1// Components for manipulating sequences of characters -*- C++ -*- 
2 
3// Copyright (C) 1997-2021 Free Software Foundation, Inc. 
4// 
5// This file is part of the GNU ISO C++ Library. This library is free 
6// software; you can redistribute it and/or modify it under the 
7// terms of the GNU General Public License as published by the 
8// Free Software Foundation; either version 3, or (at your option) 
9// any later version. 
10 
11// This library is distributed in the hope that it will be useful, 
12// but WITHOUT ANY WARRANTY; without even the implied warranty of 
13// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 
14// GNU General Public License for more details. 
15 
16// Under Section 7 of GPL version 3, you are granted additional 
17// permissions described in the GCC Runtime Library Exception, version 
18// 3.1, as published by the Free Software Foundation. 
19 
20// You should have received a copy of the GNU General Public License and 
21// a copy of the GCC Runtime Library Exception along with this program; 
22// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 
23// <http://www.gnu.org/licenses/>. 
24 
25/** @file bits/basic_string.tcc 
26 * This is an internal header file, included by other library headers. 
27 * Do not attempt to use it directly. @headername{string} 
28 */ 
29 
30// 
31// ISO C++ 14882: 21 Strings library 
32// 
33 
34// Written by Jason Merrill based upon the specification by Takanori Adachi 
35// in ANSI X3J16/94-0013R2. Rewritten by Nathan Myers to ISO-14882. 
36// Non-reference-counted implementation written by Paolo Carlini and 
37// updated by Jonathan Wakely for ISO-14882-2011. 
38 
39#ifndef _BASIC_STRING_TCC 
40#define _BASIC_STRING_TCC 1 
41 
42#pragma GCC system_header 
43 
44#include <bits/cxxabi_forced.h> 
45 
46namespace std _GLIBCXX_VISIBILITY(default) 
47{ 
48_GLIBCXX_BEGIN_NAMESPACE_VERSION 
49 
50#if _GLIBCXX_USE_CXX11_ABI 
51 
52 template<typename _CharT, typename _Traits, typename _Alloc> 
53 const typename basic_string<_CharT, _Traits, _Alloc>::size_type 
54 basic_string<_CharT, _Traits, _Alloc>::npos; 
55 
56 template<typename _CharT, typename _Traits, typename _Alloc> 
57 void 
58 basic_string<_CharT, _Traits, _Alloc>:: 
59 swap(basic_string& __s) _GLIBCXX_NOEXCEPT 
60 { 
61 if (this == &__s) 
62 return; 
63 
64 _Alloc_traits::_S_on_swap(_M_get_allocator(), __s._M_get_allocator()); 
65 
66 if (_M_is_local()) 
67 if (__s._M_is_local()) 
68 { 
69 if (length() && __s.length()) 
70 { 
71 _CharT __tmp_data[_S_local_capacity + 1]; 
72 traits_type::copy(__tmp_data, __s._M_local_buf, 
73 _S_local_capacity + 1); 
74 traits_type::copy(__s._M_local_buf, _M_local_buf, 
75 _S_local_capacity + 1); 
76 traits_type::copy(_M_local_buf, __tmp_data, 
77 _S_local_capacity + 1); 
78 } 
79 else if (__s.length()) 
80 { 
81 traits_type::copy(_M_local_buf, __s._M_local_buf, 
82 _S_local_capacity + 1); 
83 _M_length(length: __s.length()); 
84 __s._M_set_length(0); 
85 return; 
86 } 
87 else if (length()) 
88 { 
89 traits_type::copy(__s._M_local_buf, _M_local_buf, 
90 _S_local_capacity + 1); 
91 __s._M_length(length()); 
92 _M_set_length(n: 0); 
93 return; 
94 } 
95 } 
96 else 
97 { 
98 const size_type __tmp_capacity = __s._M_allocated_capacity; 
99 traits_type::copy(__s._M_local_buf, _M_local_buf, 
100 _S_local_capacity + 1); 
101 _M_data(__s._M_data()); 
102 __s._M_data(__s._M_local_buf); 
103 _M_capacity(capacity: __tmp_capacity); 
104 } 
105 else 
106 { 
107 const size_type __tmp_capacity = _M_allocated_capacity; 
108 if (__s._M_is_local()) 
109 { 
110 traits_type::copy(_M_local_buf, __s._M_local_buf, 
111 _S_local_capacity + 1); 
112 __s._M_data(_M_data()); 
113 _M_data(_M_local_buf); 
114 } 
115 else 
116 { 
117 pointer __tmp_ptr = _M_data(); 
118 _M_data(__s._M_data()); 
119 __s._M_data(__tmp_ptr); 
120 _M_capacity(capacity: __s._M_allocated_capacity); 
121 } 
122 __s._M_capacity(__tmp_capacity); 
123 } 
124 
125 const size_type __tmp_length = length(); 
126 _M_length(length: __s.length()); 
127 __s._M_length(__tmp_length); 
128 } 
129 
130 template<typename _CharT, typename _Traits, typename _Alloc> 
131 typename basic_string<_CharT, _Traits, _Alloc>::pointer 
132 basic_string<_CharT, _Traits, _Alloc>:: 
133 _M_create(size_type& __capacity, size_type __old_capacity) 
134 { 
135 // _GLIBCXX_RESOLVE_LIB_DEFECTS 
136 // 83. String::npos vs. string::max_size() 
137 if (__capacity > max_size()) 
138 std::__throw_length_error(__N("basic_string::_M_create")); 
139 
140 // The below implements an exponential growth policy, necessary to 
141 // meet amortized linear time requirements of the library: see 
142 // http://gcc.gnu.org/ml/libstdc++/2001-07/msg00085.html. 
143 if (__capacity > __old_capacity && __capacity < 2 * __old_capacity) 
144 { 
145 __capacity = 2 * __old_capacity; 
146 // Never allocate a string bigger than max_size. 
147 if (__capacity > max_size()) 
148 __capacity = max_size(); 
149 } 
150 
151 // NB: Need an array of char_type[__capacity], plus a terminating 
152 // null char_type() element. 
153 return _Alloc_traits::allocate(_M_get_allocator(), __capacity + 1); 
154 } 
155 
156 // NB: This is the special case for Input Iterators, used in 
157 // istreambuf_iterators, etc. 
158 // Input Iterators have a cost structure very different from 
159 // pointers, calling for a different coding style. 
160 template<typename _CharT, typename _Traits, typename _Alloc> 
161 template<typename _InIterator> 
162 void 
163 basic_string<_CharT, _Traits, _Alloc>:: 
164 _M_construct(_InIterator __beg, _InIterator __end, 
165 std::input_iterator_tag) 
166 { 
167 size_type __len = 0; 
168 size_type __capacity = size_type(_S_local_capacity); 
169 
170 while (__beg != __end && __len < __capacity) 
171 { 
172 _M_data()[__len++] = *__beg; 
173 ++__beg; 
174 } 
175 
176 __try 
177 { 
178 while (__beg != __end) 
179 { 
180 if (__len == __capacity) 
181 { 
182 // Allocate more space. 
183 __capacity = __len + 1; 
184 pointer __another = _M_create(__capacity, old_capacity: __len); 
185 this->_S_copy(__another, _M_data(), __len); 
186 _M_dispose(); 
187 _M_data(__another); 
188 _M_capacity(__capacity); 
189 } 
190 _M_data()[__len++] = *__beg; 
191 ++__beg; 
192 } 
193 } 
194 __catch(...) 
195 { 
196 _M_dispose(); 
197 __throw_exception_again; 
198 } 
199 
200 _M_set_length(n: __len); 
201 } 
202 
203 template<typename _CharT, typename _Traits, typename _Alloc> 
204 template<typename _InIterator> 
205 void 
206 basic_string<_CharT, _Traits, _Alloc>:: 
207 _M_construct(_InIterator __beg, _InIterator __end, 
208 std::forward_iterator_tag) 
209 { 
210 // NB: Not required, but considered best practice. 
211 if (__gnu_cxx::__is_null_pointer(__beg) && __beg != __end) 
212 std::__throw_logic_error(__N("basic_string::" 
213 "_M_construct null not valid")); 
214 
215 size_type __dnew = static_cast<size_type>(std::distance(__beg, __end)); 
216 
217 if (__dnew > size_type(_S_local_capacity)) 
218 { 
219 _M_data(_M_create(capacity&: __dnew, old_capacity: size_type(0))); 
220 _M_capacity(capacity: __dnew); 
221 } 
222 
223 // Check for out_of_range and length_error exceptions. 
224 __try 
225 { this->_S_copy_chars(_M_data(), __beg, __end); } 
226 __catch(...) 
