| blob | caeddaf2f5be35caa131298e8c00a345fe5de850 |
1 // Components for manipulating sequences of characters -*- C++ -*-
3 // Copyright (C) 1997-2024 Free Software Foundation, Inc.
4 //
5 // This file is part of the GNU ISO C++ Library. This library is free
6 // software; you can redistribute it and/or modify it under the
7 // terms of the GNU General Public License as published by the
8 // Free Software Foundation; either version 3, or (at your option)
9 // any later version.
11 // This library is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 // GNU General Public License for more details.
16 // Under Section 7 of GPL version 3, you are granted additional
17 // permissions described in the GCC Runtime Library Exception, version
18 // 3.1, as published by the Free Software Foundation.
20 // You should have received a copy of the GNU General Public License and
21 // a copy of the GCC Runtime Library Exception along with this program;
22 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23 // <http://www.gnu.org/licenses/>.
25 /** @file bits/basic_string.tcc
26 * This is an internal header file, included by other library headers.
27 * Do not attempt to use it directly. @headername{string}
28 */
30 //
31 // ISO C++ 14882: 21 Strings library
32 //
34 // Written by Jason Merrill based upon the specification by Takanori Adachi
35 // in ANSI X3J16/94-0013R2. Rewritten by Nathan Myers to ISO-14882.
36 // Non-reference-counted implementation written by Paolo Carlini and
37 // updated by Jonathan Wakely for ISO-14882-2011.
39 #ifndef _BASIC_STRING_TCC
40 #define _BASIC_STRING_TCC 1
42 #ifdef _GLIBCXX_SYSHDR
43 #pragma GCC system_header
44 #endif
46 #pragma GCC diagnostic push
47 #pragma GCC diagnostic ignored "-Wc++11-extensions"
49 #include <bits/cxxabi_forced.h>
51 namespace std _GLIBCXX_VISIBILITY(default)
52 {
53 _GLIBCXX_BEGIN_NAMESPACE_VERSION
55 #if _GLIBCXX_USE_CXX11_ABI
57 template<typename _CharT, typename _Traits, typename _Alloc>
58 const typename basic_string<_CharT, _Traits, _Alloc>::size_type
59 basic_string<_CharT, _Traits, _Alloc>::npos;
61 template<typename _CharT, typename _Traits, typename _Alloc>
62 _GLIBCXX20_CONSTEXPR
63 void
64 basic_string<_CharT, _Traits, _Alloc>::
65 swap(basic_string& __s) _GLIBCXX_NOEXCEPT
66 {
67 if (this == std::__addressof(__s))
68 return;
70 _Alloc_traits::_S_on_swap(_M_get_allocator(), __s._M_get_allocator());
72 if (_M_is_local())
73 if (__s._M_is_local())
74 {
75 if (length() && __s.length())
76 {
77 _CharT __tmp_data[_S_local_capacity + 1];
78 traits_type::copy(__tmp_data, __s._M_local_buf,
79 __s.length() + 1);
80 traits_type::copy(__s._M_local_buf, _M_local_buf,
81 length() + 1);
82 traits_type::copy(_M_local_buf, __tmp_data,
83 __s.length() + 1);
84 }
85 else if (__s.length())
86 {
87 _M_init_local_buf();
88 traits_type::copy(_M_local_buf, __s._M_local_buf,
89 __s.length() + 1);
90 _M_length(__s.length());
91 __s._M_set_length(0);
92 return;
93 }
94 else if (length())
95 {
96 __s._M_init_local_buf();
97 traits_type::copy(__s._M_local_buf, _M_local_buf,
98 length() + 1);
99 __s._M_length(length());
100 _M_set_length(0);
101 return;
102 }
103 }
104 else
105 {
106 const size_type __tmp_capacity = __s._M_allocated_capacity;
107 __s._M_init_local_buf();
108 traits_type::copy(__s._M_local_buf, _M_local_buf,
109 length() + 1);
110 _M_data(__s._M_data());
111 __s._M_data(__s._M_local_buf);
112 _M_capacity(__tmp_capacity);
113 }
114 else
115 {
116 const size_type __tmp_capacity = _M_allocated_capacity;
117 if (__s._M_is_local())
118 {
119 _M_init_local_buf();
120 traits_type::copy(_M_local_buf, __s._M_local_buf,
121 __s.length() + 1);
122 __s._M_data(_M_data());
123 _M_data(_M_local_buf);
124 }
125 else
126 {
127 pointer __tmp_ptr = _M_data();
128 _M_data(__s._M_data());
129 __s._M_data(__tmp_ptr);
130 _M_capacity(__s._M_allocated_capacity);
131 }
132 __s._M_capacity(__tmp_capacity);
133 }
135 const size_type __tmp_length = length();
136 _M_length(__s.length());
137 __s._M_length(__tmp_length);
138 }
140 template<typename _CharT, typename _Traits, typename _Alloc>
141 _GLIBCXX20_CONSTEXPR
142 typename basic_string<_CharT, _Traits, _Alloc>::pointer
143 basic_string<_CharT, _Traits, _Alloc>::
144 _M_create(size_type& __capacity, size_type __old_capacity)
145 {
146 // _GLIBCXX_RESOLVE_LIB_DEFECTS
147 // 83. String::npos vs. string::max_size()
148 if (__capacity > max_size())
149 std::__throw_length_error(__N("basic_string::_M_create"));
151 // The below implements an exponential growth policy, necessary to
152 // meet amortized linear time requirements of the library: see
153 // http://gcc.gnu.org/ml/libstdc++/2001-07/msg00085.html.
