]>
Commit | Line | Data |
---|---|---|
1 | // Reference-counted versatile string base -*- C++ -*- | |
2 | ||
3 | // Copyright (C) 2005-2025 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 ext/rc_string_base.h | |
26 | * This is an internal header file, included by other library headers. | |
27 | * Do not attempt to use it directly. @headername{ext/vstring.h} | |
28 | */ | |
29 | ||
30 | #ifndef _RC_STRING_BASE_H | |
31 | #define _RC_STRING_BASE_H 1 | |
32 | ||
33 | #include <bits/requires_hosted.h> // GNU extensions are currently omitted | |
34 | ||
35 | #include <ext/atomicity.h> | |
36 | #include <ext/alloc_traits.h> | |
37 | #include <bits/stl_iterator_base_funcs.h> | |
38 | ||
39 | namespace __gnu_cxx _GLIBCXX_VISIBILITY(default) | |
40 | { | |
41 | _GLIBCXX_BEGIN_NAMESPACE_VERSION | |
42 | ||
43 | /** | |
44 | * Documentation? What's that? | |
45 | * Nathan Myers <ncm@cantrip.org>. | |
46 | * | |
47 | * A string looks like this: | |
48 | * | |
49 | * @code | |
50 | * [_Rep] | |
51 | * _M_length | |
52 | * [__rc_string_base<char_type>] _M_capacity | |
53 | * _M_dataplus _M_refcount | |
54 | * _M_p ----------------> unnamed array of char_type | |
55 | * @endcode | |
56 | * | |
57 | * Where the _M_p points to the first character in the string, and | |
58 | * you cast it to a pointer-to-_Rep and subtract 1 to get a | |
59 | * pointer to the header. | |
60 | * | |
61 | * This approach has the enormous advantage that a string object | |
62 | * requires only one allocation. All the ugliness is confined | |
63 | * within a single pair of inline functions, which each compile to | |
64 | * a single @a add instruction: _Rep::_M_refdata(), and | |
65 | * __rc_string_base::_M_rep(); and the allocation function which gets a | |
66 | * block of raw bytes and with room enough and constructs a _Rep | |
67 | * object at the front. | |
68 | * | |
69 | * The reason you want _M_data pointing to the character array and | |
70 | * not the _Rep is so that the debugger can see the string | |
71 | * contents. (Probably we should add a non-inline member to get | |
72 | * the _Rep for the debugger to use, so users can check the actual | |
73 | * string length.) | |
74 | * | |
75 | * Note that the _Rep object is a POD so that you can have a | |
76 | * static <em>empty string</em> _Rep object already @a constructed before | |
77 | * static constructors have run. The reference-count encoding is | |
78 | * chosen so that a 0 indicates one reference, so you never try to | |
79 | * destroy the empty-string _Rep object. | |
80 | * | |
81 | * All but the last paragraph is considered pretty conventional | |
82 | * for a C++ string implementation. | |
83 | */ | |
84 | template<typename _CharT, typename _Traits, typename _Alloc> | |
85 | class __rc_string_base | |
86 | : protected __vstring_utility<_CharT, _Traits, _Alloc> | |
87 | { | |
88 | public: | |
89 | typedef _Traits traits_type; | |
90 | typedef typename _Traits::char_type value_type; | |
91 | typedef _Alloc allocator_type; | |
92 | ||
93 | typedef __vstring_utility<_CharT, _Traits, _Alloc> _Util_Base; | |
94 | typedef typename _Util_Base::_CharT_alloc_type _CharT_alloc_type; | |
95 | typedef typename _CharT_alloc_type::size_type size_type; | |
96 | ||
97 | private: | |
98 | // _Rep: string representation | |
99 | // Invariants: | |