227 { 
228 _M_dispose(); 
229 __throw_exception_again; 
230 } 
231 
232 _M_set_length(n: __dnew); 
233 } 
234 
235 template<typename _CharT, typename _Traits, typename _Alloc> 
236 void 
237 basic_string<_CharT, _Traits, _Alloc>:: 
238 _M_construct(size_type __n, _CharT __c) 
239 { 
240 if (__n > size_type(_S_local_capacity)) 
241 { 
242 _M_data(_M_create(capacity&: __n, old_capacity: size_type(0))); 
243 _M_capacity(capacity: __n); 
244 } 
245 
246 if (__n) 
247 this->_S_assign(_M_data(), __n, __c); 
248 
249 _M_set_length(__n); 
250 } 
251 
252 template<typename _CharT, typename _Traits, typename _Alloc> 
253 void 
254 basic_string<_CharT, _Traits, _Alloc>:: 
255 _M_assign(const basic_string& __str) 
256 { 
257 if (this != &__str) 
258 { 
259 const size_type __rsize = __str.length(); 
260 const size_type __capacity = capacity(); 
261 
262 if (__rsize > __capacity) 
263 { 
264 size_type __new_capacity = __rsize; 
265 pointer __tmp = _M_create(capacity&: __new_capacity, old_capacity: __capacity); 
266 _M_dispose(); 
267 _M_data(__tmp); 
268 _M_capacity(capacity: __new_capacity); 
269 } 
270 
271 if (__rsize) 
272 this->_S_copy(_M_data(), __str._M_data(), __rsize); 
273 
274 _M_set_length(n: __rsize); 
275 } 
276 } 
277 
278 template<typename _CharT, typename _Traits, typename _Alloc> 
279 void 
280 basic_string<_CharT, _Traits, _Alloc>:: 
281 reserve(size_type __res) 
282 { 
283 const size_type __capacity = capacity(); 
284 // _GLIBCXX_RESOLVE_LIB_DEFECTS 
285 // 2968. Inconsistencies between basic_string reserve and 
286 // vector/unordered_map/unordered_set reserve functions 
287 // P0966 reserve should not shrink 
288 if (__res <= __capacity) 
289 return; 
290 
291 pointer __tmp = _M_create(capacity&: __res, old_capacity: __capacity); 
292 this->_S_copy(__tmp, _M_data(), length() + 1); 
293 _M_dispose(); 
294 _M_data(__tmp); 
295 _M_capacity(capacity: __res); 
296 } 
297 
298 template<typename _CharT, typename _Traits, typename _Alloc> 
299 void 
300 basic_string<_CharT, _Traits, _Alloc>:: 
301 _M_mutate(size_type __pos, size_type __len1, const _CharT* __s, 
302 size_type __len2) 
303 { 
304 const size_type __how_much = length() - __pos - __len1; 
305 
306 size_type __new_capacity = length() + __len2 - __len1; 
307 pointer __r = _M_create(capacity&: __new_capacity, old_capacity: capacity()); 
308 
309 if (__pos) 
310 this->_S_copy(__r, _M_data(), __pos); 
311 if (__s && __len2) 
312 this->_S_copy(__r + __pos, __s, __len2); 
313 if (__how_much) 
314 this->_S_copy(__r + __pos + __len2, 
315 _M_data() + __pos + __len1, __how_much); 
316 
317 _M_dispose(); 
318 _M_data(__r); 
319 _M_capacity(capacity: __new_capacity); 
320 } 
321 
322 template<typename _CharT, typename _Traits, typename _Alloc> 
323 void 
324 basic_string<_CharT, _Traits, _Alloc>:: 
325 _M_erase(size_type __pos, size_type __n) 
326 { 
327 const size_type __how_much = length() - __pos - __n; 
328 
329 if (__how_much && __n) 
330 this->_S_move(_M_data() + __pos, _M_data() + __pos + __n, __how_much); 
331 
332 _M_set_length(n: length() - __n); 
333 } 
334 
335 template<typename _CharT, typename _Traits, typename _Alloc> 
336 void 
337 basic_string<_CharT, _Traits, _Alloc>:: 
338 reserve() 
339 { 
340 if (_M_is_local()) 
341 return; 
342 
343 const size_type __length = length(); 
344 const size_type __capacity = _M_allocated_capacity; 
345 
346 if (__length <= size_type(_S_local_capacity)) 
347 { 
348 this->_S_copy(_M_local_data(), _M_data(), __length + 1); 
349 _M_destroy(size: __capacity); 
350 _M_data(_M_local_data()); 
351 } 
352#if __cpp_exceptions 
353 else if (__length < __capacity) 
354 try 
355 { 
356 pointer __tmp 
357 = _Alloc_traits::allocate(_M_get_allocator(), __length + 1); 
358 this->_S_copy(__tmp, _M_data(), __length + 1); 
359 _M_dispose(); 
360 _M_data(__tmp); 
361 _M_capacity(capacity: __length); 
362 } 
363 catch (const __cxxabiv1::__forced_unwind&) 
364 { throw; } 
365 catch (...) 
366 { /* swallow the exception */ } 
367#endif 
368 } 
369 
370 template<typename _CharT, typename _Traits, typename _Alloc> 
371 void 
372 basic_string<_CharT, _Traits, _Alloc>:: 
373 resize(size_type __n, _CharT __c) 
374 { 
375 const size_type __size = this->size(); 
376 if (__size < __n) 
377 this->append(__n - __size, __c); 
378 else if (__n < __size) 
379 this->_M_set_length(__n); 
380 } 
381 
382 template<typename _CharT, typename _Traits, typename _Alloc> 
383 basic_string<_CharT, _Traits, _Alloc>& 
384 basic_string<_CharT, _Traits, _Alloc>:: 
385 _M_append(const _CharT* __s, size_type __n) 
386 { 
387 const size_type __len = __n + this->size(); 
388 
389 if (__len <= this->capacity()) 
390 { 
391 if (__n) 
392 this->_S_copy(this->_M_data() + this->size(), __s, __n); 
393 } 
394 else 
395 this->_M_mutate(this->size(), size_type(0), __s, __n); 
396 
397 this->_M_set_length(__len); 
398 return *this; 
399 } 
400 
401 template<typename _CharT, typename _Traits, typename _Alloc> 
402 template<typename _InputIterator> 
403 basic_string<_CharT, _Traits, _Alloc>& 
404 basic_string<_CharT, _Traits, _Alloc>:: 
405 _M_replace_dispatch(const_iterator __i1, const_iterator __i2, 
406 _InputIterator __k1, _InputIterator __k2, 
407 std::__false_type) 
408 { 
409 // _GLIBCXX_RESOLVE_LIB_DEFECTS 
410 // 2788. unintentionally require a default constructible allocator 
411 const basic_string __s(__k1, __k2, this->get_allocator()); 
412 const size_type __n1 = __i2 - __i1; 
413 return _M_replace(pos: __i1 - begin(), len1: __n1, s: __s._M_data(), 
414 len2: __s.size()); 
415 } 
416 
417 template<typename _CharT, typename _Traits, typename _Alloc> 
418 basic_string<_CharT, _Traits, _Alloc>& 
419 basic_string<_CharT, _Traits, _Alloc>:: 
420 _M_replace_aux(size_type __pos1, size_type __n1, size_type __n2, 
421 _CharT __c) 
422 { 
423 _M_check_length(__n1, __n2, s: "basic_string::_M_replace_aux"); 
424 
425 const size_type __old_size = this->size(); 
426 const size_type __new_size = __old_size + __n2 - __n1; 
427 
428 if (__new_size <= this->capacity()) 
429 { 
430 pointer __p = this->_M_data() + __pos1; 
431 
432 const size_type __how_much = __old_size - __pos1 - __n1; 
433 if (__how_much && __n1 != __n2) 
434 this->_S_move(__p + __n2, __p + __n1, __how_much); 
435 } 
436 else 
437 this->_M_mutate(__pos1, __n1, 0, __n2); 
438 
439 if (__n2) 
440 this->_S_assign(this->_M_data() + __pos1, __n2, __c); 
441 
442 this->_M_set_length(__new_size); 
443 return *this; 
444 } 
445 
446 template<typename _CharT, typename _Traits, typename _Alloc> 
447 basic_string<_CharT, _Traits, _Alloc>& 
448 basic_string<_CharT, _Traits, _Alloc>:: 
449 _M_replace(size_type __pos, size_type __len1, const _CharT* __s, 
450 const size_type __len2) 
451 { 
452 _M_check_length(n1: __len1, n2: __len2, s: "basic_string::_M_replace"); 
453 
454 const size_type __old_size = this->size(); 
455 const size_type __new_size = __old_size + __len2 - __len1; 
456 
457 if (__new_size <= this->capacity()) 
458 { 
459 pointer __p = this->_M_data() + __pos; 
460 
461 const size_type __how_much = __old_size - __pos - __len1; 
462 if (_M_disjunct(__s)) 
463 { 
464 if (__how_much && __len1 != __len2) 
465 this->_S_move(__p + __len2, __p + __len1, __how_much); 
466 if (__len2) 
467 this->_S_copy(__p, __s, __len2); 
468 } 
469 else 
470 { 
471 // Work in-place. 