154 if (__capacity > __old_capacity && __capacity < 2 * __old_capacity)
155 {
156 __capacity = 2 * __old_capacity;
157 // Never allocate a string bigger than max_size.
158 if (__capacity > max_size())
159 __capacity = max_size();
160 }
162 // NB: Need an array of char_type[__capacity], plus a terminating
163 // null char_type() element.
164 return _S_allocate(_M_get_allocator(), __capacity + 1);
165 }
167 // NB: This is the special case for Input Iterators, used in
168 // istreambuf_iterators, etc.
169 // Input Iterators have a cost structure very different from
170 // pointers, calling for a different coding style.
171 template<typename _CharT, typename _Traits, typename _Alloc>
172 template<typename _InIterator>
173 _GLIBCXX20_CONSTEXPR
174 void
175 basic_string<_CharT, _Traits, _Alloc>::
176 _M_construct(_InIterator __beg, _InIterator __end,
177 std::input_iterator_tag)
178 {
179 size_type __len = 0;
180 size_type __capacity = size_type(_S_local_capacity);
182 _M_init_local_buf();
184 while (__beg != __end && __len < __capacity)
185 {
186 _M_local_buf[__len++] = *__beg;
187 ++__beg;
188 }
190 struct _Guard
191 {
192 _GLIBCXX20_CONSTEXPR
193 explicit _Guard(basic_string* __s) : _M_guarded(__s) { }
195 _GLIBCXX20_CONSTEXPR
196 ~_Guard() { if (_M_guarded) _M_guarded->_M_dispose(); }
198 basic_string* _M_guarded;
199 } __guard(this);
201 while (__beg != __end)
202 {
203 if (__len == __capacity)
204 {
205 // Allocate more space.
206 __capacity = __len + 1;
207 pointer __another = _M_create(__capacity, __len);
208 this->_S_copy(__another, _M_data(), __len);
209 _M_dispose();
210 _M_data(__another);
211 _M_capacity(__capacity);
212 }
213 traits_type::assign(_M_data()[__len++], *__beg);
214 ++__beg;
215 }
217 __guard._M_guarded = 0;
219 _M_set_length(__len);
220 }
222 template<typename _CharT, typename _Traits, typename _Alloc>
223 template<typename _InIterator>
224 _GLIBCXX20_CONSTEXPR
225 void
226 basic_string<_CharT, _Traits, _Alloc>::
227 _M_construct(_InIterator __beg, _InIterator __end,
228 std::forward_iterator_tag)
229 {
230 size_type __dnew = static_cast<size_type>(std::distance(__beg, __end));
232 if (__dnew > size_type(_S_local_capacity))
233 {
234 _M_data(_M_create(__dnew, size_type(0)));
235 _M_capacity(__dnew);
236 }
237 else
238 _M_init_local_buf();
240 // Check for out_of_range and length_error exceptions.