100 | // 1. String really contains _M_length + 1 characters: due to 21.3.4 | |
101 | // must be kept null-terminated. | |
102 | // 2. _M_capacity >= _M_length | |
103 | // Allocated memory is always (_M_capacity + 1) * sizeof(_CharT). | |
104 | // 3. _M_refcount has three states: | |
105 | // -1: leaked, one reference, no ref-copies allowed, non-const. | |
106 | // 0: one reference, non-const. | |
107 | // n>0: n + 1 references, operations require a lock, const. | |
108 | // 4. All fields == 0 is an empty string, given the extra storage | |
109 | // beyond-the-end for a null terminator; thus, the shared | |
110 | // empty string representation needs no constructor. | |
111 | struct _Rep | |
112 | { | |
113 | union | |
114 | { | |
115 | struct | |
116 | { | |
117 | size_type _M_length; | |
118 | size_type _M_capacity; | |
119 | _Atomic_word _M_refcount; | |
120 | } _M_info; | |
121 | ||
122 | // Only for alignment purposes. | |
123 | _CharT _M_align; | |
124 | }; | |
125 | ||
126 | typedef typename __alloc_traits<_Alloc>::template rebind<_Rep>::other | |
127 | _Rep_alloc_type; | |
128 | ||
129 | _CharT* | |
130 | _M_refdata() throw() | |
131 | { return reinterpret_cast<_CharT*>(this + 1); } | |
132 | ||
133 | _CharT* | |
134 | _M_refcopy() throw() | |
135 | { | |
136 | __atomic_add_dispatch(&_M_info._M_refcount, 1); | |
137 | return _M_refdata(); | |
138 | } // XXX MT | |
139 | ||
140 | void | |
141 | _M_set_length(size_type __n) | |
142 | { | |
143 | _M_info._M_refcount = 0; // One reference. | |
144 | _M_info._M_length = __n; | |
145 | // grrr. (per 21.3.4) | |
146 | // You cannot leave those LWG people alone for a second. | |
147 | traits_type::assign(_M_refdata()[__n], _CharT()); | |
148 | } | |
149 | ||
150 | // Create & Destroy | |
151 | static _Rep* | |
152 | _S_create(size_type, size_type, const _Alloc&); | |
153 | ||
154 | void | |
155 | _M_destroy(const _Alloc&) throw(); | |
156 | ||
157 | _CharT* | |
158 | _M_clone(const _Alloc&, size_type __res = 0); | |
159 | }; | |
160 | ||
161 | struct _Rep_empty | |
162 | : public _Rep | |
163 | { | |
164 | _CharT _M_terminal; | |
165 | }; | |
166 | ||
167 | static _Rep_empty _S_empty_rep; | |
168 | ||
169 | // The maximum number of individual char_type elements of an | |
170 | // individual string is determined by _S_max_size. This is the | |
171 | // value that will be returned by max_size(). (Whereas npos | |
172 | // is the maximum number of bytes the allocator can allocate.) | |
173 | // If one was to divvy up the theoretical largest size string, | |
174 | // with a terminating character and m _CharT elements, it'd | |
175 | // look like this: | |
176 | // npos = sizeof(_Rep) + (m * sizeof(_CharT)) + sizeof(_CharT) | |
177 | // + sizeof(_Rep) - 1 | |
178 | // (NB: last two terms for rounding reasons, see _M_create below) | |
179 | // Solving for m: | |
180 | // m = ((npos - 2 * sizeof(_Rep) + 1) / sizeof(_CharT)) - 1 | |
181 | // In addition, this implementation halves this amount. | |
182 | enum { _S_max_size = (((static_cast<size_type>(-1) - 2 * sizeof(_Rep) | |
183 | + 1) / sizeof(_CharT)) - 1) / 2 }; | |
184 | ||
185 | // Data Member (private): | |
186 | mutable typename _Util_Base::template _Alloc_hider<_Alloc> _M_dataplus; | |
187 | ||
188 | void | |
189 | _M_data(_CharT* __p) | |
190 | { _M_dataplus._M_p = __p; } | |
