type c) noexcept;
71 static constexpr char_type to_char_type(int_type c) noexcept;
72 static constexpr int_type to_int_type(char_type c) noexcept;
73 static constexpr bool eq_int_type(int_type c1, int_type c2) noexcept;
74 static constexpr int_type eof() noexcept;
75};
76
77template <> struct char_traits<char>;
78template <> struct char_traits<wchar_t>;
79template <> struct char_traits<char8_t>; // C++20
80template <> struct char_traits<char16_t>;
81template <> struct char_traits<char32_t>;
82
83template<class charT, class traits = char_traits<charT>, class Allocator = allocator<charT> >
84class basic_string
85{
86public:
87// types:
88 typedef traits traits_type;
89 typedef typename traits_type::char_type value_type;
90 typedef Allocator allocator_type;
91 typedef typename allocator_type::size_type size_type;
92 typedef typename allocator_type::difference_type difference_type;
93 typedef typename allocator_type::reference reference;
94 typedef typename allocator_type::const_reference const_reference;
95 typedef typename allocator_type::pointer pointer;
96 typedef typename allocator_type::const_pointer const_pointer;
97 typedef implementation-defined iterator;
98 typedef implementation-defined const_iterator;
99 typedef std::reverse_iterator<iterator> reverse_iterator;
100 typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
101
102 static const size_type npos = -1;
103
104 basic_string()
105 noexcept(is_nothrow_default_constructible<allocator_type>::value); // constexpr since C++20
106 explicit basic_string(const allocator_type& a); // constexpr since C++20
107 basic_string(const basic_string& str); // constexpr since C++20
108 basic_string(basic_string&& str)
109 noexcept(is_nothrow_move_constructible<allocator_type>::value); // constexpr since C++20
110 basic_string(const basic_string& str, size_type pos,
111 const allocator_type& a = allocator_type()); // constexpr since C++20
112 basic_string(const basic_string& str, size_type pos, size_type n,
113 const Allocator& a = Allocator()); // constexpr since C++20
114 constexpr basic_string(
115 basic_string&& str, size_type pos, const Allocator& a = Allocator()); // since C++23
116 constexpr basic_string(
117 basic_string&& str, size_type pos, size_type n, const Allocator& a = Allocator()); // since C++23
118 template<class T>
119 basic_string(const T& t, size_type pos, size_type n, const Allocator& a = Allocator()); // C++17, constexpr since C++20
120 template <class T>
121 explicit basic_string(const T& t, const Allocator& a = Allocator()); // C++17, constexpr since C++20
122 basic_string(const value_type* s, const allocator_type& a = allocator_type()); // constexpr since C++20
123 basic_string(const value_type* s, size_type n, const allocator_type& a = allocator_type()); // constexpr since C++20
124 basic_string(nullptr_t) = delete; // C++23
125 basic_string(size_type n, value_type c, const allocator_type& a = allocator_type()); // constexpr since C++20
126 template<class InputIterator>
127 basic_string(InputIterator begin, InputIterator end,
128 const allocator_type& a = allocator_type()); // constexpr since C++20
129 template<container-compatible-range<charT> R>
130 constexpr basic_string(from_range_t, R&& rg, const Allocator& a = Allocator()); // since C++23
131 basic_string(initializer_list<value_type>, const Allocator& = Allocator()); // constexpr since C++20
132 basic_string(const basic_string&, const Allocator&); // constexpr since C++20
133 basic_string(basic_string&&, const Allocator&); // constexpr since C++20
134
135 ~basic_string(); // constexpr since C++20
136
137 operator basic_string_view<charT, traits>() const noexcept; // constexpr since C++20
138
139 basic_string& operator=(const basic_string& str); // constexpr since C++20
140 template <class T>
141 basic_string& operator=(const T& t); // C++17, constexpr since C++20
142 basic_string& operator=(basic_string&& str)
143 noexcept(
144 allocator_type::propagate_on_container_move_assignment::value ||
145 allocator_type::is_always_equal::value ); // C++17, constexpr since C++20
146 basic_string& operator=(const value_type* s); // constexpr since C++20
147 basic_string& operator=(nullptr_t) = delete; // C++23
148 basic_string& operator=(value_type c); // constexpr since C++20
149 basic_string& operator=(initializer_list<value_type>); // constexpr since C++20
150
151 iterator begin() noexcept; // constexpr since C++20
152 const_iterator begin() const noexcept; // constexpr since C++20
153 iterator end() noexcept; // constexpr since C++20
154 const_iterator end() const noexcept; // constexpr since C++20
155
156 reverse_iterator rbegin() noexcept; // constexpr since C++20
157 const_reverse_iterator rbegin() const noexcept; // constexpr since C++20
158 reverse_iterator rend() noexcept; // constexpr since C++20
159 const_reverse_iterator rend() const noexcept; // constexpr since C++20
160
161 const_iterator cbegin() const noexcept; // constexpr since C++20
162 const_iterator cend() const noexcept; // constexpr since C++20
163 const_reverse_iterator crbegin() const noexcept; // constexpr since C++20
164 const_reverse_iterator crend() const noexcept; // constexpr since C++20
165
166 size_type size() const noexcept; // constexpr since C++20
167 size_type length() const noexcept; // constexpr since C++20
168 size_type max_size() const noexcept; // constexpr since C++20
169 size_type capacity() const noexcept; // constexpr since C++20
170
171 void resize(size_type n, value_type c); // constexpr since C++20
172 void resize(size_type n); // constexpr since C++20
173
174 template<class Operation>
175 constexpr void resize_and_overwrite(size_type n, Operation op); // since C++23
176
177 void reserve(size_type res_arg); // constexpr since C++20
178 void reserve(); // deprecated in C++20, removed in C++26
179 void shrink_to_fit(); // constexpr since C++20
180 void clear() noexcept; // constexpr since C++20
181 bool empty() const noexcept; // constexpr since C++20
182
183 const_reference operator[](size_type pos) const; // constexpr since C++20
184 reference operator[](size_type pos); // constexpr since C++20
185
186 const_reference at(size_type n) const; // constexpr since C++20
187 reference at(size_type n); // constexpr since C++20
188
189 basic_string& operator+=(const basic_string& str); // constexpr since C++20
190 template <class T>
191 basic_string& operator+=(const T& t); // C++17, constexpr since C++20
192 basic_string& operator+=(const value_type* s); // constexpr since C++20
193 basic_string& operator+=(value_type c); // constexpr since C++20
194 basic_string& operator+=(initializer_list<value_type>); // constexpr since C++20
195
196 basic_string& append(const basic_string& str); // constexpr since C++20
197 template <class T>
198 basic_string& append(const T& t); // C++17, constexpr since C++20
199 basic_string& append(const basic_string& str, size_type pos, size_type n=npos); // C++14, constexpr since C++20
200 template <class T>
201 basic_string& append(const T& t, size_type pos, size_type n=npos); // C++17, constexpr since C++20
202 basic_string& append(const value_type* s, size_type n); // constexpr since C++20
203 basic_string& append(const value_type* s); // constexpr since C++20
204 basic_string& append(size_type n, value_type c); // constexpr since C++20
205 template<class InputIterator>
206 basic_string& append(InputIterator first, InputIterator last); // constexpr since C++20
207 template<container-compatible-range<charT> R>
208 constexpr basic_string& append_range(R&& rg); // C++23
209 basic_string& append(initializer_list<value_type>); // constexpr since C++20
210
211 void push_back(value_type c); // constexpr since C++20
212 void pop_back(); // constexpr since C++20
213 reference front(); // constexpr since C++20
214 const_reference front() const; // constexpr since C++20
215 reference back(); // constexpr since C++20
216 const_reference back() const; // constexpr since C++20
217
218 basic_string& assign(const basic_string& str); // constexpr since C++20
219 template <class T>
220 basic_string& assign(const T& t); // C++17, constexpr since C++20
221 basic_string& assign(basic_string&& str); // constexpr since C++20
222 basic_string& assign(const basic_string& str, size_type pos, size_type n=npos); // C++14, constexpr since C++20
223 template <class T>
224 basic_string& assign(const T& t, size_type pos, size_type n=npos); // C++17, constexpr since C++20
225 basic_string& assign(const value_type* s, size_type n); // constexpr since C++20
226 basic_string& assign(const value_type* s); // constexpr since C++20
227 basic_string& assign(size_type n, value_type c); // constexpr since C++20
228 template<class InputIterator>
229 basic_string& assign(InputIterator first, InputIterator last); // constexpr since C++20
230 template<container-compatible-range<charT> R>
231 constexpr basic_string& assign_range(R&& rg); // C++23
232 basic_string& assign(initializer_list<value_type>); // constexpr since C++20
233
234 basic_string& insert(size_type pos1, const basic_string& str); // constexpr since C++20
235 template <class T>
236 basic_string& insert(size_type pos1, const T& t); // constexpr since C++20
237 basic_string& insert(size_type pos1, const basic_string& str,
238 size_type pos2, size_type n2=npos); // constexpr since C++20
239 template <class T>
240 basic_string& insert(size_type pos1, const T& t, size_type pos2, size_type n=npos); // C++17, constexpr since C++20
241 basic_string& insert(size_type pos, const value_type* s, size_type n=npos); // C++14, constexpr since C++20
242 basic_string& insert(size_type pos, const value_type* s); // constexpr since C++20
243 basic_string& insert(size_type pos, size_type n, value_type c); // constexpr since C++20
244 iterator insert(const_iterator p, value_type c); // constexpr since C++20
245 iterator insert(const_iterator p, size_type n, value_type c); // constexpr since C++20
246 template<class InputIterator>
247 iterator insert(const_iterator p, InputIterator first, InputIterator last); // constexpr since C++20
248 template<container-compatible-range<charT> R>
249 constexpr iterator insert_range(const_iterator p, R&& rg); // C++23
250 iterator insert(const_iterator p, initializer_list<value_type>); // constexpr since C++20
251
252 basic_string& erase(size_type pos = 0, size_type n = npos); // constexpr since C++20
253 iterator erase(const_iterator position); // constexpr since C++20
254 iterator erase(const_iterator first, const_iterator last); // constexpr since C++20
255
256 basic_string& replace(size_type pos1, size_type n1, const basic_string& str); // constexpr since C++20
257 template <class T>
258 basic_string& replace(size_type pos1, size_type n1, const T& t); // C++17, constexpr since C++20
259 basic_string& replace(size_type pos1, size_type n1, const basic_string& str,
260 size_type pos2, size_type n2=npos); // C++14, constexpr since C++20
261 template <class T>
262 basic_string& replace(size_type pos1, size_type n1, const T& t,
263 size_type pos2, size_type n2=npos); // C++17, constexpr since C++20
264 basic_string& replace(size_type pos, size_type n1, const value_type* s, size_type n2); // constexpr since C++20
265 basic_string& replace(size_type pos, size_type n1, const value_type* s); // constexpr since C++20
266 basic_string& replace(size_type pos, size_type n1, size_type n2, value_type c); // constexpr since C++20
267 basic_string& replace(const_iterator i1, const_iterator i2, const basic_string& str); // constexpr since C++20
268 template <class T>
269 basic_string& replace(const_iterator i1, const_iterator i2, const T& t); // C++17, constexpr since C++20
270 basic_string& replace(const_iterator i1, const_iterator i2, const value_type* s, size_type n); // constexpr since C++20
271 basic_string& replace(const_iterator i1, const_iterator i2, const value_type* s); // constexpr since C++20
272 basic_string& replace(const_iterator i1, const_iterator i2, size_type n, value_type c); // constexpr since C++20
273 template<class InputIterator>
274 basic_string& replace(const_iterator i1, const_iterator i2, InputIterator j1, InputIterator j2); // constexpr since C++20
275 template<container-compatible-range<charT> R>
276 constexpr basic_string& replace_with_range(const_iterator i1, const_iterator i2, R&& rg); // C++23
277 basic_string& replace(const_iterator i1, const_iterator i2, initializer_list<value_type>); // constexpr since C++20
278
279 size_type copy(value_type* s, size_type n, size_type pos = 0) const; // constexpr since C++20
280 basic_string substr(size_type pos = 0, size_type n = npos) const; // constexpr in C++20, removed in C++23
281 basic_string substr(size_type pos = 0, size_type n = npos) const&; // since C++23
282 constexpr basic_string substr(size_type pos = 0, size_type n = npos) &&; // since C++23
283 constexpr basic_string_view<charT, traits> subview(size_type pos = 0,
284 size_type n = npos) const; // since C++26
285 void swap(basic_string& str)
286 noexcept(allocator_traits<allocator_type>::propagate_on_container_swap::value ||
287 allocator_traits<allocator_type>::is_always_equal::value); // C++17, constexpr since C++20
288
289 const value_type* c_str() const noexcept; // constexpr since C++20
290 const value_type* data() const noexcept; // constexpr since C++20
291 value_type* data() noexcept; // C++17, constexpr since C++20
292
293 allocator_type get_allocator() const noexcept; // constexpr since C++20
294
295 size_type find(const basic_string& str, size_type pos = 0) const noexcept; // constexpr since C++20
296 template <class T>
297 size_type find(const T& t, size_type pos = 0) const noexcept; // C++17, noexcept as an extension, constexpr since C++20
298 size_type find(const value_type* s, size_type pos, size_type n) const noexcept; // constexpr since C++20
299 size_type find(const value_type* s, size_type pos = 0) const noexcept; // constexpr since C++20
300 size_type find(value_type c, size_type pos = 0) const noexcept; // constexpr since C++20
301
302 size_type rfind(const basic_string& str, size_type pos = npos) const noexcept; // constexpr since C++20
303 template <class T>
304 size_type rfind(const T& t, size_type pos = npos) const noexcept; // C++17, noexcept as an extension, constexpr since C++20
305 size_type rfind(const value_type* s, size_type pos, size_type n) const noexcept; // constexpr since C++20
306 size_type rfind(const value_type* s, size_type pos = npos) const noexcept; // constexpr since C++20
307 size_type rfind(value_type c, size_type pos = npos) const noexcept; // constexpr since C++20
308
309 size_type find_first_of(const basic_string& str, size_type pos = 0) const noexcept; // constexpr since C++20
310 template <class T>
311 size_type find_first_of(const T& t, size_type pos = 0) const noexcept; // C++17, noexcept as an extension, constexpr since C++20
312 size_type find_first_of(const value_type* s, size_type pos, size_type n) const noexcept; // constexpr since C++20
313 size_type find_first_of(const value_type* s, size_type pos = 0) const noexcept; // constexpr since C++20
314 size_type find_first_of(value_type c, size_type pos = 0) const noexcept; // constexpr since C++20
315
316 size_type find_last_of(const basic_string& str, size_type pos = npos) const noexcept; // constexpr since C++20
317 template <class T>
318 size_type find_last_of(const T& t, size_type pos = npos) const noexcept noexcept; // C++17, noexcept as an extension, constexpr since C++20
319 size_type find_last_of(const value_type* s, size_type pos, size_type n) const noexcept; // constexpr since C++20
320 size_type find_last_of(const value_type* s, size_type pos = npos) const noexcept; // constexpr since C++20
321 size_type find_last_of(value_type c, size_type pos = npos) const noexcept; // constexpr since C++20
322
323 size_type find_first_not_of(const basic_string& str, size_type pos = 0) const noexcept; // constexpr since C++20
324 template <class T>
325 size_type find_first_not_of(const T& t, size_type pos = 0) const noexcept; // C++17, noexcept as an extension, constexpr since C++20
326 size_type find_first_not_of(const value_type* s, size_type pos, size_type n) const noexcept; // constexpr since C++20
327 size_type find_first_not_of(const value_type* s, size_type pos = 0) const noexcept; // constexpr since C++20
328 size_type find_first_not_of(value_type c, size_type pos = 0) const noexcept; // constexpr since C++20
329
330 size_type find_last_not_of(const basic_string& str, size_type pos = npos) const noexcept; // constexpr since C++20
331 template <class T>
332 size_type find_last_not_of(const T& t, size_type pos = npos) const noexcept; // C++17, noexcept as an extension, constexpr since C++20
333 size_type find_last_not_of(const value_type* s, size_type pos, size_type n) const noexcept; // constexpr since C++20
334 size_type find_last_not_of(const value_type* s, size_type pos = npos) const noexcept; // constexpr since C++20
335 size_type find_last_not_of(value_type c, size_type pos = npos) const noexcept; // constexpr since C++20
336
337 int compare(const basic_string& str) const noexcept; // constexpr since C++20
338 template <class T>
339 int compare(const T& t) const noexcept; // C++17, noexcept as an extension, constexpr since C++20
340 int compare(size_type pos1, size_type n1, const basic_string& str) const; // constexpr since C++20
341 template <class T>
342 int compare(size_type pos1, size_type n1, const T& t) const; // C++17, constexpr since C++20
343 int compare(size_type pos1, size_type n1, const basic_string& str,
344 size_type pos2, size_type n2=npos) const; // C++14, constexpr since C++20
345 template <class T>
346 int compare(size_type pos1, size_type n1, const T& t,
347 size_type pos2, size_type n2=npos) const; // C++17, constexpr since C++20
348 int compare(const value_type* s) const noexcept; // constexpr since C++20
349 int compare(size_type pos1, size_type n1, const value_type* s) const; // constexpr since C++20
350 int compare(size_type pos1, size_type n1, const value_type* s, size_type n2) const; // constexpr since C++20
351
352 constexpr bool starts_with(basic_string_view<charT, traits> sv) const noexcept; // C++20
353 constexpr bool starts_with(charT c) const noexcept; // C++20
354 constexpr bool starts_with(const charT* s) const; // C++20
355 constexpr bool ends_with(basic_string_view<charT, traits> sv) const noexcept; // C++20
356 constexpr bool ends_with(charT c) const noexcept; // C++20
357 constexpr bool ends_with(const charT* s) const; // C++20
358
359 constexpr bool contains(basic_string_view<charT, traits> sv) const noexcept; // C++23
360 constexpr bool contains(charT c) const noexcept; // C++23
361 constexpr bool contains(const charT* s) const; // C++23
362};
363
364template<class InputIterator,
365 class Allocator = allocator<typename iterator_traits<InputIterator>::value_type>>
366basic_string(InputIterator, InputIterator, Allocator = Allocator())
367 -> basic_string<typename iterator_traits<InputIterator>::value_type,
368 char_traits<typename iterator_traits<InputIterator>::value_type>,
369 Allocator>; // C++17
370
371template<ranges::input_range R,
372 class Allocator = allocator<ranges::range_value_t<R>>>
373 basic_string(from_range_t, R&&, Allocator = Allocator())
374 -> basic_string<ranges::range_value_t<R>, char_traits<ranges::range_value_t<R>>,
375 Allocator>; // C++23
376
377template<class charT,
378 class traits,
379 class Allocator = allocator<charT>>
380 explicit basic_string(basic_string_view<charT, traits>, const Allocator& = Allocator())
381 -> basic_string<charT, traits, Allocator>; // C++17
382
383template<class charT,
384 class traits,
385 class Allocator = allocator<charT>>
386 basic_string(basic_string_view<charT, traits>,
387 typename see below::size_type, typename see below::size_type,
388 const Allocator& = Allocator())
389 -> basic_string<charT, traits, Allocator>; // C++17
390
391template<class charT, class traits, class Allocator>
392basic_string<charT, traits, Allocator>
393operator+(const basic_string<charT, traits, Allocator>& lhs,
394 const basic_string<charT, traits, Allocator>& rhs); // constexpr since C++20
395
396template<class charT, class traits, class Allocator>
397basic_string<charT, traits, Allocator>
398operator+(const charT* lhs , const basic_string<charT,traits,Allocator>&rhs); // constexpr since C++20
399
400template<class charT, class traits, class Allocator>
401basic_string<charT, traits, Allocator>
402operator+(charT lhs, const basic_string<charT,traits,Allocator>& rhs); // constexpr since C++20
403
404template<class charT, class traits, class Allocator>
405basic_string<charT, traits, Allocator>
406operator+(const basic_string<charT, traits, Allocator>& lhs, const charT* rhs); // constexpr since C++20
407
408template<class charT, class traits, class Allocator>
409basic_string<charT, traits, Allocator>
410operator+(const basic_string<charT, traits, Allocator>& lhs, charT rhs); // constexpr since C++20
411
412template<class charT, class traits, class Allocator>
413 constexpr basic_string<charT, traits, Allocator>
414 operator+(const basic_string<charT, traits, Allocator>& lhs,
415 type_identity_t<basic_string_view<charT, traits>> rhs); // Since C++26
416template<class charT, class traits, class Allocator>
417 constexpr basic_string<charT, traits, Allocator>
418 operator+(basic_string<charT, traits, Allocator>&& lhs,
419 type_identity_t<basic_string_view<charT, traits>> rhs); // Since C++26
420template<class charT, class traits, class Allocator>
421 constexpr basic_string<charT, traits, Allocator>
422 operator+(type_identity_t<basic_string_view<charT, traits>> lhs,
423 const basic_string<charT, traits, Allocator>& rhs); // Since C++26
424template<class charT, class traits, class Allocator>
425 constexpr basic_string<charT, traits, Allocator>
426 operator+(type_identity_t<basic_string_view<charT, traits>> lhs,
427 basic_string<charT, traits, Allocator>&& rhs); // Since C++26
428
429
430template<class charT, class traits, class Allocator>
431bool operator==(const basic_string<charT, traits, Allocator>& lhs,
432 const basic_string<charT, traits, Allocator>& rhs) noexcept; // constexpr since C++20
433
434template<class charT, class traits, class Allocator>
435bool operator==(const charT* lhs, const basic_string<charT, traits, Allocator>& rhs) noexcept; // removed in C++20
436
437template<class charT, class traits, class Allocator>
438bool operator==(const basic_string<charT,traits,Allocator>& lhs, const charT* rhs) noexcept; // constexpr since C++20
439
440template<class charT, class traits, class Allocator>
441bool operator!=(const basic_string<charT,traits,Allocator>& lhs,
442 const basic_string<charT, traits, Allocator>& rhs) noexcept; // removed in C++20
443
444template<class charT, class traits, class Allocator>
445bool operator!=(const charT* lhs, const basic_string<charT, traits, Allocator>& rhs) noexcept; // removed in C++20
446
447template<class charT, class traits, class Allocator>
448bool operator!=(const basic_string<charT, traits, Allocator>& lhs, const charT* rhs) noexcept; // removed in C++20
449
450template<class charT, class traits, class Allocator>
451bool operator< (const basic_string<charT, traits, Allocator>& lhs,
452 const basic_string<charT, traits, Allocator>& rhs) noexcept; // removed in C++20
453
454template<class charT, class traits, class Allocator>
455bool operator< (const basic_string<charT, traits, Allocator>& lhs, const charT* rhs) noexcept; // removed in C++20
456
457template<class charT, class traits, class Allocator>
458bool operator< (const charT* lhs, const basic_string<charT, traits, Allocator>& rhs) noexcept; // removed in C++20
459
460template<class charT, class traits, class Allocator>
461bool operator> (const basic_string<charT, traits, Allocator>& lhs,
462 const basic_string<charT, traits, Allocator>& rhs) noexcept; // removed in C++20
463
464template<class charT, class traits, class Allocator>
465bool operator> (const basic_string<charT, traits, Allocator>& lhs, const charT* rhs) noexcept; // removed in C++20
466
467template<class charT, class traits, class Allocator>
468bool operator> (const charT* lhs, const basic_string<charT, traits, Allocator>& rhs) noexcept; // removed in C++20
469
470template<class charT, class traits, class Allocator>
471bool operator<=(const basic_string<charT, traits, Allocator>& lhs,