472 if (__len2 && __len2 <= __len1) 
473 this->_S_move(__p, __s, __len2); 
474 if (__how_much && __len1 != __len2) 
475 this->_S_move(__p + __len2, __p + __len1, __how_much); 
476 if (__len2 > __len1) 
477 { 
478 if (__s + __len2 <= __p + __len1) 
479 this->_S_move(__p, __s, __len2); 
480 else if (__s >= __p + __len1) 
481 { 
482 // Hint to middle end that __p and __s overlap 
483 // (PR 98465). 
484 const size_type __poff = (__s - __p) + (__len2 - __len1); 
485 this->_S_copy(__p, __p + __poff, __len2); 
486 } 
487 else 
488 { 
489 const size_type __nleft = (__p + __len1) - __s; 
490 this->_S_move(__p, __s, __nleft); 
491 this->_S_copy(__p + __nleft, __p + __len2, 
492 __len2 - __nleft); 
493 } 
494 } 
495 } 
496 } 
497 else 
498 this->_M_mutate(__pos, __len1, __s, __len2); 
499 
500 this->_M_set_length(__new_size); 
501 return *this; 
502 } 
503 
504 template<typename _CharT, typename _Traits, typename _Alloc> 
505 typename basic_string<_CharT, _Traits, _Alloc>::size_type 
506 basic_string<_CharT, _Traits, _Alloc>:: 
507 copy(_CharT* __s, size_type __n, size_type __pos) const 
508 { 
509 _M_check(__pos, s: "basic_string::copy"); 
510 __n = _M_limit(__pos, off: __n); 
511 __glibcxx_requires_string_len(__s, __n); 
512 if (__n) 
513 _S_copy(d: __s, s: _M_data() + __pos, __n); 
514 // 21.3.5.7 par 3: do not append null. (good.) 
515 return __n; 
516 } 
517 
518#else // !_GLIBCXX_USE_CXX11_ABI 
519 
520 template<typename _CharT, typename _Traits, typename _Alloc> 
521 const typename basic_string<_CharT, _Traits, _Alloc>::size_type 
522 basic_string<_CharT, _Traits, _Alloc>:: 
523 _Rep::_S_max_size = (((npos - sizeof(_Rep_base))/sizeof(_CharT)) - 1) / 4; 
524 
525 template<typename _CharT, typename _Traits, typename _Alloc> 
526 const _CharT 
527 basic_string<_CharT, _Traits, _Alloc>:: 
528 _Rep::_S_terminal = _CharT(); 
529 
530 template<typename _CharT, typename _Traits, typename _Alloc> 
531 const typename basic_string<_CharT, _Traits, _Alloc>::size_type 
532 basic_string<_CharT, _Traits, _Alloc>::npos; 
533 
534 // Linker sets _S_empty_rep_storage to all 0s (one reference, empty string) 
535 // at static init time (before static ctors are run). 
536 template<typename _CharT, typename _Traits, typename _Alloc> 
537 typename basic_string<_CharT, _Traits, _Alloc>::size_type 
538 basic_string<_CharT, _Traits, _Alloc>::_Rep::_S_empty_rep_storage[ 
539 (sizeof(_Rep_base) + sizeof(_CharT) + sizeof(size_type) - 1) / 
540 sizeof(size_type)]; 
541 
542 // NB: This is the special case for Input Iterators, used in 
543 // istreambuf_iterators, etc. 
544 // Input Iterators have a cost structure very different from 
545 // pointers, calling for a different coding style. 
546 template<typename _CharT, typename _Traits, typename _Alloc> 
547 template<typename _InIterator> 
548 _CharT* 
549 basic_string<_CharT, _Traits, _Alloc>:: 
550 _S_construct(_InIterator __beg, _InIterator __end, const _Alloc& __a, 
551 input_iterator_tag) 
552 { 
553#if _GLIBCXX_FULLY_DYNAMIC_STRING == 0 
554 if (__beg == __end && __a == _Alloc()) 
555 return _S_empty_rep()._M_refdata(); 
556#endif 
557 // Avoid reallocation for common case. 
558 _CharT __buf[128]; 
559 size_type __len = 0; 
560 while (__beg != __end && __len < sizeof(__buf) / sizeof(_CharT)) 
561 { 
562 __buf[__len++] = *__beg; 
563 ++__beg; 
564 } 
565 _Rep* __r = _Rep::_S_create(__len, size_type(0), __a); 
566 _M_copy(__r->_M_refdata(), __buf, __len); 
567 __try 
568 { 
569 while (__beg != __end) 
570 { 
571 if (__len == __r->_M_capacity) 
572 { 
573 // Allocate more space. 
574 _Rep* __another = _Rep::_S_create(__len + 1, __len, __a); 
575 _M_copy(__another->_M_refdata(), __r->_M_refdata(), __len); 
576 __r->_M_destroy(__a); 
577 __r = __another; 
578 } 
579 __r->_M_refdata()[__len++] = *__beg; 
580 ++__beg; 
581 } 
582 } 
583 __catch(...) 
584 { 
585 __r->_M_destroy(__a); 
586 __throw_exception_again; 
587 } 
588 __r->_M_set_length_and_sharable(__len); 
589 return __r->_M_refdata(); 
590 } 
591 
592 template<typename _CharT, typename _Traits, typename _Alloc> 
593 template <typename _InIterator> 
594 _CharT* 
595 basic_string<_CharT, _Traits, _Alloc>:: 
596 _S_construct(_InIterator __beg, _InIterator __end, const _Alloc& __a, 
597 forward_iterator_tag) 
598 { 
599#if _GLIBCXX_FULLY_DYNAMIC_STRING == 0 
600 if (__beg == __end && __a == _Alloc()) 
601 return _S_empty_rep()._M_refdata(); 
602#endif 
603 // NB: Not required, but considered best practice. 
604 if (__gnu_cxx::__is_null_pointer(__beg) && __beg != __end) 
605 __throw_logic_error(__N("basic_string::_S_construct null not valid")); 
606 
607 const size_type __dnew = static_cast<size_type>(std::distance(__beg, 
608 __end)); 
609 // Check for out_of_range and length_error exceptions. 
610 _Rep* __r = _Rep::_S_create(__dnew, size_type(0), __a); 
611 __try 
612 { _S_copy_chars(__r->_M_refdata(), __beg, __end); } 
613 __catch(...) 
614 { 
615 __r->_M_destroy(__a); 
616 __throw_exception_again; 
617 } 
618 __r->_M_set_length_and_sharable(__dnew); 
619 return __r->_M_refdata(); 
620 } 
621 
622 template<typename _CharT, typename _Traits, typename _Alloc> 
623 _CharT* 
624 basic_string<_CharT, _Traits, _Alloc>:: 
625 _S_construct(size_type __n, _CharT __c, const _Alloc& __a) 
626 { 
627#if _GLIBCXX_FULLY_DYNAMIC_STRING == 0 
628 if (__n == 0 && __a == _Alloc()) 
629 return _S_empty_rep()._M_refdata(); 
630#endif 
631 // Check for out_of_range and length_error exceptions. 
632 _Rep* __r = _Rep::_S_create(__n, size_type(0), __a); 
633 if (__n) 
634 _M_assign(__r->_M_refdata(), __n, __c); 
635 
636 __r->_M_set_length_and_sharable(__n); 
637 return __r->_M_refdata(); 
638 } 
639 
640 template<typename _CharT, typename _Traits, typename _Alloc> 
641 basic_string<_CharT, _Traits, _Alloc>:: 
642 basic_string(const basic_string& __str, size_type __pos, const _Alloc& __a) 
643 : _M_dataplus(_S_construct(__str._M_data() 
644 + __str._M_check(__pos, 
645 "basic_string::basic_string"), 
646 __str._M_data() + __str._M_limit(__pos, npos) 
647 + __pos, __a), __a) 
648 { } 
649 
650 template<typename _CharT, typename _Traits, typename _Alloc> 
651 basic_string<_CharT, _Traits, _Alloc>:: 
652 basic_string(const basic_string& __str, size_type __pos, size_type __n) 
653 : _M_dataplus(_S_construct(__str._M_data() 
654 + __str._M_check(__pos, 
655 "basic_string::basic_string"), 
656 __str._M_data() + __str._M_limit(__pos, __n) 
657 + __pos, _Alloc()), _Alloc()) 
658 { } 
659 
660 template<typename _CharT, typename _Traits, typename _Alloc> 
661 basic_string<_CharT, _Traits, _Alloc>:: 
662 basic_string(const basic_string& __str, size_type __pos, 
663 size_type __n, const _Alloc& __a) 
664 : _M_dataplus(_S_construct(__str._M_data() 
665 + __str._M_check(__pos, 
666 "basic_string::basic_string"), 
667 __str._M_data() + __str._M_limit(__pos, __n) 
668 + __pos, __a), __a) 
669 { } 
670 
671 template<typename _CharT, typename _Traits, typename _Alloc> 
672 basic_string<_CharT, _Traits, _Alloc>& 
673 basic_string<_CharT, _Traits, _Alloc>:: 
674 assign(const basic_string& __str) 
675 { 
676 if (_M_rep() != __str._M_rep()) 
677 { 
678 // XXX MT 
679 const allocator_type __a = this->get_allocator(); 
680 _CharT* __tmp = __str._M_rep()->_M_grab(__a, __str.get_allocator()); 
681 _M_rep()->_M_dispose(__a); 
682 _M_data(__tmp); 
683 } 
684 return *this; 
685 } 
686 
687 template<typename _CharT, typename _Traits, typename _Alloc> 
688 basic_string<_CharT, _Traits, _Alloc>& 
689 basic_string<_CharT, _Traits, _Alloc>:: 
690 assign(const _CharT* __s, size_type __n) 
691 { 
692 __glibcxx_requires_string_len(__s, __n); 
693 _M_check_length(this->size(), __n, "basic_string::assign"); 
694 if (_M_disjunct(__s) || _M_rep()->_M_is_shared()) 
695 return _M_replace_safe(size_type(0), this->size(), __s, __n); 
696 else 
697 { 
698 // Work in-place. 