191 | ||
192 | _Rep* | |
193 | _M_rep() const | |
194 | { return &((reinterpret_cast<_Rep*>(_M_data()))[-1]); } | |
195 | ||
196 | _CharT* | |
197 | _M_grab(const _Alloc& __alloc) const | |
198 | { | |
199 | return (!_M_is_leaked() && _M_get_allocator() == __alloc) | |
200 | ? _M_rep()->_M_refcopy() : _M_rep()->_M_clone(__alloc); | |
201 | } | |
202 | ||
203 | void | |
204 | _M_dispose() | |
205 | { | |
206 | // Be race-detector-friendly. For more info see bits/c++config. | |
207 | _GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_M_rep()->_M_info. | |
208 | _M_refcount); | |
209 | if (__exchange_and_add_dispatch(&_M_rep()->_M_info._M_refcount, | |
210 | -1) <= 0) | |
211 | { | |
212 | _GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_M_rep()->_M_info. | |
213 | _M_refcount); | |
214 | _M_rep()->_M_destroy(_M_get_allocator()); | |
215 | } | |
216 | } // XXX MT | |
217 | ||
218 | bool | |
219 | _M_is_leaked() const | |
220 | { return _M_rep()->_M_info._M_refcount < 0; } | |
221 | ||
222 | void | |
223 | _M_set_sharable() | |
224 | { _M_rep()->_M_info._M_refcount = 0; } | |
225 | ||
226 | void | |
227 | _M_leak_hard(); | |
228 | ||
229 | // _S_construct_aux is used to implement the 21.3.1 para 15 which | |
230 | // requires special behaviour if _InIterator is an integral type | |
231 | template<typename _InIterator> | |
232 | static _CharT* | |
233 | _S_construct_aux(_InIterator __beg, _InIterator __end, | |
234 | const _Alloc& __a, std::__false_type) | |
235 | { | |
236 | typedef typename std::iterator_traits<_InIterator>::iterator_category | |
237 | _Tag; | |
238 | return _S_construct(__beg, __end, __a, _Tag()); | |
239 | } | |
240 | ||
241 | // _GLIBCXX_RESOLVE_LIB_DEFECTS | |
242 | // 438. Ambiguity in the "do the right thing" clause | |
243 | template<typename _Integer> | |
244 | static _CharT* | |
245 | _S_construct_aux(_Integer __beg, _Integer __end, | |
246 | const _Alloc& __a, std::__true_type) | |
247 | { return _S_construct_aux_2(static_cast<size_type>(__beg), | |
248 | __end, __a); } | |
249 | ||
250 | static _CharT* | |
251 | _S_construct_aux_2(size_type __req, _CharT __c, const _Alloc& __a) | |
252 | { return _S_construct(__req, __c, __a); } | |
253 | ||
254 | template<typename _InIterator> | |
255 | static _CharT* | |
256 | _S_construct(_InIterator __beg, _InIterator __end, const _Alloc& __a) | |
257 | { | |
258 | typedef typename std::__is_integer<_InIterator>::__type _Integral; | |
259 | return _S_construct_aux(__beg, __end, __a, _Integral()); | |
260 | } | |
261 | ||
262 | // For Input Iterators, used in istreambuf_iterators, etc. | |
263 | template<typename _InIterator> | |
264 | static _CharT* | |
265 | _S_construct(_InIterator __beg, _InIterator __end, const _Alloc& __a, | |
266 | std::input_iterator_tag); | |
267 | ||
268 | // For forward_iterators up to random_access_iterators, used for | |
269 | // string::iterator, _CharT*, etc. | |
270 | template<typename _FwdIterator> | |
271 | static _CharT* | |
272 | _S_construct(_FwdIterator __beg, _FwdIterator __end, const _Alloc& __a, | |
273 | std::forward_iterator_tag); | |
274 | ||
275 | static _CharT* | |
276 | _S_construct(size_type __req, _CharT __c, const _Alloc& __a); | |
277 | ||
278 | public: | |
279 | size_type | |
280 | _M_max_size() const | |
281 | { return size_type(_S_max_size); } | |
