1// Components for manipulating sequences of characters -*- C++ -*- 
2 
3// Copyright (C) 1997-2019 Free Software Foundation, Inc. 
4// 
5// This file is part of the GNU ISO C++ Library. This library is free 
6// software; you can redistribute it and/or modify it under the 
7// terms of the GNU General Public License as published by the 
8// Free Software Foundation; either version 3, or (at your option) 
9// any later version. 
10 
11// This library is distributed in the hope that it will be useful, 
12// but WITHOUT ANY WARRANTY; without even the implied warranty of 
13// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 
14// GNU General Public License for more details. 
15 
16// Under Section 7 of GPL version 3, you are granted additional 
17// permissions described in the GCC Runtime Library Exception, version 
18// 3.1, as published by the Free Software Foundation. 
19 
20// You should have received a copy of the GNU General Public License and 
21// a copy of the GCC Runtime Library Exception along with this program; 
22// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 
23// <http://www.gnu.org/licenses/>. 
24 
25/** @file bits/basic_string.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(__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(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(__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(__s._M_allocated_capacity); 
121 } 
122 __s._M_capacity(__tmp_capacity); 
123 } 
124 
125 const size_type __tmp_length = length(); 
126 _M_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, __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(__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(__dnew, size_type(0))); 
220 _M_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(__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(__n, size_type(0))); 
243 _M_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(__new_capacity, __capacity); 
266 _M_dispose(); 
267 _M_data(__tmp); 
268 _M_capacity(__new_capacity); 
269 } 
270 
271 if (__rsize) 
272 this->_S_copy(_M_data(), __str._M_data(), __rsize); 
273 
274 _M_set_length(__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 // Make sure we don't shrink below the current size. 
284 if (__res < length()) 
285 __res = length(); 
286 
287 const size_type __capacity = capacity(); 
288 if (__res != __capacity) 
289 { 
290 if (__res > __capacity 
291 || __res > size_type(_S_local_capacity)) 
292 { 
293 pointer __tmp = _M_create(__res, __capacity); 
294 this->_S_copy(__tmp, _M_data(), length() + 1); 
295 _M_dispose(); 
296 _M_data(__tmp); 
297 _M_capacity(__res); 
298 } 
299 else if (!_M_is_local()) 
300 { 
301 this->_S_copy(_M_local_data(), _M_data(), length() + 1); 
302 _M_destroy(__capacity); 
303 _M_data(_M_local_data()); 
304 } 
305 } 
306 } 
307 
308 template<typename _CharT, typename _Traits, typename _Alloc> 
309 void 
310 basic_string<_CharT, _Traits, _Alloc>:: 
311 _M_mutate(size_type __pos, size_type __len1, const _CharT* __s, 
312 size_type __len2) 
313 { 
314 const size_type __how_much = length() - __pos - __len1; 
315 
316 size_type __new_capacity = length() + __len2 - __len1; 
317 pointer __r = _M_create(__new_capacity, capacity()); 
318 
319 if (__pos) 
320 this->_S_copy(__r, _M_data(), __pos); 
321 if (__s && __len2) 
322 this->_S_copy(__r + __pos, __s, __len2); 
323 if (__how_much) 
324 this->_S_copy(__r + __pos + __len2, 
325 _M_data() + __pos + __len1, __how_much); 
326 
327 _M_dispose(); 
328 _M_data(__r); 
329 _M_capacity(__new_capacity); 
330 } 
331 
332 template<typename _CharT, typename _Traits, typename _Alloc> 
333 void 
334 basic_string<_CharT, _Traits, _Alloc>:: 
335 _M_erase(size_type __pos, size_type __n) 
336 { 
337 const size_type __how_much = length() - __pos - __n; 
338 
339 if (__how_much && __n) 
340 this->_S_move(_M_data() + __pos, _M_data() + __pos + __n, __how_much); 
341 
342 _M_set_length(length() - __n); 
343 } 
344 
345 template<typename _CharT, typename _Traits, typename _Alloc> 
346 void 
347 basic_string<_CharT, _Traits, _Alloc>:: 
348 resize(size_type __n, _CharT __c) 
349 { 
350 const size_type __size = this->size(); 
351 if (__size < __n) 
352 this->append(__n - __size, __c); 
353 else if (__n < __size) 
354 this->_M_set_length(__n); 
355 } 
356 
357 template<typename _CharT, typename _Traits, typename _Alloc> 
358 basic_string<_CharT, _Traits, _Alloc>& 
359 basic_string<_CharT, _Traits, _Alloc>:: 
360 _M_append(const _CharT* __s, size_type __n) 
361 { 
362 const size_type __len = __n + this->size(); 
363 
364 if (__len <= this->capacity()) 
365 { 
366 if (__n) 
367 this->_S_copy(this->_M_data() + this->size(), __s, __n); 
368 } 
369 else 
370 this->_M_mutate(this->size(), size_type(0), __s, __n); 
371 
372 this->_M_set_length(__len); 
373 return *this; 
374 } 
375 
376 template<typename _CharT, typename _Traits, typename _Alloc> 
377 template<typename _InputIterator> 
378 basic_string<_CharT, _Traits, _Alloc>& 
379 basic_string<_CharT, _Traits, _Alloc>:: 
380 _M_replace_dispatch(const_iterator __i1, const_iterator __i2, 
381 _InputIterator __k1, _InputIterator __k2, 
382 std::__false_type) 
383 { 
384 const basic_string __s(__k1, __k2); 
385 const size_type __n1 = __i2 - __i1; 
386 return _M_replace(__i1 - begin(), __n1, __s._M_data(), 
387 __s.size()); 
388 } 
389 
390 template<typename _CharT, typename _Traits, typename _Alloc> 
391 basic_string<_CharT, _Traits, _Alloc>& 
392 basic_string<_CharT, _Traits, _Alloc>:: 
393 _M_replace_aux(size_type __pos1, size_type __n1, size_type __n2, 
394 _CharT __c) 
395 { 
396 _M_check_length(__n1, __n2, "basic_string::_M_replace_aux"); 
397 
398 const size_type __old_size = this->size(); 
399 const size_type __new_size = __old_size + __n2 - __n1; 
400 
401 if (__new_size <= this->capacity()) 
402 { 
403 pointer __p = this->_M_data() + __pos1; 
404 
405 const size_type __how_much = __old_size - __pos1 - __n1; 
406 if (__how_much && __n1 != __n2) 
407 this->_S_move(__p + __n2, __p + __n1, __how_much); 
408 } 
409 else 
410 this->_M_mutate(__pos1, __n1, 0, __n2); 
411 
412 if (__n2) 
413 this->_S_assign(this->_M_data() + __pos1, __n2, __c); 
414 
415 this->_M_set_length(__new_size); 
416 return *this; 
417 } 
418 
419 template<typename _CharT, typename _Traits, typename _Alloc> 
420 basic_string<_CharT, _Traits, _Alloc>& 
421 basic_string<_CharT, _Traits, _Alloc>:: 
422 _M_replace(size_type __pos, size_type __len1, const _CharT* __s, 
423 const size_type __len2) 
424 { 
425 _M_check_length(__len1, __len2, "basic_string::_M_replace"); 
426 
427 const size_type __old_size = this->size(); 
428 const size_type __new_size = __old_size + __len2 - __len1; 
429 
430 if (__new_size <= this->capacity()) 
431 { 
432 pointer __p = this->_M_data() + __pos; 
433 
434 const size_type __how_much = __old_size - __pos - __len1; 
435 if (_M_disjunct(__s)) 
436 { 
437 if (__how_much && __len1 != __len2) 
438 this->_S_move(__p + __len2, __p + __len1, __how_much); 
439 if (__len2) 
440 this->_S_copy(__p, __s, __len2); 
441 } 
442 else 
443 { 
444 // Work in-place. 