699 const size_type __pos = __s - _M_data(); 
700 if (__pos >= __n) 
701 _M_copy(_M_data(), __s, __n); 
702 else if (__pos) 
703 _M_move(_M_data(), __s, __n); 
704 _M_rep()->_M_set_length_and_sharable(__n); 
705 return *this; 
706 } 
707 } 
708 
709 template<typename _CharT, typename _Traits, typename _Alloc> 
710 basic_string<_CharT, _Traits, _Alloc>& 
711 basic_string<_CharT, _Traits, _Alloc>:: 
712 append(size_type __n, _CharT __c) 
713 { 
714 if (__n) 
715 { 
716 _M_check_length(size_type(0), __n, "basic_string::append");  
717 const size_type __len = __n + this->size(); 
718 if (__len > this->capacity() || _M_rep()->_M_is_shared()) 
719 this->reserve(__len); 
720 _M_assign(_M_data() + this->size(), __n, __c); 
721 _M_rep()->_M_set_length_and_sharable(__len); 
722 } 
723 return *this; 
724 } 
725 
726 template<typename _CharT, typename _Traits, typename _Alloc> 
727 basic_string<_CharT, _Traits, _Alloc>& 
728 basic_string<_CharT, _Traits, _Alloc>:: 
729 append(const _CharT* __s, size_type __n) 
730 { 
731 __glibcxx_requires_string_len(__s, __n); 
732 if (__n) 
733 { 
734 _M_check_length(size_type(0), __n, "basic_string::append"); 
735 const size_type __len = __n + this->size(); 
736 if (__len > this->capacity() || _M_rep()->_M_is_shared()) 
737 { 
738 if (_M_disjunct(__s)) 
739 this->reserve(__len); 
740 else 
741 { 
742 const size_type __off = __s - _M_data(); 
743 this->reserve(__len); 
744 __s = _M_data() + __off; 
745 } 
746 } 
747 _M_copy(_M_data() + this->size(), __s, __n); 
748 _M_rep()->_M_set_length_and_sharable(__len); 
749 } 
750 return *this; 
751 } 
752 
753 template<typename _CharT, typename _Traits, typename _Alloc> 
754 basic_string<_CharT, _Traits, _Alloc>& 
755 basic_string<_CharT, _Traits, _Alloc>:: 
756 append(const basic_string& __str) 
757 { 
758 const size_type __size = __str.size(); 
759 if (__size) 
760 { 
761 const size_type __len = __size + this->size(); 
762 if (__len > this->capacity() || _M_rep()->_M_is_shared()) 
763 this->reserve(__len); 
764 _M_copy(_M_data() + this->size(), __str._M_data(), __size); 
765 _M_rep()->_M_set_length_and_sharable(__len); 
766 } 
767 return *this; 
768 }  
769 
770 template<typename _CharT, typename _Traits, typename _Alloc> 
771 basic_string<_CharT, _Traits, _Alloc>& 
772 basic_string<_CharT, _Traits, _Alloc>:: 
773 append(const basic_string& __str, size_type __pos, size_type __n) 
774 { 
775 __str._M_check(__pos, "basic_string::append"); 
776 __n = __str._M_limit(__pos, __n); 
777 if (__n) 
778 { 
779 const size_type __len = __n + this->size(); 
780 if (__len > this->capacity() || _M_rep()->_M_is_shared()) 
781 this->reserve(__len); 
782 _M_copy(_M_data() + this->size(), __str._M_data() + __pos, __n); 
783 _M_rep()->_M_set_length_and_sharable(__len);  
784 } 
785 return *this; 
786 } 
787 
788 template<typename _CharT, typename _Traits, typename _Alloc> 
789 basic_string<_CharT, _Traits, _Alloc>& 
790 basic_string<_CharT, _Traits, _Alloc>:: 
791 insert(size_type __pos, const _CharT* __s, size_type __n) 
792 { 
793 __glibcxx_requires_string_len(__s, __n); 
794 _M_check(__pos, "basic_string::insert"); 
795 _M_check_length(size_type(0), __n, "basic_string::insert"); 
796 if (_M_disjunct(__s) || _M_rep()->_M_is_shared()) 
797 return _M_replace_safe(__pos, size_type(0), __s, __n); 
798 else 
799 { 
800 // Work in-place. 
801 const size_type __off = __s - _M_data(); 
802 _M_mutate(__pos, 0, __n); 
803 __s = _M_data() + __off; 
804 _CharT* __p = _M_data() + __pos; 
805 if (__s + __n <= __p) 
806 _M_copy(__p, __s, __n); 
807 else if (__s >= __p) 
808 _M_copy(__p, __s + __n, __n); 
809 else 
810 { 
811 const size_type __nleft = __p - __s; 
812 _M_copy(__p, __s, __nleft); 
813 _M_copy(__p + __nleft, __p + __n, __n - __nleft); 
814 } 
815 return *this; 
816 } 
817 } 
818 
819 template<typename _CharT, typename _Traits, typename _Alloc> 
820 typename basic_string<_CharT, _Traits, _Alloc>::iterator 
821 basic_string<_CharT, _Traits, _Alloc>:: 
822 erase(iterator __first, iterator __last) 
823 { 
824 _GLIBCXX_DEBUG_PEDASSERT(__first >= _M_ibegin() && __first <= __last 
825 && __last <= _M_iend()); 
826 
827 // NB: This isn't just an optimization (bail out early when 
828 // there is nothing to do, really), it's also a correctness 
829 // issue vs MT, see libstdc++/40518. 
830 const size_type __size = __last - __first; 
831 if (__size) 
832 { 
833 const size_type __pos = __first - _M_ibegin(); 
834 _M_mutate(__pos, __size, size_type(0)); 
835 _M_rep()->_M_set_leaked(); 
836 return iterator(_M_data() + __pos); 
837 } 
838 else 
839 return __first; 
840 } 
841 
842 template<typename _CharT, typename _Traits, typename _Alloc> 
843 basic_string<_CharT, _Traits, _Alloc>& 
844 basic_string<_CharT, _Traits, _Alloc>:: 
845 replace(size_type __pos, size_type __n1, const _CharT* __s, 
846 size_type __n2) 
847 { 
848 __glibcxx_requires_string_len(__s, __n2); 
849 _M_check(__pos, "basic_string::replace"); 
850 __n1 = _M_limit(__pos, __n1); 
851 _M_check_length(__n1, __n2, "basic_string::replace"); 
852 bool __left; 
853 if (_M_disjunct(__s) || _M_rep()->_M_is_shared()) 
854 return _M_replace_safe(__pos, __n1, __s, __n2); 
855 else if ((__left = __s + __n2 <= _M_data() + __pos) 
856 || _M_data() + __pos + __n1 <= __s) 
857 { 
858 // Work in-place: non-overlapping case. 
859 size_type __off = __s - _M_data(); 
860 __left ? __off : (__off += __n2 - __n1); 
861 _M_mutate(__pos, __n1, __n2); 
862 _M_copy(_M_data() + __pos, _M_data() + __off, __n2); 
863 return *this; 
864 } 
865 else 
866 { 
867 // Todo: overlapping case. 
