libstdc++
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00001 // Reference-counted versatile string base -*- C++ -*- 00002 00003 // Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010 00004 // Free Software Foundation, Inc. 00005 // 00006 // This file is part of the GNU ISO C++ Library. This library is free 00007 // software; you can redistribute it and/or modify it under the 00008 // terms of the GNU General Public License as published by the 00009 // Free Software Foundation; either version 3, or (at your option) 00010 // any later version. 00011 00012 // This library is distributed in the hope that it will be useful, 00013 // but WITHOUT ANY WARRANTY; without even the implied warranty of 00014 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00015 // GNU General Public License for more details. 00016 00017 // Under Section 7 of GPL version 3, you are granted additional 00018 // permissions described in the GCC Runtime Library Exception, version 00019 // 3.1, as published by the Free Software Foundation. 00020 00021 // You should have received a copy of the GNU General Public License and 00022 // a copy of the GCC Runtime Library Exception along with this program; 00023 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 00024 // <http://www.gnu.org/licenses/>. 00025 00026 /** @file ext/rc_string_base.h 00027 * This is an internal header file, included by other library headers. 00028 * Do not attempt to use it directly. @headername{ext/vstring.h} 00029 */ 00030 00031 #ifndef _RC_STRING_BASE_H 00032 #define _RC_STRING_BASE_H 1 00033 00034 #include <ext/atomicity.h> 00035 #include <bits/stl_iterator_base_funcs.h> 00036 00037 namespace __gnu_cxx _GLIBCXX_VISIBILITY(default) 00038 { 00039 _GLIBCXX_BEGIN_NAMESPACE_VERSION 00040 00041 /** 00042 * Documentation? What's that? 00043 * Nathan Myers <ncm@cantrip.org>. 00044 * 00045 * A string looks like this: 00046 * 00047 * @code 00048 * [_Rep] 00049 * _M_length 00050 * [__rc_string_base<char_type>] _M_capacity 00051 * _M_dataplus _M_refcount 00052 * _M_p ----------------> unnamed array of char_type 00053 * @endcode 00054 * 00055 * Where the _M_p points to the first character in the string, and 00056 * you cast it to a pointer-to-_Rep and subtract 1 to get a 00057 * pointer to the header. 00058 * 00059 * This approach has the enormous advantage that a string object 00060 * requires only one allocation. All the ugliness is confined 00061 * within a single pair of inline functions, which each compile to 00062 * a single @a add instruction: _Rep::_M_refdata(), and 00063 * __rc_string_base::_M_rep(); and the allocation function which gets a 00064 * block of raw bytes and with room enough and constructs a _Rep 00065 * object at the front. 00066 * 00067 * The reason you want _M_data pointing to the character array and 00068 * not the _Rep is so that the debugger can see the string 00069 * contents. (Probably we should add a non-inline member to get 00070 * the _Rep for the debugger to use, so users can check the actual 00071 * string length.) 00072 * 00073 * Note that the _Rep object is a POD so that you can have a 00074 * static <em>empty string</em> _Rep object already @a constructed before 00075 * static constructors have run. The reference-count encoding is 00076 * chosen so that a 0 indicates one reference, so you never try to 00077 * destroy the empty-string _Rep object. 00078 * 00079 * All but the last paragraph is considered pretty conventional 00080 * for a C++ string implementation. 00081 */ 00082 template<typename _CharT, typename _Traits, typename _Alloc> 00083 class __rc_string_base 00084 : protected __vstring_utility<_CharT, _Traits, _Alloc> 00085 { 00086 public: 00087 typedef _Traits traits_type; 00088 typedef typename _Traits::char_type value_type; 00089 typedef _Alloc allocator_type; 00090 00091 typedef __vstring_utility<_CharT, _Traits, _Alloc> _Util_Base; 00092 typedef typename _Util_Base::_CharT_alloc_type _CharT_alloc_type; 00093 typedef typename _CharT_alloc_type::size_type size_type; 00094 00095 private: 00096 // _Rep: string representation 00097 // Invariants: 00098 // 1. String really contains _M_length + 1 characters: due to 21.3.4 00099 // must be kept null-terminated. 00100 // 2. _M_capacity >= _M_length 00101 // Allocated memory is always (_M_capacity + 1) * sizeof(_CharT). 