472 const basic_string<charT, traits, Allocator>& rhs) noexcept; // removed in C++20
473
474template<class charT, class traits, class Allocator>
475bool operator<=(const basic_string<charT, traits, Allocator>& lhs, const charT* rhs) noexcept; // removed in C++20
476
477template<class charT, class traits, class Allocator>
478bool operator<=(const charT* lhs, const basic_string<charT, traits, Allocator>& rhs) noexcept; // removed in C++20
479
480template<class charT, class traits, class Allocator>
481bool operator>=(const basic_string<charT, traits, Allocator>& lhs,
482 const basic_string<charT, traits, Allocator>& rhs) noexcept; // removed in C++20
483
484template<class charT, class traits, class Allocator>
485bool operator>=(const basic_string<charT, traits, Allocator>& lhs, const charT* rhs) noexcept; // removed in C++20
486
487template<class charT, class traits, class Allocator>
488bool operator>=(const charT* lhs, const basic_string<charT, traits, Allocator>& rhs) noexcept; // removed in C++20
489
490template<class charT, class traits, class Allocator> // since C++20
491constexpr see below operator<=>(const basic_string<charT, traits, Allocator>& lhs,
492 const basic_string<charT, traits, Allocator>& rhs) noexcept;
493
494template<class charT, class traits, class Allocator> // since C++20
495constexpr see below operator<=>(const basic_string<charT, traits, Allocator>& lhs,
496 const charT* rhs) noexcept;
497
498template<class charT, class traits, class Allocator>
499void swap(basic_string<charT, traits, Allocator>& lhs,
500 basic_string<charT, traits, Allocator>& rhs)
501 noexcept(noexcept(lhs.swap(rhs))); // constexpr since C++20
502
503template<class charT, class traits, class Allocator>
504basic_istream<charT, traits>&
505operator>>(basic_istream<charT, traits>& is, basic_string<charT, traits, Allocator>& str);
506
507template<class charT, class traits, class Allocator>
508basic_ostream<charT, traits>&
509operator<<(basic_ostream<charT, traits>& os, const basic_string<charT, traits, Allocator>& str);
510
511template<class charT, class traits, class Allocator>
512basic_istream<charT, traits>&
513getline(basic_istream<charT, traits>& is, basic_string<charT, traits, Allocator>& str,
514 charT delim);
515
516template<class charT, class traits, class Allocator>
517basic_istream<charT, traits>&
518getline(basic_istream<charT, traits>& is, basic_string<charT, traits, Allocator>& str);
519
520template<class charT, class traits, class Allocator, class U>
521constexpr typename basic_string<charT, traits, Allocator>::size_type
522erase(basic_string<charT, traits, Allocator>& c, const U& value); // C++20
523template<class charT, class traits, class Allocator, class Predicate>
524constexpr typename basic_string<charT, traits, Allocator>::size_type
525erase_if(basic_string<charT, traits, Allocator>& c, Predicate pred); // C++20
526
527typedef basic_string<char> string;
528typedef basic_string<wchar_t> wstring;
529typedef basic_string<char8_t> u8string; // C++20
530typedef basic_string<char16_t> u16string;
531typedef basic_string<char32_t> u32string;
532
533int stoi (const string& str, size_t* idx = nullptr, int base = 10);
534long stol (const string& str, size_t* idx = nullptr, int base = 10);
535unsigned long stoul (const string& str, size_t* idx = nullptr, int base = 10);
536long long stoll (const string& str, size_t* idx = nullptr, int base = 10);
537unsigned long long stoull(const string& str, size_t* idx = nullptr, int base = 10);
538
539float stof (const string& str, size_t* idx = nullptr);
540double stod (const string& str, size_t* idx = nullptr);
541long double stold(const string& str, size_t* idx = nullptr);
542
543string to_string(int val);
544string to_string(unsigned val);
545string to_string(long val);
546string to_string(unsigned long val);
547string to_string(long long val);
548string to_string(unsigned long long val);
549string to_string(float val);
550string to_string(double val);
551string to_string(long double val);
552
553int stoi (const wstring& str, size_t* idx = nullptr, int base = 10);
554long stol (const wstring& str, size_t* idx = nullptr, int base = 10);
555unsigned long stoul (const wstring& str, size_t* idx = nullptr, int base = 10);
556long long stoll (const wstring& str, size_t* idx = nullptr, int base = 10);
557unsigned long long stoull(const wstring& str, size_t* idx = nullptr, int base = 10);
558
559float stof (const wstring& str, size_t* idx = nullptr);
560double stod (const wstring& str, size_t* idx = nullptr);
561long double stold(const wstring& str, size_t* idx = nullptr);
562
563wstring to_wstring(int val);
564wstring to_wstring(unsigned val);
565wstring to_wstring(long val);
566wstring to_wstring(unsigned long val);
567wstring to_wstring(long long val);
568wstring to_wstring(unsigned long long val);
569wstring to_wstring(float val);
570wstring to_wstring(double val);
571wstring to_wstring(long double val);
572
573template <> struct hash<string>;
574template <> struct hash<u8string>; // C++20
575template <> struct hash<u16string>;
576template <> struct hash<u32string>;
577template <> struct hash<wstring>;
578
579basic_string<char> operator""s( const char *str, size_t len ); // C++14, constexpr since C++20
580basic_string<wchar_t> operator""s( const wchar_t *str, size_t len ); // C++14, constexpr since C++20
581constexpr basic_string<char8_t> operator""s( const char8_t *str, size_t len ); // C++20
582basic_string<char16_t> operator""s( const char16_t *str, size_t len ); // C++14, constexpr since C++20
583basic_string<char32_t> operator""s( const char32_t *str, size_t len ); // C++14, constexpr since C++20
584
585} // std
586
587*/
588
589// clang-format on
590
591#if __cplusplus < 201103L && defined(_LIBCPP_USE_FROZEN_CXX03_HEADERS)
592# include <__cxx03/string>
593#else
594# include <__algorithm/max.h>
595# include <__algorithm/min.h>
596# include <__algorithm/remove.h>
597# include <__algorithm/remove_if.h>
598# include <__assert>
599# include <__config>
600# include <__debug_utils/sanitizers.h>
601# include <__format/enable_insertable.h>
602# include <__functional/hash.h>
603# include <__functional/is_transparent.h>
604# include <__functional/unary_function.h>
605# include <__fwd/string.h>
606# include <__iterator/bounded_iter.h>
607# include <__iterator/distance.h>
608# include <__iterator/iterator_traits.h>
609# include <__iterator/reverse_iterator.h>
610# include <__iterator/wrap_iter.h>
611# include <__memory/addressof.h>
612# include <__memory/allocate_at_least.h>
613# include <__memory/allocator.h>
614# include <__memory/allocator_traits.h>
615# include <__memory/compressed_pair.h>
616# include <__memory/construct_at.h>
617# include <__memory/noexcept_move_assign_container.h>
618# include <__memory/pointer_traits.h>
619# include <__memory/swap_allocator.h>
620# include <__memory_resource/polymorphic_allocator.h>
621# include <__ranges/access.h>
622# include <__ranges/concepts.h>
623# include <__ranges/container_compatible_range.h>
624# include <__ranges/from_range.h>
625# include <__string/char_traits.h>
626# include <__string/extern_template_lists.h>
627# include <__type_traits/conditional.h>
628# include <__type_traits/enable_if.h>
629# include <__type_traits/is_allocator.h>
630# include <__type_traits/is_array.h>
631# include <__type_traits/is_convertible.h>
632# include <__type_traits/is_generic_transparent_comparator.h>
633# include <__type_traits/is_nothrow_assignable.h>
634# include <__type_traits/is_nothrow_constructible.h>
635# include <__type_traits/is_same.h>
636# include <__type_traits/is_standard_layout.h>
637# include <__type_traits/is_trivially_constructible.h>
638# include <__type_traits/is_trivially_copyable.h>
639# include <__type_traits/is_trivially_relocatable.h>
640# include <__type_traits/remove_cvref.h>
641# include <__utility/default_three_way_comparator.h>
642# include <__utility/exception_guard.h>
643# include <__utility/forward.h>
644# include <__utility/is_pointer_in_range.h>
645# include <__utility/move.h>
646# include <__utility/no_destroy.h>
647# include <__utility/scope_guard.h>
648# include <__utility/swap.h>
649# include <climits>
650# include <cstdio> // EOF
651# include <cstring>
652# include <limits>
653# include <stdexcept>
654# include <string_view>
655# include <version>
656
657# if _LIBCPP_HAS_WIDE_CHARACTERS
658# include <cwchar>
659# endif
660
661// standard-mandated includes
662
663// [iterator.range]
664# include <__iterator/access.h>
665# include <__iterator/data.h>
666# include <__iterator/empty.h>
667# include <__iterator/reverse_access.h>
668# include <__iterator/size.h>
669
670// [string.syn]
671# include <compare>
672# include <initializer_list>
673
674# if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
675# pragma GCC system_header
676# endif
677
678_LIBCPP_PUSH_MACROS
679# include <__undef_macros>
680
681# if __has_feature(address_sanitizer) && _LIBCPP_INSTRUMENTED_WITH_ASAN
682# define _LIBCPP_STRING_INTERNAL_MEMORY_ACCESS __attribute__((__no_sanitize__("address")))
683// This macro disables AddressSanitizer (ASan) instrumentation for a specific function,
684// allowing memory accesses that would normally trigger ASan errors to proceed without crashing.
685// This is useful for accessing parts of objects memory, which should not be accessed,
686// such as unused bytes in short strings, that should never be accessed
687// by other parts of the program.
688# else
689# define _LIBCPP_STRING_INTERNAL_MEMORY_ACCESS
690# endif
691
692_LIBCPP_BEGIN_NAMESPACE_STD
693
694// basic_string
695
696template <class _CharT, class _Traits, class _Allocator>
697_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>
698__concatenate_strings(const _Allocator& __alloc,
699 __type_identity_t<basic_string_view<_CharT, _Traits> > __str1,
700 __type_identity_t<basic_string_view<_CharT, _Traits> > __str2);
701
702template <class _Iter>
703inline const bool __string_is_trivial_iterator_v = false;
704
705template <class _Tp>
706inline const bool __string_is_trivial_iterator_v<_Tp*> = is_arithmetic<_Tp>::value;
707
708template <class _Iter>
709inline const bool __string_is_trivial_iterator_v<__wrap_iter<_Iter> > = __string_is_trivial_iterator_v<_Iter>;
710
711template <class _CharT, class _Traits, class _Tp>
712inline const bool __can_be_converted_to_string_view_v =
713 is_convertible<const _Tp&, basic_string_view<_CharT, _Traits> >::value &&
714 !is_convertible<const _Tp&, const _CharT*>::value;
715
716struct __uninitialized_size_tag {};
717struct __init_with_sentinel_tag {};
718
719template <size_t _PaddingSize>
720struct __padding {
721 char __padding_[_PaddingSize];
722};
723
724template <>
725struct __padding<0> {};
726
727template <class _CharT, class _Traits, class _Allocator>
728class basic_string {
729public:
730 using __self _LIBCPP_NODEBUG = basic_string;
731 using __self_view _LIBCPP_NODEBUG = basic_string_view<_CharT, _Traits>;
732 using traits_type = _Traits;
733 using value_type = _CharT;
734 using allocator_type = _Allocator;
735 using __alloc_traits _LIBCPP_NODEBUG = allocator_traits<allocator_type>;
736 using size_type = typename __alloc_traits::size_type;
737 using difference_type = typename __alloc_traits::difference_type;
738 using reference = value_type&;
739 using const_reference = const value_type&;
740 using pointer = typename __alloc_traits::pointer;
741 using const_pointer = typename __alloc_traits::const_pointer;
742
743 // A basic_string contains the following members which may be trivially relocatable:
744 // - pointer: is currently assumed to be trivially relocatable, but is still checked in case that changes
745 // - size_type: is always trivially relocatable, since it has to be an integral type
746 // - value_type: is always trivially relocatable, since it has to be trivial
747 // - unsigned char: is a fundamental type, so it's trivially relocatable
748 // - allocator_type: may or may not be trivially relocatable, so it's checked
749 //
750 // This string implementation doesn't contain any references into itself. It only contains a bit that says whether
751 // it is in small or large string mode, so the entire structure is trivially relocatable if its members are.
752# if __has_feature(address_sanitizer) && _LIBCPP_INSTRUMENTED_WITH_ASAN
753 // When compiling with AddressSanitizer (ASan), basic_string cannot be trivially
754 // relocatable. Because the object's memory might be poisoned when its content
755 // is kept inside objects memory (short string optimization), instead of in allocated
756 // external memory. In such cases, the destructor is responsible for unpoisoning
757 // the memory to avoid triggering false positives.
758 // Therefore it's crucial to ensure the destructor is called.
759 using __trivially_relocatable _LIBCPP_NODEBUG = void;
760# else
761 using __trivially_relocatable _LIBCPP_NODEBUG = __conditional_t<
762 __libcpp_is_trivially_relocatable<allocator_type>::value && __libcpp_is_trivially_relocatable<pointer>::value,
763 basic_string,
764 void>;
765# endif
766
767# if __has_feature(address_sanitizer) && _LIBCPP_INSTRUMENTED_WITH_ASAN
768 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 pointer __asan_volatile_wrapper(pointer const& __ptr) const {
769 if (__libcpp_is_constant_evaluated())
770 return __ptr;
771
772 pointer volatile __copy_ptr = __ptr;
773
774 return const_cast<pointer&>(__copy_ptr);
775 }
776
777 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const_pointer
778 __asan_volatile_wrapper(const_pointer const& __ptr) const {
779 if (__libcpp_is_constant_evaluated())
780 return __ptr;
781
782 const_pointer volatile __copy_ptr = __ptr;
783
784 return const_cast<const_pointer&>(__copy_ptr);
785 }
786# define _LIBCPP_ASAN_VOLATILE_WRAPPER(PTR) __asan_volatile_wrapper(PTR)
787# else
788# define _LIBCPP_ASAN_VOLATILE_WRAPPER(PTR) PTR
789# endif
790
791 static_assert(!is_array<value_type>::value, "Character type of basic_string must not be an array");
792 static_assert(is_standard_layout<value_type>::value, "Character type of basic_string must be standard-layout");
793 static_assert(is_trivially_default_constructible<value_type>::value,
794 "Character type of basic_string must be trivially default constructible");
795 static_assert(is_trivially_copyable<value_type>::value, "Character type of basic_string must be trivially copyable");
796 static_assert(is_same<_CharT, typename traits_type::char_type>::value,
797 "traits_type::char_type must be the same type as CharT");
798 static_assert(is_same<typename allocator_type::value_type, value_type>::value,
799 "Allocator::value_type must be same type as value_type");
800 static_assert(__check_valid_allocator<allocator_type>::value, "");
801
802# ifdef _LIBCPP_ABI_BOUNDED_ITERATORS_IN_STRING
803 // Users might provide custom allocators, and prior to C++20 we have no existing way to detect whether the allocator's
804 // pointer type is contiguous (though it has to be by the Standard). Using the wrapper type ensures the iterator is
805 // considered contiguous.
806 using iterator = __bounded_iter<__wrap_iter<pointer> >;
807 using const_iterator = __bounded_iter<__wrap_iter<const_pointer> >;
808# else
809 using iterator = __wrap_iter<pointer>;
810 using const_iterator = __wrap_iter<const_pointer>;
811# endif
812 using reverse_iterator = std::reverse_iterator<iterator>;
813 using const_reverse_iterator = std::reverse_iterator<const_iterator>;
814
815 using __alloc_result _LIBCPP_NODEBUG = __allocation_result<pointer, size_type>;
816
817private:
818 static_assert(CHAR_BIT == 8, "This implementation assumes that one byte contains 8 bits");
819
820# ifdef _LIBCPP_ABI_ALTERNATE_STRING_LAYOUT
821
822 struct __long {
823 __long() = default;
824
825 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __long(__alloc_result __alloc, size_type __size)
826 : __data_(__alloc.ptr), __size_(__size), __cap_(__alloc.count / __endian_factor), __is_long_(true) {
827 _LIBCPP_ASSERT_INTERNAL(!__fits_in_sso(__alloc.count), "Long capacity should always be larger than the SSO");
828 }
829
830 pointer __data_;
831 size_type __size_;
832 size_type __cap_ : sizeof(size_type) * CHAR_BIT - 1;
833 size_type __is_long_ : 1;
834 };
835
836 enum { __min_cap = (sizeof(__long) - 1) / sizeof(value_type) > 2 ? (sizeof(__long) - 1) / sizeof(value_type) : 2 };
837
838 struct __short {
839 value_type __data_[__min_cap];
840 _LIBCPP_NO_UNIQUE_ADDRESS __padding<sizeof(value_type) - 1> __padding_;
841 unsigned char __size_ : 7;
842 unsigned char __is_long_ : 1;
843 };
844
845 // The __endian_factor is required because the field we use to store the size
846 // has one fewer bit than it would if it were not a bitfield.
847 //
848 // If the LSB is used to store the short-flag in the short string representation,
849 // we have to multiply the size by two when it is stored and divide it by two when
850 // it is loaded to make sure that we always store an even number. In the long string
851 // representation, we can ignore this because we can assume that we always allocate
852 // an even amount of value_types.
853 //
854 // If the MSB is used for the short-flag, the max_size() is numeric_limits<size_type>::max() / 2.
855 // This does not impact the short string representation, since we never need the MSB
856 // for representing the size of a short string anyway.
857
858# ifdef _LIBCPP_BIG_ENDIAN
859 static const size_type __endian_factor = 2;
860# else
861 static const size_type __endian_factor = 1;
862# endif
863
864# else // _LIBCPP_ABI_ALTERNATE_STRING_LAYOUT
865
866# ifdef _LIBCPP_BIG_ENDIAN
867 static const size_type __endian_factor = 1;
868# else
869 static const size_type __endian_factor = 2;
870# endif
871
872 // Attribute 'packed' is used to keep the layout compatible with the
873 // previous definition that did not use bit fields. This is because on
874 // some platforms bit fields have a default size rather than the actual
875 // size used, e.g., it is 4 bytes on AIX. See D128285 for details.
876 struct __long {
877 __long() = default;
878
879 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __long(__alloc_result __alloc, size_type __size)
880 : __is_long_(true), __cap_(__alloc.count / __endian_factor), __size_(__size), __data_(__alloc.ptr) {
881 _LIBCPP_ASSERT_INTERNAL(!__fits_in_sso(__alloc.count), "Long capacity should always be larger than the SSO");
882 }
883
884 struct _LIBCPP_PACKED {
885 size_type __is_long_ : 1;
886 size_type __cap_ : sizeof(size_type) * CHAR_BIT - 1;
887 };
888 size_type __size_;
889 pointer __data_;
890 };
891
892 enum { __min_cap = (sizeof(__long) - 1) / sizeof(value_type) > 2 ? (sizeof(__long) - 1) / sizeof(value_type) : 2 };
893
894 struct __short {
895 struct _LIBCPP_PACKED {
896 unsigned char __is_long_ : 1;
897 unsigned char __size_ : 7;
898 };
899 _LIBCPP_NO_UNIQUE_ADDRESS __padding<sizeof(value_type) - 1> __padding_;
900 value_type __data_[__min_cap];
901 };
902
903# endif // _LIBCPP_ABI_ALTERNATE_STRING_LAYOUT
904
905 static_assert(sizeof(__short) == (sizeof(value_type) * (__min_cap + 1)), "__short has an unexpected size.");
906
907 union __rep {
908 __short __s;
909 __long __l;
910
911 __rep() = default;
912 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __rep(__short __r) : __s(__r) {}
913 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __rep(__long __r) : __l(__r) {}
914 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __rep(__uninitialized_tag) {}
915 };
916
917 _LIBCPP_COMPRESSED_PAIR(__rep, __rep_, allocator_type, __alloc_);
918
919 // annotate the string with its size() at scope exit. The string has to be in a valid state at that point.
920 struct __annotate_new_size {
921 basic_string& __str_;
922
923 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __annotate_new_size(basic_string& __str) : __str_(__str) {}
924
925 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void operator()() { __str_.__annotate_new(__str_.size()); }
926 };
927
928 // Construct a string with the given allocator and enough storage to hold `__size` characters, but
929 // don't initialize the characters. The contents of the string, including the null terminator, must be
930 // initialized separately.
931 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 explicit basic_string(
932 __uninitialized_size_tag, size_type __size, const allocator_type& __a)
933 : __alloc_(__a) {
934 __init_internal_buffer(__size);
935 }
936
937 template <class _Iter, class _Sent>
938 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
939 basic_string(__init_with_sentinel_tag, _Iter __first, _Sent __last, const allocator_type& __a)
940 : __alloc_(__a) {
941 __init_with_sentinel(std::move(__first), std::move(__last));
942 }
943
944 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 iterator __make_iterator(pointer __p) {
945# ifdef _LIBCPP_ABI_BOUNDED_ITERATORS_IN_STRING
946 // Bound the iterator according to the size (and not the capacity, unlike vector).
947 //
948 // By the Standard, string iterators are generally not guaranteed to stay valid when the container is modified,
949 // regardless of whether reallocation occurs. This allows us to check for out-of-bounds accesses using logical size,
950 // a stricter check, since correct code can never rely on being able to access newly-added elements via an existing
951 // iterator.
952 return std::__make_bounded_iter(
953 std::__wrap_iter<pointer>(__p),
954 std::__wrap_iter<pointer>(__get_pointer()),
955 std::__wrap_iter<pointer>(__get_pointer() + size()));
956# else
957 return iterator(__p);
958# endif // _LIBCPP_ABI_BOUNDED_ITERATORS_IN_STRING
959 }
960
961 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const_iterator __make_const_iterator(const_pointer __p) const {
962# ifdef _LIBCPP_ABI_BOUNDED_ITERATORS_IN_STRING
963 // Bound the iterator according to the size (and not the capacity, unlike vector).
964 return std::__make_bounded_iter(
965 std::__wrap_iter<const_pointer>(__p),
966 std::__wrap_iter<const_pointer>(__get_pointer()),
967 std::__wrap_iter<const_pointer>(__get_pointer() + size()));
968# else
969 return const_iterator(__p);
970# endif // _LIBCPP_ABI_BOUNDED_ITERATORS_IN_STRING
971 }
972
973public:
974 _LIBCPP_TEMPLATE_DATA_VIS static const size_type npos = -1;
975
976 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string()
977 _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value)
978# if _LIBCPP_STD_VER >= 20 // TODO(LLVM 23): Remove this condition; this is a workaround for https://llvm.org/PR154567
979 : __rep_(__short())
980# else
981 : __rep_()
982# endif
983 {
984 __annotate_new(0);
985 }
986
987 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 explicit basic_string(const allocator_type& __a)
988# if _LIBCPP_STD_VER <= 14
989 _NOEXCEPT_(is_nothrow_copy_constructible<allocator_type>::value)
990# else
991 _NOEXCEPT
992# endif
993# if _LIBCPP_STD_VER >= 20 // TODO(LLVM 23): Remove this condition; this is a workaround for https://llvm.org/PR154567
994 : __rep_(__short()),
995# else
996 : __rep_(),
997# endif
998 __alloc_(__a) {
999 __annotate_new(0);
1000 }
1001
1002 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_STRING_INTERNAL_MEMORY_ACCESS basic_string(const basic_string& __str)
1003 : __alloc_(__alloc_traits::select_on_container_copy_construction(__str.__alloc_)) {
1004 if (!__str.__is_long()) {
1005 __rep_ = __str.__rep_;
1006 __annotate_new(__get_short_size());
1007 } else
1008 __init_copy_ctor_external(std::__to_address(__str.__get_long_pointer()), __str.__get_long_size());
1009 }
1010
1011 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_STRING_INTERNAL_MEMORY_ACCESS
1012 basic_string(const basic_string& __str, const allocator_type& __a)
1013 : __alloc_(__a) {
1014 if (!__str.__is_long()) {
1015 __rep_ = __str.__rep_;
1016 __annotate_new(__get_short_size());
1017 } else
1018 __init_copy_ctor_external(std::__to_address(__str.__get_long_pointer()), __str.__get_long_size());
1019 }
1020
1021# ifndef _LIBCPP_CXX03_LANG
1022 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string(basic_string&& __str)
1023# if _LIBCPP_STD_VER <= 14
1024 _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value)
1025# else
1026 _NOEXCEPT
1027# endif
1028 // Turning off ASan instrumentation for variable initialization with _LIBCPP_STRING_INTERNAL_MEMORY_ACCESS
1029 // does not work consistently during initialization of __r_, so we instead unpoison __str's memory manually first.