282 | ||
283 | _CharT* | |
284 | _M_data() const | |
285 | { return _M_dataplus._M_p; } | |
286 | ||
287 | size_type | |
288 | _M_length() const | |
289 | { return _M_rep()->_M_info._M_length; } | |
290 | ||
291 | size_type | |
292 | _M_capacity() const | |
293 | { return _M_rep()->_M_info._M_capacity; } | |
294 | ||
295 | bool | |
296 | _M_is_shared() const | |
297 | { return _M_rep()->_M_info._M_refcount > 0; } | |
298 | ||
299 | void | |
300 | _M_set_leaked() | |
301 | { _M_rep()->_M_info._M_refcount = -1; } | |
302 | ||
303 | void | |
304 | _M_leak() // for use in begin() & non-const op[] | |
305 | { | |
306 | if (!_M_is_leaked()) | |
307 | _M_leak_hard(); | |
308 | } | |
309 | ||
310 | void | |
311 | _M_set_length(size_type __n) | |
312 | { _M_rep()->_M_set_length(__n); } | |
313 | ||
314 | __rc_string_base() | |
315 | : _M_dataplus(_S_empty_rep._M_refcopy()) { } | |
316 | ||
317 | __rc_string_base(const _Alloc& __a); | |
318 | ||
319 | __rc_string_base(const __rc_string_base& __rcs); | |
320 | ||
321 | #if __cplusplus >= 201103L | |
322 | __rc_string_base(__rc_string_base&& __rcs) | |
323 | : _M_dataplus(__rcs._M_dataplus) | |
324 | { __rcs._M_data(_S_empty_rep._M_refcopy()); } | |
325 | #endif | |
326 | ||
327 | __rc_string_base(size_type __n, _CharT __c, const _Alloc& __a); | |
328 | ||
329 | template<typename _InputIterator> | |
330 | __rc_string_base(_InputIterator __beg, _InputIterator __end, | |
331 | const _Alloc& __a); | |
332 | ||
333 | ~__rc_string_base() | |
334 | { _M_dispose(); } | |
335 | ||
336 | allocator_type& | |
337 | _M_get_allocator() | |
338 | { return _M_dataplus; } | |
339 | ||
340 | const allocator_type& | |
341 | _M_get_allocator() const | |
342 | { return _M_dataplus; } | |
343 | ||
344 | void | |
345 | _M_swap(__rc_string_base& __rcs); | |
346 | ||
347 | void | |
348 | _M_assign(const __rc_string_base& __rcs); | |
349 | ||
350 | void | |
351 | _M_reserve(size_type __res); | |
352 | ||
353 | void | |
354 | _M_mutate(size_type __pos, size_type __len1, const _CharT* __s, | |
355 | size_type __len2); | |
356 | ||
357 | void | |
358 | _M_erase(size_type __pos, size_type __n); | |
359 | ||
360 | void | |
361 | _M_clear() | |
362 | { | |
363 | _M_dispose(); | |
364 | _M_data(_S_empty_rep._M_refcopy()); | |
365 | } | |
366 | ||
367 | bool | |
368 | _M_compare(const __rc_string_base&) const | |
369 | { return false; } | |
370 | }; | |
371 | ||
372 | template<typename _CharT, typename _Traits, typename _Alloc> | |
373 | typename __rc_string_base<_CharT, _Traits, _Alloc>::_Rep_empty | |
374 | __rc_string_base<_CharT, _Traits, _Alloc>::_S_empty_rep; | |
375 | ||
376 | template<typename _CharT, typename _Traits, typename _Alloc> | |
377 | typename __rc_string_base<_CharT, _Traits, _Alloc>::_Rep* | |
378 | __rc_string_base<_CharT, _Traits, _Alloc>::_Rep:: | |
379 | _S_create(size_type __capacity, size_type __old_capacity, | |
380 | const _Alloc& __alloc) | |
381 | { | |
382 | // _GLIBCXX_RESOLVE_LIB_DEFECTS | |
383 | // 83. String::npos vs. string::max_size() | |
384 | if (__capacity > size_type(_S_max_size)) | |
385 | std::__throw_length_error(__N("__rc_string_base::_Rep::_S_create")); | |
386 | ||
387 | // The standard places no restriction on allocating more memory | |
388 | // than is strictly needed within this layer at the moment or as | |