445 if (__len2 && __len2 <= __len1) 
446 this->_S_move(__p, __s, __len2); 
447 if (__how_much && __len1 != __len2) 
448 this->_S_move(__p + __len2, __p + __len1, __how_much); 
449 if (__len2 > __len1) 
450 { 
451 if (__s + __len2 <= __p + __len1) 
452 this->_S_move(__p, __s, __len2); 
453 else if (__s >= __p + __len1) 
454 this->_S_copy(__p, __s + __len2 - __len1, __len2); 
455 else 
456 { 
457 const size_type __nleft = (__p + __len1) - __s; 
458 this->_S_move(__p, __s, __nleft); 
459 this->_S_copy(__p + __nleft, __p + __len2, 
460 __len2 - __nleft); 
461 } 
462 } 
463 } 
464 } 
465 else 
466 this->_M_mutate(__pos, __len1, __s, __len2); 
467 
468 this->_M_set_length(__new_size); 
469 return *this; 
470 } 
471 
472 template<typename _CharT, typename _Traits, typename _Alloc> 
473 typename basic_string<_CharT, _Traits, _Alloc>::size_type 
474 basic_string<_CharT, _Traits, _Alloc>:: 
475 copy(_CharT* __s, size_type __n, size_type __pos) const 
476 { 
477 _M_check(__pos, "basic_string::copy"); 
478 __n = _M_limit(__pos, __n); 
479 __glibcxx_requires_string_len(__s, __n); 
480 if (__n) 
481 _S_copy(__s, _M_data() + __pos, __n); 
482 // 21.3.5.7 par 3: do not append null. (good.) 
483 return __n; 
484 } 
485 
486#else // !_GLIBCXX_USE_CXX11_ABI 
487 
488 template<typename _CharT, typename _Traits, typename _Alloc> 
489 const typename basic_string<_CharT, _Traits, _Alloc>::size_type 
490 basic_string<_CharT, _Traits, _Alloc>:: 
491 _Rep::_S_max_size = (((npos - sizeof(_Rep_base))/sizeof(_CharT)) - 1) / 4; 
492 
493 template<typename _CharT, typename _Traits, typename _Alloc> 
494 const _CharT 
495 basic_string<_CharT, _Traits, _Alloc>:: 
496 _Rep::_S_terminal = _CharT(); 
497 
498 template<typename _CharT, typename _Traits, typename _Alloc> 
499 const typename basic_string<_CharT, _Traits, _Alloc>::size_type 
500 basic_string<_CharT, _Traits, _Alloc>::npos; 
501 
502 // Linker sets _S_empty_rep_storage to all 0s (one reference, empty string) 
503 // at static init time (before static ctors are run). 
504 template<typename _CharT, typename _Traits, typename _Alloc> 
505 typename basic_string<_CharT, _Traits, _Alloc>::size_type 
506 basic_string<_CharT, _Traits, _Alloc>::_Rep::_S_empty_rep_storage[ 
507 (sizeof(_Rep_base) + sizeof(_CharT) + sizeof(size_type) - 1) / 
508 sizeof(size_type)]; 
509 
510 // NB: This is the special case for Input Iterators, used in 
511 // istreambuf_iterators, etc. 
512 // Input Iterators have a cost structure very different from 
513 // pointers, calling for a different coding style. 
514 template<typename _CharT, typename _Traits, typename _Alloc> 
515 template<typename _InIterator> 
516 _CharT* 
517 basic_string<_CharT, _Traits, _Alloc>:: 
518 _S_construct(_InIterator __beg, _InIterator __end, const _Alloc& __a, 
519 input_iterator_tag) 
520 { 
521#if _GLIBCXX_FULLY_DYNAMIC_STRING == 0 
522 if (__beg == __end && __a == _Alloc()) 
523 return _S_empty_rep()._M_refdata(); 
524#endif 
525 // Avoid reallocation for common case. 
526 _CharT __buf[128]; 
527 size_type __len = 0; 
528 while (__beg != __end && __len < sizeof(__buf) / sizeof(_CharT)) 
529 { 
530 __buf[__len++] = *__beg; 
531 ++__beg; 
532 } 
533 _Rep* __r = _Rep::_S_create(__len, size_type(0), __a); 
534 _M_copy(__r->_M_refdata(), __buf, __len); 
535 __try 
536 { 
537 while (__beg != __end) 
538 { 
539 if (__len == __r->_M_capacity) 
540 { 
541 // Allocate more space. 
542 _Rep* __another = _Rep::_S_create(__len + 1, __len, __a); 
543 _M_copy(__another->_M_refdata(), __r->_M_refdata(), __len); 
544 __r->_M_destroy(__a); 
545 __r = __another; 
546 } 
547 __r->_M_refdata()[__len++] = *__beg; 
548 ++__beg; 
549 } 
550 } 
551 __catch(...) 
552 { 
553 __r->_M_destroy(__a); 
554 __throw_exception_again; 
555 } 
556 __r->_M_set_length_and_sharable(__len); 
557 return __r->_M_refdata(); 
558 } 
559 
560 template<typename _CharT, typename _Traits, typename _Alloc> 
561 template <typename _InIterator> 
562 _CharT* 
563 basic_string<_CharT, _Traits, _Alloc>:: 
564 _S_construct(_InIterator __beg, _InIterator __end, const _Alloc& __a, 
565 forward_iterator_tag) 
566 { 
567#if _GLIBCXX_FULLY_DYNAMIC_STRING == 0 
568 if (__beg == __end && __a == _Alloc()) 
569 return _S_empty_rep()._M_refdata(); 
570#endif 
571 // NB: Not required, but considered best practice. 
572 if (__gnu_cxx::__is_null_pointer(__beg) && __beg != __end) 
573 __throw_logic_error(__N("basic_string::_S_construct null not valid")); 
574 
575 const size_type __dnew = static_cast<size_type>(std::distance(__beg, 
576 __end)); 
577 // Check for out_of_range and length_error exceptions. 
578 _Rep* __r = _Rep::_S_create(__dnew, size_type(0), __a); 
579 __try 
580 { _S_copy_chars(__r->_M_refdata(), __beg, __end); } 
581 __catch(...) 
582 { 
583 __r->_M_destroy(__a); 
584 __throw_exception_again; 
585 } 
586 __r->_M_set_length_and_sharable(__dnew); 
587 return __r->_M_refdata(); 
588 } 
589 
590 template<typename _CharT, typename _Traits, typename _Alloc> 
591 _CharT* 
592 basic_string<_CharT, _Traits, _Alloc>:: 
593 _S_construct(size_type __n, _CharT __c, const _Alloc& __a) 
594 { 
595#if _GLIBCXX_FULLY_DYNAMIC_STRING == 0 
596 if (__n == 0 && __a == _Alloc()) 
597 return _S_empty_rep()._M_refdata(); 
598#endif 
599 // Check for out_of_range and length_error exceptions. 