1030 // __str's memory needs to be unpoisoned only in the case where it's a short string.
1031 : __rep_([](basic_string& __s) -> decltype(__s.__rep_)&& {
1032 if (!__s.__is_long())
1033 __s.__annotate_delete();
1034 return std::move(__s.__rep_);
1035 }(__str)),
1036 __alloc_(std::move(__str.__alloc_)) {
1037 __str.__rep_ = __rep();
1038 __str.__annotate_new(0);
1039 if (!__is_long())
1040 __annotate_new(size());
1041 }
1042
1043 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string(basic_string&& __str, const allocator_type& __a)
1044 : __alloc_(__a) {
1045 if (__str.__is_long() && __a != __str.__alloc_) // copy, not move
1046 __init(std::__to_address(__str.__get_long_pointer()), __str.__get_long_size());
1047 else {
1048 if (__libcpp_is_constant_evaluated())
1049 __rep_ = __rep();
1050 if (!__str.__is_long())
1051 __str.__annotate_delete();
1052 __rep_ = __str.__rep_;
1053 __str.__rep_ = __rep();
1054 __str.__annotate_new(0);
1055 if (!__is_long() && this != std::addressof(__str))
1056 __annotate_new(size());
1057 }
1058 }
1059# endif // _LIBCPP_CXX03_LANG
1060
1061 template <__enable_if_t<__is_allocator_v<_Allocator>, int> = 0>
1062 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string(const _CharT* _LIBCPP_DIAGNOSE_NULLPTR __s) {
1063 _LIBCPP_ASSERT_NON_NULL(__s != nullptr, "basic_string(const char*) detected nullptr");
1064 __init(__s, traits_type::length(__s));
1065 }
1066
1067 template <__enable_if_t<__is_allocator_v<_Allocator>, int> = 0>
1068 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
1069 basic_string(const _CharT* _LIBCPP_DIAGNOSE_NULLPTR __s, const _Allocator& __a)
1070 : __alloc_(__a) {
1071 _LIBCPP_ASSERT_NON_NULL(__s != nullptr, "basic_string(const char*, allocator) detected nullptr");
1072 __init(__s, traits_type::length(__s));
1073 }
1074
1075# if _LIBCPP_STD_VER >= 23
1076 basic_string(nullptr_t) = delete;
1077# endif
1078
1079 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string(const _CharT* __s, size_type __n)
1080 _LIBCPP_DIAGNOSE_NULLPTR_IF(__n != 0 && __s == nullptr, " if n is not zero") {
1081 _LIBCPP_ASSERT_NON_NULL(__n == 0 || __s != nullptr, "basic_string(const char*, n) detected nullptr");
1082 __init(__s, __n);
1083 }
1084
1085 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
1086 basic_string(const _CharT* __s, size_type __n, const _Allocator& __a)
1087 _LIBCPP_DIAGNOSE_NULLPTR_IF(__n != 0 && __s == nullptr, " if n is not zero")
1088 : __alloc_(__a) {
1089 _LIBCPP_ASSERT_NON_NULL(__n == 0 || __s != nullptr, "basic_string(const char*, n, allocator) detected nullptr");
1090 __init(__s, __n);
1091 }
1092
1093 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string(size_type __n, _CharT __c) { __init(__n, __c); }
1094
1095# if _LIBCPP_STD_VER >= 23
1096 _LIBCPP_HIDE_FROM_ABI constexpr basic_string(
1097 basic_string&& __str, size_type __pos, const _Allocator& __alloc = _Allocator())
1098 : basic_string(std::move(__str), __pos, npos, __alloc) {}
1099
1100 _LIBCPP_HIDE_FROM_ABI constexpr basic_string(
1101 basic_string&& __str, size_type __pos, size_type __n, const _Allocator& __alloc = _Allocator())
1102 : __alloc_(__alloc) {
1103 if (__pos > __str.size())
1104 this->__throw_out_of_range();
1105
1106 auto __len = std::min<size_type>(__n, __str.size() - __pos);
1107 if (__alloc_traits::is_always_equal::value || __alloc == __str.__alloc_) {
1108 __move_assign(std::move(__str), __pos, __len);
1109 } else {
1110 // Perform a copy because the allocators are not compatible.
1111 __init(__str.data() + __pos, __len);
1112 }
1113 }
1114# endif
1115
1116 template <__enable_if_t<__is_allocator_v<_Allocator>, int> = 0>
1117 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string(size_type __n, _CharT __c, const _Allocator& __a)
1118 : __alloc_(__a) {
1119 __init(__n, __c);
1120 }
1121
1122 _LIBCPP_CONSTEXPR_SINCE_CXX20
1123 basic_string(const basic_string& __str, size_type __pos, size_type __n, const _Allocator& __a = _Allocator())
1124 : __alloc_(__a) {
1125 size_type __str_sz = __str.size();
1126 if (__pos > __str_sz)
1127 this->__throw_out_of_range();
1128 __init(__str.data() + __pos, std::min(__n, __str_sz - __pos));
1129 }
1130
1131 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
1132 basic_string(const basic_string& __str, size_type __pos, const _Allocator& __a = _Allocator())
1133 : __alloc_(__a) {
1134 size_type __str_sz = __str.size();
1135 if (__pos > __str_sz)
1136 this->__throw_out_of_range();
1137 __init(__str.data() + __pos, __str_sz - __pos);
1138 }
1139
1140 template <class _Tp,
1141 __enable_if_t<__can_be_converted_to_string_view_v<_CharT, _Traits, _Tp> &&
1142 !is_same<__remove_cvref_t<_Tp>, basic_string>::value,
1143 int> = 0>
1144 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
1145 basic_string(const _Tp& __t, size_type __pos, size_type __n, const allocator_type& __a = allocator_type())
1146 : __alloc_(__a) {
1147 __self_view __sv0 = __t;
1148 __self_view __sv = __sv0.substr(__pos, __n);
1149 __init(__sv.data(), __sv.size());
1150 }
1151
1152 template <class _Tp,
1153 __enable_if_t<__can_be_converted_to_string_view_v<_CharT, _Traits, _Tp> &&
1154 !is_same<__remove_cvref_t<_Tp>, basic_string>::value,
1155 int> = 0>
1156 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 explicit basic_string(const _Tp& __t) {
1157 __self_view __sv = __t;
1158 __init(__sv.data(), __sv.size());
1159 }
1160
1161 template <class _Tp,
1162 __enable_if_t<__can_be_converted_to_string_view_v<_CharT, _Traits, _Tp> &&
1163 !is_same<__remove_cvref_t<_Tp>, basic_string>::value,
1164 int> = 0>
1165 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 explicit basic_string(const _Tp& __t, const allocator_type& __a)
1166 : __alloc_(__a) {
1167 __self_view __sv = __t;
1168 __init(__sv.data(), __sv.size());
1169 }
1170
1171 template <class _InputIterator, __enable_if_t<__has_input_iterator_category<_InputIterator>::value, int> = 0>
1172 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string(_InputIterator __first, _InputIterator __last) {
1173 __init(__first, __last);
1174 }
1175
1176 template <class _InputIterator, __enable_if_t<__has_input_iterator_category<_InputIterator>::value, int> = 0>
1177 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
1178 basic_string(_InputIterator __first, _InputIterator __last, const allocator_type& __a)
1179 : __alloc_(__a) {
1180 __init(__first, __last);
1181 }
1182
1183# if _LIBCPP_STD_VER >= 23
1184 template <_ContainerCompatibleRange<_CharT> _Range>
1185 _LIBCPP_HIDE_FROM_ABI constexpr basic_string(
1186 from_range_t, _Range&& __range, const allocator_type& __a = allocator_type())
1187 : __alloc_(__a) {
1188 if constexpr (ranges::forward_range<_Range> || ranges::sized_range<_Range>) {
1189 __init_with_size(ranges::begin(__range), ranges::end(__range), ranges::distance(__range));
1190 } else {
1191 __init_with_sentinel(ranges::begin(__range), ranges::end(__range));
1192 }
1193 }
1194# endif
1195
1196# ifndef _LIBCPP_CXX03_LANG
1197 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string(initializer_list<_CharT> __il) {
1198 __init(__il.begin(), __il.end());
1199 }
1200
1201 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string(initializer_list<_CharT> __il, const _Allocator& __a)
1202 : __alloc_(__a) {
1203 __init(__il.begin(), __il.end());
1204 }
1205# endif // _LIBCPP_CXX03_LANG
1206
1207 // TODO(boomanaiden154): Once we mark this in destructors as dead on return,
1208 // we can use a normal call to __reset_internal_buffer and remove the extra
1209 // __rep constructor.
1210 inline _LIBCPP_CONSTEXPR_SINCE_CXX20 ~basic_string() { __reset_internal_buffer(__rep(__uninitialized_tag())); }
1211
1212 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 operator __self_view() const _NOEXCEPT {
1213 return __self_view(typename __self_view::__assume_valid(), data(), size());
1214 }
1215
1216 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_STRING_INTERNAL_MEMORY_ACCESS basic_string&
1217 operator=(const basic_string& __str);
1218
1219 template <class _Tp,
1220 __enable_if_t<__can_be_converted_to_string_view_v<_CharT, _Traits, _Tp> &&
1221 !is_same<__remove_cvref_t<_Tp>, basic_string>::value,
1222 int> = 0>
1223 _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& operator=(const _Tp& __t) {
1224 __self_view __sv = __t;
1225 return assign(__sv);
1226 }
1227
1228# ifndef _LIBCPP_CXX03_LANG
1229 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&
1230 operator=(basic_string&& __str) noexcept(__noexcept_move_assign_container<_Allocator, __alloc_traits>::value) {
1231 __move_assign(__str, integral_constant<bool, __alloc_traits::propagate_on_container_move_assignment::value>());
1232 return *this;
1233 }
1234
1235 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& operator=(initializer_list<value_type> __il) {
1236 return assign(__il.begin(), __il.size());
1237 }
1238# endif
1239 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&
1240 operator=(const value_type* _LIBCPP_DIAGNOSE_NULLPTR __s) {
1241 return assign(__s);
1242 }
1243# if _LIBCPP_STD_VER >= 23
1244 basic_string& operator=(nullptr_t) = delete;
1245# endif
1246 _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& operator=(value_type __c);
1247
1248 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 iterator begin() _NOEXCEPT {
1249 return __make_iterator(__get_pointer());
1250 }
1251 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const_iterator begin() const _NOEXCEPT {
1252 return __make_const_iterator(__get_pointer());
1253 }
1254 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 iterator end() _NOEXCEPT {
1255 return __make_iterator(__get_pointer() + size());
1256 }
1257 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const_iterator end() const _NOEXCEPT {
1258 return __make_const_iterator(__get_pointer() + size());
1259 }
1260
1261 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 reverse_iterator rbegin() _NOEXCEPT {
1262 return reverse_iterator(end());
1263 }
1264 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const_reverse_iterator
1265 rbegin() const _NOEXCEPT {
1266 return const_reverse_iterator(end());
1267 }
1268 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 reverse_iterator rend() _NOEXCEPT {
1269 return reverse_iterator(begin());
1270 }
1271 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const_reverse_iterator rend() const _NOEXCEPT {
1272 return const_reverse_iterator(begin());
1273 }
1274
1275 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const_iterator cbegin() const _NOEXCEPT {
1276 return begin();
1277 }
1278 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const_iterator cend() const _NOEXCEPT {
1279 return end();
1280 }
1281 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const_reverse_iterator
1282 crbegin() const _NOEXCEPT {
1283 return rbegin();
1284 }
1285 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const_reverse_iterator crend() const _NOEXCEPT {
1286 return rend();
1287 }
1288
1289 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type size() const _NOEXCEPT {
1290 return __is_long() ? __get_long_size() : __get_short_size();
1291 }
1292 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type length() const _NOEXCEPT {
1293 return size();
1294 }
1295
1296 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type max_size() const _NOEXCEPT {
1297 if (size_type __m = __alloc_traits::max_size(__alloc_); __m <= std::numeric_limits<size_type>::max() / 2) {
1298 size_type __res = __m - __alignment;
1299
1300 // When the __endian_factor == 2, our string representation assumes that the capacity
1301 // (including the null terminator) is always even, so we have to make sure the lowest bit isn't set when the
1302 // string grows to max_size()
1303 if (__endian_factor == 2)
1304 __res &= ~size_type(1);
1305
1306 // We have to allocate space for the null terminator, but max_size() doesn't include it.
1307 return __res - 1;
1308 } else {
1309 bool __uses_lsb = __endian_factor == 2;
1310 return __uses_lsb ? __m - __alignment - 1 : (__m / 2) - __alignment - 1;
1311 }
1312 }
1313
1314 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type capacity() const _NOEXCEPT {
1315 return (__is_long() ? __get_long_cap() : static_cast<size_type>(__min_cap)) - 1;
1316 }
1317
1318 _LIBCPP_CONSTEXPR_SINCE_CXX20 void resize(size_type __n, value_type __c);
1319 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void resize(size_type __n) { resize(__n, value_type()); }
1320
1321 _LIBCPP_CONSTEXPR_SINCE_CXX20 void reserve(size_type __requested_capacity);
1322
1323# if _LIBCPP_STD_VER >= 23
1324 template <class _Op>
1325 _LIBCPP_HIDE_FROM_ABI constexpr void resize_and_overwrite(size_type __n, _Op __op) {
1326 using __result_type = decltype(std::move(__op)(data(), auto(__n)));
1327 static_assert(__integer_like<__result_type>, "Operation return type must be integer-like");
1328 size_type __sz = size();
1329 size_type __cap = capacity();
1330 if (__n > __cap)
1331 __grow_by_without_replace(__cap, __n - __cap, __sz, __sz, 0);
1332 __annotate_delete();
1333 __set_size(__n);
1334 __annotate_new(__n);
1335 __erase_to_end(std::move(__op)(data(), auto(__n)));
1336 }
1337# endif
1338
1339# if _LIBCPP_STD_VER < 26 || defined(_LIBCPP_ENABLE_CXX26_REMOVED_STRING_RESERVE)
1340 _LIBCPP_DEPRECATED_IN_CXX20 _LIBCPP_HIDE_FROM_ABI void reserve() _NOEXCEPT { shrink_to_fit(); }
1341# endif
1342 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void shrink_to_fit() _NOEXCEPT;
1343 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void clear() _NOEXCEPT;
1344
1345 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool empty() const _NOEXCEPT {
1346 return size() == 0;
1347 }
1348
1349 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const_reference
1350 operator[](size_type __pos) const _NOEXCEPT {
1351 _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(__pos <= size(), "string index out of bounds");
1352 if (__builtin_constant_p(__pos) && !__fits_in_sso(__pos)) {
1353 return *(__get_long_pointer() + __pos);
1354 }
1355 return *(data() + __pos);
1356 }
1357
1358 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 reference
1359 operator[](size_type __pos) _NOEXCEPT {
1360 _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(__pos <= size(), "string index out of bounds");
1361 if (__builtin_constant_p(__pos) && !__fits_in_sso(__pos)) {
1362 return *(__get_long_pointer() + __pos);
1363 }
1364 return *(__get_pointer() + __pos);
1365 }
1366
1367 [[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX20 const_reference at(size_type __n) const;
1368 [[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX20 reference at(size_type __n);
1369
1370 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& operator+=(const basic_string& __str) {
1371 return append(__str);
1372 }
1373
1374 template <class _Tp,
1375 __enable_if_t<__can_be_converted_to_string_view_v<_CharT, _Traits, _Tp> &&
1376 !is_same<__remove_cvref_t<_Tp>, basic_string >::value,
1377 int> = 0>
1378 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& operator+=(const _Tp& __t) {
1379 __self_view __sv = __t;
1380 return append(__sv);
1381 }
1382
1383 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&
1384 operator+=(const value_type* _LIBCPP_DIAGNOSE_NULLPTR __s) {
1385 return append(__s);
1386 }
1387
1388 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& operator+=(value_type __c) {
1389 push_back(__c);
1390 return *this;
1391 }
1392
1393# ifndef _LIBCPP_CXX03_LANG
1394 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& operator+=(initializer_list<value_type> __il) {
1395 return append(__il);
1396 }
1397# endif // _LIBCPP_CXX03_LANG
1398
1399 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& append(const basic_string& __str) {
1400 return append(__str.data(), __str.size());
1401 }
1402
1403 template <class _Tp,
1404 __enable_if_t<__can_be_converted_to_string_view_v<_CharT, _Traits, _Tp> &&
1405 !is_same<__remove_cvref_t<_Tp>, basic_string>::value,
1406 int> = 0>
1407 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& append(const _Tp& __t) {
1408 __self_view __sv = __t;
1409 return append(__sv.data(), __sv.size());
1410 }
1411
1412 _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& append(const basic_string& __str, size_type __pos, size_type __n = npos);
1413
1414 template <class _Tp,
1415 __enable_if_t<__can_be_converted_to_string_view_v<_CharT, _Traits, _Tp> &&
1416 !is_same<__remove_cvref_t<_Tp>, basic_string>::value,
1417 int> = 0>
1418 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&
1419 append(const _Tp& __t, size_type __pos, size_type __n = npos) {
1420 __self_view __sv = __t;
1421 size_type __sz = __sv.size();
1422 if (__pos > __sz)
1423 __throw_out_of_range();
1424 return append(__sv.data() + __pos, std::min(__n, __sz - __pos));
1425 }
1426
1427 _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& append(const value_type* __s, size_type __n)
1428 _LIBCPP_DIAGNOSE_NULLPTR_IF(__n != 0 && __s == nullptr, " if n is not zero");
1429 _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& append(const value_type* _LIBCPP_DIAGNOSE_NULLPTR __s);
1430 _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& append(size_type __n, value_type __c);
1431
1432 template <class _InputIterator, __enable_if_t<__has_exactly_input_iterator_category<_InputIterator>::value, int> = 0>
1433 _LIBCPP_HIDE_FROM_ABI _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&
1434 append(_InputIterator __first, _InputIterator __last) {
1435 const basic_string __temp(__first, __last, __alloc_);
1436 append(__temp.data(), __temp.size());
1437 return *this;
1438 }
1439
1440 template <class _ForwardIterator, __enable_if_t<__has_forward_iterator_category<_ForwardIterator>::value, int> = 0>
1441 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&
1442 append(_ForwardIterator __first, _ForwardIterator __last) {
1443 size_type __sz = size();
1444 size_type __cap = capacity();
1445 size_type __n = static_cast<size_type>(std::distance(__first, __last));
1446 if (__n == 0)
1447 return *this;
1448
1449 if (__string_is_trivial_iterator_v<_ForwardIterator> && !__addr_in_range(*__first)) {
1450 if (__cap - __sz < __n)
1451 __grow_by_without_replace(__cap, __sz + __n - __cap, __sz, __sz, 0);
1452 __annotate_increase(__n);
1453 auto __end = __copy_non_overlapping_range(__first, __last, std::__to_address(__get_pointer() + __sz));
1454 traits_type::assign(*__end, value_type());
1455 __set_size(__sz + __n);
1456 return *this;
1457 } else {
1458 const basic_string __temp(__first, __last, __alloc_);
1459 return append(__temp.data(), __temp.size());
1460 }
1461 }
1462
1463# if _LIBCPP_STD_VER >= 23
1464 template <_ContainerCompatibleRange<_CharT> _Range>
1465 _LIBCPP_HIDE_FROM_ABI constexpr basic_string& append_range(_Range&& __range) {
1466 insert_range(end(), std::forward<_Range>(__range));
1467 return *this;
1468 }
1469# endif
1470
1471# ifndef _LIBCPP_CXX03_LANG
1472 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& append(initializer_list<value_type> __il) {
1473 return append(__il.begin(), __il.size());
1474 }
1475# endif // _LIBCPP_CXX03_LANG
1476
1477 _LIBCPP_CONSTEXPR_SINCE_CXX20 void push_back(value_type __c);
1478 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void pop_back();
1479
1480 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 reference front() _NOEXCEPT {
1481 _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(!empty(), "string::front(): string is empty");
1482 return *__get_pointer();
1483 }
1484
1485 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const_reference front() const _NOEXCEPT {
1486 _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(!empty(), "string::front(): string is empty");
1487 return *data();
1488 }
1489
1490 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 reference back() _NOEXCEPT {
1491 _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(!empty(), "string::back(): string is empty");
1492 return *(__get_pointer() + size() - 1);
1493 }
1494
1495 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const_reference back() const _NOEXCEPT {
1496 _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(!empty(), "string::back(): string is empty");
1497 return *(data() + size() - 1);
1498 }
1499
1500 template <class _Tp, __enable_if_t<__can_be_converted_to_string_view_v<_CharT, _Traits, _Tp>, int> = 0>
1501 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& assign(const _Tp& __t) {
1502 __self_view __sv = __t;
1503 return assign(__sv.data(), __sv.size());
1504 }
1505
1506# if _LIBCPP_STD_VER >= 20
1507 _LIBCPP_HIDE_FROM_ABI constexpr void __move_assign(basic_string&& __str, size_type __pos, size_type __len) {
1508 // Pilfer the allocation from __str.