389 | // requested by an explicit application call to reserve(). | |
390 | ||
391 | // Many malloc implementations perform quite poorly when an | |
392 | // application attempts to allocate memory in a stepwise fashion | |
393 | // growing each allocation size by only 1 char. Additionally, | |
394 | // it makes little sense to allocate less linear memory than the | |
395 | // natural blocking size of the malloc implementation. | |
396 | // Unfortunately, we would need a somewhat low-level calculation | |
397 | // with tuned parameters to get this perfect for any particular | |
398 | // malloc implementation. Fortunately, generalizations about | |
399 | // common features seen among implementations seems to suffice. | |
400 | ||
401 | // __pagesize need not match the actual VM page size for good | |
402 | // results in practice, thus we pick a common value on the low | |
403 | // side. __malloc_header_size is an estimate of the amount of | |
404 | // overhead per memory allocation (in practice seen N * sizeof | |
405 | // (void*) where N is 0, 2 or 4). According to folklore, | |
406 | // picking this value on the high side is better than | |
407 | // low-balling it (especially when this algorithm is used with | |
408 | // malloc implementations that allocate memory blocks rounded up | |
409 | // to a size which is a power of 2). | |
410 | const size_type __pagesize = 4096; | |
411 | const size_type __malloc_header_size = 4 * sizeof(void*); | |
412 | ||
413 | // The below implements an exponential growth policy, necessary to | |
414 | // meet amortized linear time requirements of the library: see | |
415 | // http://gcc.gnu.org/ml/libstdc++/2001-07/msg00085.html. | |
416 | if (__capacity > __old_capacity && __capacity < 2 * __old_capacity) | |
417 | { | |
418 | __capacity = 2 * __old_capacity; | |
419 | // Never allocate a string bigger than _S_max_size. | |
420 | if (__capacity > size_type(_S_max_size)) | |
421 | __capacity = size_type(_S_max_size); | |
422 | } | |
423 | ||
424 | // NB: Need an array of char_type[__capacity], plus a terminating | |
425 | // null char_type() element, plus enough for the _Rep data structure, | |
426 | // plus sizeof(_Rep) - 1 to upper round to a size multiple of | |
427 | // sizeof(_Rep). | |
428 | // Whew. Seemingly so needy, yet so elemental. | |
429 | size_type __size = ((__capacity + 1) * sizeof(_CharT) | |
430 | + 2 * sizeof(_Rep) - 1); | |
431 | ||
432 | const size_type __adj_size = __size + __malloc_header_size; | |
433 | if (__adj_size > __pagesize && __capacity > __old_capacity) | |
434 | { | |
435 | const size_type __extra = __pagesize - __adj_size % __pagesize; | |
436 | __capacity += __extra / sizeof(_CharT); | |
437 | if (__capacity > size_type(_S_max_size)) | |
438 | __capacity = size_type(_S_max_size); | |
439 | __size = (__capacity + 1) * sizeof(_CharT) + 2 * sizeof(_Rep) - 1; | |
440 | } | |
441 | ||
442 | // NB: Might throw, but no worries about a leak, mate: _Rep() | |
443 | // does not throw. | |
444 | _Rep* __place = _Rep_alloc_type(__alloc).allocate(__size / sizeof(_Rep)); | |
445 | _Rep* __p = new (__place) _Rep; | |
446 | __p->_M_info._M_capacity = __capacity; | |
447 | return __p; | |
448 | } | |
449 | ||
450 | template<typename _CharT, typename _Traits, typename _Alloc> | |
451 | void | |