241 struct _Guard
242 {
243 _GLIBCXX20_CONSTEXPR
244 explicit _Guard(basic_string* __s) : _M_guarded(__s) { }
246 _GLIBCXX20_CONSTEXPR
247 ~_Guard() { if (_M_guarded) _M_guarded->_M_dispose(); }
249 basic_string* _M_guarded;
250 } __guard(this);
252 this->_S_copy_chars(_M_data(), __beg, __end);
254 __guard._M_guarded = 0;
256 _M_set_length(__dnew);
257 }
259 template<typename _CharT, typename _Traits, typename _Alloc>
260 _GLIBCXX20_CONSTEXPR
261 void
262 basic_string<_CharT, _Traits, _Alloc>::
263 _M_construct(size_type __n, _CharT __c)
264 {
265 if (__n > size_type(_S_local_capacity))
266 {
267 _M_data(_M_create(__n, size_type(0)));
268 _M_capacity(__n);
269 }
270 else
271 _M_init_local_buf();
273 if (__n)
274 this->_S_assign(_M_data(), __n, __c);
276 _M_set_length(__n);
277 }
279 template<typename _CharT, typename _Traits, typename _Alloc>
280 _GLIBCXX20_CONSTEXPR
281 void
282 basic_string<_CharT, _Traits, _Alloc>::
283 _M_assign(const basic_string& __str)
284 {
285 if (this != std::__addressof(__str))
286 {
287 const size_type __rsize = __str.length();
288 const size_type __capacity = capacity();
290 if (__rsize > __capacity)
291 {
292 size_type __new_capacity = __rsize;
293 pointer __tmp = _M_create(__new_capacity, __capacity);
294 _M_dispose();
295 _M_data(__tmp);
296 _M_capacity(__new_capacity);
297 }
299 if (__rsize)
300 this->_S_copy(_M_data(), __str._M_data(), __rsize);
302 _M_set_length(__rsize);
303 }
304 }
306 template<typename _CharT, typename _Traits, typename _Alloc>
307 _GLIBCXX20_CONSTEXPR
308 void
309 basic_string<_CharT, _Traits, _Alloc>::
310 reserve(size_type __res)
311 {
312 const size_type __capacity = capacity();
313 // _GLIBCXX_RESOLVE_LIB_DEFECTS
314 // 2968. Inconsistencies between basic_string reserve and
315 // vector/unordered_map/unordered_set reserve functions
316 // P0966 reserve should not shrink
317 if (__res <= __capacity)
318 return;
320 pointer __tmp = _M_create(__res, __capacity);
321 this->_S_copy(__tmp, _M_data(), length() + 1);
322 _M_dispose();
323 _M_data(__tmp);
324 _M_capacity(__res);
325 }
327 template<typename _CharT, typename _Traits, typename _Alloc>
328 _GLIBCXX20_CONSTEXPR
329 void
330 basic_string<_CharT, _Traits, _Alloc>::
331 _M_mutate(size_type __pos, size_type __len1, const _CharT* __s,
332 size_type __len2)
333 {
334 const size_type __how_much = length() - __pos - __len1;
336 size_type __new_capacity = length() + __len2 - __len1;
337 pointer __r = _M_create(__new_capacity, capacity());
339 if (__pos)
340 this->_S_copy(__r, _M_data(), __pos);
341 if (__s && __len2)
342 this->_S_copy(__r + __pos, __s, __len2);
343 if (__how_much)
344 this->_S_copy(__r + __pos + __len2,
345 _M_data() + __pos + __len1, __how_much);
347 _M_dispose();
348 _M_data(__r);
349 _M_capacity(__new_capacity);
350 }
352 template<typename _CharT, typename _Traits, typename _Alloc>
353 _GLIBCXX20_CONSTEXPR
354 void
355 basic_string<_CharT, _Traits, _Alloc>::
356 _M_erase(size_type __pos, size_type __n)
357 {
358 const size_type __how_much = length() - __pos - __n;
360 if (__how_much && __n)
361 this->_S_move(_M_data() + __pos, _M_data() + __pos + __n, __how_much);
363 _M_set_length(length() - __n);
364 }
366 template<typename _CharT, typename _Traits, typename _Alloc>
367 _GLIBCXX20_CONSTEXPR
368 void
369 basic_string<_CharT, _Traits, _Alloc>::
370 reserve()
371 {
372 if (_M_is_local())
373 return;
375 const size_type __length = length();
376 const size_type __capacity = _M_allocated_capacity;
378 if (__length <= size_type(_S_local_capacity))
379 {
380 _M_init_local_buf();
381 this->_S_copy(_M_local_buf, _M_data(), __length + 1);
382 _M_destroy(__capacity);
383 _M_data(_M_local_data());
384 }
385 #if __cpp_exceptions
386 else if (__length < __capacity)
387 try
388 {
389 pointer __tmp = _S_allocate(_M_get_allocator(), __length + 1);
390 this->_S_copy(__tmp, _M_data(), __length + 1);
391 _M_dispose();
392 _M_data(__tmp);
393 _M_capacity(__length);
394 }
395 catch (const __cxxabiv1::__forced_unwind&)
396 { throw; }
397 catch (...)