868 const basic_string __tmp(__s, __n2); 
869 return _M_replace_safe(__pos, __n1, __tmp._M_data(), __n2); 
870 } 
871 } 
872 
873 template<typename _CharT, typename _Traits, typename _Alloc> 
874 void 
875 basic_string<_CharT, _Traits, _Alloc>::_Rep:: 
876 _M_destroy(const _Alloc& __a) throw () 
877 { 
878 const size_type __size = sizeof(_Rep_base) + 
879 (this->_M_capacity + 1) * sizeof(_CharT); 
880 _Raw_bytes_alloc(__a).deallocate(reinterpret_cast<char*>(this), __size); 
881 } 
882 
883 template<typename _CharT, typename _Traits, typename _Alloc> 
884 void 
885 basic_string<_CharT, _Traits, _Alloc>:: 
886 _M_leak_hard() 
887 { 
888#if _GLIBCXX_FULLY_DYNAMIC_STRING == 0 
889 if (_M_rep() == &_S_empty_rep()) 
890 return; 
891#endif 
892 if (_M_rep()->_M_is_shared()) 
893 _M_mutate(0, 0, 0); 
894 _M_rep()->_M_set_leaked(); 
895 } 
896 
897 template<typename _CharT, typename _Traits, typename _Alloc> 
898 void 
899 basic_string<_CharT, _Traits, _Alloc>:: 
900 _M_mutate(size_type __pos, size_type __len1, size_type __len2) 
901 { 
902 const size_type __old_size = this->size(); 
903 const size_type __new_size = __old_size + __len2 - __len1; 
904 const size_type __how_much = __old_size - __pos - __len1; 
905 
906 if (__new_size > this->capacity() || _M_rep()->_M_is_shared()) 
907 { 
908 // Must reallocate. 
909 const allocator_type __a = get_allocator(); 
910 _Rep* __r = _Rep::_S_create(__new_size, this->capacity(), __a); 
911 
912 if (__pos) 
913 _M_copy(__r->_M_refdata(), _M_data(), __pos); 
914 if (__how_much) 
915 _M_copy(__r->_M_refdata() + __pos + __len2, 
916 _M_data() + __pos + __len1, __how_much); 
917 
918 _M_rep()->_M_dispose(__a); 
919 _M_data(__r->_M_refdata()); 
920 } 
921 else if (__how_much && __len1 != __len2) 
922 { 
923 // Work in-place. 
924 _M_move(_M_data() + __pos + __len2, 
925 _M_data() + __pos + __len1, __how_much); 
926 } 
927 _M_rep()->_M_set_length_and_sharable(__new_size); 
928 } 
929 
930 template<typename _CharT, typename _Traits, typename _Alloc> 
931 void 
932 basic_string<_CharT, _Traits, _Alloc>:: 
933 reserve(size_type __res) 
934 { 
935 const size_type __capacity = capacity(); 
936 
937 // _GLIBCXX_RESOLVE_LIB_DEFECTS 
938 // 2968. Inconsistencies between basic_string reserve and 
939 // vector/unordered_map/unordered_set reserve functions 
940 // P0966 reserve should not shrink 
941 if (__res <= __capacity) 
942 { 
943 if (!_M_rep()->_M_is_shared()) 
944 return; 
945 
946 // unshare, but keep same capacity 
947 __res = __capacity; 
948 } 
949 
950 const allocator_type __a = get_allocator(); 
951 _CharT* __tmp = _M_rep()->_M_clone(__a, __res - this->size()); 
952 _M_rep()->_M_dispose(__a); 
953 _M_data(__tmp); 
954 } 
955 
956 template<typename _CharT, typename _Traits, typename _Alloc> 
957 void 
958 basic_string<_CharT, _Traits, _Alloc>:: 
959 swap(basic_string& __s) 
960 _GLIBCXX_NOEXCEPT_IF(allocator_traits<_Alloc>::is_always_equal::value) 
961 { 
962 if (_M_rep()->_M_is_leaked()) 
963 _M_rep()->_M_set_sharable(); 
964 if (__s._M_rep()->_M_is_leaked()) 
965 __s._M_rep()->_M_set_sharable(); 
966 if (this->get_allocator() == __s.get_allocator()) 
967 { 
968 _CharT* __tmp = _M_data(); 
969 _M_data(__s._M_data()); 
970 __s._M_data(__tmp); 
971 } 
972 // The code below can usually be optimized away. 
973 else 
974 { 
975 const basic_string __tmp1(_M_ibegin(), _M_iend(), 
976 __s.get_allocator()); 
977 const basic_string __tmp2(__s._M_ibegin(), __s._M_iend(), 
978 this->get_allocator()); 
979 *this = __tmp2; 
980 __s = __tmp1; 
981 } 
982 } 
983 
984 template<typename _CharT, typename _Traits, typename _Alloc> 
985 typename basic_string<_CharT, _Traits, _Alloc>::_Rep* 
986 basic_string<_CharT, _Traits, _Alloc>::_Rep:: 
987 _S_create(size_type __capacity, size_type __old_capacity, 
988 const _Alloc& __alloc) 
989 { 
990 // _GLIBCXX_RESOLVE_LIB_DEFECTS 
991 // 83. String::npos vs. string::max_size() 
992 if (__capacity > _S_max_size) 
993 __throw_length_error(__N("basic_string::_S_create")); 
994 
995 // The standard places no restriction on allocating more memory 
996 // than is strictly needed within this layer at the moment or as 
997 // requested by an explicit application call to reserve(n). 
998 
999 // Many malloc implementations perform quite poorly when an 
1000 // application attempts to allocate memory in a stepwise fashion 
1001 // growing each allocation size by only 1 char. Additionally, 
1002 // it makes little sense to allocate less linear memory than the 
1003 // natural blocking size of the malloc implementation. 
1004 // Unfortunately, we would need a somewhat low-level calculation 
1005 // with tuned parameters to get this perfect for any particular 
1006 // malloc implementation. Fortunately, generalizations about 
1007 // common features seen among implementations seems to suffice. 
1008 
1009 // __pagesize need not match the actual VM page size for good 
1010 // results in practice, thus we pick a common value on the low 
1011 // side. __malloc_header_size is an estimate of the amount of 
1012 // overhead per memory allocation (in practice seen N * sizeof 
1013 // (void*) where N is 0, 2 or 4). According to folklore, 
1014 // picking this value on the high side is better than 
1015 // low-balling it (especially when this algorithm is used with 
1016 // malloc implementations that allocate memory blocks rounded up 
1017 // to a size which is a power of 2). 
1018 const size_type __pagesize = 4096; 
1019 const size_type __malloc_header_size = 4 * sizeof(void*); 
1020 
1021 // The below implements an exponential growth policy, necessary to 
1022 // meet amortized linear time requirements of the library: see 
1023 // http://gcc.gnu.org/ml/libstdc++/2001-07/msg00085.html. 
1024 // It's active for allocations requiring an amount of memory above 
1025 // system pagesize. This is consistent with the requirements of the 
1026 // standard: http://gcc.gnu.org/ml/libstdc++/2001-07/msg00130.html 
1027 if (__capacity > __old_capacity && __capacity < 2 * __old_capacity) 
1028 __capacity = 2 * __old_capacity; 
1029 
1030 // NB: Need an array of char_type[__capacity], plus a terminating 
1031 // null char_type() element, plus enough for the _Rep data structure. 
1032 // Whew. Seemingly so needy, yet so elemental. 
1033 size_type __size = (__capacity + 1) * sizeof(_CharT) + sizeof(_Rep); 
1034 
1035 const size_type __adj_size = __size + __malloc_header_size; 
1036 if (__adj_size > __pagesize && __capacity > __old_capacity) 
1037 { 
1038 const size_type __extra = __pagesize - __adj_size % __pagesize; 
1039 __capacity += __extra / sizeof(_CharT); 
1040 // Never allocate a string bigger than _S_max_size. 
1041 if (__capacity > _S_max_size) 
1042 __capacity = _S_max_size; 
1043 __size = (__capacity + 1) * sizeof(_CharT) + sizeof(_Rep); 
1044 } 
1045 
1046 // NB: Might throw, but no worries about a leak, mate: _Rep() 
1047 // does not throw. 
1048 void* __place = _Raw_bytes_alloc(__alloc).allocate(__size); 
1049 _Rep *__p = new (__place) _Rep; 
1050 __p->_M_capacity = __capacity; 
1051 // ABI compatibility - 3.4.x set in _S_create both 
1052 // _M_refcount and _M_length. All callers of _S_create 
1053 // in basic_string.tcc then set just _M_length. 
1054 // In 4.0.x and later both _M_refcount and _M_length 
1055 // are initialized in the callers, unfortunately we can 
1056 // have 3.4.x compiled code with _S_create callers inlined 
1057 // calling 4.0.x+ _S_create. 
1058 __p->_M_set_sharable(); 
1059 return __p; 
1060 } 
1061 
1062 template<typename _CharT, typename _Traits, typename _Alloc> 
1063 _CharT* 
1064 basic_string<_CharT, _Traits, _Alloc>::_Rep:: 
1065 _M_clone(const _Alloc& __alloc, size_type __res) 
1066 { 
1067 // Requested capacity of the clone. 