00102 // 3. _M_refcount has three states: 00103 // -1: leaked, one reference, no ref-copies allowed, non-const. 00104 // 0: one reference, non-const. 00105 // n>0: n + 1 references, operations require a lock, const. 00106 // 4. All fields == 0 is an empty string, given the extra storage 00107 // beyond-the-end for a null terminator; thus, the shared 00108 // empty string representation needs no constructor. 00109 struct _Rep 00110 { 00111 union 00112 { 00113 struct 00114 { 00115 size_type _M_length; 00116 size_type _M_capacity; 00117 _Atomic_word _M_refcount; 00118 } _M_info; 00119 00120 // Only for alignment purposes. 00121 _CharT _M_align; 00122 }; 00123 00124 typedef typename _Alloc::template rebind<_Rep>::other _Rep_alloc_type; 00125 00126 _CharT* 00127 _M_refdata() throw() 00128 { return reinterpret_cast<_CharT*>(this + 1); } 00129 00130 _CharT* 00131 _M_refcopy() throw() 00132 { 00133 __atomic_add_dispatch(&_M_info._M_refcount, 1); 00134 return _M_refdata(); 00135 } // XXX MT 00136 00137 void 00138 _M_set_length(size_type __n) 00139 { 00140 _M_info._M_refcount = 0; // One reference. 00141 _M_info._M_length = __n; 00142 // grrr. (per 21.3.4) 00143 // You cannot leave those LWG people alone for a second. 00144 traits_type::assign(_M_refdata()[__n], _CharT()); 00145 } 00146 00147 // Create & Destroy 00148 static _Rep* 00149 _S_create(size_type, size_type, const _Alloc&); 00150 00151 void 00152 _M_destroy(const _Alloc&) throw(); 00153 00154 _CharT* 00155 _M_clone(const _Alloc&, size_type __res = 0); 00156 }; 00157 00158 struct _Rep_empty 00159 : public _Rep 00160 { 00161 _CharT _M_terminal; 00162 }; 00163 00164 static _Rep_empty _S_empty_rep; 00165 00166 // The maximum number of individual char_type elements of an 00167 // individual string is determined by _S_max_size. This is the 00168 // value that will be returned by max_size(). (Whereas npos 00169 // is the maximum number of bytes the allocator can allocate.) 00170 // If one was to divvy up the theoretical largest size string, 00171 // with a terminating character and m _CharT elements, it'd 00172 // look like this: 00173 // npos = sizeof(_Rep) + (m * sizeof(_CharT)) + sizeof(_CharT) 00174 // + sizeof(_Rep) - 1 00175 // (NB: last two terms for rounding reasons, see _M_create below) 00176 // Solving for m: 00177 // m = ((npos - 2 * sizeof(_Rep) + 1) / sizeof(_CharT)) - 1 00178 // In addition, this implementation halves this amount. 00179 enum { _S_max_size = (((static_cast<size_type>(-1) - 2 * sizeof(_Rep) 00180 + 1) / sizeof(_CharT)) - 1) / 2 }; 00181 00182 // Data Member (private): 00183 mutable typename _Util_Base::template _Alloc_hider<_Alloc> _M_dataplus; 00184 00185 void 00186 _M_data(_CharT* __p) 00187 { _M_dataplus._M_p = __p; } 00188 00189 _Rep* 00190 _M_rep() const 00191 { return &((reinterpret_cast<_Rep*>(_M_data()))[-1]); } 00192 00193 _CharT* 00194 _M_grab(const _Alloc& __alloc) const 00195 { 00196 return (!_M_is_leaked() && _M_get_allocator() == __alloc) 00197 ? _M_rep()->_M_refcopy() : _M_rep()->_M_clone(__alloc); 00198 } 00199 00200 void 00201 _M_dispose() 00202 { 00203 // Be race-detector-friendly. For more info see bits/c++config. 00204 _GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_M_rep()->_M_info. 00205 _M_refcount); 00206 if (__exchange_and_add_dispatch(&_M_rep()->_M_info._M_refcount, 00207 -1) <= 0) 00208 { 00209 _GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_M_rep()->_M_info. 00210 _M_refcount); 00211 _M_rep()->_M_destroy(_M_get_allocator()); 00212 } 00213 } // XXX MT 00214 00215 bool 00216 _M_is_leaked() const 00217 { return _M_rep()->_M_info._M_refcount < 0; } 00218 00219 void 00220 _M_set_sharable() 00221 { _M_rep()->_M_info._M_refcount = 0; } 00222 00223 void 00224 _M_leak_hard(); 00225 00226 // _S_construct_aux is used to implement the 21.3.1 para 15 which 00227 // requires special behaviour if _InIterator is an integral type 00228 template<typename _InIterator> 00229 static _CharT* 00230 _S_construct_aux(_InIterator __beg, _InIterator __end, 00231 const _Alloc& __a, std::__false_type) 00232 { 00233 typedef typename iterator_traits<_InIterator>::iterator_category _Tag; 00234 return _S_construct(__beg, __end, __a, _Tag()); 00235 } 00236 00237 // _GLIBCXX_RESOLVE_LIB_DEFECTS 00238 // 