1509 _LIBCPP_ASSERT_INTERNAL(__alloc_ == __str.__alloc_, "__move_assign called with wrong allocator");
1510 size_type __old_sz = __str.size();
1511 if (!__str.__is_long())
1512 __str.__annotate_delete();
1513 __rep_ = __str.__rep_;
1514 __str.__rep_ = __rep();
1515 __str.__annotate_new(0);
1516
1517 _Traits::move(data(), data() + __pos, __len);
1518 __set_size(__len);
1519 _Traits::assign(data()[__len], value_type());
1520
1521 if (!__is_long()) {
1522 __annotate_new(__len);
1523 } else if (__old_sz > __len) {
1524 __annotate_shrink(__old_sz);
1525 }
1526 }
1527# endif
1528
1529 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& assign(const basic_string& __str) {
1530 return *this = __str;
1531 }
1532# ifndef _LIBCPP_CXX03_LANG
1533 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&
1534 assign(basic_string&& __str) noexcept(__noexcept_move_assign_container<_Allocator, __alloc_traits>::value) {
1535 *this = std::move(__str);
1536 return *this;
1537 }
1538# endif
1539 _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& assign(const basic_string& __str, size_type __pos, size_type __n = npos);
1540
1541 template <class _Tp,
1542 __enable_if_t<__can_be_converted_to_string_view_v<_CharT, _Traits, _Tp> &&
1543 !is_same<__remove_cvref_t<_Tp>, basic_string>::value,
1544 int> = 0>
1545 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&
1546 assign(const _Tp& __t, size_type __pos, size_type __n = npos) {
1547 __self_view __sv = __t;
1548 size_type __sz = __sv.size();
1549 if (__pos > __sz)
1550 __throw_out_of_range();
1551 return assign(__sv.data() + __pos, std::min(__n, __sz - __pos));
1552 }
1553
1554 _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& assign(const value_type* __s, size_type __n)
1555 _LIBCPP_DIAGNOSE_NULLPTR_IF(__n != 0 && __s == nullptr, " if n is not zero");
1556 _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& assign(const value_type* _LIBCPP_DIAGNOSE_NULLPTR __s);
1557 _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& assign(size_type __n, value_type __c);
1558
1559 template <class _InputIterator, __enable_if_t<__has_exactly_input_iterator_category<_InputIterator>::value, int> = 0>
1560 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&
1561 assign(_InputIterator __first, _InputIterator __last) {
1562 __assign_with_sentinel(__first, __last);
1563 return *this;
1564 }
1565
1566 template <class _ForwardIterator, __enable_if_t<__has_forward_iterator_category<_ForwardIterator>::value, int> = 0>
1567 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&
1568 assign(_ForwardIterator __first, _ForwardIterator __last) {
1569 if (__string_is_trivial_iterator_v<_ForwardIterator>) {
1570 size_type __n = static_cast<size_type>(std::distance(__first, __last));
1571 __assign_trivial(__first, __last, __n);
1572 } else {
1573 __assign_with_sentinel(__first, __last);
1574 }
1575
1576 return *this;
1577 }
1578
1579# if _LIBCPP_STD_VER >= 23
1580 template <_ContainerCompatibleRange<_CharT> _Range>
1581 _LIBCPP_HIDE_FROM_ABI constexpr basic_string& assign_range(_Range&& __range) {
1582 if constexpr (__string_is_trivial_iterator_v<ranges::iterator_t<_Range>> &&
1583 (ranges::forward_range<_Range> || ranges::sized_range<_Range>)) {
1584 size_type __n = static_cast<size_type>(ranges::distance(__range));
1585 __assign_trivial(ranges::begin(__range), ranges::end(__range), __n);
1586
1587 } else {
1588 __assign_with_sentinel(ranges::begin(__range), ranges::end(__range));
1589 }
1590
1591 return *this;
1592 }
1593# endif
1594
1595# ifndef _LIBCPP_CXX03_LANG
1596 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& assign(initializer_list<value_type> __il) {
1597 return assign(__il.begin(), __il.size());
1598 }
1599# endif // _LIBCPP_CXX03_LANG
1600
1601 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&
1602 insert(size_type __pos1, const basic_string& __str) {
1603 return insert(__pos1, __str.data(), __str.size());
1604 }
1605
1606 template <class _Tp, __enable_if_t<__can_be_converted_to_string_view_v<_CharT, _Traits, _Tp>, int> = 0>
1607 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& insert(size_type __pos1, const _Tp& __t) {
1608 __self_view __sv = __t;
1609 return insert(__pos1, __sv.data(), __sv.size());
1610 }
1611
1612 template <class _Tp,
1613 __enable_if_t<__can_be_converted_to_string_view_v<_CharT, _Traits, _Tp> &&
1614 !is_same<__remove_cvref_t<_Tp>, basic_string>::value,
1615 int> = 0>
1616 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&
1617 insert(size_type __pos1, const _Tp& __t, size_type __pos2, size_type __n = npos) {
1618 __self_view __sv = __t;
1619 size_type __str_sz = __sv.size();
1620 if (__pos2 > __str_sz)
1621 __throw_out_of_range();
1622 return insert(__pos1, __sv.data() + __pos2, std::min(__n, __str_sz - __pos2));
1623 }
1624
1625 _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&
1626 insert(size_type __pos1, const basic_string& __str, size_type __pos2, size_type __n = npos);
1627 _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& insert(size_type __pos, const value_type* __s, size_type __n)
1628 _LIBCPP_DIAGNOSE_NULLPTR_IF(__n != 0 && __s == nullptr, " if n is not zero");
1629 _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& insert(size_type __pos, const value_type* _LIBCPP_DIAGNOSE_NULLPTR __s);
1630 _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& insert(size_type __pos, size_type __n, value_type __c);
1631 _LIBCPP_CONSTEXPR_SINCE_CXX20 iterator insert(const_iterator __pos, value_type __c);
1632
1633# if _LIBCPP_STD_VER >= 23
1634 template <_ContainerCompatibleRange<_CharT> _Range>
1635 _LIBCPP_HIDE_FROM_ABI constexpr iterator insert_range(const_iterator __position, _Range&& __range) {
1636 if constexpr (ranges::forward_range<_Range> || ranges::sized_range<_Range>) {
1637 auto __n = static_cast<size_type>(ranges::distance(__range));
1638 return __insert_with_size(__position, ranges::begin(__range), ranges::end(__range), __n);
1639
1640 } else {
1641 basic_string __temp(from_range, std::forward<_Range>(__range), __alloc_);
1642 return insert(__position, __temp.data(), __temp.data() + __temp.size());
1643 }
1644 }
1645# endif
1646
1647 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 iterator
1648 insert(const_iterator __pos, size_type __n, value_type __c) {
1649 difference_type __p = __pos - begin();
1650 insert(static_cast<size_type>(__p), __n, __c);
1651 return begin() + __p;
1652 }
1653
1654 template <class _InputIterator, __enable_if_t<__has_exactly_input_iterator_category<_InputIterator>::value, int> = 0>
1655 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 iterator
1656 insert(const_iterator __pos, _InputIterator __first, _InputIterator __last) {
1657 const basic_string __temp(__first, __last, __alloc_);
1658 return insert(__pos, __temp.data(), __temp.data() + __temp.size());
1659 }
1660
1661 template <class _ForwardIterator, __enable_if_t<__has_forward_iterator_category<_ForwardIterator>::value, int> = 0>
1662 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 iterator
1663 insert(const_iterator __pos, _ForwardIterator __first, _ForwardIterator __last) {
1664 auto __n = static_cast<size_type>(std::distance(__first, __last));
1665 return __insert_with_size(__pos, __first, __last, __n);
1666 }
1667
1668# ifndef _LIBCPP_CXX03_LANG
1669 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 iterator
1670 insert(const_iterator __pos, initializer_list<value_type> __il) {
1671 return insert(__pos, __il.begin(), __il.end());
1672 }
1673# endif // _LIBCPP_CXX03_LANG
1674
1675 _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& erase(size_type __pos = 0, size_type __n = npos);
1676 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 iterator erase(const_iterator __pos);
1677 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 iterator erase(const_iterator __first, const_iterator __last);
1678
1679 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&
1680 replace(size_type __pos1, size_type __n1, const basic_string& __str) {
1681 return replace(__pos1, __n1, __str.data(), __str.size());
1682 }
1683
1684 template <class _Tp, __enable_if_t<__can_be_converted_to_string_view_v<_CharT, _Traits, _Tp>, int> = 0>
1685 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&
1686 replace(size_type __pos1, size_type __n1, const _Tp& __t) {
1687 __self_view __sv = __t;
1688 return replace(__pos1, __n1, __sv.data(), __sv.size());
1689 }
1690
1691 _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&
1692 replace(size_type __pos1, size_type __n1, const basic_string& __str, size_type __pos2, size_type __n2 = npos);
1693
1694 template <class _Tp,
1695 __enable_if_t<__can_be_converted_to_string_view_v<_CharT, _Traits, _Tp> &&
1696 !is_same<__remove_cvref_t<_Tp>, basic_string>::value,
1697 int> = 0>
1698 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&
1699 replace(size_type __pos1, size_type __n1, const _Tp& __t, size_type __pos2, size_type __n2 = npos) {
1700 __self_view __sv = __t;
1701 size_type __str_sz = __sv.size();
1702 if (__pos2 > __str_sz)
1703 __throw_out_of_range();
1704 return replace(__pos1, __n1, __sv.data() + __pos2, std::min(__n2, __str_sz - __pos2));
1705 }
1706
1707 _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&
1708 replace(size_type __pos, size_type __n1, const value_type* __s, size_type __n2)
1709 _LIBCPP_DIAGNOSE_NULLPTR_IF(__n2 != 0 && __s == nullptr, " if n2 is not zero");
1710 _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&
1711 replace(size_type __pos, size_type __n1, const value_type* _LIBCPP_DIAGNOSE_NULLPTR __s);
1712 _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& replace(size_type __pos, size_type __n1, size_type __n2, value_type __c);
1713
1714 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&
1715 replace(const_iterator __i1, const_iterator __i2, const basic_string& __str) {
1716 return replace(
1717 static_cast<size_type>(__i1 - begin()), static_cast<size_type>(__i2 - __i1), __str.data(), __str.size());
1718 }
1719
1720 template <class _Tp, __enable_if_t<__can_be_converted_to_string_view_v<_CharT, _Traits, _Tp>, int> = 0>
1721 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&
1722 replace(const_iterator __i1, const_iterator __i2, const _Tp& __t) {
1723 __self_view __sv = __t;
1724 return replace(__i1 - begin(), __i2 - __i1, __sv);
1725 }
1726
1727 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&
1728 replace(const_iterator __i1, const_iterator __i2, const value_type* __s, size_type __n) {
1729 return replace(static_cast<size_type>(__i1 - begin()), static_cast<size_type>(__i2 - __i1), __s, __n);
1730 }
1731
1732 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&
1733 replace(const_iterator __i1, const_iterator __i2, const value_type* __s) {
1734 return replace(static_cast<size_type>(__i1 - begin()), static_cast<size_type>(__i2 - __i1), __s);
1735 }
1736
1737 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&
1738 replace(const_iterator __i1, const_iterator __i2, size_type __n, value_type __c) {
1739 return replace(static_cast<size_type>(__i1 - begin()), static_cast<size_type>(__i2 - __i1), __n, __c);
1740 }
1741
1742 template <class _InputIterator, __enable_if_t<__has_input_iterator_category<_InputIterator>::value, int> = 0>
1743 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&
1744 replace(const_iterator __i1, const_iterator __i2, _InputIterator __j1, _InputIterator __j2) {
1745 const basic_string __temp(__j1, __j2, __alloc_);
1746 return replace(__i1, __i2, __temp);
1747 }
1748
1749# if _LIBCPP_STD_VER >= 23
1750 template <_ContainerCompatibleRange<_CharT> _Range>
1751 _LIBCPP_HIDE_FROM_ABI constexpr basic_string&
1752 replace_with_range(const_iterator __i1, const_iterator __i2, _Range&& __range) {
1753 basic_string __temp(from_range, std::forward<_Range>(__range), __alloc_);
1754 return replace(__i1, __i2, __temp);
1755 }
1756# endif
1757
1758# ifndef _LIBCPP_CXX03_LANG
1759 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&
1760 replace(const_iterator __i1, const_iterator __i2, initializer_list<value_type> __il) {
1761 return replace(__i1, __i2, __il.begin(), __il.end());
1762 }
1763# endif // _LIBCPP_CXX03_LANG
1764
1765 _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type copy(value_type* __s, size_type __n, size_type __pos = 0) const;
1766
1767# if _LIBCPP_STD_VER <= 20
1768 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI
1769 _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string substr(size_type __pos = 0, size_type __n = npos) const {
1770 return basic_string(*this, __pos, __n);
1771 }
1772# else
1773 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr basic_string substr(size_type __pos = 0, size_type __n = npos) const& {
1774 return basic_string(*this, __pos, __n);
1775 }
1776
1777 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr basic_string substr(size_type __pos = 0, size_type __n = npos) && {
1778 return basic_string(std::move(*this), __pos, __n);
1779 }
1780# endif
1781# if _LIBCPP_STD_VER >= 26
1782 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr __self_view subview(size_type __pos = 0, size_type __n = npos) const {
1783 return __self_view(*this).subview(__pos, __n);
1784 }
1785# endif
1786
1787 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void swap(basic_string& __str)
1788# if _LIBCPP_STD_VER >= 14
1789 _NOEXCEPT;
1790# else
1791 _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value || __is_nothrow_swappable_v<allocator_type>);
1792# endif
1793
1794 // [string.ops]
1795 // ------------
1796
1797 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const value_type* c_str() const _NOEXCEPT {
1798 return data();
1799 }
1800
1801 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const value_type* data() const _NOEXCEPT {
1802 return std::__to_address(__get_pointer());
1803 }
1804# if _LIBCPP_STD_VER >= 17
1805 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 value_type* data() _NOEXCEPT {
1806 return std::__to_address(__get_pointer());
1807 }
1808# endif
1809
1810 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 allocator_type get_allocator() const _NOEXCEPT {
1811 return __alloc_;
1812 }
1813
1814 // find
1815
1816 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type
1817 find(const basic_string& __str, size_type __pos = 0) const _NOEXCEPT {
1818 return std::__str_find<value_type, size_type, traits_type, npos>(data(), size(), __str.data(), __pos, __str.size());
1819 }
1820
1821 template <class _Tp, __enable_if_t<__can_be_converted_to_string_view_v<_CharT, _Traits, _Tp>, int> = 0>
1822 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type
1823 find(const _Tp& __t, size_type __pos = 0) const _NOEXCEPT {
1824 __self_view __sv = __t;
1825 return std::__str_find<value_type, size_type, traits_type, npos>(data(), size(), __sv.data(), __pos, __sv.size());
1826 }
1827
1828 [[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type
1829 find(const value_type* __s, size_type __pos, size_type __n) const _NOEXCEPT
1830 _LIBCPP_DIAGNOSE_NULLPTR_IF(__n != 0 && __s == nullptr, " if n is not zero") {
1831 _LIBCPP_ASSERT_NON_NULL(__n == 0 || __s != nullptr, "string::find(): received nullptr");
1832 return std::__str_find<value_type, size_type, traits_type, npos>(data(), size(), __s, __pos, __n);
1833 }
1834
1835 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type
1836 find(const value_type* _LIBCPP_DIAGNOSE_NULLPTR __s, size_type __pos = 0) const _NOEXCEPT {
1837 _LIBCPP_ASSERT_NON_NULL(__s != nullptr, "string::find(): received nullptr");
1838 return std::__str_find<value_type, size_type, traits_type, npos>(
1839 data(), size(), __s, __pos, traits_type::length(__s));
1840 }
1841
1842 [[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type find(value_type __c, size_type __pos = 0) const _NOEXCEPT {
1843 return std::__str_find<value_type, size_type, traits_type, npos>(data(), size(), __c, __pos);
1844 }
1845
1846 // rfind
1847
1848 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type
1849 rfind(const basic_string& __str, size_type __pos = npos) const _NOEXCEPT {
1850 return std::__str_rfind<value_type, size_type, traits_type, npos>(
1851 data(), size(), __str.data(), __pos, __str.size());
1852 }
1853
1854 template <class _Tp, __enable_if_t<__can_be_converted_to_string_view_v<_CharT, _Traits, _Tp>, int> = 0>
1855 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type
1856 rfind(const _Tp& __t, size_type __pos = npos) const _NOEXCEPT {
1857 __self_view __sv = __t;
1858 return std::__str_rfind<value_type, size_type, traits_type, npos>(data(), size(), __sv.data(), __pos, __sv.size());
1859 }
1860
1861 [[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type
1862 rfind(const value_type* __s, size_type __pos, size_type __n) const _NOEXCEPT
1863 _LIBCPP_DIAGNOSE_NULLPTR_IF(__n != 0 && __s == nullptr, " if n is not zero") {
1864 _LIBCPP_ASSERT_NON_NULL(__n == 0 || __s != nullptr, "string::rfind(): received nullptr");
1865 return std::__str_rfind<value_type, size_type, traits_type, npos>(data(), size(), __s, __pos, __n);
1866 }
1867
1868 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type
1869 rfind(const value_type* _LIBCPP_DIAGNOSE_NULLPTR __s, size_type __pos = npos) const _NOEXCEPT {
1870 _LIBCPP_ASSERT_NON_NULL(__s != nullptr, "string::rfind(): received nullptr");
1871 return std::__str_rfind<value_type, size_type, traits_type, npos>(
1872 data(), size(), __s, __pos, traits_type::length(__s));
1873 }
1874
1875 [[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type
1876 rfind(value_type __c, size_type __pos = npos) const _NOEXCEPT {
1877 return std::__str_rfind<value_type, size_type, traits_type, npos>(data(), size(), __c, __pos);
1878 }
1879
1880 // find_first_of
1881
1882 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type
1883 find_first_of(const basic_string& __str, size_type __pos = 0) const _NOEXCEPT {
1884 return std::__str_find_first_of<value_type, size_type, traits_type, npos>(
1885 data(), size(), __str.data(), __pos, __str.size());
1886 }
1887
1888 template <class _Tp, __enable_if_t<__can_be_converted_to_string_view_v<_CharT, _Traits, _Tp>, int> = 0>
1889 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type
1890 find_first_of(const _Tp& __t, size_type __pos = 0) const _NOEXCEPT {
1891 __self_view __sv = __t;
1892 return std::__str_find_first_of<value_type, size_type, traits_type, npos>(
1893 data(), size(), __sv.data(), __pos, __sv.size());
1894 }
1895
1896 [[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type
1897 find_first_of(const value_type* __s, size_type __pos, size_type __n) const _NOEXCEPT
1898 _LIBCPP_DIAGNOSE_NULLPTR_IF(__n != 0 && __s == nullptr, " if n is not zero") {
1899 _LIBCPP_ASSERT_NON_NULL(__n == 0 || __s != nullptr, "string::find_first_of(): received nullptr");
1900 return std::__str_find_first_of<value_type, size_type, traits_type, npos>(data(), size(), __s, __pos, __n);
1901 }
1902
1903 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type
1904 find_first_of(const value_type* _LIBCPP_DIAGNOSE_NULLPTR __s, size_type __pos = 0) const _NOEXCEPT {
1905 _LIBCPP_ASSERT_NON_NULL(__s != nullptr, "string::find_first_of(): received nullptr");
1906 return std::__str_find_first_of<value_type, size_type, traits_type, npos>(
1907 data(), size(), __s, __pos, traits_type::length(__s));
1908 }
1909
1910 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type
1911 find_first_of(value_type __c, size_type __pos = 0) const _NOEXCEPT {
1912 return find(__c, __pos);
1913 }
1914
1915 // find_last_of
1916
1917 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type
1918 find_last_of(const basic_string& __str, size_type __pos = npos) const _NOEXCEPT {
1919 return std::__str_find_last_of<value_type, size_type, traits_type, npos>(
1920 data(), size(), __str.data(), __pos, __str.size());
1921 }
1922
1923 template <class _Tp, __enable_if_t<__can_be_converted_to_string_view_v<_CharT, _Traits, _Tp>, int> = 0>
1924 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type
1925 find_last_of(const _Tp& __t, size_type __pos = npos) const _NOEXCEPT {
1926 __self_view __sv = __t;
1927 return std::__str_find_last_of<value_type, size_type, traits_type, npos>(
1928 data(), size(), __sv.data(), __pos, __sv.size());
1929 }
1930
1931 [[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type
1932 find_last_of(const value_type* __s, size_type __pos, size_type __n) const _NOEXCEPT
1933 _LIBCPP_DIAGNOSE_NULLPTR_IF(__n != 0 && __s == nullptr, " if n is not zero") {
1934 _LIBCPP_ASSERT_NON_NULL(__n == 0 || __s != nullptr, "string::find_last_of(): received nullptr");
1935 return std::__str_find_last_of<value_type, size_type, traits_type, npos>(data(), size(), __s, __pos, __n);
1936 }
1937
1938 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type
1939 find_last_of(const value_type* _LIBCPP_DIAGNOSE_NULLPTR __s, size_type __pos = npos) const _NOEXCEPT {
1940 _LIBCPP_ASSERT_NON_NULL(__s != nullptr, "string::find_last_of(): received nullptr");
1941 return std::__str_find_last_of<value_type, size_type, traits_type, npos>(
1942 data(), size(), __s, __pos, traits_type::length(__s));
1943 }
1944
1945 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type
1946 find_last_of(value_type __c, size_type __pos = npos) const _NOEXCEPT {
1947 return rfind(__c, __pos);
1948 }
1949
1950 // find_first_not_of
1951
1952 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type
1953 find_first_not_of(const basic_string& __str, size_type __pos = 0) const _NOEXCEPT {
1954 return std::__str_find_first_not_of<value_type, size_type, traits_type, npos>(
1955 data(), size(), __str.data(), __pos, __str.size());
1956 }
1957
1958 template <class _Tp, __enable_if_t<__can_be_converted_to_string_view_v<_CharT, _Traits, _Tp>, int> = 0>
1959 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type
1960 find_first_not_of(const _Tp& __t, size_type __pos = 0) const _NOEXCEPT {
1961 __self_view __sv = __t;
1962 return std::__str_find_first_not_of<value_type, size_type, traits_type, npos>(
1963 data(), size(), __sv.data(), __pos, __sv.size());
1964 }
1965
1966 [[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type
1967 find_first_not_of(const value_type* __s, size_type __pos, size_type __n) const _NOEXCEPT
1968 _LIBCPP_DIAGNOSE_NULLPTR_IF(__n != 0 && __s == nullptr, " if n is not zero") {
1969 _LIBCPP_ASSERT_NON_NULL(__n == 0 || __s != nullptr, "string::find_first_not_of(): received nullptr");
1970 return std::__str_find_first_not_of<value_type, size_type, traits_type, npos>(data(), size(), __s, __pos, __n);
1971 }
1972
1973 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type
1974 find_first_not_of(const value_type* _LIBCPP_DIAGNOSE_NULLPTR __s, size_type __pos = 0) const _NOEXCEPT {
1975 _LIBCPP_ASSERT_NON_NULL(__s != nullptr, "string::find_first_not_of(): received nullptr");
1976 return std::__str_find_first_not_of<value_type, size_type, traits_type, npos>(
1977 data(), size(), __s, __pos, traits_type::length(__s));
1978 }
1979
1980 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type
1981 find_first_not_of(value_type __c, size_type __pos = 0) const _NOEXCEPT {
1982 return std::__str_find_first_not_of<value_type, size_type, traits_type, npos>(data(), size(), __c, __pos);
1983 }
1984
1985 // find_last_not_of
1986
1987 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type
1988 find_last_not_of(const basic_string& __str, size_type __pos = npos) const _NOEXCEPT {
1989 return std::__str_find_last_not_of<value_type, size_type, traits_type, npos>(
1990 data(), size(), __str.data(), __pos, __str.size());
1991 }
1992
1993 template <class _Tp, __enable_if_t<__can_be_converted_to_string_view_v<_CharT, _Traits, _Tp>, int> = 0>
1994 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type
1995 find_last_not_of(const _Tp& __t, size_type __pos = npos) const _NOEXCEPT {
1996 __self_view __sv = __t;
1997 return std::__str_find_last_not_of<value_type, size_type, traits_type, npos>(
1998 data(), size(), __sv.data(), __pos, __sv.size());
1999 }
2000
2001 [[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type
2002 find_last_not_of(const value_type* __s, size_type __pos, size_type __n) const _NOEXCEPT
2003 _LIBCPP_DIAGNOSE_NULLPTR_IF(__n != 0 && __s == nullptr, " if n is not zero") {
2004 _LIBCPP_ASSERT_NON_NULL(__n == 0 || __s != nullptr, "string::find_last_not_of(): received nullptr");
2005 return std::__str_find_last_not_of<value_type, size_type, traits_type, npos>(data(), size(), __s, __pos, __n);
2006 }
2007
2008 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type
2009 find_last_not_of(const value_type* _LIBCPP_DIAGNOSE_NULLPTR __s, size_type __pos = npos) const _NOEXCEPT {
2010 _LIBCPP_ASSERT_NON_NULL(__s != nullptr, "string::find_last_not_of(): received nullptr");
2011 return std::__str_find_last_not_of<value_type, size_type, traits_type, npos>(
2012 data(), size(), __s, __pos, traits_type::length(__s));
2013 }
2014
2015 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type
2016 find_last_not_of(value_type __c, size_type __pos = npos) const _NOEXCEPT {
2017 return std::__str_find_last_not_of<value_type, size_type, traits_type, npos>(data(), size(), __c, __pos);
2018 }
2019
2020 // compare
2021
2022 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 int
2023 compare(const basic_string& __str) const _NOEXCEPT {
2024 return compare(__self_view(__str));
2025 }
2026
2027 template <class _Tp, __enable_if_t<__can_be_converted_to_string_view_v<_CharT, _Traits, _Tp>, int> = 0>
2028 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 int compare(const _Tp& __t) const _NOEXCEPT {
2029 __self_view __sv = __t;
2030 size_t __lhs_sz = size();
2031 size_t __rhs_sz = __sv.size();
2032 int __result = traits_type::compare(data(), __sv.data(), std::min(__lhs_sz, __rhs_sz));
2033 if (__result != 0)
2034 return __result;
2035 if (__lhs_sz < __rhs_sz)
2036 return -1;
2037 if (__lhs_sz > __rhs_sz)
2038 return 1;
2039 return 0;
2040 }
2041
2042 template <class _Tp, __enable_if_t<__can_be_converted_to_string_view_v<_CharT, _Traits, _Tp>, int> = 0>
2043 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 int
2044 compare(size_type __pos1, size_type __n1, const _Tp& __t) const {
2045 __self_view __sv = __t;
2046 return compare(__pos1, __n1, __sv.data(), __sv.size());
2047 }
2048
2049 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 int
2050 compare(size_type __pos1, size_type __n1, const basic_string& __str) const {
2051 return compare(__pos1, __n1, __str.data(), __str.size());
2052 }
2053
2054 [[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX20 int
2055 compare(size_type __pos1, size_type __n1, const basic_string& __str, size_type __pos2, size_type __n2 = npos) const {
2056 return compare(__pos1, __n1, __self_view(__str), __pos2, __n2);
2057 }
2058
2059 template <class _Tp,
2060 __enable_if_t<__can_be_converted_to_string_view_v<_CharT, _Traits, _Tp> &&
2061 !is_same<__remove_cvref_t<_Tp>, basic_string>::value,
2062 int> = 0>
2063 [[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 int
2064 compare(size_type __pos1, size_type __n1, const _Tp& __t, size_type __pos2, size_type __n2 = npos) const {
2065 __self_view __sv = __t;
2066 return __self_view(*this).substr(__pos1, __n1).compare(__sv.substr(__pos2, __n2));
2067 }
2068
2069 [[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX20 int
2070 compare(const value_type* _LIBCPP_DIAGNOSE_NULLPTR __s) const _NOEXCEPT {
2071 _LIBCPP_ASSERT_NON_NULL(__s != nullptr, "string::compare(): received nullptr");
2072 return compare(0, npos, __s, traits_type::length(__s));
2073 }
2074
2075 [[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX20 int
2076 compare(size_type __pos1, size_type __n1, const value_type* _LIBCPP_DIAGNOSE_NULLPTR __s) const {
2077 _LIBCPP_ASSERT_NON_NULL(__s != nullptr, "string::compare(): received nullptr");
2078 return compare(__pos1, __n1, __s, traits_type::length(__s));
2079 }
2080
2081 [[__nodiscard__]] _LIBCPP_CONSTEXPR_SINCE_CXX20 int
2082 compare(size_type __pos1, size_type __n1, const value_type* __s, size_type __n2) const
2083 _LIBCPP_DIAGNOSE_NULLPTR_IF(__n2 != 0 && __s == nullptr, " if n2 is not zero");
2084
2085 // starts_with
2086
2087# if _LIBCPP_STD_VER >= 20
2088 [[__nodiscard__]] constexpr _LIBCPP_HIDE_FROM_ABI bool starts_with(__self_view __sv) const noexcept {
2089 return __self_view(typename __self_view::__assume_valid(), data(), size()).starts_with(__sv);
2090 }
2091
2092 [[__nodiscard__]] constexpr _LIBCPP_HIDE_FROM_ABI bool starts_with(value_type __c) const noexcept {
2093 return !empty() && _Traits::eq(front(), __c);
2094 }
2095
2096 [[__nodiscard__]] constexpr _LIBCPP_HIDE_FROM_ABI bool
2097 starts_with(const value_type* _LIBCPP_DIAGNOSE_NULLPTR __s) const noexcept {
2098 return starts_with(__self_view(__s));
2099 }
2100
2101 // ends_with
2102
2103 [[__nodiscard__]] constexpr _LIBCPP_HIDE_FROM_ABI bool ends_with(__self_view __sv) const noexcept {
2104 return __self_view(typename __self_view::__assume_valid(), data(), size()).ends_with(__sv);
2105 }
2106
2107 [[__nodiscard__]] constexpr _LIBCPP_HIDE_FROM_ABI bool ends_with(value_type __c) const noexcept {
2108 return !empty() && _Traits::eq(back(), __c);
2109 }
2110
2111 [[__nodiscard__]] constexpr _LIBCPP_HIDE_FROM_ABI bool
2112 ends_with(const value_type* _LIBCPP_DIAGNOSE_NULLPTR __s) const noexcept {
2113 return ends_with(__self_view(__s));
2114 }
2115# endif
2116
2117 // contains
2118
2119# if _LIBCPP_STD_VER >= 23
2120 [[__nodiscard__]] constexpr _LIBCPP_HIDE_FROM_ABI bool contains(__self_view __sv) const noexcept {
2121 return __self_view(typename __self_view::__assume_valid(), data(), size()).contains(__sv);
2122 }
2123
2124 [[__nodiscard__]] constexpr _LIBCPP_HIDE_FROM_ABI bool contains(value_type __c) const noexcept {
2125 return __self_view(typename __self_view::__assume_valid(), data(), size()).contains(__c);
2126 }
2127
2128 [[__nodiscard__]] constexpr _LIBCPP_HIDE_FROM_ABI bool
2129 contains(const value_type* _LIBCPP_DIAGNOSE_NULLPTR __s) const {
2130 return __self_view(typename __self_view::__assume_valid(), data(), size()).contains(__s);
2131 }
2132# endif
2133
2134 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool __invariants() const;
2135
2136private:
2137 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_STRING_INTERNAL_MEMORY_ACCESS bool
2138 __is_long() const _NOEXCEPT {
2139 if (__libcpp_is_constant_evaluated() && __builtin_constant_p(__rep_.__l.__is_long_)) {
2140 return __rep_.__l.__is_long_;
2141 }
2142 return __rep_.__s.__is_long_;
2143 }
2144
2145 _LIBCPP_CONSTEXPR _LIBCPP_HIDE_FROM_ABI static bool __fits_in_sso(size_type __sz) { return __sz < __min_cap; }
2146
2147 template <class _Iterator, class _Sentinel>
2148 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void
2149 __assign_trivial(_Iterator __first, _Sentinel __last, size_type __n);
2150
2151 template <class _Iterator, class _Sentinel>
2152 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __assign_with_sentinel(_Iterator __first, _Sentinel __last);
2153
2154 // Copy [__first, __last) into [__dest, __dest + (__last - __first)). Assumes that the ranges don't overlap.