1068 const size_type __requested_cap = this->_M_length + __res; 
1069 _Rep* __r = _Rep::_S_create(__requested_cap, this->_M_capacity, 
1070 __alloc); 
1071 if (this->_M_length) 
1072 _M_copy(__r->_M_refdata(), _M_refdata(), this->_M_length); 
1073 
1074 __r->_M_set_length_and_sharable(this->_M_length); 
1075 return __r->_M_refdata(); 
1076 } 
1077 
1078 template<typename _CharT, typename _Traits, typename _Alloc> 
1079 void 
1080 basic_string<_CharT, _Traits, _Alloc>:: 
1081 resize(size_type __n, _CharT __c) 
1082 { 
1083 const size_type __size = this->size(); 
1084 _M_check_length(__size, __n, "basic_string::resize"); 
1085 if (__size < __n) 
1086 this->append(__n - __size, __c); 
1087 else if (__n < __size) 
1088 this->erase(__n); 
1089 // else nothing (in particular, avoid calling _M_mutate() unnecessarily.) 
1090 } 
1091 
1092 template<typename _CharT, typename _Traits, typename _Alloc> 
1093 template<typename _InputIterator> 
1094 basic_string<_CharT, _Traits, _Alloc>& 
1095 basic_string<_CharT, _Traits, _Alloc>:: 
1096 _M_replace_dispatch(iterator __i1, iterator __i2, _InputIterator __k1, 
1097 _InputIterator __k2, __false_type) 
1098 { 
1099 const basic_string __s(__k1, __k2); 
1100 const size_type __n1 = __i2 - __i1; 
1101 _M_check_length(__n1, __s.size(), "basic_string::_M_replace_dispatch"); 
1102 return _M_replace_safe(__i1 - _M_ibegin(), __n1, __s._M_data(), 
1103 __s.size()); 
1104 } 
1105 
1106 template<typename _CharT, typename _Traits, typename _Alloc> 
1107 basic_string<_CharT, _Traits, _Alloc>& 
1108 basic_string<_CharT, _Traits, _Alloc>:: 
1109 _M_replace_aux(size_type __pos1, size_type __n1, size_type __n2, 
1110 _CharT __c) 
1111 { 
1112 _M_check_length(__n1, __n2, "basic_string::_M_replace_aux"); 
1113 _M_mutate(__pos1, __n1, __n2); 
1114 if (__n2) 
1115 _M_assign(_M_data() + __pos1, __n2, __c); 
1116 return *this; 
1117 } 
1118 
1119 template<typename _CharT, typename _Traits, typename _Alloc> 
1120 basic_string<_CharT, _Traits, _Alloc>& 
1121 basic_string<_CharT, _Traits, _Alloc>:: 
1122 _M_replace_safe(size_type __pos1, size_type __n1, const _CharT* __s, 
1123 size_type __n2) 
1124 { 
1125 _M_mutate(__pos1, __n1, __n2); 
1126 if (__n2) 
1127 _M_copy(_M_data() + __pos1, __s, __n2); 
1128 return *this; 
1129 } 
1130 
1131 template<typename _CharT, typename _Traits, typename _Alloc> 
1132 void 
1133 basic_string<_CharT, _Traits, _Alloc>:: 
1134 reserve() 
1135 { 
1136#if __cpp_exceptions 
1137 if (length() < capacity() || _M_rep()->_M_is_shared()) 
1138 try 
1139 { 
1140 const allocator_type __a = get_allocator(); 
1141 _CharT* __tmp = _M_rep()->_M_clone(__a); 
1142 _M_rep()->_M_dispose(__a); 
1143 _M_data(__tmp); 
1144 } 
1145 catch (const __cxxabiv1::__forced_unwind&) 
1146 { throw; } 
1147 catch (...) 
1148 { /* swallow the exception */ } 
1149#endif 
1150 } 
1151 
1152 template<typename _CharT, typename _Traits, typename _Alloc> 
1153 typename basic_string<_CharT, _Traits, _Alloc>::size_type 
1154 basic_string<_CharT, _Traits, _Alloc>:: 
1155 copy(_CharT* __s, size_type __n, size_type __pos) const 
1156 { 
1157 _M_check(__pos, "basic_string::copy"); 
1158 __n = _M_limit(__pos, __n); 
1159 __glibcxx_requires_string_len(__s, __n); 
1160 if (__n) 
1161 _M_copy(__s, _M_data() + __pos, __n); 
1162 // 21.3.5.7 par 3: do not append null. (good.) 
1163 return __n; 
1164 } 
1165#endif // !_GLIBCXX_USE_CXX11_ABI 
1166  
1167 template<typename _CharT, typename _Traits, typename _Alloc> 
1168 basic_string<_CharT, _Traits, _Alloc> 
1169 operator+(const _CharT* __lhs, 
1170 const basic_string<_CharT, _Traits, _Alloc>& __rhs) 
1171 { 
1172 __glibcxx_requires_string(__lhs); 
1173 typedef basic_string<_CharT, _Traits, _Alloc> __string_type; 
1174 typedef typename __string_type::size_type __size_type; 
1175 typedef typename __gnu_cxx::__alloc_traits<_Alloc>::template 
1176 rebind<_CharT>::other _Char_alloc_type; 
1177 typedef __gnu_cxx::__alloc_traits<_Char_alloc_type> _Alloc_traits; 
1178 const __size_type __len = _Traits::length(__lhs); 
1179 __string_type __str(_Alloc_traits::_S_select_on_copy( 
1180 __rhs.get_allocator())); 
1181 __str.reserve(__len + __rhs.size()); 
1182 __str.append(__lhs, __len); 
1183 __str.append(__rhs); 
1184 return __str; 
1185 } 
1186 
1187 template<typename _CharT, typename _Traits, typename _Alloc> 
1188 basic_string<_CharT, _Traits, _Alloc> 
1189 operator+(_CharT __lhs, const basic_string<_CharT, _Traits, _Alloc>& __rhs) 
1190 { 
1191 typedef basic_string<_CharT, _Traits, _Alloc> __string_type; 
1192 typedef typename __string_type::size_type __size_type; 
1193 typedef typename __gnu_cxx::__alloc_traits<_Alloc>::template 
1194 rebind<_CharT>::other _Char_alloc_type; 
1195 typedef __gnu_cxx::__alloc_traits<_Char_alloc_type> _Alloc_traits; 
1196 __string_type __str(_Alloc_traits::_S_select_on_copy( 
1197 __rhs.get_allocator())); 
1198 const __size_type __len = __rhs.size(); 
1199 __str.reserve(__len + 1); 
1200 __str.append(__size_type(1), __lhs); 
1201 __str.append(__rhs); 
1202 return __str; 
1203 } 
1204 
1205 template<typename _CharT, typename _Traits, typename _Alloc> 
1206 typename basic_string<_CharT, _Traits, _Alloc>::size_type 
1207 basic_string<_CharT, _Traits, _Alloc>:: 
1208 find(const _CharT* __s, size_type __pos, size_type __n) const 
1209 _GLIBCXX_NOEXCEPT 
1210 { 
1211 __glibcxx_requires_string_len(__s, __n); 
1212 const size_type __size = this->size(); 
1213 
1214 if (__n == 0) 
1215 return __pos <= __size ? __pos : npos; 
1216 if (__pos >= __size) 
1217 return npos; 
1218 
1219 const _CharT __elem0 = __s[0]; 
1220 const _CharT* const __data = data(); 
1221 const _CharT* __first = __data + __pos; 
1222 const _CharT* const __last = __data + __size; 
1223 size_type __len = __size - __pos; 
1224 
1225 while (__len >= __n) 
1226 { 
1227 // Find the first occurrence of __elem0: 
1228 __first = traits_type::find(__first, __len - __n + 1, __elem0); 
1229 if (!__first) 
1230 return npos; 
1231 // Compare the full strings from the first occurrence of __elem0. 
1232 // We already know that __first[0] == __s[0] but compare them again 
1233 // anyway because __s is probably aligned, which helps memcmp. 