452 | __rc_string_base<_CharT, _Traits, _Alloc>::_Rep:: | |
453 | _M_destroy(const _Alloc& __a) throw () | |
454 | { | |
455 | const size_type __size = ((_M_info._M_capacity + 1) * sizeof(_CharT) | |
456 | + 2 * sizeof(_Rep) - 1); | |
457 | _Rep_alloc_type(__a).deallocate(this, __size / sizeof(_Rep)); | |
458 | } | |
459 | ||
460 | template<typename _CharT, typename _Traits, typename _Alloc> | |
461 | _CharT* | |
462 | __rc_string_base<_CharT, _Traits, _Alloc>::_Rep:: | |
463 | _M_clone(const _Alloc& __alloc, size_type __res) | |
464 | { | |
465 | // Requested capacity of the clone. | |
466 | const size_type __requested_cap = _M_info._M_length + __res; | |
467 | _Rep* __r = _Rep::_S_create(__requested_cap, _M_info._M_capacity, | |
468 | __alloc); | |
469 | ||
470 | if (_M_info._M_length) | |
471 | __rc_string_base::_S_copy(__r->_M_refdata(), _M_refdata(), _M_info._M_length); | |
472 | ||
473 | __r->_M_set_length(_M_info._M_length); | |
474 | return __r->_M_refdata(); | |
475 | } | |
476 | ||
477 | template<typename _CharT, typename _Traits, typename _Alloc> | |
478 | __rc_string_base<_CharT, _Traits, _Alloc>:: | |
479 | __rc_string_base(const _Alloc& __a) | |
480 | : _M_dataplus(__a, _S_construct(size_type(), _CharT(), __a)) { } | |
481 | ||
482 | template<typename _CharT, typename _Traits, typename _Alloc> | |
483 | __rc_string_base<_CharT, _Traits, _Alloc>:: | |
484 | __rc_string_base(const __rc_string_base& __rcs) | |
485 | : _M_dataplus(__rcs._M_get_allocator(), | |
486 | __rcs._M_grab(__rcs._M_get_allocator())) { } | |
487 | ||
488 | template<typename _CharT, typename _Traits, typename _Alloc> | |
489 | __rc_string_base<_CharT, _Traits, _Alloc>:: | |
490 | __rc_string_base(size_type __n, _CharT __c, const _Alloc& __a) | |
491 | : _M_dataplus(__a, _S_construct(__n, __c, __a)) { } | |
492 | ||
493 | template<typename _CharT, typename _Traits, typename _Alloc> | |
494 | template<typename _InputIterator> | |
495 | __rc_string_base<_CharT, _Traits, _Alloc>:: | |
496 | __rc_string_base(_InputIterator __beg, _InputIterator __end, | |
497 | const _Alloc& __a) | |
498 | : _M_dataplus(__a, _S_construct(__beg, __end, __a)) { } | |
499 | ||
500 | template<typename _CharT, typename _Traits, typename _Alloc> | |
501 | void | |
502 | __rc_string_base<_CharT, _Traits, _Alloc>:: | |
503 | _M_leak_hard() | |
504 | { | |
505 | if (_M_is_shared()) | |
506 | _M_erase(0, 0); | |
507 | _M_set_leaked(); | |
508 | } | |
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 | __rc_string_base<_CharT, _Traits, _Alloc>:: | |
518 | _S_construct(_InIterator __beg, _InIterator __end, const _Alloc& __a, | |
519 | std::input_iterator_tag) | |
520 | { | |
521 | if (__beg == __end && __a == _Alloc()) | |
522 | return _S_empty_rep._M_refcopy(); | |
523 | ||
524 | // Avoid reallocation for common case. | |
525 | _CharT __buf[128]; | |
526 | size_type __len = 0; | |
527 | while (__beg != __end && __len < sizeof(__buf) / sizeof(_CharT)) | |
528 | { | |
529 | __buf[__len++] = *__beg; | |
530 | ++__beg; | |
531 | } | |
532 | _Rep* __r = _Rep::_S_create(__len, size_type(0), __a); | |
533 | _S_copy(__r->_M_refdata(), __buf, __len); | |
534 | __try | |
535 | { | |
536 | while (__beg != __end) | |
537 | { | |
538 | if (__len == __r->_M_info._M_capacity) | |
539 | { | |
540 | // Allocate more space. | |