398 { /* swallow the exception */ }
399 #endif
400 }
402 template<typename _CharT, typename _Traits, typename _Alloc>
403 _GLIBCXX20_CONSTEXPR
404 void
405 basic_string<_CharT, _Traits, _Alloc>::
406 resize(size_type __n, _CharT __c)
407 {
408 const size_type __size = this->size();
409 if (__size < __n)
410 this->append(__n - __size, __c);
411 else if (__n < __size)
412 this->_M_set_length(__n);
413 }
415 template<typename _CharT, typename _Traits, typename _Alloc>
416 _GLIBCXX20_CONSTEXPR
417 basic_string<_CharT, _Traits, _Alloc>&
418 basic_string<_CharT, _Traits, _Alloc>::
419 _M_append(const _CharT* __s, size_type __n)
420 {
421 const size_type __len = __n + this->size();
423 if (__len <= this->capacity())
424 {
425 if (__n)
426 this->_S_copy(this->_M_data() + this->size(), __s, __n);
427 }
428 else
429 this->_M_mutate(this->size(), size_type(0), __s, __n);
431 this->_M_set_length(__len);
432 return *this;
433 }
435 template<typename _CharT, typename _Traits, typename _Alloc>
436 template<typename _InputIterator>
437 _GLIBCXX20_CONSTEXPR
438 basic_string<_CharT, _Traits, _Alloc>&
439 basic_string<_CharT, _Traits, _Alloc>::
440 _M_replace_dispatch(const_iterator __i1, const_iterator __i2,
441 _InputIterator __k1, _InputIterator __k2,
442 std::__false_type)
443 {
444 // _GLIBCXX_RESOLVE_LIB_DEFECTS
445 // 2788. unintentionally require a default constructible allocator
446 const basic_string __s(__k1, __k2, this->get_allocator());
447 const size_type __n1 = __i2 - __i1;
448 return _M_replace(__i1 - begin(), __n1, __s._M_data(),
449 __s.size());
450 }
452 template<typename _CharT, typename _Traits, typename _Alloc>
453 _GLIBCXX20_CONSTEXPR
454 basic_string<_CharT, _Traits, _Alloc>&
455 basic_string<_CharT, _Traits, _Alloc>::
456 _M_replace_aux(size_type __pos1, size_type __n1, size_type __n2,
457 _CharT __c)
458 {
459 _M_check_length(__n1, __n2, "basic_string::_M_replace_aux");
461 const size_type __old_size = this->size();
462 const size_type __new_size = __old_size + __n2 - __n1;
464 if (__new_size <= this->capacity())
465 {
466 pointer __p = this->_M_data() + __pos1;
468 const size_type __how_much = __old_size - __pos1 - __n1;
469 if (__how_much && __n1 != __n2)
470 this->_S_move(__p + __n2, __p + __n1, __how_much);
471 }
472 else
473 this->_M_mutate(__pos1, __n1, 0, __n2);
475 if (__n2)
476 this->_S_assign(this->_M_data() + __pos1, __n2, __c);
478 this->_M_set_length(__new_size);
479 return *this;
480 }
482 template<typename _CharT, typename _Traits, typename _Alloc>
483 __attribute__((__noinline__, __noclone__, __cold__)) void
484 basic_string<_CharT, _Traits, _Alloc>::
485 _M_replace_cold(pointer __p, size_type __len1, const _CharT* __s,
486 const size_type __len2, const size_type __how_much)
487 {
488 // Work in-place.
489 if (__len2 && __len2 <= __len1)
490 this->_S_move(__p, __s, __len2);
491 if (__how_much && __len1 != __len2)
492 this->_S_move(__p + __len2, __p + __len1, __how_much);
493 if (__len2 > __len1)
494 {
495 if (__s + __len2 <= __p + __len1)
496 this->_S_move(__p, __s, __len2);
497 else if (__s >= __p + __len1)
498 {
499 // Hint to middle end that __p and __s overlap
500 // (PR 98465).
501 const size_type __poff = (__s - __p) + (__len2 - __len1);
502 this->_S_copy(__p, __p + __poff, __len2);
503 }
504 else
505 {
506 const size_type __nleft = (__p + __len1) - __s;
507 this->_S_move(__p, __s, __nleft);
508 this->_S_copy(__p + __nleft, __p + __len2, __len2 - __nleft);
509 }
510 }
511 }
513 template<typename _CharT, typename _Traits, typename _Alloc>
514 _GLIBCXX20_CONSTEXPR
515 basic_string<_CharT, _Traits, _Alloc>&
516 basic_string<_CharT, _Traits, _Alloc>::
517 _M_replace(size_type __pos, size_type __len1, const _CharT* __s,
518 const size_type __len2)
519 {
520 _M_check_length(__len1, __len2, "basic_string::_M_replace");
522 const size_type __old_size = this->size();
523 const size_type __new_size = __old_size + __len2 - __len1;
525 if (__new_size <= this->capacity())
526 {
527 pointer __p = this->_M_data() + __pos;
529 const size_type __how_much = __old_size - __pos - __len1;
530 #if __cpp_lib_is_constant_evaluated
531 if (std::is_constant_evaluated())
532 {
533 auto __newp = _S_allocate(_M_get_allocator(), __new_size);
534 _S_copy(__newp, this->_M_data(), __pos);
535 _S_copy(__newp + __pos, __s, __len2);
536 _S_copy(__newp + __pos + __len2, __p + __len1, __how_much);
537 _S_copy(this->_M_data(), __newp, __new_size);
538 this->_M_get_allocator().deallocate(__newp, __new_size);
539 }
540 else
541 #endif
542 if (__builtin_expect(_M_disjunct(__s), true))
543 {
544 if (__how_much && __len1 != __len2)
545 this->_S_move(__p + __len2, __p + __len1, __how_much);
546 if (__len2)
547 this->_S_copy(__p, __s, __len2);
548 }
549 else
550 _M_replace_cold(__p, __len1, __s, __len2, __how_much);
551 }
552 else
553 this->_M_mutate(__pos, __len1, __s, __len2);
555 this->_M_set_length(__new_size);
556 return *this;
557 }
559 template<typename _CharT, typename _Traits, typename _Alloc>
560 _GLIBCXX20_CONSTEXPR
561 typename basic_string<_CharT, _Traits, _Alloc>::size_type
562 basic_string<_CharT, _Traits, _Alloc>::
563 copy(_CharT* __s, size_type __n, size_type __pos) const
564 {
565 _M_check(__pos, "basic_string::copy");
566 __n = _M_limit(__pos, __n);
567 __glibcxx_requires_string_len(__s, __n);
568 if (__n)
569 _S_copy(__s, _M_data() + __pos, __n);
570 // 21.3.5.7 par 3: do not append null. (good.)