600 _Rep* __r = _Rep::_S_create(__n, size_type(0), __a); 
601 if (__n) 
602 _M_assign(__r->_M_refdata(), __n, __c); 
603 
604 __r->_M_set_length_and_sharable(__n); 
605 return __r->_M_refdata(); 
606 } 
607 
608 template<typename _CharT, typename _Traits, typename _Alloc> 
609 basic_string<_CharT, _Traits, _Alloc>:: 
610 basic_string(const basic_string& __str) 
611 : _M_dataplus(__str._M_rep()->_M_grab(_Alloc(__str.get_allocator()), 
612 __str.get_allocator()), 
613 __str.get_allocator()) 
614 { } 
615 
616 template<typename _CharT, typename _Traits, typename _Alloc> 
617 basic_string<_CharT, _Traits, _Alloc>:: 
618 basic_string(const _Alloc& __a) 
619 : _M_dataplus(_S_construct(size_type(), _CharT(), __a), __a) 
620 { } 
621 
622 template<typename _CharT, typename _Traits, typename _Alloc> 
623 basic_string<_CharT, _Traits, _Alloc>:: 
624 basic_string(const basic_string& __str, size_type __pos, const _Alloc& __a) 
625 : _M_dataplus(_S_construct(__str._M_data() 
626 + __str._M_check(__pos, 
627 "basic_string::basic_string"), 
628 __str._M_data() + __str._M_limit(__pos, npos) 
629 + __pos, __a), __a) 
630 { } 
631 
632 template<typename _CharT, typename _Traits, typename _Alloc> 
633 basic_string<_CharT, _Traits, _Alloc>:: 
634 basic_string(const basic_string& __str, size_type __pos, size_type __n) 
635 : _M_dataplus(_S_construct(__str._M_data() 
636 + __str._M_check(__pos, 
637 "basic_string::basic_string"), 
638 __str._M_data() + __str._M_limit(__pos, __n) 
639 + __pos, _Alloc()), _Alloc()) 
640 { } 
641 
642 template<typename _CharT, typename _Traits, typename _Alloc> 
643 basic_string<_CharT, _Traits, _Alloc>:: 
644 basic_string(const basic_string& __str, size_type __pos, 
645 size_type __n, const _Alloc& __a) 
646 : _M_dataplus(_S_construct(__str._M_data() 
647 + __str._M_check(__pos, 
648 "basic_string::basic_string"), 
649 __str._M_data() + __str._M_limit(__pos, __n) 
650 + __pos, __a), __a) 
651 { } 
652 
653 // TBD: DPG annotate 
654 template<typename _CharT, typename _Traits, typename _Alloc> 
655 basic_string<_CharT, _Traits, _Alloc>:: 
656 basic_string(const _CharT* __s, size_type __n, const _Alloc& __a) 
657 : _M_dataplus(_S_construct(__s, __s + __n, __a), __a) 
658 { } 
659 
660 // TBD: DPG annotate 
661 template<typename _CharT, typename _Traits, typename _Alloc> 
662 basic_string<_CharT, _Traits, _Alloc>:: 
663 basic_string(const _CharT* __s, const _Alloc& __a) 
664 : _M_dataplus(_S_construct(__s, __s ? __s + traits_type::length(__s) : 
665 __s + npos, __a), __a) 
666 { } 
667 
668 template<typename _CharT, typename _Traits, typename _Alloc> 
669 basic_string<_CharT, _Traits, _Alloc>:: 
670 basic_string(size_type __n, _CharT __c, const _Alloc& __a) 
671 : _M_dataplus(_S_construct(__n, __c, __a), __a) 
672 { } 
673 
674 // TBD: DPG annotate 
675 template<typename _CharT, typename _Traits, typename _Alloc> 
676 template<typename _InputIterator> 
677 basic_string<_CharT, _Traits, _Alloc>:: 
678 basic_string(_InputIterator __beg, _InputIterator __end, const _Alloc& __a) 
679 : _M_dataplus(_S_construct(__beg, __end, __a), __a) 
680 { } 
681 
682#if __cplusplus >= 201103L 
683 template<typename _CharT, typename _Traits, typename _Alloc> 
684 basic_string<_CharT, _Traits, _Alloc>:: 
685 basic_string(initializer_list<_CharT> __l, const _Alloc& __a) 
686 : _M_dataplus(_S_construct(__l.begin(), __l.end(), __a), __a) 
687 { } 
688#endif 
689 
690 template<typename _CharT, typename _Traits, typename _Alloc> 
691 basic_string<_CharT, _Traits, _Alloc>& 
692 basic_string<_CharT, _Traits, _Alloc>:: 
693 assign(const basic_string& __str) 
694 { 
695 if (_M_rep() != __str._M_rep()) 
696 { 
697 // XXX MT 
698 const allocator_type __a = this->get_allocator(); 
699 _CharT* __tmp = __str._M_rep()->_M_grab(__a, __str.get_allocator()); 
700 _M_rep()->_M_dispose(__a); 
701 _M_data(__tmp); 
702 } 
703 return *this; 
704 } 
705 
706 template<typename _CharT, typename _Traits, typename _Alloc> 
707 basic_string<_CharT, _Traits, _Alloc>& 
708 basic_string<_CharT, _Traits, _Alloc>:: 
709 assign(const _CharT* __s, size_type __n) 
710 { 
711 __glibcxx_requires_string_len(__s, __n); 
712 _M_check_length(this->size(), __n, "basic_string::assign"); 
713 if (_M_disjunct(__s) || _M_rep()->_M_is_shared()) 
714 return _M_replace_safe(size_type(0), this->size(), __s, __n); 
715 else 
716 { 
717 // Work in-place. 
718 const size_type __pos = __s - _M_data(); 
719 if (__pos >= __n) 
720 _M_copy(_M_data(), __s, __n); 
721 else if (__pos) 
722 _M_move(_M_data(), __s, __n); 
723 _M_rep()->_M_set_length_and_sharable(__n); 
724 return *this; 
725 } 
726 } 
727 
728 template<typename _CharT, typename _Traits, typename _Alloc> 
729 basic_string<_CharT, _Traits, _Alloc>& 
730 basic_string<_CharT, _Traits, _Alloc>:: 
731 append(size_type __n, _CharT __c) 
732 { 
733 if (__n) 
734 { 
735 _M_check_length(size_type(0), __n, "basic_string::append");  
736 const size_type __len = __n + this->size(); 
737 if (__len > this->capacity() || _M_rep()->_M_is_shared()) 
738 this->reserve(__len); 
739 _M_assign(_M_data() + this->size(), __n, __c); 
740 _M_rep()->_M_set_length_and_sharable(__len); 
741 } 
742 return *this; 
743 } 
744 
745 template<typename _CharT, typename _Traits, typename _Alloc> 
746 basic_string<_CharT, _Traits, _Alloc>& 
747 basic_string<_CharT, _Traits, _Alloc>:: 
748 append(const _CharT* __s, size_type __n) 
749 { 
750 __glibcxx_requires_string_len(__s, __n); 
751 if (__n) 
752 { 
753 _M_check_length(size_type(0), __n, "basic_string::append"); 
754 const size_type __len = __n + this->size(); 
755 if (__len > this->capacity() || _M_rep()->_M_is_shared()) 
756 { 
757 if (_M_disjunct(__s)) 
758 this->reserve(__len); 
759 else 
760 { 
761 const size_type __off = __s - _M_data(); 
762 this->reserve(__len); 
763 __s = _M_data() + __off; 
764 } 
765 } 
766 _M_copy(_M_data() + this->size(), __s, __n); 
767 _M_rep()->_M_set_length_and_sharable(__len); 
768 } 
769 return *this; 
770 } 
771 
772 template<typename _CharT, typename _Traits, typename _Alloc> 
773 basic_string<_CharT, _Traits, _Alloc>& 
774 basic_string<_CharT, _Traits, _Alloc>:: 
775 append(const basic_string& __str) 
776 { 
777 const size_type __size = __str.size(); 
778 if (__size) 
779 { 
780 const size_type __len = __size + this->size(); 
781 if (__len > this->capacity() || _M_rep()->_M_is_shared()) 
782 this->reserve(__len); 
783 _M_copy(_M_data() + this->size(), __str._M_data(), __size); 
784 _M_rep()->_M_set_length_and_sharable(__len); 
785 } 
786 return *this; 
787 }  
788 
789 template<typename _CharT, typename _Traits, typename _Alloc> 
790 basic_string<_CharT, _Traits, _Alloc>& 
791 basic_string<_CharT, _Traits, _Alloc>:: 
792 append(const basic_string& __str, size_type __pos, size_type __n) 
793 { 
794 __str._M_check(__pos, "basic_string::append"); 
795 __n = __str._M_limit(__pos, __n); 
796 if (__n) 
797 { 
798 const size_type __len = __n + this->size(); 
799 if (__len > this->capacity() || _M_rep()->_M_is_shared()) 
800 this->reserve(__len); 
801 _M_copy(_M_data() + this->size(), __str._M_data() + __pos, __n); 
802 _M_rep()->_M_set_length_and_sharable(__len);  
803 } 
804 return *this; 
805 } 
806 
807 template<typename _CharT, typename _Traits, typename _Alloc> 
808 basic_string<_CharT, _Traits, _Alloc>& 
809 basic_string<_CharT, _Traits, _Alloc>:: 
810 insert(size_type __pos, const _CharT* __s, size_type __n) 
811 { 
812 __glibcxx_requires_string_len(__s, __n); 
813 _M_check(__pos, "basic_string::insert"); 
814 _M_check_length(size_type(0), __n, "basic_string::insert"); 
815 if (_M_disjunct(__s) || _M_rep()->_M_is_shared()) 
816 return _M_replace_safe(__pos, size_type(0), __s, __n); 
817 else 
818 { 
819 // Work in-place. 