541 | _Rep* __another = _Rep::_S_create(__len + 1, __len, __a); | |
542 | _S_copy(__another->_M_refdata(), __r->_M_refdata(), __len); | |
543 | __r->_M_destroy(__a); | |
544 | __r = __another; | |
545 | } | |
546 | __r->_M_refdata()[__len++] = *__beg; | |
547 | ++__beg; | |
548 | } | |
549 | } | |
550 | __catch(...) | |
551 | { | |
552 | __r->_M_destroy(__a); | |
553 | __throw_exception_again; | |
554 | } | |
555 | __r->_M_set_length(__len); | |
556 | return __r->_M_refdata(); | |
557 | } | |
558 | ||
559 | template<typename _CharT, typename _Traits, typename _Alloc> | |
560 | template<typename _InIterator> | |
561 | _CharT* | |
562 | __rc_string_base<_CharT, _Traits, _Alloc>:: | |
563 | _S_construct(_InIterator __beg, _InIterator __end, const _Alloc& __a, | |
564 | std::forward_iterator_tag) | |
565 | { | |
566 | if (__beg == __end && __a == _Alloc()) | |
567 | return _S_empty_rep._M_refcopy(); | |
568 | ||
569 | // NB: Not required, but considered best practice. | |
570 | if (__is_null_pointer(__beg) && __beg != __end) | |
571 | std::__throw_logic_error(__N("__rc_string_base::" | |
572 | "_S_construct null not valid")); | |
573 | ||
574 | const size_type __dnew = static_cast<size_type>(std::distance(__beg, | |
575 | __end)); | |
576 | // Check for out_of_range and length_error exceptions. | |
577 | _Rep* __r = _Rep::_S_create(__dnew, size_type(0), __a); | |
578 | __try | |
579 | { __rc_string_base::_S_copy_chars(__r->_M_refdata(), __beg, __end); } | |
580 | __catch(...) | |
581 | { | |
582 | __r->_M_destroy(__a); | |
583 | __throw_exception_again; | |
584 | } | |
585 | __r->_M_set_length(__dnew); | |
586 | return __r->_M_refdata(); | |
587 | } | |
588 | ||
589 | template<typename _CharT, typename _Traits, typename _Alloc> | |
590 | _CharT* | |
591 | __rc_string_base<_CharT, _Traits, _Alloc>:: | |
592 | _S_construct(size_type __n, _CharT __c, const _Alloc& __a) | |
593 | { | |
594 | if (__n == 0 && __a == _Alloc()) | |
595 | return _S_empty_rep._M_refcopy(); | |
596 | ||
597 | // Check for out_of_range and length_error exceptions. | |
598 | _Rep* __r = _Rep::_S_create(__n, size_type(0), __a); | |
599 | if (__n) | |
600 | __rc_string_base::_S_assign(__r->_M_refdata(), __n, __c); | |
601 | ||
602 | __r->_M_set_length(__n); | |
603 | return __r->_M_refdata(); | |
604 | } | |
605 | ||
606 | template<typename _CharT, typename _Traits, typename _Alloc> | |
607 | void | |
608 | __rc_string_base<_CharT, _Traits, _Alloc>:: | |
609 | _M_swap(__rc_string_base& __rcs) | |
610 | { | |
611 | if (_M_is_leaked()) | |
612 | _M_set_sharable(); | |
613 | if (__rcs._M_is_leaked()) | |
614 | __rcs._M_set_sharable(); | |
615 | ||
616 | _CharT* __tmp = _M_data(); | |
617 | _M_data(__rcs._M_data()); | |
618 | __rcs._M_data(__tmp); | |
619 | ||
620 | // _GLIBCXX_RESOLVE_LIB_DEFECTS | |
621 | // 431. Swapping containers with unequal allocators. | |
622 | std::__alloc_swap<allocator_type>::_S_do_it(_M_get_allocator(), | |
623 | __rcs._M_get_allocator()); | |
624 | } | |
625 | ||
626 | template<typename _CharT, typename _Traits, typename _Alloc> | |
627 | void | |
628 | __rc_string_base<_CharT, _Traits, _Alloc>:: | |
629 | _M_assign(const __rc_string_base& __rcs) | |
630 | { | |
631 | if (_M_rep() != __rcs._M_rep()) | |
632 | { | |
633 | _CharT* __tmp = __rcs._M_grab(_M_get_allocator()); | |