1234 if (traits_type::compare(__first, __s, __n) == 0) 
1235 return __first - __data; 
1236 __len = __last - ++__first; 
1237 } 
1238 return npos; 
1239 } 
1240 
1241 template<typename _CharT, typename _Traits, typename _Alloc> 
1242 typename basic_string<_CharT, _Traits, _Alloc>::size_type 
1243 basic_string<_CharT, _Traits, _Alloc>:: 
1244 find(_CharT __c, size_type __pos) const _GLIBCXX_NOEXCEPT 
1245 { 
1246 size_type __ret = npos; 
1247 const size_type __size = this->size(); 
1248 if (__pos < __size) 
1249 { 
1250 const _CharT* __data = _M_data(); 
1251 const size_type __n = __size - __pos; 
1252 const _CharT* __p = traits_type::find(__data + __pos, __n, __c); 
1253 if (__p) 
1254 __ret = __p - __data; 
1255 } 
1256 return __ret; 
1257 } 
1258 
1259 template<typename _CharT, typename _Traits, typename _Alloc> 
1260 typename basic_string<_CharT, _Traits, _Alloc>::size_type 
1261 basic_string<_CharT, _Traits, _Alloc>:: 
1262 rfind(const _CharT* __s, size_type __pos, size_type __n) const 
1263 _GLIBCXX_NOEXCEPT 
1264 { 
1265 __glibcxx_requires_string_len(__s, __n); 
1266 const size_type __size = this->size(); 
1267 if (__n <= __size) 
1268 { 
1269 __pos = std::min(size_type(__size - __n), __pos); 
1270 const _CharT* __data = _M_data(); 
1271 do 
1272 { 
1273 if (traits_type::compare(__data + __pos, __s, __n) == 0) 
1274 return __pos; 
1275 } 
1276 while (__pos-- > 0); 
1277 } 
1278 return npos; 
1279 } 
1280 
1281 template<typename _CharT, typename _Traits, typename _Alloc> 
1282 typename basic_string<_CharT, _Traits, _Alloc>::size_type 
1283 basic_string<_CharT, _Traits, _Alloc>:: 
1284 rfind(_CharT __c, size_type __pos) const _GLIBCXX_NOEXCEPT 
1285 { 
1286 size_type __size = this->size(); 
1287 if (__size) 
1288 { 
1289 if (--__size > __pos) 
1290 __size = __pos; 
1291 for (++__size; __size-- > 0; ) 
1292 if (traits_type::eq(_M_data()[__size], __c)) 
1293 return __size; 
1294 } 
1295 return npos; 
1296 } 
1297 
1298 template<typename _CharT, typename _Traits, typename _Alloc> 
1299 typename basic_string<_CharT, _Traits, _Alloc>::size_type 
1300 basic_string<_CharT, _Traits, _Alloc>:: 
1301 find_first_of(const _CharT* __s, size_type __pos, size_type __n) const 
1302 _GLIBCXX_NOEXCEPT 
1303 { 
1304 __glibcxx_requires_string_len(__s, __n); 
1305 for (; __n && __pos < this->size(); ++__pos) 
1306 { 
1307 const _CharT* __p = traits_type::find(__s, __n, _M_data()[__pos]); 
1308 if (__p) 
1309 return __pos; 
1310 } 
1311 return npos; 
1312 } 
1313 
1314 template<typename _CharT, typename _Traits, typename _Alloc> 
1315 typename basic_string<_CharT, _Traits, _Alloc>::size_type 
1316 basic_string<_CharT, _Traits, _Alloc>:: 
1317 find_last_of(const _CharT* __s, size_type __pos, size_type __n) const 
1318 _GLIBCXX_NOEXCEPT 
1319 { 
1320 __glibcxx_requires_string_len(__s, __n); 
1321 size_type __size = this->size(); 
1322 if (__size && __n) 
1323 { 
1324 if (--__size > __pos) 
1325 __size = __pos; 
1326 do 
1327 { 
1328 if (traits_type::find(__s, __n, _M_data()[__size])) 
1329 return __size; 
1330 } 
1331 while (__size-- != 0); 
1332 } 
1333 return npos; 
1334 } 
1335 
1336 template<typename _CharT, typename _Traits, typename _Alloc> 
1337 typename basic_string<_CharT, _Traits, _Alloc>::size_type 
1338 basic_string<_CharT, _Traits, _Alloc>:: 
1339 find_first_not_of(const _CharT* __s, size_type __pos, size_type __n) const 
1340 _GLIBCXX_NOEXCEPT 
1341 { 
1342 __glibcxx_requires_string_len(__s, __n); 
1343 for (; __pos < this->size(); ++__pos) 
1344 if (!traits_type::find(__s, __n, _M_data()[__pos])) 
1345 return __pos; 
1346 return npos; 
1347 } 
1348 
1349 template<typename _CharT, typename _Traits, typename _Alloc> 
1350 typename basic_string<_CharT, _Traits, _Alloc>::size_type 
1351 basic_string<_CharT, _Traits, _Alloc>:: 
1352 find_first_not_of(_CharT __c, size_type __pos) const _GLIBCXX_NOEXCEPT 
1353 { 
1354 for (; __pos < this->size(); ++__pos) 
1355 if (!traits_type::eq(_M_data()[__pos], __c)) 
1356 return __pos; 
1357 return npos; 
1358 } 
1359 
1360 template<typename _CharT, typename _Traits, typename _Alloc> 
1361 typename basic_string<_CharT, _Traits, _Alloc>::size_type 
1362 basic_string<_CharT, _Traits, _Alloc>:: 
1363 find_last_not_of(const _CharT* __s, size_type __pos, size_type __n) const 
1364 _GLIBCXX_NOEXCEPT 
1365 { 
1366 __glibcxx_requires_string_len(__s, __n); 
1367 size_type __size = this->size(); 
1368 if (__size) 
1369 { 
1370 if (--__size > __pos) 
1371 __size = __pos; 
1372 do 
1373 { 
1374 if (!traits_type::find(__s, __n, _M_data()[__size])) 
1375 return __size; 
1376 } 
1377 while (__size--); 
1378 } 
1379 return npos; 
1380 } 
1381 
1382 template<typename _CharT, typename _Traits, typename _Alloc> 
1383 typename basic_string<_CharT, _Traits, _Alloc>::size_type 
1384 basic_string<_CharT, _Traits, _Alloc>:: 
1385 find_last_not_of(_CharT __c, size_type __pos) const _GLIBCXX_NOEXCEPT 
1386 { 
1387 size_type __size = this->size(); 
1388 if (__size) 
1389 { 
1390 if (--__size > __pos) 
1391 __size = __pos; 
1392 do 
1393 { 
1394 if (!traits_type::eq(_M_data()[__size], __c)) 
1395 return __size; 
1396 } 
1397 while (__size--); 
1398 } 
1399 return npos; 
1400 } 
1401 
1402 template<typename _CharT, typename _Traits, typename _Alloc> 
1403 int 
1404 basic_string<_CharT, _Traits, _Alloc>:: 
1405 compare(size_type __pos, size_type __n, const basic_string& __str) const 
1406 { 
1407 _M_check(__pos, s: "basic_string::compare"); 
1408 __n = _M_limit(__pos, off: __n); 
1409 const size_type __osize = __str.size(); 
1410 const size_type __len = std::min(__n, __osize); 
1411 int __r = traits_type::compare(_M_data() + __pos, __str.data(), __len); 
1412 if (!__r) 
1413 __r = _S_compare(n1: __n, n2: __osize); 
1414 return __r; 
1415 } 
1416 
1417 template<typename _CharT, typename _Traits, typename _Alloc> 
1418 int 
1419 basic_string<_CharT, _Traits, _Alloc>:: 
1420 compare(size_type __pos1, size_type __n1, const basic_string& __str, 
1421 size_type __pos2, size_type __n2) const 
1422 { 
1423 _M_check(pos: __pos1, s: "basic_string::compare"); 
1424 __str._M_check(__pos2, "basic_string::compare"); 
1425 __n1 = _M_limit(pos: __pos1, off: __n1); 
1426 __n2 = __str._M_limit(__pos2, __n2); 
1427 const size_type __len = std::min(__n1, __n2); 
1428 int __r = traits_type::compare(_M_data() + __pos1, 
1429 __str.data() + __pos2, __len); 
1430 if (!__r) 
1431 __r = _S_compare(__n1, __n2); 
1432 return __r; 
1433 } 
1434 
1435 template<typename _CharT, typename _Traits, typename _Alloc> 
1436 int 
1437 basic_string<_CharT, _Traits, _Alloc>:: 
1438 compare(const _CharT* __s) const _GLIBCXX_NOEXCEPT 
1439 { 
1440 __glibcxx_requires_string(__s); 
1441 const size_type __size = this->size(); 
1442 const size_type __osize = traits_type::length(__s); 
1443 const size_type __len = std::min(__size, __osize); 
1444 int __r = traits_type::compare(_M_data(), __s, __len); 
1445 if (!__r) 
1446 __r = _S_compare(n1: __size, n2: __osize); 
1447 return __r; 
1448 } 
1449 
1450 template<typename _CharT, typename _Traits, typename _Alloc> 
1451 int 
1452 basic_string <_CharT, _Traits, _Alloc>:: 
1453 compare(size_type __pos, size_type __n1, const _CharT* __s) const 
1454 { 
1455 __glibcxx_requires_string(__s); 
1456 _M_check(__pos, s: "basic_string::compare"); 
1457 __n1 = _M_limit(__pos, off: __n1); 
1458 const size_type __osize = traits_type::length(__s); 
1459 const size_type __len = std::min(__n1, __osize); 
1460 int __r = traits_type::compare(_M_data() + __pos, __s, __len); 
1461 if (!__r) 
1462 __r = _S_compare(__n1, n2: __osize); 
1463 return __r; 
1464 } 
1465 
1466 template<typename _CharT, typename _Traits, typename _Alloc> 
1467 int 
1468 basic_string <_CharT, _Traits, _Alloc>:: 
1469 compare(size_type __pos, size_type __n1, const _CharT* __s, 
1470 size_type __n2) const 
1471 { 
1472 __glibcxx_requires_string_len(__s, __n2); 
1473 _M_check(__pos, s: "basic_string::compare"); 
1474 __n1 = _M_limit(__pos, off: __n1); 
1475 const size_type __len = std::min(__n1, __n2); 
1476 int __r = traits_type::compare(_M_data() + __pos, __s, __len); 
1477 if (!__r) 
1478 __r = _S_compare(__n1, __n2); 
1479 return __r; 
1480 } 
1481 
1482 // 21.3.7.9 basic_string::getline and operators 
1483 template<typename _CharT, typename _Traits, typename _Alloc> 
1484 basic_istream<_CharT, _Traits>& 
1485 operator>>(basic_istream<_CharT, _Traits>& __in, 
1486 basic_string<_CharT, _Traits, _Alloc>& __str) 
1487 { 
1488 typedef basic_istream<_CharT, _Traits> __istream_type; 
1489 typedef basic_string<_CharT, _Traits, _Alloc> __string_type; 
1490 typedef typename __istream_type::ios_base __ios_base; 
1491 typedef typename __istream_type::int_type __int_type; 
1492 typedef typename __string_type::size_type __size_type; 
1493 typedef ctype<_CharT> __ctype_type; 
1494 typedef typename __ctype_type::ctype_base __ctype_base; 
1495 
1496 __size_type __extracted = 0; 
1497 typename __ios_base::iostate __err = __ios_base::goodbit; 
1498 typename __istream_type::sentry __cerb(__in, false); 
1499 if (__cerb) 
1500 { 
1501 __try 
1502 { 
1503 // Avoid reallocation for common case. 