2155 template <class _ForwardIter, class _Sent>
2156 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 static value_type*
2157 __copy_non_overlapping_range(_ForwardIter __first, _Sent __last, value_type* __dest) {
2158# ifndef _LIBCPP_CXX03_LANG
2159 if constexpr (__libcpp_is_contiguous_iterator<_ForwardIter>::value &&
2160 is_same<value_type, __remove_cvref_t<decltype(*__first)>>::value &&
2161 is_same<_ForwardIter, _Sent>::value) {
2162 _LIBCPP_ASSERT_INTERNAL(
2163 !std::__is_overlapping_range(std::__to_address(__first), std::__to_address(__last), __dest),
2164 "__copy_non_overlapping_range called with an overlapping range!");
2165 traits_type::copy(__dest, std::__to_address(__first), __last - __first);
2166 return __dest + (__last - __first);
2167 }
2168# endif
2169
2170 for (; __first != __last; ++__first)
2171 traits_type::assign(*__dest++, *__first);
2172 return __dest;
2173 }
2174
2175 template <class _ForwardIterator, class _Sentinel>
2176 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 iterator
2177 __insert_from_safe_copy(size_type __n, size_type __ip, _ForwardIterator __first, _Sentinel __last) {
2178 size_type __sz = size();
2179 size_type __cap = capacity();
2180 value_type* __p;
2181 if (__cap - __sz >= __n) {
2182 __annotate_increase(__n);
2183 __p = std::__to_address(__get_pointer());
2184 size_type __n_move = __sz - __ip;
2185 if (__n_move != 0)
2186 traits_type::move(__p + __ip + __n, __p + __ip, __n_move);
2187 } else {
2188 __grow_by_without_replace(__cap, __sz + __n - __cap, __sz, __ip, 0, __n);
2189 __p = std::__to_address(__get_long_pointer());
2190 }
2191 __sz += __n;
2192 __set_size(__sz);
2193 traits_type::assign(__p[__sz], value_type());
2194 __copy_non_overlapping_range(std::move(__first), std::move(__last), __p + __ip);
2195
2196 return begin() + __ip;
2197 }
2198
2199 template <class _Iterator, class _Sentinel>
2200 _LIBCPP_CONSTEXPR_SINCE_CXX20 iterator
2201 __insert_with_size(const_iterator __pos, _Iterator __first, _Sentinel __last, size_type __n);
2202
2203 // internal buffer accessors
2204 // -------------------------
2205
2206 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_STRING_INTERNAL_MEMORY_ACCESS void
2207 __set_short_size(size_type __s) _NOEXCEPT {
2208 _LIBCPP_ASSERT_INTERNAL(__s < __min_cap, "__s should never be greater than or equal to the short string capacity");
2209 __rep_.__s.__size_ = __s;
2210 __rep_.__s.__is_long_ = false;
2211 }
2212
2213 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_STRING_INTERNAL_MEMORY_ACCESS size_type
2214 __get_short_size() const _NOEXCEPT {
2215 _LIBCPP_ASSERT_INTERNAL(!__rep_.__s.__is_long_, "String has to be short when trying to get the short size");
2216 return __rep_.__s.__size_;
2217 }
2218
2219 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void __set_long_size(size_type __s) _NOEXCEPT {
2220 __rep_.__l.__size_ = __s;
2221 }
2222
2223 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type __get_long_size() const _NOEXCEPT {
2224 _LIBCPP_ASSERT_INTERNAL(__rep_.__l.__is_long_, "String has to be long when trying to get the long size");
2225 return __rep_.__l.__size_;
2226 }
2227
2228 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void __set_size(size_type __s) _NOEXCEPT {
2229 if (__is_long())
2230 __set_long_size(__s);
2231 else
2232 __set_short_size(__s);
2233 }
2234
2235 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type __get_long_cap() const _NOEXCEPT {
2236 _LIBCPP_ASSERT_INTERNAL(__rep_.__l.__is_long_, "String has to be long when trying to get the long capacity");
2237 return __rep_.__l.__cap_ * __endian_factor;
2238 }
2239
2240 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 pointer __get_long_pointer() _NOEXCEPT {
2241 _LIBCPP_ASSERT_INTERNAL(__rep_.__l.__is_long_, "String has to be long when trying to get the long pointer");
2242 return _LIBCPP_ASAN_VOLATILE_WRAPPER(__rep_.__l.__data_);
2243 }
2244
2245 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const_pointer __get_long_pointer() const _NOEXCEPT {
2246 _LIBCPP_ASSERT_INTERNAL(__rep_.__l.__is_long_, "String has to be long when trying to get the long pointer");
2247 return _LIBCPP_ASAN_VOLATILE_WRAPPER(__rep_.__l.__data_);
2248 }
2249
2250 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_STRING_INTERNAL_MEMORY_ACCESS pointer
2251 __get_short_pointer() _NOEXCEPT {
2252 return _LIBCPP_ASAN_VOLATILE_WRAPPER(pointer_traits<pointer>::pointer_to(__rep_.__s.__data_[0]));
2253 }
2254
2255 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_STRING_INTERNAL_MEMORY_ACCESS const_pointer
2256 __get_short_pointer() const _NOEXCEPT {
2257 return _LIBCPP_ASAN_VOLATILE_WRAPPER(pointer_traits<const_pointer>::pointer_to(__rep_.__s.__data_[0]));
2258 }
2259
2260 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 pointer __get_pointer() _NOEXCEPT {
2261 return __is_long() ? __get_long_pointer() : __get_short_pointer();
2262 }
2263 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const_pointer __get_pointer() const _NOEXCEPT {
2264 return __is_long() ? __get_long_pointer() : __get_short_pointer();
2265 }
2266
2267 // Internal buffer management
2268 // --------------------------
2269 //
2270 // These functions are only responsible for managing the buffer itself, not the value inside the buffer. As such,
2271 // none of these facilities ensure that there is a null terminator at `data()[size()]`.
2272
2273 // Allocate a buffer of __capacity size with __alloc and return it
2274 _LIBCPP_HIDE_FROM_ABI static _LIBCPP_CONSTEXPR_SINCE_CXX20 __long
2275 __allocate_long_buffer(_Allocator& __alloc, size_type __capacity) {
2276 _LIBCPP_ASSERT_INTERNAL(!__fits_in_sso(__capacity),
2277 "Trying to allocate long buffer for a capacity what would fit into the small buffer");
2278 auto __buffer = std::__allocate_at_least(__alloc, __align_allocation_size(__capacity));
2279
2280 if (__libcpp_is_constant_evaluated()) {
2281 for (size_type __i = 0; __i != __buffer.count; ++__i)
2282 std::__construct_at(std::addressof(__buffer.ptr[__i]));
2283 }
2284
2285 return __long(__buffer, __capacity);
2286 }
2287
2288 // Replace the current buffer with __new_rep. Deallocate the old long buffer if it exists.
2289 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void __reset_internal_buffer(__rep __new_rep = __short()) {
2290 __annotate_delete();
2291 if (__is_long())
2292 __alloc_traits::deallocate(__alloc_, __get_long_pointer(), __get_long_cap());
2293 __rep_ = __new_rep;
2294 }
2295
2296 // Initialize the internal buffer to hold __size elements
2297 // The elements and null terminator have to be set by the caller
2298 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 pointer __init_internal_buffer(size_type __size) {
2299 if (__libcpp_is_constant_evaluated())
2300 __rep_ = __rep();
2301
2302 if (__size > max_size())
2303 __throw_length_error();
2304
2305 if (__fits_in_sso(__size)) {
2306 __set_short_size(__size);
2307 __annotate_new(__size);
2308 return __get_short_pointer();
2309 } else {
2310 __rep_.__l = __allocate_long_buffer(__alloc_, __size);
2311 __annotate_new(__size);
2312 return __get_long_pointer();
2313 }
2314 }
2315
2316 // ASan annotation helpers
2317 // -----------------------
2318
2319 // The following functions are no-ops outside of AddressSanitizer mode.
2320 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void
2321 __annotate_contiguous_container(const void* __old_mid, const void* __new_mid) const {
2322 (void)__old_mid;
2323 (void)__new_mid;
2324# if _LIBCPP_INSTRUMENTED_WITH_ASAN
2325# if defined(__APPLE__)
2326 // TODO: remove after addressing issue #96099 (https://llvm.org/PR96099)
2327 if (!__is_long())
2328 return;
2329# endif
2330 std::__annotate_contiguous_container<_Allocator>(data(), data() + capacity() + 1, __old_mid, __new_mid);
2331# endif
2332 }
2333
2334 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void __annotate_new(size_type __current_size) const _NOEXCEPT {
2335 __annotate_contiguous_container(data() + capacity() + 1, data() + __current_size + 1);
2336 }
2337
2338 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void __annotate_delete() const _NOEXCEPT {
2339 __annotate_contiguous_container(data() + size() + 1, data() + capacity() + 1);
2340 }
2341
2342 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void __annotate_increase(size_type __n) const _NOEXCEPT {
2343 __annotate_contiguous_container(data() + size() + 1, data() + size() + 1 + __n);
2344 }
2345
2346 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void __annotate_shrink(size_type __old_size) const _NOEXCEPT {
2347 __annotate_contiguous_container(data() + __old_size + 1, data() + size() + 1);
2348 }
2349
2350 // Disable ASan annotations and enable them again when going out of scope. It is assumed that the string is in a valid
2351 // state at that point, so `size()` can be called safely.
2352 struct [[__nodiscard__]] __annotation_guard {
2353 __annotation_guard(const __annotation_guard&) = delete;
2354 __annotation_guard& operator=(const __annotation_guard&) = delete;
2355
2356 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __annotation_guard(basic_string& __str) : __str_(__str) {
2357 __str_.__annotate_delete();
2358 }
2359
2360 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 ~__annotation_guard() { __str_.__annotate_new(__str_.size()); }
2361
2362 basic_string& __str_;
2363 };
2364
2365 template <size_type __a>
2366 static _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type __align_it(size_type __s) _NOEXCEPT {
2367 return (__s + (__a - 1)) & ~(__a - 1);
2368 }
2369 enum { __alignment = 8 };
2370
2371 // This makes sure that we're using a capacity with some extra alignment, since allocators almost always over-align
2372 // the allocations anyways, improving memory usage. More importantly, this ensures that the lowest bit is never set
2373 // if __endian_factor == 2, allowing us to store whether we're in the long string inside the lowest bit.
2374 _LIBCPP_HIDE_FROM_ABI static _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type
2375 __align_allocation_size(size_type __size) _NOEXCEPT {
2376 _LIBCPP_ASSERT_INTERNAL(
2377 !__fits_in_sso(__size), "Trying to align allocation of a size which would fit into the SSO");
2378 const size_type __boundary = sizeof(value_type) < __alignment ? __alignment / sizeof(value_type) : __endian_factor;
2379 size_type __guess = __align_it<__boundary>(__size + 1);
2380 if (__guess == __min_cap + 1)
2381 __guess += __endian_factor;
2382
2383 _LIBCPP_ASSERT_INTERNAL(__guess >= __size, "aligned allocation size is below the requested size");
2384 return __guess;
2385 }
2386
2387 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type
2388 __get_amortized_growth_capacity(size_type __required_capacity) {
2389 size_type __max_size = max_size();
2390 if (__required_capacity > __max_size)
2391 __throw_length_error();
2392 size_type __current_cap = capacity();
2393 _LIBCPP_ASSERT_INTERNAL(
2394 __current_cap < __required_capacity, "Trying to grow string even though there is enough capacity already?");
2395 if (__current_cap > __max_size / 2 - __alignment)
2396 return __max_size;
2397 return std::max(__required_capacity, 2 * __current_cap);
2398 }
2399
2400 inline _LIBCPP_CONSTEXPR_SINCE_CXX20 void __init(const value_type* __s, size_type __sz);
2401 inline _LIBCPP_CONSTEXPR_SINCE_CXX20 void __init(size_type __n, value_type __c);
2402
2403 // Slow path for the (inlined) copy constructor for 'long' strings.
2404 // Always externally instantiated and not inlined.
2405 // Requires that __s is zero terminated.
2406 // The main reason for this function to exist is because for unstable, we
2407 // want to allow inlining of the copy constructor. However, we don't want
2408 // to call the __init() functions as those are marked as inline which may
2409 // result in over-aggressive inlining by the compiler, where our aim is
2410 // to only inline the fast path code directly in the ctor.
2411 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_NOINLINE void __init_copy_ctor_external(const value_type* __s, size_type __sz);
2412
2413 template <class _InputIterator, __enable_if_t<__has_exactly_input_iterator_category<_InputIterator>::value, int> = 0>
2414 inline _LIBCPP_CONSTEXPR_SINCE_CXX20 void __init(_InputIterator __first, _InputIterator __last);
2415
2416 template <class _ForwardIterator, __enable_if_t<__has_forward_iterator_category<_ForwardIterator>::value, int> = 0>
2417 inline _LIBCPP_CONSTEXPR_SINCE_CXX20 void __init(_ForwardIterator __first, _ForwardIterator __last);
2418
2419 template <class _InputIterator, class _Sentinel>
2420 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void
2421 __init_with_sentinel(_InputIterator __first, _Sentinel __last);
2422 template <class _InputIterator, class _Sentinel>
2423 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void
2424 __init_with_size(_InputIterator __first, _Sentinel __last, size_type __sz);
2425
2426 _LIBCPP_CONSTEXPR_SINCE_CXX20
2427# if _LIBCPP_ABI_VERSION >= 2 // We want to use the function in the dylib in ABIv1
2428 _LIBCPP_HIDE_FROM_ABI
2429# endif
2430 _LIBCPP_DEPRECATED_("use __grow_by_without_replace") void __grow_by(
2431 size_type __old_cap,
2432 size_type __delta_cap,
2433 size_type __old_sz,
2434 size_type __n_copy,
2435 size_type __n_del,
2436 size_type __n_add = 0);
2437 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __grow_by_without_replace(
2438 size_type __old_cap,
2439 size_type __delta_cap,
2440 size_type __old_sz,
2441 size_type __n_copy,
2442 size_type __n_del,
2443 size_type __n_add = 0);
2444 _LIBCPP_CONSTEXPR_SINCE_CXX20 void __grow_by_and_replace(
2445 size_type __old_cap,
2446 size_type __delta_cap,
2447 size_type __old_sz,
2448 size_type __n_copy,
2449 size_type __n_del,
2450 size_type __n_add,
2451 const value_type* __p_new_stuff);
2452
2453 // __assign_no_alias is invoked for assignment operations where we
2454 // have proof that the input does not alias the current instance.
2455 // For example, operator=(basic_string) performs a 'self' check.
2456 template <bool __is_short>
2457 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_NOINLINE basic_string& __assign_no_alias(const value_type* __s, size_type __n);
2458
2459 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void __erase_to_end(size_type __pos) {
2460 _LIBCPP_ASSERT_INTERNAL(__pos <= capacity(), "Trying to erase at position outside the strings capacity!");
2461 __null_terminate_at(std::__to_address(__get_pointer()), __pos);
2462 }
2463
2464 // __erase_external_with_move is invoked for erase() invocations where
2465 // `n ~= npos`, likely requiring memory moves on the string data.
2466 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_NOINLINE void
2467 __erase_external_with_move(size_type __pos, size_type __n) _NOEXCEPT;
2468
2469 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void __copy_assign_alloc(const basic_string& __str) {
2470 __copy_assign_alloc(
2471 __str, integral_constant<bool, __alloc_traits::propagate_on_container_copy_assignment::value>());
2472 }
2473
2474 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void __copy_assign_alloc(const basic_string& __str, true_type) {
2475 if (__alloc_ == __str.__alloc_)
2476 __alloc_ = __str.__alloc_;
2477 else {
2478 if (!__str.__is_long()) {
2479 __reset_internal_buffer();
2480 __alloc_ = __str.__alloc_;
2481 } else {
2482 __annotate_delete();
2483 auto __guard = std::__make_scope_guard(__annotate_new_size(*this));
2484 auto __alloc = __str.__alloc_;
2485 __reset_internal_buffer(__allocate_long_buffer(__alloc, __str.size()));
2486 __alloc_ = std::move(__alloc);
2487 }
2488 }
2489 }
2490
2491 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void
2492 __copy_assign_alloc(const basic_string&, false_type) _NOEXCEPT {}
2493
2494# ifndef _LIBCPP_CXX03_LANG
2495 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void
2496 __move_assign(basic_string& __str, false_type) noexcept(__alloc_traits::is_always_equal::value);
2497 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_STRING_INTERNAL_MEMORY_ACCESS void
2498 __move_assign(basic_string& __str, true_type)
2499# if _LIBCPP_STD_VER >= 17
2500 noexcept;
2501# else
2502 noexcept(is_nothrow_move_assignable<allocator_type>::value);
2503# endif
2504# endif
2505
2506 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void __move_assign_alloc(basic_string& __str)
2507 _NOEXCEPT_(!__alloc_traits::propagate_on_container_move_assignment::value ||
2508 is_nothrow_move_assignable<allocator_type>::value) {
2509 __move_assign_alloc(
2510 __str, integral_constant<bool, __alloc_traits::propagate_on_container_move_assignment::value>());
2511 }
2512
2513 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void __move_assign_alloc(basic_string& __c, true_type)
2514 _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value) {
2515 __alloc_ = std::move(__c.__alloc_);
2516 }
2517
2518 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void __move_assign_alloc(basic_string&, false_type) _NOEXCEPT {}
2519
2520 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_NOINLINE basic_string& __assign_external(const value_type* __s);
2521 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_NOINLINE basic_string& __assign_external(const value_type* __s, size_type __n);
2522
2523 // Assigns the value in __s, guaranteed to be __n < __min_cap in length.