571 return __n;
572 }
574 #ifdef __glibcxx_string_resize_and_overwrite // C++ >= 23
575 template<typename _CharT, typename _Traits, typename _Alloc>
576 template<typename _Operation>
577 [[__gnu__::__always_inline__]]
578 constexpr void
579 basic_string<_CharT, _Traits, _Alloc>::
580 __resize_and_overwrite(const size_type __n, _Operation __op)
581 { resize_and_overwrite<_Operation&>(__n, __op); }
582 #endif
584 #if __cplusplus >= 201103L
585 template<typename _CharT, typename _Traits, typename _Alloc>
586 template<typename _Operation>
587 _GLIBCXX20_CONSTEXPR void
588 basic_string<_CharT, _Traits, _Alloc>::
589 #ifdef __glibcxx_string_resize_and_overwrite // C++ >= 23
590 resize_and_overwrite(const size_type __n, _Operation __op)
591 #else
592 __resize_and_overwrite(const size_type __n, _Operation __op)
593 #endif
594 {
595 reserve(__n);
596 _CharT* const __p = _M_data();
597 #if __cpp_lib_is_constant_evaluated
598 if (std::__is_constant_evaluated() && __n > size())
599 traits_type::assign(__p + size(), __n - size(), _CharT());
600 #endif
601 struct _Terminator {
602 _GLIBCXX20_CONSTEXPR ~_Terminator() { _M_this->_M_set_length(_M_r); }
603 basic_string* _M_this;
604 size_type _M_r;
605 };
606 _Terminator __term{this, 0};
607 auto __r = std::move(__op)(__p + 0, __n + 0);
608 #ifdef __cpp_lib_concepts
609 static_assert(ranges::__detail::__is_integer_like<decltype(__r)>);
610 #else
611 static_assert(__gnu_cxx::__is_integer_nonstrict<decltype(__r)>::__value,
612 "resize_and_overwrite operation must return an integer");
613 #endif
614 _GLIBCXX_DEBUG_ASSERT(__r >= 0 && size_type(__r) <= __n);
615 __term._M_r = size_type(__r);
616 if (__term._M_r > __n)
617 __builtin_unreachable();
618 }
619 #endif // C++11
621 #endif // _GLIBCXX_USE_CXX11_ABI
623 #if __glibcxx_constexpr_string >= 201907L
624 # define _GLIBCXX_STRING_CONSTEXPR constexpr
625 #else
626 # define _GLIBCXX_STRING_CONSTEXPR
627 #endif
628 template<typename _CharT, typename _Traits, typename _Alloc>
629 _GLIBCXX_STRING_CONSTEXPR
630 typename basic_string<_CharT, _Traits, _Alloc>::size_type
631 basic_string<_CharT, _Traits, _Alloc>::
632 find(const _CharT* __s, size_type __pos, size_type __n) const
633 _GLIBCXX_NOEXCEPT
634 {
635 __glibcxx_requires_string_len(__s, __n);
636 const size_type __size = this->size();
638 if (__n == 0)
639 return __pos <= __size ? __pos : npos;
640 if (__pos >= __size)
641 return npos;
643 const _CharT __elem0 = __s[0];
644 const _CharT* const __data = data();
645 const _CharT* __first = __data + __pos;
646 const _CharT* const __last = __data + __size;
647 size_type __len = __size - __pos;
649 while (__len >= __n)
650 {
651 // Find the first occurrence of __elem0:
652 __first = traits_type::find(__first, __len - __n + 1, __elem0);
653 if (!__first)
654 return npos;
655 // Compare the full strings from the first occurrence of __elem0.
656 // We already know that __first[0] == __s[0] but compare them again
657 // anyway because __s is probably aligned, which helps memcmp.