820 const size_type __off = __s - _M_data(); 
821 _M_mutate(__pos, 0, __n); 
822 __s = _M_data() + __off; 
823 _CharT* __p = _M_data() + __pos; 
824 if (__s + __n <= __p) 
825 _M_copy(__p, __s, __n); 
826 else if (__s >= __p) 
827 _M_copy(__p, __s + __n, __n); 
828 else 
829 { 
830 const size_type __nleft = __p - __s; 
831 _M_copy(__p, __s, __nleft); 
832 _M_copy(__p + __nleft, __p + __n, __n - __nleft); 
833 } 
834 return *this; 
835 } 
836 } 
837 
838 template<typename _CharT, typename _Traits, typename _Alloc> 
839 typename basic_string<_CharT, _Traits, _Alloc>::iterator 
840 basic_string<_CharT, _Traits, _Alloc>:: 
841 erase(iterator __first, iterator __last) 
842 { 
843 _GLIBCXX_DEBUG_PEDASSERT(__first >= _M_ibegin() && __first <= __last 
844 && __last <= _M_iend()); 
845 
846 // NB: This isn't just an optimization (bail out early when 
847 // there is nothing to do, really), it's also a correctness 
848 // issue vs MT, see libstdc++/40518. 
849 const size_type __size = __last - __first; 
850 if (__size) 
851 { 
852 const size_type __pos = __first - _M_ibegin(); 
853 _M_mutate(__pos, __size, size_type(0)); 
854 _M_rep()->_M_set_leaked(); 
855 return iterator(_M_data() + __pos); 
856 } 
857 else 
858 return __first; 
859 } 
860 
861 template<typename _CharT, typename _Traits, typename _Alloc> 
862 basic_string<_CharT, _Traits, _Alloc>& 
863 basic_string<_CharT, _Traits, _Alloc>:: 
864 replace(size_type __pos, size_type __n1, const _CharT* __s, 
865 size_type __n2) 
866 { 
867 __glibcxx_requires_string_len(__s, __n2); 
868 _M_check(__pos, "basic_string::replace"); 
869 __n1 = _M_limit(__pos, __n1); 
870 _M_check_length(__n1, __n2, "basic_string::replace"); 
871 bool __left; 
872 if (_M_disjunct(__s) || _M_rep()->_M_is_shared()) 
873 return _M_replace_safe(__pos, __n1, __s, __n2); 
874 else if ((__left = __s + __n2 <= _M_data() + __pos) 
875 || _M_data() + __pos + __n1 <= __s) 
876 { 
877 // Work in-place: non-overlapping case. 
878 size_type __off = __s - _M_data(); 
879 __left ? __off : (__off += __n2 - __n1); 
880 _M_mutate(__pos, __n1, __n2); 
881 _M_copy(_M_data() + __pos, _M_data() + __off, __n2); 
882 return *this; 
883 } 
884 else 
885 { 
886 // Todo: overlapping case. 
887 const basic_string __tmp(__s, __n2); 
888 return _M_replace_safe(__pos, __n1, __tmp._M_data(), __n2); 
889 } 
890 } 
891 
892 template<typename _CharT, typename _Traits, typename _Alloc> 
893 void 
894 basic_string<_CharT, _Traits, _Alloc>::_Rep:: 
895 _M_destroy(const _Alloc& __a) throw () 
896 { 
897 const size_type __size = sizeof(_Rep_base) + 
898 (this->_M_capacity + 1) * sizeof(_CharT); 
899 _Raw_bytes_alloc(__a).deallocate(reinterpret_cast<char*>(this), __size); 
900 } 
901 
902 template<typename _CharT, typename _Traits, typename _Alloc> 
903 void 
904 basic_string<_CharT, _Traits, _Alloc>:: 
905 _M_leak_hard() 
906 { 
907#if _GLIBCXX_FULLY_DYNAMIC_STRING == 0 
908 if (_M_rep() == &_S_empty_rep()) 
909 return; 
910#endif 
911 if (_M_rep()->_M_is_shared()) 
912 _M_mutate(0, 0, 0); 
913 _M_rep()->_M_set_leaked(); 
914 } 
915 
916 template<typename _CharT, typename _Traits, typename _Alloc> 
917 void 
918 basic_string<_CharT, _Traits, _Alloc>:: 
919 _M_mutate(size_type __pos, size_type __len1, size_type __len2) 
920 { 
921 const size_type __old_size = this->size(); 
922 const size_type __new_size = __old_size + __len2 - __len1; 
923 const size_type __how_much = __old_size - __pos - __len1; 
924 
925 if (__new_size > this->capacity() || _M_rep()->_M_is_shared()) 
926 { 
927 // Must reallocate. 
928 const allocator_type __a = get_allocator(); 
929 _Rep* __r = _Rep::_S_create(__new_size, this->capacity(), __a); 
930 
931 if (__pos) 
932 _M_copy(__r->_M_refdata(), _M_data(), __pos); 
933 if (__how_much) 
934 _M_copy(__r->_M_refdata() + __pos + __len2, 
935 _M_data() + __pos + __len1, __how_much); 
936 
937 _M_rep()->_M_dispose(__a); 
938 _M_data(__r->_M_refdata()); 
939 } 
940 else if (__how_much && __len1 != __len2) 
941 { 
942 // Work in-place. 
943 _M_move(_M_data() + __pos + __len2, 
944 _M_data() + __pos + __len1, __how_much); 
945 } 
946 _M_rep()->_M_set_length_and_sharable(__new_size); 
947 } 
948 
949 template<typename _CharT, typename _Traits, typename _Alloc> 
950 void 
951 basic_string<_CharT, _Traits, _Alloc>:: 
952 reserve(size_type __res) 
953 { 
954 if (__res != this->capacity() || _M_rep()->_M_is_shared()) 
955 { 
956 // Make sure we don't shrink below the current size 
957 if (__res < this->size()) 
958 __res = this->size(); 
959 const allocator_type __a = get_allocator(); 
960 _CharT* __tmp = _M_rep()->_M_clone(__a, __res - this->size()); 
961 _M_rep()->_M_dispose(__a); 
962 _M_data(__tmp); 
963 } 
964 } 
965 
966 template<typename _CharT, typename _Traits, typename _Alloc> 
967 void 
968 basic_string<_CharT, _Traits, _Alloc>:: 
969 swap(basic_string& __s) 
970 _GLIBCXX_NOEXCEPT_IF(allocator_traits<_Alloc>::is_always_equal::value) 
971 { 
972 if (_M_rep()->_M_is_leaked()) 
973 _M_rep()->_M_set_sharable(); 
974 if (__s._M_rep()->_M_is_leaked()) 
975 __s._M_rep()->_M_set_sharable(); 
976 if (this->get_allocator() == __s.get_allocator()) 
977 { 
978 _CharT* __tmp = _M_data(); 
979 _M_data(__s._M_data()); 
980 __s._M_data(__tmp); 
981 } 
982 // The code below can usually be optimized away. 