2524 inline _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& __assign_short(const value_type* __s, size_type __n) {
2525 size_type __old_size = size();
2526 if (__n > __old_size)
2527 __annotate_increase(__n - __old_size);
2528 pointer __p;
2529 if (__is_long()) {
2530 __set_long_size(__n);
2531 __p = __get_long_pointer();
2532 } else {
2533 __set_short_size(__n);
2534 __p = __get_short_pointer();
2535 }
2536 traits_type::move(std::__to_address(__p), __s, __n);
2537 traits_type::assign(__p[__n], value_type());
2538 if (__old_size > __n)
2539 __annotate_shrink(__old_size);
2540 return *this;
2541 }
2542
2543 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&
2544 __null_terminate_at(value_type* __p, size_type __newsz) {
2545 size_type __old_size = size();
2546 if (__newsz > __old_size)
2547 __annotate_increase(__newsz - __old_size);
2548 __set_size(__newsz);
2549 traits_type::assign(__p[__newsz], value_type());
2550 if (__old_size > __newsz)
2551 __annotate_shrink(__old_size);
2552 return *this;
2553 }
2554
2555 template <class _Tp>
2556 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool __addr_in_range(const _Tp& __v) const {
2557 return std::__is_pointer_in_range(data(), data() + size() + 1, std::addressof(__v));
2558 }
2559
2560 [[__noreturn__]] _LIBCPP_HIDE_FROM_ABI static void __throw_length_error() {
2561 std::__throw_length_error("basic_string");
2562 }
2563
2564 [[__noreturn__]] _LIBCPP_HIDE_FROM_ABI static void __throw_out_of_range() {
2565 std::__throw_out_of_range("basic_string");
2566 }
2567
2568 friend _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string
2569 __concatenate_strings<>(const _Allocator&, __type_identity_t<__self_view>, __type_identity_t<__self_view>);
2570
2571 template <class _CharT2, class _Traits2, class _Allocator2>
2572 friend inline _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI bool
2573 operator==(const basic_string<_CharT2, _Traits2, _Allocator2>&, const _CharT2*) _NOEXCEPT;
2574
2575 // These functions aren't used anymore but are part of out ABI, so we need to provide them in the dylib for backwards
2576 // compatibility
2577# ifdef _LIBCPP_BUILDING_LIBRARY
2578 void __init(const value_type* __s, size_type __sz, size_type __reserve);
2579# endif
2580};
2581
2582// These declarations must appear before any functions are implicitly used
2583// so that they have the correct visibility specifier.
2584# define _LIBCPP_DECLARE(...) extern template _LIBCPP_EXPORTED_FROM_ABI __VA_ARGS__;
2585# ifdef _LIBCPP_ABI_STRING_OPTIMIZED_EXTERNAL_INSTANTIATION
2586_LIBCPP_STRING_UNSTABLE_EXTERN_TEMPLATE_LIST(_LIBCPP_DECLARE, char)
2587# if _LIBCPP_HAS_WIDE_CHARACTERS
2588_LIBCPP_STRING_UNSTABLE_EXTERN_TEMPLATE_LIST(_LIBCPP_DECLARE, wchar_t)
2589# endif
2590# else
2591_LIBCPP_STRING_V1_EXTERN_TEMPLATE_LIST(_LIBCPP_DECLARE, char)
2592# if _LIBCPP_HAS_WIDE_CHARACTERS
2593_LIBCPP_STRING_V1_EXTERN_TEMPLATE_LIST(_LIBCPP_DECLARE, wchar_t)
2594# endif
2595# endif
2596# undef _LIBCPP_DECLARE
2597
2598# if _LIBCPP_STD_VER <= 17 || !__has_builtin(__builtin_lt_synthesizes_from_spaceship)
2599template <class _CharT, class _Traits, class _Alloc>
2600struct __default_three_way_comparator<basic_string<_CharT, _Traits, _Alloc>, basic_string<_CharT, _Traits, _Alloc> > {
2601 using __string_t _LIBCPP_NODEBUG = basic_string<_CharT, _Traits, _Alloc>;
2602
2603 _LIBCPP_HIDE_FROM_ABI static int operator()(const __string_t& __lhs, const __string_t& __rhs) {
2604 auto __min_len = std::min(__lhs.size(), __rhs.size());
2605 auto __ret = _Traits::compare(__lhs.data(), __rhs.data(), __min_len);
2606 if (__ret == 0)
2607 return __lhs.size() == __rhs.size() ? 0 : __lhs.size() < __rhs.size() ? -1 : 1;
2608 return __ret;
2609 }
2610};
2611# endif
2612
2613template <class _Comparator, class _CharT, class _Traits, class _Alloc>
2614inline const bool __is_transparently_comparable_v<_Comparator,
2615 basic_string<_CharT, _Traits, _Alloc>,
2616 const _CharT*,
2617 __enable_if_t<__is_generic_transparent_comparator_v<_Comparator> > > =
2618 true;
2619
2620template <class _Comparator, class _CharT, class _Traits, class _Alloc, size_t _Np>
2621inline const bool __is_transparently_comparable_v<_Comparator,
2622 basic_string<_CharT, _Traits, _Alloc>,
2623 _CharT[_Np],
2624 __enable_if_t<__is_generic_transparent_comparator_v<_Comparator> > > =
2625 true;
2626
2627# if _LIBCPP_STD_VER >= 17
2628template <class _InputIterator,
2629 class _CharT = __iterator_value_type<_InputIterator>,
2630 class _Allocator = allocator<_CharT>,
2631 class = enable_if_t<__has_input_iterator_category<_InputIterator>::value>,
2632 class = enable_if_t<__is_allocator_v<_Allocator>>>
2633basic_string(_InputIterator, _InputIterator, _Allocator = _Allocator())
2634 -> basic_string<_CharT, char_traits<_CharT>, _Allocator>;
2635
2636template <class _CharT,
2637 class _Traits,
2638 class _Allocator = allocator<_CharT>,
2639 class = enable_if_t<__is_allocator_v<_Allocator>>>
2640explicit basic_string(basic_string_view<_CharT, _Traits>, const _Allocator& = _Allocator())
2641 -> basic_string<_CharT, _Traits, _Allocator>;
2642
2643template <class _CharT,
2644 class _Traits,
2645 class _Allocator = allocator<_CharT>,
2646 class = enable_if_t<__is_allocator_v<_Allocator>>,
2647 class _Sz = typename allocator_traits<_Allocator>::size_type >
2648basic_string(basic_string_view<_CharT, _Traits>, _Sz, _Sz, const _Allocator& = _Allocator())
2649 -> basic_string<_CharT, _Traits, _Allocator>;
2650# endif
2651
2652# if _LIBCPP_STD_VER >= 23
2653template <ranges::input_range _Range,
2654 class _Allocator = allocator<ranges::range_value_t<_Range>>,
2655 class = enable_if_t<__is_allocator_v<_Allocator>>>
2656basic_string(from_range_t, _Range&&, _Allocator = _Allocator())
2657 -> basic_string<ranges::range_value_t<_Range>, char_traits<ranges::range_value_t<_Range>>, _Allocator>;
2658# endif
2659
2660template <class _CharT, class _Traits, class _Allocator>
2661_LIBCPP_CONSTEXPR_SINCE_CXX20 void
2662basic_string<_CharT, _Traits, _Allocator>::__init(const value_type* __s, size_type __sz) {
2663 pointer __p = __init_internal_buffer(__sz);
2664 traits_type::copy(std::__to_address(__p), __s, __sz);
2665 traits_type::assign(__p[__sz], value_type());
2666}
2667
2668template <class _CharT, class _Traits, class _Allocator>
2669_LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_NOINLINE void
2670basic_string<_CharT, _Traits, _Allocator>::__init_copy_ctor_external(const value_type* __s, size_type __sz) {
2671 pointer __p = __init_internal_buffer(__sz);
2672 traits_type::copy(std::__to_address(__p), __s, __sz + 1);
2673}
2674
2675template <class _CharT, class _Traits, class _Allocator>
2676_LIBCPP_CONSTEXPR_SINCE_CXX20 void basic_string<_CharT, _Traits, _Allocator>::__init(size_type __n, value_type __c) {
2677 pointer __p = __init_internal_buffer(__n);
2678 traits_type::assign(std::__to_address(__p), __n, __c);
2679 traits_type::assign(__p[__n], value_type());
2680}
2681
2682template <class _CharT, class _Traits, class _Allocator>
2683template <class _InputIterator, __enable_if_t<__has_exactly_input_iterator_category<_InputIterator>::value, int> >
2684_LIBCPP_CONSTEXPR_SINCE_CXX20 void
2685basic_string<_CharT, _Traits, _Allocator>::__init(_InputIterator __first, _InputIterator __last) {
2686 __init_with_sentinel(std::move(__first), std::move(__last));
2687}
2688
2689template <class _CharT, class _Traits, class _Allocator>
2690template <class _InputIterator, class _Sentinel>
2691_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void
2692basic_string<_CharT, _Traits, _Allocator>::__init_with_sentinel(_InputIterator __first, _Sentinel __last) {
2693 __rep_ = __rep();
2694 __annotate_new(0);
2695
2696 auto __guard = std::__make_exception_guard([this] { __reset_internal_buffer(); });
2697 for (; __first != __last; ++__first)
2698 push_back(*__first);
2699 __guard.__complete();
2700}
2701
2702template <class _CharT, class _Traits, class _Allocator>
2703template <class _ForwardIterator, __enable_if_t<__has_forward_iterator_category<_ForwardIterator>::value, int> >
2704_LIBCPP_CONSTEXPR_SINCE_CXX20 void
2705basic_string<_CharT, _Traits, _Allocator>::__init(_ForwardIterator __first, _ForwardIterator __last) {
2706 size_type __sz = static_cast<size_type>(std::distance(__first, __last));
2707 __init_with_size(__first, __last, __sz);
2708}
2709
2710template <class _CharT, class _Traits, class _Allocator>
2711template <class _InputIterator, class _Sentinel>
2712_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void
2713basic_string<_CharT, _Traits, _Allocator>::__init_with_size(_InputIterator __first, _Sentinel __last, size_type __sz) {
2714 pointer __p = __init_internal_buffer(__sz);
2715
2716 auto __guard = std::__make_exception_guard([this] { __reset_internal_buffer(); });
2717 auto __end = __copy_non_overlapping_range(std::move(__first), std::move(__last), std::__to_address(__p));
2718 traits_type::assign(*__end, value_type());
2719 __guard.__complete();
2720}
2721
2722template <class _CharT, class _Traits, class _Allocator>
2723_LIBCPP_CONSTEXPR_SINCE_CXX20 void basic_string<_CharT, _Traits, _Allocator>::__grow_by_and_replace(
2724 size_type __old_cap,
2725 size_type __delta_cap,
2726 size_type __old_sz,
2727 size_type __n_copy,
2728 size_type __n_del,
2729 size_type __n_add,
2730 const value_type* __p_new_stuff) {
2731 __long __buffer = __allocate_long_buffer(__alloc_, __get_amortized_growth_capacity(__old_cap + __delta_cap));
2732 pointer __old_p = __get_pointer();
2733 __annotate_delete();
2734 auto __guard = std::__make_scope_guard(__annotate_new_size(*this));
2735 if (__n_copy != 0)
2736 traits_type::copy(std::__to_address(__buffer.__data_), std::__to_address(__old_p), __n_copy);
2737 if (__n_add != 0)
2738 traits_type::copy(std::__to_address(__buffer.__data_) + __n_copy, __p_new_stuff, __n_add);
2739 size_type __sec_cp_sz = __old_sz - __n_del - __n_copy;
2740 if (__sec_cp_sz != 0)
2741 traits_type::copy(std::__to_address(__buffer.__data_) + __n_copy + __n_add,
2742 std::__to_address(__old_p) + __n_copy + __n_del,
2743 __sec_cp_sz);
2744 __buffer.__size_ = __n_copy + __n_add + __sec_cp_sz;
2745 traits_type::assign(__buffer.__data_[__buffer.__size_], value_type());
2746 __reset_internal_buffer(__buffer);
2747}
2748
2749// __grow_by is deprecated because it does not set the size. It may not update the size when the size is changed, and it
2750// may also not set the size at all when the string was short initially. This leads to unpredictable size value. It is
2751// not removed or changed to avoid breaking the ABI.
2752template <class _CharT, class _Traits, class _Allocator>
2753void _LIBCPP_CONSTEXPR_SINCE_CXX20
2754# if _LIBCPP_ABI_VERSION >= 2 // We want to use the function in the dylib in ABIv1
2755_LIBCPP_HIDE_FROM_ABI
2756# endif
2757_LIBCPP_DEPRECATED_("use __grow_by_without_replace") basic_string<_CharT, _Traits, _Allocator>::__grow_by(
2758 size_type __old_cap,
2759 size_type __delta_cap,
2760 size_type __old_sz,
2761 size_type __n_copy,
2762 size_type __n_del,
2763 size_type __n_add) {
2764 __long __buffer = __allocate_long_buffer(__alloc_, __get_amortized_growth_capacity(__old_cap + __delta_cap));
2765 pointer __old_p = __get_pointer();
2766 if (__n_copy != 0)
2767 traits_type::copy(std::__to_address(__buffer.__data_), std::__to_address(__old_p), __n_copy);
2768 size_type __sec_cp_sz = __old_sz - __n_del - __n_copy;
2769 if (__sec_cp_sz != 0)
2770 traits_type::copy(std::__to_address(__buffer.__data_) + __n_copy + __n_add,
2771 std::__to_address(__old_p) + __n_copy + __n_del,
2772 __sec_cp_sz);
2773
2774 // This is -1 to make sure the caller sets the size properly, since old versions of this function didn't set the size
2775 // at all.
2776 __buffer.__size_ = -1;
2777 __reset_internal_buffer(__buffer);
2778}
2779
2780template <class _CharT, class _Traits, class _Allocator>
2781void _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI
2782basic_string<_CharT, _Traits, _Allocator>::__grow_by_without_replace(
2783 size_type __old_cap,
2784 size_type __delta_cap,
2785 size_type __old_sz,
2786 size_type __n_copy,
2787 size_type __n_del,
2788 size_type __n_add) {
2789 __annotate_delete();
2790 auto __guard = std::__make_scope_guard(__annotate_new_size(*this));
2791 _LIBCPP_SUPPRESS_DEPRECATED_PUSH
2792 __grow_by(__old_cap, __delta_cap, __old_sz, __n_copy, __n_del, __n_add);
2793 _LIBCPP_SUPPRESS_DEPRECATED_POP
2794 // Due to the ABI of __grow_by we have to set the size after calling it.
2795 __set_long_size(__old_sz - __n_del + __n_add);
2796}
2797
2798// assign
2799
2800template <class _CharT, class _Traits, class _Allocator>
2801template <bool __is_short>
2802_LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_NOINLINE basic_string<_CharT, _Traits, _Allocator>&
2803basic_string<_CharT, _Traits, _Allocator>::__assign_no_alias(const value_type* __s, size_type __n) {
2804 const auto __cap = __is_short ? static_cast<size_type>(__min_cap) : __get_long_cap();
2805 const auto __size = __is_short ? __get_short_size() : __get_long_size();
2806 if (__n >= __cap) {
2807 __grow_by_and_replace(__cap - 1, __n - __cap + 1, __size, 0, __size, __n, __s);
2808 return *this;
2809 }
2810
2811 __annotate_delete();
2812 auto __guard = std::__make_scope_guard(__annotate_new_size(*this));
2813 pointer __p;
2814 if (__is_short) {
2815 __p = __get_short_pointer();
2816 __set_short_size(__n);
2817 } else {
2818 __p = __get_long_pointer();
2819 __set_long_size(__n);
2820 }
2821 traits_type::copy(std::__to_address(__p), __s, __n);
2822 traits_type::assign(__p[__n], value_type());
2823 return *this;
2824}
2825
2826template <class _CharT, class _Traits, class _Allocator>
2827_LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_NOINLINE basic_string<_CharT, _Traits, _Allocator>&
2828basic_string<_CharT, _Traits, _Allocator>::__assign_external(const value_type* __s, size_type __n) {
2829 const auto __cap = capacity();
2830 const auto __size = size();
2831 if (__cap >= __n) {
2832 if (__n > __size)
2833 __annotate_increase(__n - __size);
2834 value_type* __p = std::__to_address(__get_pointer());
2835 traits_type::move(__p, __s, __n);
2836 return __null_terminate_at(__p, __n);
2837 } else {
2838 __grow_by_and_replace(__cap, __n - __cap, __size, 0, __size, __n, __s);
2839 return *this;
2840 }
2841}
2842
2843template <class _CharT, class _Traits, class _Allocator>
2844_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>&
2845basic_string<_CharT, _Traits, _Allocator>::assign(const value_type* __s, size_type __n) {
2846 _LIBCPP_ASSERT_NON_NULL(__n == 0 || __s != nullptr, "string::assign received nullptr");
2847 return (__builtin_constant_p(__n) && __fits_in_sso(__n)) ? __assign_short(__s, __n) : __assign_external(__s, __n);
2848}
2849
2850template <class _CharT, class _Traits, class _Allocator>
2851_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>&
2852basic_string<_CharT, _Traits, _Allocator>::assign(size_type __n, value_type __c) {
2853 size_type __cap = capacity();
2854 size_type __old_size = size();
2855 if (__cap < __n) {
2856 __grow_by_without_replace(__cap, __n - __cap, __old_size, 0, __old_size);
2857 __annotate_increase(__n);
2858 } else if (__n > __old_size)
2859 __annotate_increase(__n - __old_size);
2860 value_type* __p = std::__to_address(__get_pointer());
2861 traits_type::assign(__p, __n, __c);
2862 return __null_terminate_at(__p, __n);
2863}
2864
2865template <class _CharT, class _Traits, class _Allocator>
2866_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>&
2867basic_string<_CharT, _Traits, _Allocator>::operator=(value_type __c) {
2868 size_type __old_size = size();
2869 if (__old_size == 0)
2870 __annotate_increase(1);
2871 pointer __p;
2872 if (__is_long()) {
2873 __p = __get_long_pointer();
2874 __set_long_size(1);
2875 } else {
2876 __p = __get_short_pointer();
2877 __set_short_size(1);
2878 }
2879 traits_type::assign(*__p, __c);
2880 traits_type::assign(*++__p, value_type());
2881 if (__old_size > 1)
2882 __annotate_shrink(__old_size);
2883 return *this;
2884}
2885
2886template <class _CharT, class _Traits, class _Allocator>
2887_LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_STRING_INTERNAL_MEMORY_ACCESS basic_string<_CharT, _Traits, _Allocator>&
2888basic_string<_CharT, _Traits, _Allocator>::operator=(const basic_string& __str) {
2889 if (this == std::addressof(__str))
2890 return *this;
2891
2892 __copy_assign_alloc(__str);
2893
2894 if (__is_long())
2895 return __assign_no_alias<false>(__str.data(), __str.size());
2896
2897 if (__str.__is_long())
2898 return __assign_no_alias<true>(__str.data(), __str.size());
2899
2900 __annotate_delete();
2901 auto __guard = std::__make_scope_guard(__annotate_new_size(*this));
2902 __rep_ = __str.__rep_;
2903
2904 return *this;
2905}
2906
2907# ifndef _LIBCPP_CXX03_LANG
2908
2909template <class _CharT, class _Traits, class _Allocator>
2910inline _LIBCPP_CONSTEXPR_SINCE_CXX20 void basic_string<_CharT, _Traits, _Allocator>::__move_assign(
2911 basic_string& __str, false_type) noexcept(__alloc_traits::is_always_equal::value) {
2912 if (__alloc_ != __str.__alloc_)
2913 assign(__str);
2914 else
2915 __move_assign(__str, true_type());
2916}
2917
2918template <class _CharT, class _Traits, class _Allocator>
2919inline _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_STRING_INTERNAL_MEMORY_ACCESS void
2920basic_string<_CharT, _Traits, _Allocator>::__move_assign(basic_string& __str, true_type)
2921# if _LIBCPP_STD_VER >= 17
2922 noexcept
2923# else
2924 noexcept(is_nothrow_move_assignable<allocator_type>::value)
2925# endif
2926{
2927 __annotate_delete();
2928 if (__is_long()) {
2929 __reset_internal_buffer();
2930# if _LIBCPP_STD_VER <= 14
2931 if (!is_nothrow_move_assignable<allocator_type>::value) {
2932 __set_short_size(0);
2933 traits_type::assign(__get_short_pointer()[0], value_type());
2934 __annotate_new(0);
2935 }
2936# endif
2937 }
2938 size_type __str_old_size = __str.size();
2939 bool __str_was_short = !__str.__is_long();
2940
2941 __move_assign_alloc(__str);
2942 __rep_ = __str.__rep_;
2943 __str.__set_short_size(0);
2944 traits_type::assign(__str.__get_short_pointer()[0], value_type());
2945
2946 if (__str_was_short && this != std::addressof(__str))
2947 __str.__annotate_shrink(__str_old_size);
2948 else
2949 // ASan annotations: was long, so object memory is unpoisoned as new.
2950 // Or is same as *this, and __annotate_delete() was called.
2951 __str.__annotate_new(0);
2952
2953 // ASan annotations: Guard against `std::string s; s = std::move(s);`
2954 // You can find more here: https://en.cppreference.com/w/cpp/utility/move
2955 // Quote: "Unless otherwise specified, all standard library objects that have been moved
2956 // from are placed in a "valid but unspecified state", meaning the object's class
2957 // invariants hold (so functions without preconditions, such as the assignment operator,
2958 // can be safely used on the object after it was moved from):"
2959 // Quote: "v = std::move(v); // the value of v is unspecified"
2960 if (!__is_long() && std::addressof(__str) != this)
2961 // If it is long string, delete was never called on original __str's buffer.
2962 __annotate_new(__get_short_size());
2963}
2964
2965# endif
2966
2967template <class _CharT, class _Traits, class _Allocator>
2968template <class _InputIterator, class _Sentinel>
2969_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void
2970basic_string<_CharT, _Traits, _Allocator>::__assign_with_sentinel(_InputIterator __first, _Sentinel __last) {
2971 const basic_string __temp(__init_with_sentinel_tag(), std::move(__first), std::move(__last), __alloc_);
2972 assign(__temp.data(), __temp.size());
2973}
2974
2975template <class _CharT, class _Traits, class _Allocator>
2976template <class _Iterator, class _Sentinel>
2977_LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void
2978basic_string<_CharT, _Traits, _Allocator>::__assign_trivial(_Iterator __first, _Sentinel __last, size_type __n) {
2979 _LIBCPP_ASSERT_INTERNAL(
2980 __string_is_trivial_iterator_v<_Iterator>, "The iterator type given to `__assign_trivial` must be trivial");
2981
2982 size_type __old_size = size();
2983 size_type __cap = capacity();
2984 if (__cap < __n) {
2985 // Unlike `append` functions, if the input range points into the string itself, there is no case that the input
2986 // range could get invalidated by reallocation:
2987 // 1. If the input range is a subset of the string itself, its size cannot exceed the capacity of the string,
2988 // thus no reallocation would happen.
2989 // 2. In the exotic case where the input range is the byte representation of the string itself, the string
2990 // object itself stays valid even if reallocation happens.