658 if (traits_type::compare(__first, __s, __n) == 0)
659 return __first - __data;
660 __len = __last - ++__first;
661 }
662 return npos;
663 }
665 template<typename _CharT, typename _Traits, typename _Alloc>
666 _GLIBCXX_STRING_CONSTEXPR
667 typename basic_string<_CharT, _Traits, _Alloc>::size_type
668 basic_string<_CharT, _Traits, _Alloc>::
669 find(_CharT __c, size_type __pos) const _GLIBCXX_NOEXCEPT
670 {
671 size_type __ret = npos;
672 const size_type __size = this->size();
673 if (__pos < __size)
674 {
675 const _CharT* __data = _M_data();
676 const size_type __n = __size - __pos;
677 const _CharT* __p = traits_type::find(__data + __pos, __n, __c);
678 if (__p)
679 __ret = __p - __data;
680 }
681 return __ret;
682 }
684 template<typename _CharT, typename _Traits, typename _Alloc>
685 _GLIBCXX_STRING_CONSTEXPR
686 typename basic_string<_CharT, _Traits, _Alloc>::size_type
687 basic_string<_CharT, _Traits, _Alloc>::
688 rfind(const _CharT* __s, size_type __pos, size_type __n) const
689 _GLIBCXX_NOEXCEPT
690 {
691 __glibcxx_requires_string_len(__s, __n);
692 const size_type __size = this->size();
693 if (__n <= __size)
694 {
695 __pos = std::min(size_type(__size - __n), __pos);
696 const _CharT* __data = _M_data();
697 do
698 {
699 if (traits_type::compare(__data + __pos, __s, __n) == 0)
700 return __pos;
701 }
702 while (__pos-- > 0);
703 }
704 return npos;
705 }
707 template<typename _CharT, typename _Traits, typename _Alloc>
708 _GLIBCXX_STRING_CONSTEXPR
709 typename basic_string<_CharT, _Traits, _Alloc>::size_type
710 basic_string<_CharT, _Traits, _Alloc>::
711 rfind(_CharT __c, size_type __pos) const _GLIBCXX_NOEXCEPT
712 {
713 size_type __size = this->size();
714 if (__size)
715 {
716 if (--__size > __pos)
717 __size = __pos;
718 for (++__size; __size-- > 0; )
719 if (traits_type::eq(_M_data()[__size], __c))
720 return __size;
721 }
722 return npos;
723 }
725 template<typename _CharT, typename _Traits, typename _Alloc>
726 _GLIBCXX_STRING_CONSTEXPR
727 typename basic_string<_CharT, _Traits, _Alloc>::size_type
728 basic_string<_CharT, _Traits, _Alloc>::
729 find_first_of(const _CharT* __s, size_type __pos, size_type __n) const
730 _GLIBCXX_NOEXCEPT
731 {
732 __glibcxx_requires_string_len(__s, __n);
733 for (; __n && __pos < this->size(); ++__pos)
734 {
735 const _CharT* __p = traits_type::find(__s, __n, _M_data()[__pos]);
736 if (__p)
737 return __pos;
738 }
739 return npos;
740 }
742 template<typename _CharT, typename _Traits, typename _Alloc>
743 _GLIBCXX_STRING_CONSTEXPR
744 typename basic_string<_CharT, _Traits, _Alloc>::size_type
745 basic_string<_CharT, _Traits, _Alloc>::
746 find_last_of(const _CharT* __s, size_type __pos, size_type __n) const
747 _GLIBCXX_NOEXCEPT
748 {
749 __glibcxx_requires_string_len(__s, __n);
750 size_type __size = this->size();
751 if (__size && __n)
752 {
753 if (--__size > __pos)
754 __size = __pos;
755 do
756 {
757 if (traits_type::find(__s, __n, _M_data()[__size]))
758 return __size;
759 }
760 while (__size-- != 0);
761 }
762 return npos;
763 }
765 template<typename _CharT, typename _Traits, typename _Alloc>
766 _GLIBCXX_STRING_CONSTEXPR
767 typename basic_string<_CharT, _Traits, _Alloc>::size_type
768 basic_string<_CharT, _Traits, _Alloc>::
769 find_first_not_of(const _CharT* __s, size_type __pos, size_type __n) const
770 _GLIBCXX_NOEXCEPT
771 {
772 __glibcxx_requires_string_len(__s, __n);
773 for (; __pos < this->size(); ++__pos)
774 if (!traits_type::find(__s, __n, _M_data()[__pos]))
775 return __pos;
776 return npos;