983 else 
984 { 
985 const basic_string __tmp1(_M_ibegin(), _M_iend(), 
986 __s.get_allocator()); 
987 const basic_string __tmp2(__s._M_ibegin(), __s._M_iend(), 
988 this->get_allocator()); 
989 *this = __tmp2; 
990 __s = __tmp1; 
991 } 
992 } 
993 
994 template<typename _CharT, typename _Traits, typename _Alloc> 
995 typename basic_string<_CharT, _Traits, _Alloc>::_Rep* 
996 basic_string<_CharT, _Traits, _Alloc>::_Rep:: 
997 _S_create(size_type __capacity, size_type __old_capacity, 
998 const _Alloc& __alloc) 
999 { 
1000 // _GLIBCXX_RESOLVE_LIB_DEFECTS 
1001 // 83. String::npos vs. string::max_size() 
1002 if (__capacity > _S_max_size) 
1003 __throw_length_error(__N("basic_string::_S_create")); 
1004 
1005 // The standard places no restriction on allocating more memory 
1006 // than is strictly needed within this layer at the moment or as 
1007 // requested by an explicit application call to reserve(). 
1008 
1009 // Many malloc implementations perform quite poorly when an 
1010 // application attempts to allocate memory in a stepwise fashion 
1011 // growing each allocation size by only 1 char. Additionally, 
1012 // it makes little sense to allocate less linear memory than the 
1013 // natural blocking size of the malloc implementation. 
1014 // Unfortunately, we would need a somewhat low-level calculation 
1015 // with tuned parameters to get this perfect for any particular 
1016 // malloc implementation. Fortunately, generalizations about 
1017 // common features seen among implementations seems to suffice. 
1018 
1019 // __pagesize need not match the actual VM page size for good 
1020 // results in practice, thus we pick a common value on the low 
1021 // side. __malloc_header_size is an estimate of the amount of 
1022 // overhead per memory allocation (in practice seen N * sizeof 
1023 // (void*) where N is 0, 2 or 4). According to folklore, 
1024 // picking this value on the high side is better than 
1025 // low-balling it (especially when this algorithm is used with 
1026 // malloc implementations that allocate memory blocks rounded up 
1027 // to a size which is a power of 2). 
1028 const size_type __pagesize = 4096; 
1029 const size_type __malloc_header_size = 4 * sizeof(void*); 
1030 
1031 // The below implements an exponential growth policy, necessary to 
1032 // meet amortized linear time requirements of the library: see 
1033 // http://gcc.gnu.org/ml/libstdc++/2001-07/msg00085.html. 
1034 // It's active for allocations requiring an amount of memory above 
1035 // system pagesize. This is consistent with the requirements of the 
1036 // standard: http://gcc.gnu.org/ml/libstdc++/2001-07/msg00130.html 
1037 if (__capacity > __old_capacity && __capacity < 2 * __old_capacity) 
1038 __capacity = 2 * __old_capacity; 
1039 
1040 // NB: Need an array of char_type[__capacity], plus a terminating 
1041 // null char_type() element, plus enough for the _Rep data structure. 
1042 // Whew. Seemingly so needy, yet so elemental. 
1043 size_type __size = (__capacity + 1) * sizeof(_CharT) + sizeof(_Rep); 
1044 
1045 const size_type __adj_size = __size + __malloc_header_size; 
1046 if (__adj_size > __pagesize && __capacity > __old_capacity) 
1047 { 
1048 const size_type __extra = __pagesize - __adj_size % __pagesize; 
1049 __capacity += __extra / sizeof(_CharT); 
1050 // Never allocate a string bigger than _S_max_size. 
1051 if (__capacity > _S_max_size) 
1052 __capacity = _S_max_size; 
1053 __size = (__capacity + 1) * sizeof(_CharT) + sizeof(_Rep); 
1054 } 
1055 
1056 // NB: Might throw, but no worries about a leak, mate: _Rep() 
1057 // does not throw. 
1058 void* __place = _Raw_bytes_alloc(__alloc).allocate(__size); 
1059 _Rep *__p = new (__place) _Rep; 
1060 __p->_M_capacity = __capacity; 
1061 // ABI compatibility - 3.4.x set in _S_create both 
1062 // _M_refcount and _M_length. All callers of _S_create 
1063 // in basic_string.tcc then set just _M_length. 
1064 // In 4.0.x and later both _M_refcount and _M_length 
1065 // are initialized in the callers, unfortunately we can 
1066 // have 3.4.x compiled code with _S_create callers inlined 
1067 // calling 4.0.x+ _S_create. 
1068 __p->_M_set_sharable(); 
1069 return __p; 
1070 } 
1071 
1072 template<typename _CharT, typename _Traits, typename _Alloc> 
1073 _CharT* 
1074 basic_string<_CharT, _Traits, _Alloc>::_Rep:: 
1075 _M_clone(const _Alloc& __alloc, size_type __res) 
1076 { 
1077 // Requested capacity of the clone. 
1078 const size_type __requested_cap = this->_M_length + __res; 
1079 _Rep* __r = _Rep::_S_create(__requested_cap, this->_M_capacity, 
1080 __alloc); 
1081 if (this->_M_length) 
1082 _M_copy(__r->_M_refdata(), _M_refdata(), this->_M_length); 
1083 
1084 __r->_M_set_length_and_sharable(this->_M_length); 
1085 return __r->_M_refdata(); 
1086 } 
1087 
1088 template<typename _CharT, typename _Traits, typename _Alloc> 
1089 void 
1090 basic_string<_CharT, _Traits, _Alloc>:: 
1091 resize(size_type __n, _CharT __c) 
1092 { 
1093 const size_type __size = this->size(); 
1094 _M_check_length(__size, __n, "basic_string::resize"); 
1095 if (__size < __n) 
1096 this->append(__n - __size, __c); 
1097 else if (__n < __size) 
1098 this->erase(__n); 
1099 // else nothing (in particular, avoid calling _M_mutate() unnecessarily.) 
1100 } 
1101 
1102 template<typename _CharT, typename _Traits, typename _Alloc> 
1103 template<typename _InputIterator> 
1104 basic_string<_CharT, _Traits, _Alloc>& 
1105 basic_string<_CharT, _Traits, _Alloc>:: 
1106 _M_replace_dispatch(iterator __i1, iterator __i2, _InputIterator __k1, 
1107 _InputIterator __k2, __false_type) 
1108 { 
1109 const basic_string __s(__k1, __k2); 
1110 const size_type __n1 = __i2 - __i1; 
1111 _M_check_length(__n1, __s.size(), "basic_string::_M_replace_dispatch"); 
1112 return _M_replace_safe(__i1 - _M_ibegin(), __n1, __s._M_data(), 
1113 __s.size()); 
1114 } 
1115 
1116 template<typename _CharT, typename _Traits, typename _Alloc> 
1117 basic_string<_CharT, _Traits, _Alloc>& 
1118 basic_string<_CharT, _Traits, _Alloc>:: 
1119 _M_replace_aux(size_type __pos1, size_type __n1, size_type __n2, 
1120 _CharT __c) 
1121 { 
1122 _M_check_length(__n1, __n2, "basic_string::_M_replace_aux"); 
1123 _M_mutate(__pos1, __n1, __n2); 
1124 if (__n2) 
1125 _M_assign(_M_data() + __pos1, __n2, __c); 
1126 return *this; 
1127 } 
1128 
1129 template<typename _CharT, typename _Traits, typename _Alloc> 
1130 basic_string<_CharT, _Traits, _Alloc>& 
1131 basic_string<_CharT, _Traits, _Alloc>:: 
1132 _M_replace_safe(size_type __pos1, size_type __n1, const _CharT* __s, 
1133 size_type __n2) 
1134 { 
1135 _M_mutate(__pos1, __n1, __n2); 
1136 if (__n2) 
1137 _M_copy(_M_data() + __pos1, __s, __n2); 
1138 return *this; 
1139 } 
1140 
1141 template<typename _CharT, typename _Traits, typename _Alloc> 
1142 typename basic_string<_CharT, _Traits, _Alloc>::size_type 
1143 basic_string<_CharT, _Traits, _Alloc>:: 
1144 copy(_CharT* __s, size_type __n, size_type __pos) const 
1145 { 
1146 _M_check(__pos, "basic_string::copy"); 
1147 __n = _M_limit(__pos, __n); 
1148 __glibcxx_requires_string_len(__s, __n); 
1149 if (__n) 
1150 _M_copy(__s, _M_data() + __pos, __n); 
1151 // 21.3.5.7 par 3: do not append null. (good.) 