2991 size_type __sz = size();
2992 __grow_by_without_replace(__cap, __n - __cap, __sz, 0, __sz);
2993 __annotate_increase(__n);
2994 } else if (__n > __old_size)
2995 __annotate_increase(__n - __old_size);
2996 pointer __p = __get_pointer();
2997 for (; __first != __last; ++__p, (void)++__first)
2998 traits_type::assign(*__p, *__first);
2999 traits_type::assign(*__p, value_type());
3000 __set_size(__n);
3001 if (__n < __old_size)
3002 __annotate_shrink(__old_size);
3003}
3004
3005template <class _CharT, class _Traits, class _Allocator>
3006_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>&
3007basic_string<_CharT, _Traits, _Allocator>::assign(const basic_string& __str, size_type __pos, size_type __n) {
3008 size_type __sz = __str.size();
3009 if (__pos > __sz)
3010 this->__throw_out_of_range();
3011 return assign(__str.data() + __pos, std::min(__n, __sz - __pos));
3012}
3013
3014template <class _CharT, class _Traits, class _Allocator>
3015_LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_NOINLINE basic_string<_CharT, _Traits, _Allocator>&
3016basic_string<_CharT, _Traits, _Allocator>::__assign_external(const value_type* __s) {
3017 return __assign_external(__s, traits_type::length(__s));
3018}
3019
3020template <class _CharT, class _Traits, class _Allocator>
3021_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>&
3022basic_string<_CharT, _Traits, _Allocator>::assign(const value_type* __s) {
3023 _LIBCPP_ASSERT_NON_NULL(__s != nullptr, "string::assign received nullptr");
3024 if (auto __len = traits_type::length(__s); __builtin_constant_p(__len) && __fits_in_sso(__len))
3025 return __assign_short(__s, __len);
3026 return __assign_external(__s);
3027}
3028// append
3029
3030template <class _CharT, class _Traits, class _Allocator>
3031_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>&
3032basic_string<_CharT, _Traits, _Allocator>::append(const value_type* __s, size_type __n) {
3033 _LIBCPP_ASSERT_NON_NULL(__n == 0 || __s != nullptr, "string::append received nullptr");
3034 size_type __cap = capacity();
3035 size_type __sz = size();
3036 if (__cap - __sz < __n) {
3037 __grow_by_and_replace(__cap, __sz + __n - __cap, __sz, __sz, 0, __n, __s);
3038 return *this;
3039 }
3040
3041 if (__n == 0)
3042 return *this;
3043
3044 __annotate_increase(__n);
3045 value_type* __p = std::__to_address(__get_pointer());
3046 traits_type::copy(__p + __sz, __s, __n);
3047 __sz += __n;
3048 __set_size(__sz);
3049 traits_type::assign(__p[__sz], value_type());
3050 return *this;
3051}
3052
3053template <class _CharT, class _Traits, class _Allocator>
3054_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>&
3055basic_string<_CharT, _Traits, _Allocator>::append(size_type __n, value_type __c) {
3056 if (__n == 0)
3057 return *this;
3058
3059 size_type __cap = capacity();
3060 size_type __sz = size();
3061 if (__cap - __sz < __n)
3062 __grow_by_without_replace(__cap, __sz + __n - __cap, __sz, __sz, 0);
3063 __annotate_increase(__n);
3064 pointer __p = __get_pointer();
3065 traits_type::assign(std::__to_address(__p) + __sz, __n, __c);
3066 __sz += __n;
3067 __set_size(__sz);
3068 traits_type::assign(__p[__sz], value_type());
3069 return *this;
3070}
3071
3072template <class _CharT, class _Traits, class _Allocator>
3073_LIBCPP_CONSTEXPR_SINCE_CXX20 void basic_string<_CharT, _Traits, _Allocator>::push_back(value_type __c) {
3074 bool __is_short = !__is_long();
3075 size_type __cap;
3076 size_type __sz;
3077 if (__is_short) {
3078 __cap = __min_cap - 1;
3079 __sz = __get_short_size();
3080 } else {
3081 __cap = __get_long_cap() - 1;
3082 __sz = __get_long_size();
3083 }
3084 if (__sz == __cap) {
3085 __grow_by_without_replace(__cap, 1, __sz, __sz, 0);
3086 __is_short = false; // the string is always long after __grow_by
3087 }
3088 __annotate_increase(1);
3089 pointer __p;
3090 if (__is_short) {
3091 __p = __get_short_pointer() + __sz;
3092 __set_short_size(__sz + 1);
3093 } else {
3094 __p = __get_long_pointer() + __sz;
3095 __set_long_size(__sz + 1);
3096 }
3097 traits_type::assign(*__p, __c);
3098 traits_type::assign(*++__p, value_type());
3099}
3100
3101template <class _CharT, class _Traits, class _Allocator>
3102_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>&
3103basic_string<_CharT, _Traits, _Allocator>::append(const basic_string& __str, size_type __pos, size_type __n) {
3104 size_type __sz = __str.size();
3105 if (__pos > __sz)
3106 this->__throw_out_of_range();
3107 return append(__str.data() + __pos, std::min(__n, __sz - __pos));
3108}
3109
3110template <class _CharT, class _Traits, class _Allocator>
3111_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>&
3112basic_string<_CharT, _Traits, _Allocator>::append(const value_type* __s) {
3113 _LIBCPP_ASSERT_NON_NULL(__s != nullptr, "string::append received nullptr");
3114 return append(__s, traits_type::length(__s));
3115}
3116
3117// insert
3118
3119template <class _CharT, class _Traits, class _Allocator>
3120_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>&
3121basic_string<_CharT, _Traits, _Allocator>::insert(size_type __pos, const value_type* __s, size_type __n) {
3122 _LIBCPP_ASSERT_NON_NULL(__n == 0 || __s != nullptr, "string::insert received nullptr");
3123 size_type __sz = size();
3124 if (__pos > __sz)
3125 this->__throw_out_of_range();
3126 size_type __cap = capacity();
3127
3128 if (__cap - __sz < __n) {
3129 __grow_by_and_replace(__cap, __sz + __n - __cap, __sz, __pos, 0, __n, __s);
3130 return *this;
3131 }
3132
3133 if (__n == 0)
3134 return *this;
3135
3136 __annotate_increase(__n);
3137 value_type* __p = std::__to_address(__get_pointer());
3138 size_type __n_move = __sz - __pos;
3139 if (__n_move != 0) {
3140 if (std::__is_pointer_in_range(__p + __pos, __p + __sz, __s))
3141 __s += __n;
3142 traits_type::move(__p + __pos + __n, __p + __pos, __n_move);
3143 }
3144 traits_type::move(__p + __pos, __s, __n);
3145 __sz += __n;
3146 __set_size(__sz);
3147 traits_type::assign(__p[__sz], value_type());
3148 return *this;
3149}
3150
3151template <class _CharT, class _Traits, class _Allocator>
3152_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>&
3153basic_string<_CharT, _Traits, _Allocator>::insert(size_type __pos, size_type __n, value_type __c) {
3154 size_type __sz = size();
3155 if (__pos > __sz)
3156 this->__throw_out_of_range();
3157
3158 if (__n == 0)
3159 return *this;
3160
3161 size_type __cap = capacity();
3162 value_type* __p;
3163 if (__cap - __sz >= __n) {
3164 __annotate_increase(__n);
3165 __p = std::__to_address(__get_pointer());
3166 size_type __n_move = __sz - __pos;
3167 if (__n_move != 0)
3168 traits_type::move(__p + __pos + __n, __p + __pos, __n_move);
3169 } else {
3170 __grow_by_without_replace(__cap, __sz + __n - __cap, __sz, __pos, 0, __n);
3171 __p = std::__to_address(__get_long_pointer());
3172 }
3173 traits_type::assign(__p + __pos, __n, __c);
3174 __sz += __n;
3175 __set_size(__sz);
3176 traits_type::assign(__p[__sz], value_type());
3177 return *this;
3178}
3179
3180template <class _CharT, class _Traits, class _Allocator>
3181template <class _Iterator, class _Sentinel>
3182_LIBCPP_CONSTEXPR_SINCE_CXX20 typename basic_string<_CharT, _Traits, _Allocator>::iterator
3183basic_string<_CharT, _Traits, _Allocator>::__insert_with_size(
3184 const_iterator __pos, _Iterator __first, _Sentinel __last, size_type __n) {
3185 size_type __ip = static_cast<size_type>(__pos - begin());
3186 if (__n == 0)
3187 return begin() + __ip;
3188
3189 if (__string_is_trivial_iterator_v<_Iterator> && !__addr_in_range(*__first)) {
3190 return __insert_from_safe_copy(__n, __ip, std::move(__first), std::move(__last));
3191 } else {
3192 const basic_string __temp(__init_with_sentinel_tag(), std::move(__first), std::move(__last), __alloc_);
3193 return __insert_from_safe_copy(__n, __ip, __temp.begin(), __temp.end());
3194 }
3195}
3196
3197template <class _CharT, class _Traits, class _Allocator>
3198_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>&
3199basic_string<_CharT, _Traits, _Allocator>::insert(
3200 size_type __pos1, const basic_string& __str, size_type __pos2, size_type __n) {
3201 size_type __str_sz = __str.size();
3202 if (__pos2 > __str_sz)
3203 this->__throw_out_of_range();
3204 return insert(__pos1, __str.data() + __pos2, std::min(__n, __str_sz - __pos2));
3205}
3206
3207template <class _CharT, class _Traits, class _Allocator>
3208_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>&
3209basic_string<_CharT, _Traits, _Allocator>::insert(size_type __pos, const value_type* __s) {
3210 _LIBCPP_ASSERT_NON_NULL(__s != nullptr, "string::insert received nullptr");
3211 return insert(__pos, __s, traits_type::length(__s));
3212}
3213
3214template <class _CharT, class _Traits, class _Allocator>
3215_LIBCPP_CONSTEXPR_SINCE_CXX20 typename basic_string<_CharT, _Traits, _Allocator>::iterator
3216basic_string<_CharT, _Traits, _Allocator>::insert(const_iterator __pos, value_type __c) {
3217 size_type __ip = static_cast<size_type>(__pos - begin());
3218 size_type __sz = size();
3219 size_type __cap = capacity();
3220 value_type* __p;
3221 if (__cap == __sz) {
3222 __grow_by_without_replace(__cap, 1, __sz, __ip, 0, 1);
3223 __p = std::__to_address(__get_long_pointer());
3224 } else {
3225 __annotate_increase(1);
3226 __p = std::__to_address(__get_pointer());
3227 size_type __n_move = __sz - __ip;
3228 if (__n_move != 0)
3229 traits_type::move(__p + __ip + 1, __p + __ip, __n_move);
3230 }
3231 traits_type::assign(__p[__ip], __c);
3232 traits_type::assign(__p[++__sz], value_type());
3233 __set_size(__sz);
3234 return begin() + static_cast<difference_type>(__ip);
3235}
3236
3237// replace
3238
3239template <class _CharT, class _Traits, class _Allocator>
3240_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>&
3241basic_string<_CharT, _Traits, _Allocator>::replace(
3242 size_type __pos, size_type __n1, const value_type* __s, size_type __n2)
3243 _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK {
3244 _LIBCPP_ASSERT_NON_NULL(__n2 == 0 || __s != nullptr, "string::replace received nullptr");
3245 size_type __sz = size();
3246 if (__pos > __sz)
3247 this->__throw_out_of_range();
3248 __n1 = std::min(__n1, __sz - __pos);
3249 size_type __cap = capacity();
3250 if (__cap - __sz + __n1 < __n2) {
3251 __grow_by_and_replace(__cap, __sz - __n1 + __n2 - __cap, __sz, __pos, __n1, __n2, __s);
3252 return *this;
3253 }
3254
3255 value_type* __p = std::__to_address(__get_pointer());
3256 if (__n1 != __n2) {
3257 if (__n2 > __n1)
3258 __annotate_increase(__n2 - __n1);
3259 size_type __n_move = __sz - __pos - __n1;
3260 if (__n_move != 0) {
3261 if (__n1 > __n2) {
3262 traits_type::move(__p + __pos, __s, __n2);
3263 traits_type::move(__p + __pos + __n2, __p + __pos + __n1, __n_move);
3264 return __null_terminate_at(__p, __sz + (__n2 - __n1));
3265 }
3266 if (std::__is_pointer_in_range(__p + __pos + 1, __p + __sz, __s)) {
3267 if (__p + __pos + __n1 <= __s) {
3268 __s += __n2 - __n1;
3269 } else { // __p + __pos < __s < __p + __pos + __n1
3270 traits_type::move(__p + __pos, __s, __n1);
3271 __pos += __n1;
3272 __s += __n2;
3273 __n2 -= __n1;
3274 __n1 = 0;
3275 }
3276 }
3277 traits_type::move(__p + __pos + __n2, __p + __pos + __n1, __n_move);
3278 }
3279 }
3280 traits_type::move(__p + __pos, __s, __n2);
3281 return __null_terminate_at(__p, __sz + (__n2 - __n1));
3282}
3283
3284template <class _CharT, class _Traits, class _Allocator>
3285_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>&
3286basic_string<_CharT, _Traits, _Allocator>::replace(size_type __pos, size_type __n1, size_type __n2, value_type __c) {
3287 size_type __sz = size();
3288 if (__pos > __sz)
3289 this->__throw_out_of_range();
3290 __n1 = std::min(__n1, __sz - __pos);
3291 size_type __cap = capacity();
3292 value_type* __p;
3293 if (__cap - __sz + __n1 >= __n2) {
3294 __p = std::__to_address(__get_pointer());
3295 if (__n1 != __n2) {
3296 if (__n2 > __n1)
3297 __annotate_increase(__n2 - __n1);
3298 size_type __n_move = __sz - __pos - __n1;
3299 if (__n_move != 0)
3300 traits_type::move(__p + __pos + __n2, __p + __pos + __n1, __n_move);
3301 }
3302 } else {
3303 __grow_by_without_replace(__cap, __sz - __n1 + __n2 - __cap, __sz, __pos, __n1, __n2);
3304 __p = std::__to_address(__get_long_pointer());
3305 }
3306 traits_type::assign(__p + __pos, __n2, __c);
3307 return __null_terminate_at(__p, __sz - (__n1 - __n2));
3308}
3309
3310template <class _CharT, class _Traits, class _Allocator>
3311_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>&
3312basic_string<_CharT, _Traits, _Allocator>::replace(
3313 size_type __pos1, size_type __n1, const basic_string& __str, size_type __pos2, size_type __n2) {
3314 size_type __str_sz = __str.size();
3315 if (__pos2 > __str_sz)
3316 this->__throw_out_of_range();
3317 return replace(__pos1, __n1, __str.data() + __pos2, std::min(__n2, __str_sz - __pos2));
3318}
3319
3320template <class _CharT, class _Traits, class _Allocator>
3321_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>&
3322basic_string<_CharT, _Traits, _Allocator>::replace(size_type __pos, size_type __n1, const value_type* __s) {
3323 _LIBCPP_ASSERT_NON_NULL(__s != nullptr, "string::replace received nullptr");
3324 return replace(__pos, __n1, __s, traits_type::length(__s));
3325}
3326
3327// erase
3328
3329// 'externally instantiated' erase() implementation, called when __n != npos.
3330// Does not check __pos against size()
3331template <class _CharT, class _Traits, class _Allocator>
3332_LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_NOINLINE void
3333basic_string<_CharT, _Traits, _Allocator>::__erase_external_with_move(size_type __pos, size_type __n) _NOEXCEPT {
3334 if (__n == 0)
3335 return;
3336
3337 size_type __sz = size();
3338 value_type* __p = std::__to_address(__get_pointer());
3339 __n = std::min(__n, __sz - __pos);
3340 size_type __n_move = __sz - __pos - __n;
3341 if (__n_move != 0)
3342 traits_type::move(__p + __pos, __p + __pos + __n, __n_move);
3343 __null_terminate_at(__p, __sz - __n);
3344}
3345
3346template <class _CharT, class _Traits, class _Allocator>
3347_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>&
3348basic_string<_CharT, _Traits, _Allocator>::erase(size_type __pos, size_type __n) {
3349 if (__pos > size())
3350 this->__throw_out_of_range();
3351 if (__n == npos) {
3352 __erase_to_end(__pos);
3353 } else {
3354 __erase_external_with_move(__pos, __n);
3355 }
3356 return *this;
3357}
3358
3359template <class _CharT, class _Traits, class _Allocator>
3360inline _LIBCPP_CONSTEXPR_SINCE_CXX20 typename basic_string<_CharT, _Traits, _Allocator>::iterator
3361basic_string<_CharT, _Traits, _Allocator>::erase(const_iterator __pos) {
3362 _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
3363 __pos != end(), "string::erase(iterator) called with a non-dereferenceable iterator");
3364 iterator __b = begin();
3365 size_type __r = static_cast<size_type>(__pos - __b);
3366 erase(__r, 1);
3367 return __b + static_cast<difference_type>(__r);
3368}
3369
3370template <class _CharT, class _Traits, class _Allocator>
3371inline _LIBCPP_CONSTEXPR_SINCE_CXX20 typename basic_string<_CharT, _Traits, _Allocator>::iterator
3372basic_string<_CharT, _Traits, _Allocator>::erase(const_iterator __first, const_iterator __last) {
3373 _LIBCPP_ASSERT_VALID_INPUT_RANGE(__first <= __last, "string::erase(first, last) called with invalid range");
3374 iterator __b = begin();
3375 size_type __r = static_cast<size_type>(__first - __b);
3376 erase(__r, static_cast<size_type>(__last - __first));
3377 return __b + static_cast<difference_type>(__r);
3378}
3379
3380template <class _CharT, class _Traits, class _Allocator>
3381inline _LIBCPP_CONSTEXPR_SINCE_CXX20 void basic_string<_CharT, _Traits, _Allocator>::pop_back() {
3382 _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(!empty(), "string::pop_back(): string is already empty");
3383 __erase_to_end(size() - 1);
3384}
3385
3386template <class _CharT, class _Traits, class _Allocator>
3387inline _LIBCPP_CONSTEXPR_SINCE_CXX20 void basic_string<_CharT, _Traits, _Allocator>::clear() _NOEXCEPT {
3388 size_type __old_size;
3389 if (__is_long()) {
3390 __old_size = __get_long_size();
3391 traits_type::assign(*__get_long_pointer(), value_type());
3392 __set_long_size(0);
3393 } else {
3394 __old_size = __get_short_size();
3395 traits_type::assign(*__get_short_pointer(), value_type());
3396 __set_short_size(0);
3397 }
3398 __annotate_shrink(__old_size);
3399}
3400
3401template <class _CharT, class _Traits, class _Allocator>
3402_LIBCPP_CONSTEXPR_SINCE_CXX20 void basic_string<_CharT, _Traits, _Allocator>::resize(size_type __n, value_type __c) {
3403 size_type __sz = size();
3404 if (__n > __sz)
3405 append(__n - __sz, __c);
3406 else
3407 __erase_to_end(__n);
3408}
3409
3410template <class _CharT, class _Traits, class _Allocator>
3411_LIBCPP_CONSTEXPR_SINCE_CXX20 void basic_string<_CharT, _Traits, _Allocator>::reserve(size_type __requested_capacity) {
3412 if (__requested_capacity > max_size())
3413 this->__throw_length_error();
3414
3415 // Make sure reserve(n) never shrinks. This is technically only required in C++20
3416 // and later (since P0966R1), however we provide consistent behavior in all Standard
3417 // modes because this function is instantiated in the shared library.
3418 if (__requested_capacity <= capacity())
3419 return;
3420
3421 __annotation_guard __g(*this);
3422 __long __buffer = __allocate_long_buffer(__alloc_, __requested_capacity);
3423 __buffer.__size_ = size();
3424 traits_type::copy(std::__to_address(__buffer.__data_), data(), __buffer.__size_ + 1);
3425 __reset_internal_buffer(__buffer);
3426}
3427
3428template <class _CharT, class _Traits, class _Allocator>
3429inline _LIBCPP_CONSTEXPR_SINCE_CXX20 void basic_string<_CharT, _Traits, _Allocator>::shrink_to_fit() _NOEXCEPT {
3430 if (!__is_long())
3431 return;
3432
3433 const auto __ptr = __get_long_pointer();
3434 const auto __size = __get_long_size();
3435 const auto __cap = __get_long_cap();
3436
3437 // We're a long string and we're shrinking into the small buffer.
3438 if (__fits_in_sso(__size)) {
3439 __annotation_guard __g(*this);
3440 __set_short_size(__size);
3441 traits_type::copy(std::__to_address(__get_short_pointer()), std::__to_address(__ptr), __size + 1);
3442 __alloc_traits::deallocate(__alloc_, __ptr, __cap);
3443 return;
3444 }
3445
3446 if (__align_allocation_size(__size) == __cap)
3447 return;
3448
3449# if _LIBCPP_HAS_EXCEPTIONS
3450 try {
3451# endif // _LIBCPP_HAS_EXCEPTIONS
3452 __annotation_guard __g(*this);
3453 __long __buffer = __allocate_long_buffer(__alloc_, __size);
3454
3455 // The Standard mandates shrink_to_fit() does not increase the capacity.
3456 // With equal capacity keep the existing buffer. This avoids extra work
3457 // due to swapping the elements.