777 }
779 template<typename _CharT, typename _Traits, typename _Alloc>
780 _GLIBCXX_STRING_CONSTEXPR
781 typename basic_string<_CharT, _Traits, _Alloc>::size_type
782 basic_string<_CharT, _Traits, _Alloc>::
783 find_first_not_of(_CharT __c, size_type __pos) const _GLIBCXX_NOEXCEPT
784 {
785 for (; __pos < this->size(); ++__pos)
786 if (!traits_type::eq(_M_data()[__pos], __c))
787 return __pos;
788 return npos;
789 }
791 template<typename _CharT, typename _Traits, typename _Alloc>
792 _GLIBCXX_STRING_CONSTEXPR
793 typename basic_string<_CharT, _Traits, _Alloc>::size_type
794 basic_string<_CharT, _Traits, _Alloc>::
795 find_last_not_of(const _CharT* __s, size_type __pos, size_type __n) const
796 _GLIBCXX_NOEXCEPT
797 {
798 __glibcxx_requires_string_len(__s, __n);
799 size_type __size = this->size();
800 if (__size)
801 {
802 if (--__size > __pos)
803 __size = __pos;
804 do
805 {
806 if (!traits_type::find(__s, __n, _M_data()[__size]))
807 return __size;
808 }
809 while (__size--);
810 }
811 return npos;
812 }
814 template<typename _CharT, typename _Traits, typename _Alloc>
815 _GLIBCXX_STRING_CONSTEXPR
816 typename basic_string<_CharT, _Traits, _Alloc>::size_type
817 basic_string<_CharT, _Traits, _Alloc>::
818 find_last_not_of(_CharT __c, size_type __pos) const _GLIBCXX_NOEXCEPT
819 {
820 size_type __size = this->size();
821 if (__size)
822 {
823 if (--__size > __pos)
824 __size = __pos;
825 do
826 {
827 if (!traits_type::eq(_M_data()[__size], __c))
828 return __size;
829 }
830 while (__size--);
831 }
832 return npos;
833 }
835 #undef _GLIBCXX_STRING_CONSTEXPR
837 // 21.3.7.9 basic_string::getline and operators
838 template<typename _CharT, typename _Traits, typename _Alloc>
839 basic_istream<_CharT, _Traits>&
840 operator>>(basic_istream<_CharT, _Traits>& __in,
841 basic_string<_CharT, _Traits, _Alloc>& __str)
842 {
843 typedef basic_istream<_CharT, _Traits> __istream_type;
844 typedef basic_string<_CharT, _Traits, _Alloc> __string_type;
845 typedef typename __istream_type::ios_base __ios_base;
846 typedef typename __istream_type::int_type __int_type;
847 typedef typename __string_type::size_type __size_type;
848 typedef ctype<_CharT> __ctype_type;
849 typedef typename __ctype_type::ctype_base __ctype_base;
851 __size_type __extracted = 0;
852 typename __ios_base::iostate __err = __ios_base::goodbit;
853 typename __istream_type::sentry __cerb(__in, false);
854 if (__cerb)
855 {
856 __try
857 {
858 // Avoid reallocation for common case.
859 __str.erase();
860 _CharT __buf[128];
861 __size_type __len = 0;
862 const streamsize __w = __in.width();
863 const __size_type __n = __w > 0 ? static_cast<__size_type>(__w)
864 : __str.max_size();
865 const __ctype_type& __ct = use_facet<__ctype_type>(__in.getloc());
866 const __int_type __eof = _Traits::eof();
867 __int_type __c = __in.rdbuf()->sgetc();
869 while (__extracted < __n
870 && !_Traits::eq_int_type(__c, __eof)
871 && !__ct.is(__ctype_base::space,
872 _Traits::to_char_type(__c)))
873 {
874 if (__len == sizeof(__buf) / sizeof(_CharT))
875 {
876 __str.append(__buf, sizeof(__buf) / sizeof(_CharT));
877 __len = 0;
878 }
879 __buf[__len++] = _Traits::to_char_type(__c);
880 ++__extracted;
881 __c = __in.rdbuf()->snextc();
882 }
883 __str.append(__buf, __len);
885 if (__extracted < __n && _Traits::eq_int_type(__c, __eof))
886 __err |= __ios_base::eofbit;
887 __in.width(0);
888 }
889 __catch(__cxxabiv1::__forced_unwind&)
890 {
891 __in._M_setstate(__ios_base::badbit);
892 __throw_exception_again;
893 }
894 __catch(...)