1152 return __n; 
1153 } 
1154#endif // !_GLIBCXX_USE_CXX11_ABI 
1155  
1156 template<typename _CharT, typename _Traits, typename _Alloc> 
1157 basic_string<_CharT, _Traits, _Alloc> 
1158 operator+(const _CharT* __lhs, 
1159 const basic_string<_CharT, _Traits, _Alloc>& __rhs) 
1160 { 
1161 __glibcxx_requires_string(__lhs); 
1162 typedef basic_string<_CharT, _Traits, _Alloc> __string_type; 
1163 typedef typename __string_type::size_type __size_type; 
1164 const __size_type __len = _Traits::length(__lhs); 
1165 __string_type __str; 
1166 __str.reserve(__len + __rhs.size()); 
1167 __str.append(__lhs, __len); 
1168 __str.append(__rhs); 
1169 return __str; 
1170 } 
1171 
1172 template<typename _CharT, typename _Traits, typename _Alloc> 
1173 basic_string<_CharT, _Traits, _Alloc> 
1174 operator+(_CharT __lhs, const basic_string<_CharT, _Traits, _Alloc>& __rhs) 
1175 { 
1176 typedef basic_string<_CharT, _Traits, _Alloc> __string_type; 
1177 typedef typename __string_type::size_type __size_type; 
1178 __string_type __str; 
1179 const __size_type __len = __rhs.size(); 
1180 __str.reserve(__len + 1); 
1181 __str.append(__size_type(1), __lhs); 
1182 __str.append(__rhs); 
1183 return __str; 
1184 } 
1185 
1186 template<typename _CharT, typename _Traits, typename _Alloc> 
1187 typename basic_string<_CharT, _Traits, _Alloc>::size_type 
1188 basic_string<_CharT, _Traits, _Alloc>:: 
1189 find(const _CharT* __s, size_type __pos, size_type __n) const 
1190 _GLIBCXX_NOEXCEPT 
1191 { 
1192 __glibcxx_requires_string_len(__s, __n); 
1193 const size_type __size = this->size(); 
1194 
1195 if (__n == 0) 
1196 return __pos <= __size ? __pos : npos; 
1197 if (__pos >= __size) 
1198 return npos; 
1199 
1200 const _CharT __elem0 = __s[0]; 
1201 const _CharT* const __data = data(); 
1202 const _CharT* __first = __data + __pos; 
1203 const _CharT* const __last = __data + __size; 
1204 size_type __len = __size - __pos; 
1205 
1206 while (__len >= __n) 
1207 { 
1208 // Find the first occurrence of __elem0: 
1209 __first = traits_type::find(__first, __len - __n + 1, __elem0); 
1210 if (!__first) 
1211 return npos; 
1212 // Compare the full strings from the first occurrence of __elem0. 
1213 // We already know that __first[0] == __s[0] but compare them again 
1214 // anyway because __s is probably aligned, which helps memcmp. 
1215 if (traits_type::compare(__first, __s, __n) == 0) 
1216 return __first - __data; 
1217 __len = __last - ++__first; 
1218 } 
1219 return npos; 
1220 } 
1221 
1222 template<typename _CharT, typename _Traits, typename _Alloc> 
1223 typename basic_string<_CharT, _Traits, _Alloc>::size_type 
1224 basic_string<_CharT, _Traits, _Alloc>:: 
1225 find(_CharT __c, size_type __pos) const _GLIBCXX_NOEXCEPT 
1226 { 
1227 size_type __ret = npos; 
1228 const size_type __size = this->size(); 
1229 if (__pos < __size) 
1230 { 
1231 const _CharT* __data = _M_data(); 
1232 const size_type __n = __size - __pos; 
1233 const _CharT* __p = traits_type::find(__data + __pos, __n, __c); 
1234 if (__p) 
1235 __ret = __p - __data; 
1236 } 
1237 return __ret; 
1238 } 
1239 
1240 template<typename _CharT, typename _Traits, typename _Alloc> 
1241 typename basic_string<_CharT, _Traits, _Alloc>::size_type 
1242 basic_string<_CharT, _Traits, _Alloc>:: 
1243 rfind(const _CharT* __s, size_type __pos, size_type __n) const 
1244 _GLIBCXX_NOEXCEPT 
1245 { 
1246 __glibcxx_requires_string_len(__s, __n); 
1247 const size_type __size = this->size(); 
1248 if (__n <= __size) 
1249 { 
1250 __pos = std::min(size_type(__size - __n), __pos); 
1251 const _CharT* __data = _M_data(); 
1252 do 
1253 { 
1254 if (traits_type::compare(__data + __pos, __s, __n) == 0) 
1255 return __pos; 
1256 } 
1257 while (__pos-- > 0); 
1258 } 
1259 return npos; 
1260 } 
1261 
1262 template<typename _CharT, typename _Traits, typename _Alloc> 
1263 typename basic_string<_CharT, _Traits, _Alloc>::size_type 
1264 basic_string<_CharT, _Traits, _Alloc>:: 
1265 rfind(_CharT __c, size_type __pos) const _GLIBCXX_NOEXCEPT 
1266 { 
1267 size_type __size = this->size(); 
1268 if (__size) 
1269 { 
1270 if (--__size > __pos) 
1271 __size = __pos; 
1272 for (++__size; __size-- > 0; ) 
1273 if (traits_type::eq(_M_data()[__size], __c)) 
1274 return __size; 
1275 } 
1276 return npos; 
1277 } 
1278 
1279 template<typename _CharT, typename _Traits, typename _Alloc> 
1280 typename basic_string<_CharT, _Traits, _Alloc>::size_type 
1281 basic_string<_CharT, _Traits, _Alloc>:: 
1282 find_first_of(const _CharT* __s, size_type __pos, size_type __n) const 
1283 _GLIBCXX_NOEXCEPT 
1284 { 
1285 __glibcxx_requires_string_len(__s, __n); 
1286 for (; __n && __pos < this->size(); ++__pos) 
1287 { 
1288 const _CharT* __p = traits_type::find(__s, __n, _M_data()[__pos]); 
1289 if (__p) 
1290 return __pos; 
1291 } 
1292 return npos; 
1293 } 
1294 
1295 template<typename _CharT, typename _Traits, typename _Alloc> 
1296 typename basic_string<_CharT, _Traits, _Alloc>::size_type 
1297 basic_string<_CharT, _Traits, _Alloc>:: 
1298 find_last_of(const _CharT* __s, size_type __pos, size_type __n) const 
1299 _GLIBCXX_NOEXCEPT 
1300 { 
1301 __glibcxx_requires_string_len(__s, __n); 
1302 size_type __size = this->size(); 
1303 if (__size && __n) 
1304 { 
1305 if (--__size > __pos) 
1306 __size = __pos; 
1307 do 
1308 { 
1309 if (traits_type::find(__s, __n, _M_data()[__size])) 
1310 return __size; 
1311 } 
1312 while (__size-- != 0); 
1313 } 
1314 return npos; 
1315 } 
1316 
1317 template<typename _CharT, typename _Traits, typename _Alloc> 
1318 typename basic_string<_CharT, _Traits, _Alloc>::size_type 
1319 basic_string<_CharT, _Traits, _Alloc>:: 
1320 find_first_not_of(const _CharT* __s, size_type __pos, size_type __n) const 