3458 if (__buffer.__cap_ * __endian_factor - 1 >= capacity()) {
3459 __alloc_traits::deallocate(__alloc_, __buffer.__data_, __buffer.__cap_ * __endian_factor);
3460 return;
3461 }
3462
3463 traits_type::copy(std::__to_address(__buffer.__data_), std::__to_address(__get_long_pointer()), __size + 1);
3464 __reset_internal_buffer(__buffer);
3465# if _LIBCPP_HAS_EXCEPTIONS
3466 } catch (...) {
3467 return;
3468 }
3469# endif // _LIBCPP_HAS_EXCEPTIONS
3470}
3471
3472template <class _CharT, class _Traits, class _Allocator>
3473_LIBCPP_CONSTEXPR_SINCE_CXX20 typename basic_string<_CharT, _Traits, _Allocator>::const_reference
3474basic_string<_CharT, _Traits, _Allocator>::at(size_type __n) const {
3475 if (__n >= size())
3476 this->__throw_out_of_range();
3477 return (*this)[__n];
3478}
3479
3480template <class _CharT, class _Traits, class _Allocator>
3481_LIBCPP_CONSTEXPR_SINCE_CXX20 typename basic_string<_CharT, _Traits, _Allocator>::reference
3482basic_string<_CharT, _Traits, _Allocator>::at(size_type __n) {
3483 if (__n >= size())
3484 this->__throw_out_of_range();
3485 return (*this)[__n];
3486}
3487
3488template <class _CharT, class _Traits, class _Allocator>
3489_LIBCPP_CONSTEXPR_SINCE_CXX20 typename basic_string<_CharT, _Traits, _Allocator>::size_type
3490basic_string<_CharT, _Traits, _Allocator>::copy(value_type* __s, size_type __n, size_type __pos) const {
3491 size_type __sz = size();
3492 if (__pos > __sz)
3493 this->__throw_out_of_range();
3494 size_type __rlen = std::min(__n, __sz - __pos);
3495 traits_type::copy(__s, data() + __pos, __rlen);
3496 return __rlen;
3497}
3498
3499template <class _CharT, class _Traits, class _Allocator>
3500inline _LIBCPP_CONSTEXPR_SINCE_CXX20 void basic_string<_CharT, _Traits, _Allocator>::swap(basic_string& __str)
3501# if _LIBCPP_STD_VER >= 14
3502 _NOEXCEPT
3503# else
3504 _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value || __is_nothrow_swappable_v<allocator_type>)
3505# endif
3506{
3507 _LIBCPP_ASSERT_COMPATIBLE_ALLOCATOR(
3508 __alloc_traits::propagate_on_container_swap::value || __alloc_traits::is_always_equal::value ||
3509 __alloc_ == __str.__alloc_,
3510 "swapping non-equal allocators");
3511 if (!__is_long())
3512 __annotate_delete();
3513 if (this != std::addressof(__str) && !__str.__is_long())
3514 __str.__annotate_delete();
3515 std::swap(__rep_, __str.__rep_);
3516 std::__swap_allocator(__alloc_, __str.__alloc_);
3517 if (!__is_long())
3518 __annotate_new(__get_short_size());
3519 if (this != std::addressof(__str) && !__str.__is_long())
3520 __str.__annotate_new(__str.__get_short_size());
3521}
3522
3523// compare
3524
3525template <class _CharT, class _Traits, class _Allocator>
3526inline _LIBCPP_CONSTEXPR_SINCE_CXX20 int basic_string<_CharT, _Traits, _Allocator>::compare(
3527 size_type __pos1, size_type __n1, const value_type* __s, size_type __n2) const {
3528 _LIBCPP_ASSERT_NON_NULL(__n2 == 0 || __s != nullptr, "string::compare(): received nullptr");
3529 size_type __sz = size();
3530 if (__pos1 > __sz || __n2 == npos)
3531 this->__throw_out_of_range();
3532 size_type __rlen = std::min(__n1, __sz - __pos1);
3533 int __r = traits_type::compare(data() + __pos1, __s, std::min(__rlen, __n2));
3534 if (__r == 0) {
3535 if (__rlen < __n2)
3536 __r = -1;
3537 else if (__rlen > __n2)
3538 __r = 1;
3539 }
3540 return __r;
3541}
3542
3543// __invariants
3544
3545template <class _CharT, class _Traits, class _Allocator>
3546inline _LIBCPP_CONSTEXPR_SINCE_CXX20 bool basic_string<_CharT, _Traits, _Allocator>::__invariants() const {
3547 if (size() > capacity())
3548 return false;
3549 if (capacity() < __min_cap - 1)
3550 return false;
3551 if (data() == nullptr)
3552 return false;
3553 if (!_Traits::eq(data()[size()], value_type()))
3554 return false;
3555 return true;
3556}
3557
3558// operator==
3559
3560template <class _CharT, class _Traits, class _Allocator>
3561inline _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI bool
3562operator==(const basic_string<_CharT, _Traits, _Allocator>& __lhs,
3563 const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT {
3564 size_t __lhs_sz = __lhs.size();
3565 return __lhs_sz == __rhs.size() && _Traits::compare(__lhs.data(), __rhs.data(), __lhs_sz) == 0;
3566}
3567
3568template <class _CharT, class _Traits, class _Allocator>
3569inline _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI bool
3570operator==(const basic_string<_CharT, _Traits, _Allocator>& __lhs,
3571 const _CharT* _LIBCPP_DIAGNOSE_NULLPTR __rhs) _NOEXCEPT {
3572 _LIBCPP_ASSERT_NON_NULL(__rhs != nullptr, "operator==(basic_string, char*): received nullptr");
3573
3574 using _String = basic_string<_CharT, _Traits, _Allocator>;
3575
3576 size_t __rhs_len = _Traits::length(__rhs);
3577 if (__builtin_constant_p(__rhs_len) && !_String::__fits_in_sso(__rhs_len)) {
3578 if (!__lhs.__is_long())
3579 return false;
3580 }
3581 if (__rhs_len != __lhs.size())
3582 return false;
3583 return __lhs.compare(0, _String::npos, __rhs, __rhs_len) == 0;
3584}
3585
3586# if _LIBCPP_STD_VER <= 17
3587template <class _CharT, class _Traits, class _Allocator>
3588inline _LIBCPP_HIDE_FROM_ABI bool
3589operator==(const _CharT* __lhs, const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT {
3590 return __rhs == __lhs;
3591}
3592# endif // _LIBCPP_STD_VER <= 17
3593
3594# if _LIBCPP_STD_VER >= 20
3595
3596template <class _CharT, class _Traits, class _Allocator>
3597_LIBCPP_HIDE_FROM_ABI constexpr auto operator<=>(const basic_string<_CharT, _Traits, _Allocator>& __lhs,
3598 const basic_string<_CharT, _Traits, _Allocator>& __rhs) noexcept {
3599 return basic_string_view<_CharT, _Traits>(__lhs) <=> basic_string_view<_CharT, _Traits>(__rhs);
3600}
3601
3602template <class _CharT, class _Traits, class _Allocator>
3603_LIBCPP_HIDE_FROM_ABI constexpr auto
3604operator<=>(const basic_string<_CharT, _Traits, _Allocator>& __lhs, const _CharT* __rhs) {
3605 return basic_string_view<_CharT, _Traits>(__lhs) <=> basic_string_view<_CharT, _Traits>(__rhs);
3606}
3607
3608# else // _LIBCPP_STD_VER >= 20
3609
3610template <class _CharT, class _Traits, class _Allocator>
3611inline _LIBCPP_HIDE_FROM_ABI bool operator!=(const basic_string<_CharT, _Traits, _Allocator>& __lhs,
3612 const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT {
3613 return !(__lhs == __rhs);
3614}
3615
3616template <class _CharT, class _Traits, class _Allocator>
3617inline _LIBCPP_HIDE_FROM_ABI bool
3618operator!=(const _CharT* __lhs, const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT {
3619 return !(__lhs == __rhs);
3620}
3621
3622template <class _CharT, class _Traits, class _Allocator>
3623inline _LIBCPP_HIDE_FROM_ABI bool
3624operator!=(const basic_string<_CharT, _Traits, _Allocator>& __lhs, const _CharT* __rhs) _NOEXCEPT {
3625 return !(__lhs == __rhs);
3626}
3627
3628// operator<
3629
3630template <class _CharT, class _Traits, class _Allocator>
3631inline _LIBCPP_HIDE_FROM_ABI bool operator<(const basic_string<_CharT, _Traits, _Allocator>& __lhs,
3632 const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT {
3633 return __lhs.compare(__rhs) < 0;
3634}
3635
3636template <class _CharT, class _Traits, class _Allocator>
3637inline _LIBCPP_HIDE_FROM_ABI bool
3638operator<(const basic_string<_CharT, _Traits, _Allocator>& __lhs, const _CharT* __rhs) _NOEXCEPT {
3639 return __lhs.compare(__rhs) < 0;
3640}
3641
3642template <class _CharT, class _Traits, class _Allocator>
3643inline _LIBCPP_HIDE_FROM_ABI bool
3644operator<(const _CharT* __lhs, const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT {
3645 return __rhs.compare(__lhs) > 0;
3646}
3647
3648// operator>
3649
3650template <class _CharT, class _Traits, class _Allocator>
3651inline _LIBCPP_HIDE_FROM_ABI bool operator>(const basic_string<_CharT, _Traits, _Allocator>& __lhs,
3652 const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT {
3653 return __rhs < __lhs;
3654}
3655
3656template <class _CharT, class _Traits, class _Allocator>
3657inline _LIBCPP_HIDE_FROM_ABI bool
3658operator>(const basic_string<_CharT, _Traits, _Allocator>& __lhs, const _CharT* __rhs) _NOEXCEPT {
3659 return __rhs < __lhs;
3660}
3661
3662template <class _CharT, class _Traits, class _Allocator>
3663inline _LIBCPP_HIDE_FROM_ABI bool
3664operator>(const _CharT* __lhs, const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT {
3665 return __rhs < __lhs;
3666}
3667
3668// operator<=
3669
3670template <class _CharT, class _Traits, class _Allocator>
3671inline _LIBCPP_HIDE_FROM_ABI bool operator<=(const basic_string<_CharT, _Traits, _Allocator>& __lhs,
3672 const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT {
3673 return !(__rhs < __lhs);
3674}
3675
3676template <class _CharT, class _Traits, class _Allocator>
3677inline _LIBCPP_HIDE_FROM_ABI bool
3678operator<=(const basic_string<_CharT, _Traits, _Allocator>& __lhs, const _CharT* __rhs) _NOEXCEPT {
3679 return !(__rhs < __lhs);
3680}
3681
3682template <class _CharT, class _Traits, class _Allocator>
3683inline _LIBCPP_HIDE_FROM_ABI bool
3684operator<=(const _CharT* __lhs, const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT {
3685 return !(__rhs < __lhs);
3686}
3687
3688// operator>=
3689
3690template <class _CharT, class _Traits, class _Allocator>
3691inline _LIBCPP_HIDE_FROM_ABI bool operator>=(const basic_string<_CharT, _Traits, _Allocator>& __lhs,
3692 const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT {
3693 return !(__lhs < __rhs);
3694}
3695
3696template <class _CharT, class _Traits, class _Allocator>
3697inline _LIBCPP_HIDE_FROM_ABI bool
3698operator>=(const basic_string<_CharT, _Traits, _Allocator>& __lhs, const _CharT* __rhs) _NOEXCEPT {
3699 return !(__lhs < __rhs);
3700}
3701
3702template <class _CharT, class _Traits, class _Allocator>
3703inline _LIBCPP_HIDE_FROM_ABI bool
3704operator>=(const _CharT* __lhs, const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT {
3705 return !(__lhs < __rhs);
3706}
3707# endif // _LIBCPP_STD_VER >= 20
3708
3709// operator +
3710
3711template <class _CharT, class _Traits, class _Allocator>
3712_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>
3713__concatenate_strings(const _Allocator& __alloc,
3714 __type_identity_t<basic_string_view<_CharT, _Traits> > __str1,
3715 __type_identity_t<basic_string_view<_CharT, _Traits> > __str2) {
3716 using _String = basic_string<_CharT, _Traits, _Allocator>;
3717 _String __r(__uninitialized_size_tag(),
3718 __str1.size() + __str2.size(),
3719 _String::__alloc_traits::select_on_container_copy_construction(__alloc));
3720 auto __ptr = std::__to_address(__r.__get_pointer());
3721 _Traits::copy(__ptr, __str1.data(), __str1.size());
3722 _Traits::copy(__ptr + __str1.size(), __str2.data(), __str2.size());
3723 _Traits::assign(__ptr[__str1.size() + __str2.size()], _CharT());
3724 return __r;
3725}
3726
3727template <class _CharT, class _Traits, class _Allocator>
3728_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>
3729operator+(const basic_string<_CharT, _Traits, _Allocator>& __lhs,
3730 const basic_string<_CharT, _Traits, _Allocator>& __rhs) {
3731 return std::__concatenate_strings<_CharT, _Traits>(__lhs.get_allocator(), __lhs, __rhs);
3732}
3733
3734template <class _CharT, class _Traits, class _Allocator>
3735_LIBCPP_HIDDEN _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>
3736operator+(const _CharT* __lhs, const basic_string<_CharT, _Traits, _Allocator>& __rhs) {
3737 return std::__concatenate_strings<_CharT, _Traits>(__rhs.get_allocator(), __lhs, __rhs);
3738}
3739
3740extern template _LIBCPP_EXPORTED_FROM_ABI string operator+
3741 <char, char_traits<char>, allocator<char> >(char const*, string const&);
3742
3743template <class _CharT, class _Traits, class _Allocator>
3744_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>
3745operator+(_CharT __lhs, const basic_string<_CharT, _Traits, _Allocator>& __rhs) {
3746 return std::__concatenate_strings<_CharT, _Traits>(
3747 __rhs.get_allocator(), basic_string_view<_CharT, _Traits>(std::addressof(__lhs), 1), __rhs);
3748}
3749
3750template <class _CharT, class _Traits, class _Allocator>
3751_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>
3752operator+(const basic_string<_CharT, _Traits, _Allocator>& __lhs, const _CharT* __rhs) {
3753 return std::__concatenate_strings<_CharT, _Traits>(__lhs.get_allocator(), __lhs, __rhs);
3754}
3755
3756template <class _CharT, class _Traits, class _Allocator>
3757_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>
3758operator+(const basic_string<_CharT, _Traits, _Allocator>& __lhs, _CharT __rhs) {
3759 return std::__concatenate_strings<_CharT, _Traits>(
3760 __lhs.get_allocator(), __lhs, basic_string_view<_CharT, _Traits>(std::addressof(__rhs), 1));
3761}
3762# if _LIBCPP_STD_VER >= 26
3763
3764template <class _CharT, class _Traits, class _Allocator>
3765_LIBCPP_HIDE_FROM_ABI constexpr basic_string<_CharT, _Traits, _Allocator>
3766operator+(const basic_string<_CharT, _Traits, _Allocator>& __lhs,
3767 type_identity_t<basic_string_view<_CharT, _Traits>> __rhs) {
3768 return std::__concatenate_strings<_CharT, _Traits>(__lhs.get_allocator(), __lhs, __rhs);
3769}
3770
3771template <class _CharT, class _Traits, class _Allocator>
3772_LIBCPP_HIDE_FROM_ABI constexpr basic_string<_CharT, _Traits, _Allocator>
3773operator+(type_identity_t<basic_string_view<_CharT, _Traits>> __lhs,
3774 const basic_string<_CharT, _Traits, _Allocator>& __rhs) {
3775 return std::__concatenate_strings<_CharT, _Traits>(__rhs.get_allocator(), __lhs, __rhs);
3776}
3777
3778# endif // _LIBCPP_STD_VER >= 26
3779
3780# ifndef _LIBCPP_CXX03_LANG
3781
3782template <class _CharT, class _Traits, class _Allocator>
3783inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>
3784operator+(basic_string<_CharT, _Traits, _Allocator>&& __lhs, const basic_string<_CharT, _Traits, _Allocator>& __rhs) {
3785 return std::move(__lhs.append(__rhs));
3786}
3787
3788template <class _CharT, class _Traits, class _Allocator>
3789inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>
3790operator+(const basic_string<_CharT, _Traits, _Allocator>& __lhs, basic_string<_CharT, _Traits, _Allocator>&& __rhs) {
3791 return std::move(__rhs.insert(0, __lhs));
3792}
3793
3794template <class _CharT, class _Traits, class _Allocator>
3795inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>
3796operator+(basic_string<_CharT, _Traits, _Allocator>&& __lhs, basic_string<_CharT, _Traits, _Allocator>&& __rhs) {
3797 return std::move(__lhs.append(__rhs));
3798}
3799
3800template <class _CharT, class _Traits, class _Allocator>
3801inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>
3802operator+(const _CharT* __lhs, basic_string<_CharT, _Traits, _Allocator>&& __rhs) {
3803 return std::move(__rhs.insert(0, __lhs));
3804}
3805
3806template <class _CharT, class _Traits, class _Allocator>
3807inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>
3808operator+(_CharT __lhs, basic_string<_CharT, _Traits, _Allocator>&& __rhs) {
3809 __rhs.insert(__rhs.begin(), __lhs);
3810 return std::move(__rhs);
3811}
3812
3813template <class _CharT, class _Traits, class _Allocator>
3814inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>
3815operator+(basic_string<_CharT, _Traits, _Allocator>&& __lhs, const _CharT* __rhs) {
3816 return std::move(__lhs.append(__rhs));
3817}
3818
3819template <class _CharT, class _Traits, class _Allocator>
3820inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>
3821operator+(basic_string<_CharT, _Traits, _Allocator>&& __lhs, _CharT __rhs) {
3822 __lhs.push_back(__rhs);
3823 return std::move(__lhs);
3824}
3825
3826# endif // _LIBCPP_CXX03_LANG
3827
3828# if _LIBCPP_STD_VER >= 26
3829
3830template <class _CharT, class _Traits, class _Allocator>
3831_LIBCPP_HIDE_FROM_ABI constexpr basic_string<_CharT, _Traits, _Allocator>
3832operator+(basic_string<_CharT, _Traits, _Allocator>&& __lhs,
3833 type_identity_t<basic_string_view<_CharT, _Traits>> __rhs) {
3834 return std::move(__lhs.append(__rhs));
3835}
3836
3837template <class _CharT, class _Traits, class _Allocator>
3838_LIBCPP_HIDE_FROM_ABI constexpr basic_string<_CharT, _Traits, _Allocator>
3839operator+(type_identity_t<basic_string_view<_CharT, _Traits>> __lhs,
3840 basic_string<_CharT, _Traits, _Allocator>&& __rhs) {
3841 return std::move(__rhs.insert(0, __lhs));
3842}
3843
3844# endif // _LIBCPP_STD_VER >= 26
3845
3846// swap
3847
3848template <class _CharT, class _Traits, class _Allocator>
3849inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void
3850swap(basic_string<_CharT, _Traits, _Allocator>& __lhs, basic_string<_CharT, _Traits, _Allocator>& __rhs)
3851 _NOEXCEPT_(_NOEXCEPT_(__lhs.swap(__rhs))) {
3852 __lhs.swap(__rhs);
3853}
3854
3855[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI int stoi(const string& __str, size_t* __idx = nullptr, int __base = 10);
3856[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI unsigned long
3857stoul(const string& __str, size_t* __idx = nullptr, int __base = 10);
3858[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI long stol(const string& __str, size_t* __idx = nullptr, int __base = 10);
3859[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI long long
3860stoll(const string& __str, size_t* __idx = nullptr, int __base = 10);
3861[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI unsigned long long
3862stoull(const string& __str, size_t* __idx = nullptr, int __base = 10);
3863
3864[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI float stof(const string& __str, size_t* __idx = nullptr);
3865[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI double stod(const string& __str, size_t* __idx = nullptr);
3866[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI long double stold(const string& __str, size_t* __idx = nullptr);
3867
3868[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI string to_string(int __val);
3869[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI string to_string(unsigned __val);
3870[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI string to_string(long __val);
3871[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI string to_string(unsigned long __val);
3872[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI string to_string(long long __val);
3873[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI string to_string(unsigned long long __val);
3874[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI string to_string(float __val);
3875[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI string to_string(double __val);
3876[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI string to_string(long double __val);
3877
3878# if _LIBCPP_HAS_WIDE_CHARACTERS
3879[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI int stoi(const wstring& __str, size_t* __idx = nullptr, int __base = 10);
3880[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI long stol(const wstring& __str, size_t* __idx = nullptr, int __base = 10);
3881[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI unsigned long
3882stoul(const wstring& __str, size_t* __idx = nullptr, int __base = 10);
3883[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI long long
3884stoll(const wstring& __str, size_t* __idx = nullptr, int __base = 10);
3885[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI unsigned long long
3886stoull(const wstring& __str, size_t* __idx = nullptr, int __base = 10);
3887
3888[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI float stof(const wstring& __str, size_t* __idx = nullptr);
3889[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI double stod(const wstring& __str, size_t* __idx = nullptr);
3890[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI long double stold(const wstring& __str, size_t* __idx = nullptr);
3891
3892[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI wstring to_wstring(int __val);
3893[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI wstring to_wstring(unsigned __val);
3894[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI wstring to_wstring(long __val);
3895[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI wstring to_wstring(unsigned long __val);
3896[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI wstring to_wstring(long long __val);
3897[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI wstring to_wstring(unsigned long long __val);
3898[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI wstring to_wstring(float __val);
3899[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI wstring to_wstring(double __val);
3900[[__nodiscard__]] _LIBCPP_EXPORTED_FROM_ABI wstring to_wstring(long double __val);
3901# endif // _LIBCPP_HAS_WIDE_CHARACTERS
3902
3903template <class _CharT, class _Traits, class _Allocator>
3904_LIBCPP_TEMPLATE_DATA_VIS const typename basic_string<_CharT, _Traits, _Allocator>::size_type
3905 basic_string<_CharT, _Traits, _Allocator>::npos;
3906
3907template <class _CharT, class _Allocator>
3908struct __string_hash : public __unary_function<basic_string<_CharT, char_traits<_CharT>, _Allocator>, size_t> {
3909 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI size_t
3910 operator()(const basic_string<_CharT, char_traits<_CharT>, _Allocator>& __val) const _NOEXCEPT {
3911 return std::__do_string_hash(__val.data(), __val.data() + __val.size());
3912 }
3913};
3914
3915template <class _Allocator>
3916struct hash<basic_string<char, char_traits<char>, _Allocator> > : __string_hash<char, _Allocator> {};
3917
3918# if _LIBCPP_HAS_CHAR8_T
3919template <class _Allocator>
3920struct hash<basic_string<char8_t, char_traits<char8_t>, _Allocator> > : __string_hash<char8_t, _Allocator> {};
3921# endif
3922
3923template <class _Allocator>
3924struct hash<basic_string<char16_t, char_traits<char16_t>, _Allocator> > : __string_hash<char16_t, _Allocator> {};
3925
3926template <class _Allocator>
3927struct hash<basic_string<char32_t, char_traits<char32_t>, _Allocator> > : __string_hash<char32_t, _Allocator> {};
3928
3929# if _LIBCPP_HAS_WIDE_CHARACTERS
3930template <class _Allocator>
3931struct hash<basic_string<wchar_t, char_traits<wchar_t>, _Allocator> > : __string_hash<wchar_t, _Allocator> {};
3932# endif
3933
3934template <class _CharT, class _Traits, class _Allocator>
3935_LIBCPP_HIDE_FROM_ABI basic_ostream<_CharT, _Traits>&
3936operator<<(basic_ostream<_CharT, _Traits>& __os, const basic_string<_CharT, _Traits, _Allocator>& __str);
3937
3938template <class _CharT, class _Traits, class _Allocator>
3939_LIBCPP_HIDE_FROM_ABI basic_istream<_CharT, _Traits>&
3940operator>>(basic_istream<_CharT, _Traits>& __is, basic_string<_CharT, _Traits, _Allocator>& __str);
3941
3942template <class _CharT, class _Traits, class _Allocator>
3943_LIBCPP_HIDE_FROM_ABI basic_istream<_CharT, _Traits>&
3944getline(basic_istream<_CharT, _Traits>& __is, basic_string<_CharT, _Traits, _Allocator>& __str, _CharT __dlm);
3945
3946template <class _CharT, class _Traits, class _Allocator>
3947inline _LIBCPP_HIDE_FROM_ABI basic_istream<_CharT, _Traits>&
3948getline(basic_istream<_CharT, _Traits>& __is, basic_string<_CharT, _Traits, _Allocator>& __str);
3949
3950template <class _CharT, class _Traits, class _Allocator>
3951inline _LIBCPP_HIDE_FROM_ABI basic_istream<_CharT, _Traits>&
3952getline(basic_istream<_CharT, _Traits>&& __is, basic_string<_CharT, _Traits, _Allocator>& __str, _CharT __dlm);
3953
3954template <class _CharT, class _Traits, class _Allocator>
3955inline _LIBCPP_HIDE_FROM_ABI basic_istream<_CharT, _Traits>&
3956getline(basic_istream<_CharT, _Traits>&& __is, basic_string<_CharT, _Traits, _Allocator>& __str);
3957
3958# if _LIBCPP_STD_VER >= 20
3959template <class _CharT, class _Traits, class _Allocator, class _Up>
3960inline _LIBCPP_HIDE_FROM_ABI constexpr typename basic_string<_CharT, _Traits, _Allocator>::size_type
3961erase(basic_string<_CharT, _Traits, _Allocator>& __str, const _Up& __v) {
3962 auto __old_size = __str.size();
3963 __str.erase(std::remove(__str.begin(), __str.end(), __v), __str.end());
3964 return __old_size - __str.size();
3965}
3966
3967template <class _CharT, class _Traits, class _Allocator, class _Predicate>
3968inline _LIBCPP_HIDE_FROM_ABI constexpr typename basic_string<_CharT, _Traits, _Allocator>::size_type
3969erase_if(basic_string<_CharT, _Traits, _Allocator>& __str, _Predicate __pred) {
3970 auto __old_size = __str.size();
3971 __str.erase(std::remove_if(__str.begin(), __str.end(), __pred), __str.end());
3972 return __old_size - __str.size();
3973}
3974# endif
3975
3976# if _LIBCPP_STD_VER >= 14
3977// Literal suffixes for basic_string [basic.string.literals]
3978inline namespace literals {
3979inline namespace string_literals {
3980[[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<char>
3981operator""s(const char* __str, size_t __len) {
3982 return basic_string<char>(__str, __len);
3983}
3984
3985# if _LIBCPP_HAS_WIDE_CHARACTERS
3986[[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI
3987_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<wchar_t> operator""s(const wchar_t* __str, size_t __len) {
3988 return basic_string<wchar_t>(__str, __len);
3989}
3990# endif
3991
3992# if _LIBCPP_HAS_CHAR8_T
3993[[__nodiscard__]] inline
3994 _LIBCPP_HIDE_FROM_ABI constexpr basic_string<char8_t> operator""s(const char8_t* __str, size_t __len) {
3995 return basic_string<char8_t>(__str, __len);
3996}
3997# endif
3998
3999[[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI
4000_LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<char16_t> operator""s(const char16_t* __str, size_t __len) {
4001 return basic_string<char16_t>(__str, __len);
4002}
4003
4004[[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<char32_t>
4005operator""s(const char32_t* __str, size_t __len) {
4006 return basic_string<char32_t>(__str, __len);
4007}
4008} // namespace string_literals
4009} // namespace literals
4010
4011# if _LIBCPP_STD_VER >= 20
4012template <>
4013inline constexpr bool __format::__enable_insertable<std::basic_string<char>> = true;
4014# if _LIBCPP_HAS_WIDE_CHARACTERS
4015template <>
4016inline constexpr bool __format::__enable_insertable<std::basic_string<wchar_t>> = true;
4017# endif
4018# endif
4019
4020# endif
4021
4022_LIBCPP_END_NAMESPACE_STD
4023
4024_LIBCPP_POP_MACROS
4025
4026# if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 20
4027# include <algorithm>
4028# include <concepts>
4029# include <cstdlib>
4030# include <iterator>
4031# include <new>
4032# include <optional>
4033# include <type_traits>
4034# include <typeinfo>
4035# include <utility>
4036# endif
4037#endif // __cplusplus < 201103L && defined(_LIBCPP_USE_FROZEN_CXX03_HEADERS)
4038
4039#endif // _LIBCPP_STRING