895 {
896 // _GLIBCXX_RESOLVE_LIB_DEFECTS
897 // 91. Description of operator>> and getline() for string<>
898 // might cause endless loop
899 __in._M_setstate(__ios_base::badbit);
900 }
901 }
902 // 211. operator>>(istream&, string&) doesn't set failbit
903 if (!__extracted)
904 __err |= __ios_base::failbit;
905 if (__err)
906 __in.setstate(__err);
907 return __in;
908 }
910 template<typename _CharT, typename _Traits, typename _Alloc>
911 basic_istream<_CharT, _Traits>&
912 getline(basic_istream<_CharT, _Traits>& __in,
913 basic_string<_CharT, _Traits, _Alloc>& __str, _CharT __delim)
914 {
915 typedef basic_istream<_CharT, _Traits> __istream_type;
916 typedef basic_string<_CharT, _Traits, _Alloc> __string_type;
917 typedef typename __istream_type::ios_base __ios_base;
918 typedef typename __istream_type::int_type __int_type;
919 typedef typename __string_type::size_type __size_type;
921 __size_type __extracted = 0;
922 const __size_type __n = __str.max_size();
923 typename __ios_base::iostate __err = __ios_base::goodbit;
924 typename __istream_type::sentry __cerb(__in, true);
925 if (__cerb)
926 {
927 __try
928 {
929 __str.erase();
930 const __int_type __idelim = _Traits::to_int_type(__delim);
931 const __int_type __eof = _Traits::eof();
932 __int_type __c = __in.rdbuf()->sgetc();
934 while (__extracted < __n
935 && !_Traits::eq_int_type(__c, __eof)
936 && !_Traits::eq_int_type(__c, __idelim))
937 {
938 __str += _Traits::to_char_type(__c);
939 ++__extracted;
940 __c = __in.rdbuf()->snextc();
941 }
943 if (_Traits::eq_int_type(__c, __eof))
944 __err |= __ios_base::eofbit;
945 else if (_Traits::eq_int_type(__c, __idelim))
946 {
947 ++__extracted;
948 __in.rdbuf()->sbumpc();
949 }
950 else
951 __err |= __ios_base::failbit;
952 }
953 __catch(__cxxabiv1::__forced_unwind&)
954 {
955 __in._M_setstate(__ios_base::badbit);
956 __throw_exception_again;
957 }
958 __catch(...)
959 {
960 // _GLIBCXX_RESOLVE_LIB_DEFECTS
961 // 91. Description of operator>> and getline() for string<>
962 // might cause endless loop
963 __in._M_setstate(__ios_base::badbit);
964 }
965 }
966 if (!__extracted)
967 __err |= __ios_base::failbit;
968 if (__err)
969 __in.setstate(__err);
970 return __in;
971 }
973 // Inhibit implicit instantiations for required instantiations,
974 // which are defined via explicit instantiations elsewhere.
975 #if _GLIBCXX_EXTERN_TEMPLATE
976 // The explicit instantiation definitions in src/c++11/string-inst.cc and
977 // src/c++17/string-inst.cc only instantiate the members required for C++17
978 // and earlier standards (so not C++20's starts_with and ends_with).
979 // Suppress the explicit instantiation declarations for C++20, so C++20
980 // code will implicitly instantiate std::string and std::wstring as needed.
981 # if __cplusplus <= 201703L && _GLIBCXX_EXTERN_TEMPLATE > 0
982 extern template class basic_string<char>;
983 # elif ! _GLIBCXX_USE_CXX11_ABI
984 // Still need to prevent implicit instantiation of the COW empty rep,
985 // to ensure the definition in libstdc++.so is unique (PR 86138).
986 extern template basic_string<char>::size_type
987 basic_string<char>::_Rep::_S_empty_rep_storage[];
988 # elif _GLIBCXX_EXTERN_TEMPLATE > 0
989 // Export _M_replace_cold even for C++20.
990 extern template void
991 basic_string<char>::_M_replace_cold(char *, size_type, const char*,
992 const size_type, const size_type);
993 # endif
995 extern template
996 basic_istream<char>&
997 operator>>(basic_istream<char>&, string&);
998 extern template
999 basic_ostream<char>&
1000 operator<<(basic_ostream<char>&, const string&);
1001 extern template
1002 basic_istream<char>&
1003 getline(basic_istream<char>&, string&, char);
1004 extern template
1005 basic_istream<char>&
1006 getline(basic_istream<char>&, string&);
1008 #ifdef _GLIBCXX_USE_WCHAR_T
1009 # if __cplusplus <= 201703L && _GLIBCXX_EXTERN_TEMPLATE > 0
1010 extern template class basic_string<wchar_t>;
1011 # elif ! _GLIBCXX_USE_CXX11_ABI
1012 extern template basic_string<wchar_t>::size_type
1013 basic_string<wchar_t>::_Rep::_S_empty_rep_storage[];
1014 # elif _GLIBCXX_EXTERN_TEMPLATE > 0
1015 // Export _M_replace_cold even for C++20.
1016 extern template void
1017 basic_string<wchar_t>::_M_replace_cold(wchar_t*, size_type, const wchar_t*,
1018 const size_type, const size_type);
1019 # endif
1021 extern template
1022 basic_istream<wchar_t>&
1023 operator>>(basic_istream<wchar_t>&, wstring&);
1024 extern template
1025 basic_ostream<wchar_t>&
1026 operator<<(basic_ostream<wchar_t>&, const wstring&);
1027 extern template
1028 basic_istream<wchar_t>&
1029 getline(basic_istream<wchar_t>&, wstring&, wchar_t);
1030 extern template
1031 basic_istream<wchar_t>&
1032 getline(basic_istream<wchar_t>&, wstring&);
1033 #endif // _GLIBCXX_USE_WCHAR_T
1034 #endif // _GLIBCXX_EXTERN_TEMPLATE
1036 _GLIBCXX_END_NAMESPACE_VERSION
1037 } // namespace std
1039 #pragma GCC diagnostic pop
1040 #endif