1321 _GLIBCXX_NOEXCEPT 
1322 { 
1323 __glibcxx_requires_string_len(__s, __n); 
1324 for (; __pos < this->size(); ++__pos) 
1325 if (!traits_type::find(__s, __n, _M_data()[__pos])) 
1326 return __pos; 
1327 return npos; 
1328 } 
1329 
1330 template<typename _CharT, typename _Traits, typename _Alloc> 
1331 typename basic_string<_CharT, _Traits, _Alloc>::size_type 
1332 basic_string<_CharT, _Traits, _Alloc>:: 
1333 find_first_not_of(_CharT __c, size_type __pos) const _GLIBCXX_NOEXCEPT 
1334 { 
1335 for (; __pos < this->size(); ++__pos) 
1336 if (!traits_type::eq(_M_data()[__pos], __c)) 
1337 return __pos; 
1338 return npos; 
1339 } 
1340 
1341 template<typename _CharT, typename _Traits, typename _Alloc> 
1342 typename basic_string<_CharT, _Traits, _Alloc>::size_type 
1343 basic_string<_CharT, _Traits, _Alloc>:: 
1344 find_last_not_of(const _CharT* __s, size_type __pos, size_type __n) const 
1345 _GLIBCXX_NOEXCEPT 
1346 { 
1347 __glibcxx_requires_string_len(__s, __n); 
1348 size_type __size = this->size(); 
1349 if (__size) 
1350 { 
1351 if (--__size > __pos) 
1352 __size = __pos; 
1353 do 
1354 { 
1355 if (!traits_type::find(__s, __n, _M_data()[__size])) 
1356 return __size; 
1357 } 
1358 while (__size--); 
1359 } 
1360 return npos; 
1361 } 
1362 
1363 template<typename _CharT, typename _Traits, typename _Alloc> 
1364 typename basic_string<_CharT, _Traits, _Alloc>::size_type 
1365 basic_string<_CharT, _Traits, _Alloc>:: 
1366 find_last_not_of(_CharT __c, size_type __pos) const _GLIBCXX_NOEXCEPT 
1367 { 
1368 size_type __size = this->size(); 
1369 if (__size) 
1370 { 
1371 if (--__size > __pos) 
1372 __size = __pos; 
1373 do 
1374 { 
1375 if (!traits_type::eq(_M_data()[__size], __c)) 
1376 return __size; 
1377 } 
1378 while (__size--); 
1379 } 
1380 return npos; 
1381 } 
1382 
1383 template<typename _CharT, typename _Traits, typename _Alloc> 
1384 int 
1385 basic_string<_CharT, _Traits, _Alloc>:: 
1386 compare(size_type __pos, size_type __n, const basic_string& __str) const 
1387 { 
1388 _M_check(__pos, "basic_string::compare"); 
1389 __n = _M_limit(__pos, __n); 
1390 const size_type __osize = __str.size(); 
1391 const size_type __len = std::min(__n, __osize); 
1392 int __r = traits_type::compare(_M_data() + __pos, __str.data(), __len); 
1393 if (!__r) 
1394 __r = _S_compare(__n, __osize); 
1395 return __r; 
1396 } 
1397 
1398 template<typename _CharT, typename _Traits, typename _Alloc> 
1399 int 
1400 basic_string<_CharT, _Traits, _Alloc>:: 
1401 compare(size_type __pos1, size_type __n1, const basic_string& __str, 
1402 size_type __pos2, size_type __n2) const 
1403 { 
1404 _M_check(__pos1, "basic_string::compare"); 
1405 __str._M_check(__pos2, "basic_string::compare"); 
1406 __n1 = _M_limit(__pos1, __n1); 
1407 __n2 = __str._M_limit(__pos2, __n2); 
1408 const size_type __len = std::min(__n1, __n2); 
1409 int __r = traits_type::compare(_M_data() + __pos1, 
1410 __str.data() + __pos2, __len); 
1411 if (!__r) 
1412 __r = _S_compare(__n1, __n2); 
1413 return __r; 
1414 } 
1415 
1416 template<typename _CharT, typename _Traits, typename _Alloc> 
1417 int 
1418 basic_string<_CharT, _Traits, _Alloc>:: 
1419 compare(const _CharT* __s) const _GLIBCXX_NOEXCEPT 
1420 { 
1421 __glibcxx_requires_string(__s); 
1422 const size_type __size = this->size(); 
1423 const size_type __osize = traits_type::length(__s); 
1424 const size_type __len = std::min(__size, __osize); 
1425 int __r = traits_type::compare(_M_data(), __s, __len); 
1426 if (!__r) 
1427 __r = _S_compare(__size, __osize); 
1428 return __r; 
1429 } 
1430 
1431 template<typename _CharT, typename _Traits, typename _Alloc> 
1432 int 
1433 basic_string <_CharT, _Traits, _Alloc>:: 
1434 compare(size_type __pos, size_type __n1, const _CharT* __s) const 
1435 { 
1436 __glibcxx_requires_string(__s); 
1437 _M_check(__pos, "basic_string::compare"); 
1438 __n1 = _M_limit(__pos, __n1); 
1439 const size_type __osize = traits_type::length(__s); 
1440 const size_type __len = std::min(__n1, __osize); 
1441 int __r = traits_type::compare(_M_data() + __pos, __s, __len); 
1442 if (!__r) 
1443 __r = _S_compare(__n1, __osize); 
1444 return __r; 
1445 } 
1446 
1447 template<typename _CharT, typename _Traits, typename _Alloc> 
1448 int 
1449 basic_string <_CharT, _Traits, _Alloc>:: 
1450 compare(size_type __pos, size_type __n1, const _CharT* __s, 
1451 size_type __n2) const 
1452 { 
1453 __glibcxx_requires_string_len(__s, __n2); 
1454 _M_check(__pos, "basic_string::compare"); 
1455 __n1 = _M_limit(__pos, __n1); 
1456 const size_type __len = std::min(__n1, __n2); 
1457 int __r = traits_type::compare(_M_data() + __pos, __s, __len); 
1458 if (!__r) 
1459 __r = _S_compare(__n1, __n2); 
1460 return __r; 
1461 } 
1462 
1463 // 21.3.7.9 basic_string::getline and operators 
1464 template<typename _CharT, typename _Traits, typename _Alloc> 
1465 basic_istream<_CharT, _Traits>& 
1466 operator>>(basic_istream<_CharT, _Traits>& __in, 
1467 basic_string<_CharT, _Traits, _Alloc>& __str) 
1468 { 
1469 typedef basic_istream<_CharT, _Traits> __istream_type; 
1470 typedef basic_string<_CharT, _Traits, _Alloc> __string_type; 
1471 typedef typename __istream_type::ios_base __ios_base; 
1472 typedef typename __istream_type::int_type __int_type; 
1473 typedef typename __string_type::size_type __size_type; 
1474 typedef ctype<_CharT> __ctype_type; 
1475 typedef typename __ctype_type::ctype_base __ctype_base; 
1476 
1477 __size_type __extracted = 0; 
1478 typename __ios_base::iostate __err = __ios_base::goodbit; 
1479 typename __istream_type::sentry __cerb(__in, false); 
1480 if (__cerb) 
1481 { 
1482 __try 
1483 { 
1484 // Avoid reallocation for common case. 