634 | _M_dispose(); | |
635 | _M_data(__tmp); | |
636 | } | |
637 | } | |
638 | ||
639 | template<typename _CharT, typename _Traits, typename _Alloc> | |
640 | void | |
641 | __rc_string_base<_CharT, _Traits, _Alloc>:: | |
642 | _M_reserve(size_type __res) | |
643 | { | |
644 | // Make sure we don't shrink below the current size. | |
645 | if (__res < _M_length()) | |
646 | __res = _M_length(); | |
647 | ||
648 | if (__res != _M_capacity() || _M_is_shared()) | |
649 | { | |
650 | _CharT* __tmp = _M_rep()->_M_clone(_M_get_allocator(), | |
651 | __res - _M_length()); | |
652 | _M_dispose(); | |
653 | _M_data(__tmp); | |
654 | } | |
655 | } | |
656 | ||
657 | template<typename _CharT, typename _Traits, typename _Alloc> | |
658 | void | |
659 | __rc_string_base<_CharT, _Traits, _Alloc>:: | |
660 | _M_mutate(size_type __pos, size_type __len1, const _CharT* __s, | |
661 | size_type __len2) | |
662 | { | |
663 | const size_type __how_much = _M_length() - __pos - __len1; | |
664 | ||
665 | _Rep* __r = _Rep::_S_create(_M_length() + __len2 - __len1, | |
666 | _M_capacity(), _M_get_allocator()); | |
667 | ||
668 | if (__pos) | |
669 | this->_S_copy(__r->_M_refdata(), _M_data(), __pos); | |
670 | if (__s && __len2) | |
671 | this->_S_copy(__r->_M_refdata() + __pos, __s, __len2); | |
672 | if (__how_much) | |
673 | this->_S_copy(__r->_M_refdata() + __pos + __len2, | |
674 | _M_data() + __pos + __len1, __how_much); | |
675 | ||
676 | _M_dispose(); | |
677 | _M_data(__r->_M_refdata()); | |
678 | } | |
679 | ||
680 | template<typename _CharT, typename _Traits, typename _Alloc> | |
681 | void | |
682 | __rc_string_base<_CharT, _Traits, _Alloc>:: | |
683 | _M_erase(size_type __pos, size_type __n) | |
684 | { | |
685 | const size_type __new_size = _M_length() - __n; | |
686 | const size_type __how_much = _M_length() - __pos - __n; | |
687 | ||
688 | if (_M_is_shared()) | |
689 | { | |
690 | // Must reallocate. | |
691 | _Rep* __r = _Rep::_S_create(__new_size, _M_capacity(), | |
692 | _M_get_allocator()); | |
693 | ||
694 | if (__pos) | |
695 | this->_S_copy(__r->_M_refdata(), _M_data(), __pos); | |
696 | if (__how_much) | |
697 | this->_S_copy(__r->_M_refdata() + __pos, | |
698 | _M_data() + __pos + __n, __how_much); | |
699 | ||
700 | _M_dispose(); | |
701 | _M_data(__r->_M_refdata()); | |
702 | } | |
703 | else if (__how_much && __n) | |
704 | { | |
705 | // Work in-place. | |
706 | this->_S_move(_M_data() + __pos, | |
707 | _M_data() + __pos + __n, __how_much); | |
708 | } | |
709 | ||
710 | _M_rep()->_M_set_length(__new_size); | |
711 | } | |
712 | ||
713 | template<> | |
714 | inline bool | |
715 | __rc_string_base<char, std::char_traits<char>, | |
716 | std::allocator<char> >:: | |
717 | _M_compare(const __rc_string_base& __rcs) const | |
718 | { | |
719 | if (_M_rep() == __rcs._M_rep()) | |
720 | return true; | |
721 | return false; | |
722 | } | |
723 | ||
724 | template<> | |
725 | inline bool | |
726 | __rc_string_base<wchar_t, std::char_traits<wchar_t>, | |
727 | std::allocator<wchar_t> >:: | |
728 | _M_compare(const __rc_string_base& __rcs) const | |
729 | { | |
730 | if (_M_rep() == __rcs._M_rep()) | |
731 | return true; | |
732 | return false; | |
733 | } | |
734 | ||
735 | _GLIBCXX_END_NAMESPACE_VERSION | |
736 | } // namespace | |
737 | ||
738 | #endif /* _RC_STRING_BASE_H */ |