1504 __str.erase(); 
1505 _CharT __buf[128]; 
1506 __size_type __len = 0;  
1507 const streamsize __w = __in.width(); 
1508 const __size_type __n = __w > 0 ? static_cast<__size_type>(__w) 
1509 : __str.max_size(); 
1510 const __ctype_type& __ct = use_facet<__ctype_type>(__in.getloc()); 
1511 const __int_type __eof = _Traits::eof(); 
1512 __int_type __c = __in.rdbuf()->sgetc(); 
1513 
1514 while (__extracted < __n 
1515 && !_Traits::eq_int_type(__c, __eof) 
1516 && !__ct.is(__ctype_base::space, 
1517 _Traits::to_char_type(__c))) 
1518 { 
1519 if (__len == sizeof(__buf) / sizeof(_CharT)) 
1520 { 
1521 __str.append(__buf, sizeof(__buf) / sizeof(_CharT)); 
1522 __len = 0; 
1523 } 
1524 __buf[__len++] = _Traits::to_char_type(__c); 
1525 ++__extracted; 
1526 __c = __in.rdbuf()->snextc(); 
1527 } 
1528 __str.append(__buf, __len); 
1529 
1530 if (__extracted < __n && _Traits::eq_int_type(__c, __eof)) 
1531 __err |= __ios_base::eofbit; 
1532 __in.width(0); 
1533 } 
1534 __catch(__cxxabiv1::__forced_unwind&) 
1535 { 
1536 __in._M_setstate(__ios_base::badbit); 
1537 __throw_exception_again; 
1538 } 
1539 __catch(...) 
1540 { 
1541 // _GLIBCXX_RESOLVE_LIB_DEFECTS 
1542 // 91. Description of operator>> and getline() for string<> 
1543 // might cause endless loop 
1544 __in._M_setstate(__ios_base::badbit); 
1545 } 
1546 } 
1547 // 211. operator>>(istream&, string&) doesn't set failbit 
1548 if (!__extracted) 
1549 __err |= __ios_base::failbit; 
1550 if (__err) 
1551 __in.setstate(__err); 
1552 return __in; 
1553 } 
1554 
1555 template<typename _CharT, typename _Traits, typename _Alloc> 
1556 basic_istream<_CharT, _Traits>& 
1557 getline(basic_istream<_CharT, _Traits>& __in, 
1558 basic_string<_CharT, _Traits, _Alloc>& __str, _CharT __delim) 
1559 { 
1560 typedef basic_istream<_CharT, _Traits> __istream_type; 
1561 typedef basic_string<_CharT, _Traits, _Alloc> __string_type; 
1562 typedef typename __istream_type::ios_base __ios_base; 
1563 typedef typename __istream_type::int_type __int_type; 
1564 typedef typename __string_type::size_type __size_type; 
1565 
1566 __size_type __extracted = 0; 
1567 const __size_type __n = __str.max_size(); 
1568 typename __ios_base::iostate __err = __ios_base::goodbit; 
1569 typename __istream_type::sentry __cerb(__in, true); 
1570 if (__cerb) 
1571 { 
1572 __try 
1573 { 
1574 __str.erase(); 
1575 const __int_type __idelim = _Traits::to_int_type(__delim); 
1576 const __int_type __eof = _Traits::eof(); 
1577 __int_type __c = __in.rdbuf()->sgetc(); 
1578 
1579 while (__extracted < __n 
1580 && !_Traits::eq_int_type(__c, __eof) 
1581 && !_Traits::eq_int_type(__c, __idelim)) 
1582 { 
1583 __str += _Traits::to_char_type(__c); 
1584 ++__extracted; 
1585 __c = __in.rdbuf()->snextc(); 
1586 } 
1587 
1588 if (_Traits::eq_int_type(__c, __eof)) 
1589 __err |= __ios_base::eofbit; 
1590 else if (_Traits::eq_int_type(__c, __idelim)) 
1591 { 
1592 ++__extracted;  
1593 __in.rdbuf()->sbumpc(); 
1594 } 
1595 else 
1596 __err |= __ios_base::failbit; 
1597 } 
1598 __catch(__cxxabiv1::__forced_unwind&) 
1599 { 
1600 __in._M_setstate(__ios_base::badbit); 
1601 __throw_exception_again; 
1602 } 
1603 __catch(...) 
1604 { 
1605 // _GLIBCXX_RESOLVE_LIB_DEFECTS 
1606 // 91. Description of operator>> and getline() for string<> 
1607 // might cause endless loop 
1608 __in._M_setstate(__ios_base::badbit); 
1609 } 
1610 } 
1611 if (!__extracted) 
1612 __err |= __ios_base::failbit; 
1613 if (__err) 
1614 __in.setstate(__err); 
1615 return __in; 
1616 } 
1617 
1618 // Inhibit implicit instantiations for required instantiations, 
1619 // which are defined via explicit instantiations elsewhere. 
1620#if _GLIBCXX_EXTERN_TEMPLATE 
1621 // The explicit instantiation definitions in src/c++11/string-inst.cc and 
1622 // src/c++17/string-inst.cc only instantiate the members required for C++17 
1623 // and earlier standards (so not C++20's starts_with and ends_with). 
1624 // Suppress the explicit instantiation declarations for C++20, so C++20 
1625 // code will implicitly instantiate std::string and std::wstring as needed. 
1626# if __cplusplus <= 201703L && _GLIBCXX_EXTERN_TEMPLATE > 0 
1627 extern template class basic_string<char>; 
1628# elif ! _GLIBCXX_USE_CXX11_ABI 
1629 // Still need to prevent implicit instantiation of the COW empty rep, 
1630 // to ensure the definition in libstdc++.so is unique (PR 86138). 
1631 extern template basic_string<char>::size_type 
1632 basic_string<char>::_Rep::_S_empty_rep_storage[]; 
1633# endif 
1634 
1635 extern template 
1636 basic_istream<char>& 
1637 operator>>(basic_istream<char>&, string&); 
1638 extern template 
1639 basic_ostream<char>& 
1640 operator<<(basic_ostream<char>&, const string&); 
1641 extern template 
1642 basic_istream<char>& 
1643 getline(basic_istream<char>&, string&, char); 
1644 extern template 
1645 basic_istream<char>& 
1646 getline(basic_istream<char>&, string&); 
1647 
1648#ifdef _GLIBCXX_USE_WCHAR_T 
1649# if __cplusplus <= 201703L && _GLIBCXX_EXTERN_TEMPLATE > 0 
1650 extern template class basic_string<wchar_t>; 
1651# elif ! _GLIBCXX_USE_CXX11_ABI 
1652 extern template basic_string<wchar_t>::size_type 
1653 basic_string<wchar_t>::_Rep::_S_empty_rep_storage[]; 
1654# endif 
1655 
1656 extern template 
1657 basic_istream<wchar_t>& 
1658 operator>>(basic_istream<wchar_t>&, wstring&); 
1659 extern template 
1660 basic_ostream<wchar_t>& 
1661 operator<<(basic_ostream<wchar_t>&, const wstring&); 
1662 extern template 
1663 basic_istream<wchar_t>& 
1664 getline(basic_istream<wchar_t>&, wstring&, wchar_t); 
1665 extern template 
1666 basic_istream<wchar_t>& 
1667 getline(basic_istream<wchar_t>&, wstring&); 
1668#endif // _GLIBCXX_USE_WCHAR_T 
1669#endif // _GLIBCXX_EXTERN_TEMPLATE 
1670 
1671_GLIBCXX_END_NAMESPACE_VERSION 
1672} // namespace std 
1673 
1674#endif 
1675