1485 __str.erase(); 
1486 _CharT __buf[128]; 
1487 __size_type __len = 0;  
1488 const streamsize __w = __in.width(); 
1489 const __size_type __n = __w > 0 ? static_cast<__size_type>(__w) 
1490 : __str.max_size(); 
1491 const __ctype_type& __ct = use_facet<__ctype_type>(__in.getloc()); 
1492 const __int_type __eof = _Traits::eof(); 
1493 __int_type __c = __in.rdbuf()->sgetc(); 
1494 
1495 while (__extracted < __n 
1496 && !_Traits::eq_int_type(__c, __eof) 
1497 && !__ct.is(__ctype_base::space, 
1498 _Traits::to_char_type(__c))) 
1499 { 
1500 if (__len == sizeof(__buf) / sizeof(_CharT)) 
1501 { 
1502 __str.append(__buf, sizeof(__buf) / sizeof(_CharT)); 
1503 __len = 0; 
1504 } 
1505 __buf[__len++] = _Traits::to_char_type(__c); 
1506 ++__extracted; 
1507 __c = __in.rdbuf()->snextc(); 
1508 } 
1509 __str.append(__buf, __len); 
1510 
1511 if (_Traits::eq_int_type(__c, __eof)) 
1512 __err |= __ios_base::eofbit; 
1513 __in.width(0); 
1514 } 
1515 __catch(__cxxabiv1::__forced_unwind&) 
1516 { 
1517 __in._M_setstate(__ios_base::badbit); 
1518 __throw_exception_again; 
1519 } 
1520 __catch(...) 
1521 { 
1522 // _GLIBCXX_RESOLVE_LIB_DEFECTS 
1523 // 91. Description of operator>> and getline() for string<> 
1524 // might cause endless loop 
1525 __in._M_setstate(__ios_base::badbit); 
1526 } 
1527 } 
1528 // 211. operator>>(istream&, string&) doesn't set failbit 
1529 if (!__extracted) 
1530 __err |= __ios_base::failbit; 
1531 if (__err) 
1532 __in.setstate(__err); 
1533 return __in; 
1534 } 
1535 
1536 template<typename _CharT, typename _Traits, typename _Alloc> 
1537 basic_istream<_CharT, _Traits>& 
1538 getline(basic_istream<_CharT, _Traits>& __in, 
1539 basic_string<_CharT, _Traits, _Alloc>& __str, _CharT __delim) 
1540 { 
1541 typedef basic_istream<_CharT, _Traits> __istream_type; 
1542 typedef basic_string<_CharT, _Traits, _Alloc> __string_type; 
1543 typedef typename __istream_type::ios_base __ios_base; 
1544 typedef typename __istream_type::int_type __int_type; 
1545 typedef typename __string_type::size_type __size_type; 
1546 
1547 __size_type __extracted = 0; 
1548 const __size_type __n = __str.max_size(); 
1549 typename __ios_base::iostate __err = __ios_base::goodbit; 
1550 typename __istream_type::sentry __cerb(__in, true); 
1551 if (__cerb) 
1552 { 
1553 __try 
1554 { 
1555 __str.erase(); 
1556 const __int_type __idelim = _Traits::to_int_type(__delim); 
1557 const __int_type __eof = _Traits::eof(); 
1558 __int_type __c = __in.rdbuf()->sgetc(); 
1559 
1560 while (__extracted < __n 
1561 && !_Traits::eq_int_type(__c, __eof) 
1562 && !_Traits::eq_int_type(__c, __idelim)) 
1563 { 
1564 __str += _Traits::to_char_type(__c); 
1565 ++__extracted; 
1566 __c = __in.rdbuf()->snextc(); 
1567 } 
1568 
1569 if (_Traits::eq_int_type(__c, __eof)) 
1570 __err |= __ios_base::eofbit; 
1571 else if (_Traits::eq_int_type(__c, __idelim)) 
1572 { 
1573 ++__extracted;  
1574 __in.rdbuf()->sbumpc(); 
1575 } 
1576 else 
1577 __err |= __ios_base::failbit; 
1578 } 
1579 __catch(__cxxabiv1::__forced_unwind&) 
1580 { 
1581 __in._M_setstate(__ios_base::badbit); 
1582 __throw_exception_again; 
1583 } 
1584 __catch(...) 
1585 { 
1586 // _GLIBCXX_RESOLVE_LIB_DEFECTS 
1587 // 91. Description of operator>> and getline() for string<> 
1588 // might cause endless loop 
1589 __in._M_setstate(__ios_base::badbit); 
1590 } 
1591 } 
1592 if (!__extracted) 
1593 __err |= __ios_base::failbit; 
1594 if (__err) 
1595 __in.setstate(__err); 
1596 return __in; 
1597 } 
1598 
1599 // Inhibit implicit instantiations for required instantiations, 
1600 // which are defined via explicit instantiations elsewhere. 
1601#if _GLIBCXX_EXTERN_TEMPLATE 
1602 // The explicit instantiations definitions in src/c++11/string-inst.cc 
1603 // are compiled as C++14, so the new C++17 members aren't instantiated. 
1604 // Until those definitions are compiled as C++17 suppress the declaration, 
1605 // so C++17 code will implicitly instantiate std::string and std::wstring 
1606 // as needed. 
1607# if __cplusplus <= 201703L && _GLIBCXX_EXTERN_TEMPLATE > 0 
1608 extern template class basic_string<char>; 
1609# elif ! _GLIBCXX_USE_CXX11_ABI 
1610 // Still need to prevent implicit instantiation of the COW empty rep, 
1611 // to ensure the definition in libstdc++.so is unique (PR 86138). 
1612 extern template basic_string<char>::size_type 
1613 basic_string<char>::_Rep::_S_empty_rep_storage[]; 
1614# endif 
1615 
1616 extern template 
1617 basic_istream<char>& 
1618 operator>>(basic_istream<char>&, string&); 
1619 extern template 
1620 basic_ostream<char>& 
1621 operator<<(basic_ostream<char>&, const string&); 
1622 extern template 
1623 basic_istream<char>& 
1624 getline(basic_istream<char>&, string&, char); 
1625 extern template 
1626 basic_istream<char>& 
1627 getline(basic_istream<char>&, string&); 
1628 
1629#ifdef _GLIBCXX_USE_WCHAR_T 
1630# if __cplusplus <= 201703L && _GLIBCXX_EXTERN_TEMPLATE > 0 
1631 extern template class basic_string<wchar_t>; 
1632# elif ! _GLIBCXX_USE_CXX11_ABI 
1633 extern template basic_string<wchar_t>::size_type 
1634 basic_string<wchar_t>::_Rep::_S_empty_rep_storage[]; 
1635# endif 
1636 
1637 extern template 
1638 basic_istream<wchar_t>& 
1639 operator>>(basic_istream<wchar_t>&, wstring&); 
1640 extern template 
1641 basic_ostream<wchar_t>& 
1642 operator<<(basic_ostream<wchar_t>&, const wstring&); 
1643 extern template 
1644 basic_istream<wchar_t>& 
1645 getline(basic_istream<wchar_t>&, wstring&, wchar_t); 
1646 extern template 
1647 basic_istream<wchar_t>& 
1648 getline(basic_istream<wchar_t>&, wstring&); 
1649#endif // _GLIBCXX_USE_WCHAR_T 
1650#endif // _GLIBCXX_EXTERN_TEMPLATE 
1651 
1652_GLIBCXX_END_NAMESPACE_VERSION 
1653} // namespace std 
1654 
1655#endif 
1656