438. Ambiguity in the "do the right thing" clause 00239 template<typename _Integer> 00240 static _CharT* 00241 _S_construct_aux(_Integer __beg, _Integer __end, 00242 const _Alloc& __a, std::__true_type) 00243 { return _S_construct_aux_2(static_cast<size_type>(__beg), 00244 __end, __a); } 00245 00246 static _CharT* 00247 _S_construct_aux_2(size_type __req, _CharT __c, const _Alloc& __a) 00248 { return _S_construct(__req, __c, __a); } 00249 00250 template<typename _InIterator> 00251 static _CharT* 00252 _S_construct(_InIterator __beg, _InIterator __end, const _Alloc& __a) 00253 { 00254 typedef typename std::__is_integer<_InIterator>::__type _Integral; 00255 return _S_construct_aux(__beg, __end, __a, _Integral()); 00256 } 00257 00258 // For Input Iterators, used in istreambuf_iterators, etc. 00259 template<typename _InIterator> 00260 static _CharT* 00261 _S_construct(_InIterator __beg, _InIterator __end, const _Alloc& __a, 00262 std::input_iterator_tag); 00263 00264 // For forward_iterators up to random_access_iterators, used for 00265 // string::iterator, _CharT*, etc. 00266 template<typename _FwdIterator> 00267 static _CharT* 00268 _S_construct(_FwdIterator __beg, _FwdIterator __end, const _Alloc& __a, 00269 std::forward_iterator_tag); 00270 00271 static _CharT* 00272 _S_construct(size_type __req, _CharT __c, const _Alloc& __a); 00273 00274 public: 00275 size_type 00276 _M_max_size() const 00277 { return size_type(_S_max_size); } 00278 00279 _CharT* 00280 _M_data() const 00281 { return _M_dataplus._M_p; } 00282 00283 size_type 00284 _M_length() const 00285 { return _M_rep()->_M_info._M_length; } 00286 00287 size_type 00288 _M_capacity() const 00289 { return _M_rep()->_M_info._M_capacity; } 00290 00291 bool 00292 _M_is_shared() const 00293 { return _M_rep()->_M_info._M_refcount > 0; } 00294 00295 void 00296 _M_set_leaked() 00297 { _M_rep()->_M_info._M_refcount = -1; } 00298 00299 void 00300 _M_leak() // for use in begin() & non-const op[] 00301 { 00302 if (!_M_is_leaked()) 00303 _M_leak_hard(); 00304 } 00305 00306 void 00307 _M_set_length(size_type __n) 00308 { _M_rep()->_M_set_length(__n); } 00309 00310 __rc_string_base() 00311 : _M_dataplus(_S_empty_rep._M_refcopy()) { } 00312 00313 __rc_string_base(const _Alloc& __a); 00314 00315 __rc_string_base(const __rc_string_base& __rcs); 00316 00317 #ifdef __GXX_EXPERIMENTAL_CXX0X__ 00318 __rc_string_base(__rc_string_base&& __rcs) 00319 : _M_dataplus(__rcs._M_dataplus) 00320 { __rcs._M_data(_S_empty_rep._M_refcopy()); } 00321 #endif 00322 00323 __rc_string_base(size_type __n, _CharT __c, const _Alloc& __a); 00324 00325 template<typename _InputIterator> 00326 __rc_string_base(_InputIterator __beg, _InputIterator __end, 00327 const _Alloc& __a); 00328 00329 ~__rc_string_base() 00330 { _M_dispose(); } 00331 00332 allocator_type& 00333 _M_get_allocator() 00334 { return _M_dataplus; } 00335 00336 const allocator_type& 00337 _M_get_allocator() const 00338 { return _M_dataplus; } 00339 00340 void 00341 _M_swap(__rc_string_base& __rcs); 00342 00343 void 00344 _M_assign(const __rc_string_base& __rcs); 00345 00346 void 00347 _M_reserve(size_type __res); 00348 00349 void 00350 _M_mutate(size_type __pos, size_type __len1, const _CharT* __s, 00351 size_type __len2); 00352 00353 void 00354 _M_erase(size_type __pos, size_type __n); 00355 00356 void 00357 _M_clear() 00358 { _M_erase(size_type(0), _M_length()); } 00359 00360 bool 00361 _M_compare(const __rc_string_base&) const 00362 { return false; } 00363 }; 00364 00365 template<typename _CharT, typename _Traits, typename _Alloc> 00366 typename __rc_string_base<_CharT, _Traits, _Alloc>::_Rep_empty 00367 __rc_string_base<_CharT, _Traits, _Alloc>::_S_empty_rep; 00368 00369 template<typename _CharT, typename _Traits, typename _Alloc> 00370 typename __rc_string_base<_CharT, _Traits, _Alloc>::_Rep* 00371 __rc_string_base<_CharT, _Traits, _Alloc>::_Rep:: 00372 _S_create(size_type __capacity, size_type __old_capacity, 00373 const _Alloc& __alloc) 00374 { 00375 // _GLIBCXX_RESOLVE_LIB_DEFECTS 00376 // 83. String::npos vs. string::max_size() 00377 if (__capacity > size_type(_S_max_size)) 00378 std::__throw_length_error(__N("__rc_string_base::_Rep::_S_create")); 00379 00380 // The standard places no restriction on allocating more memory 00381 // than is strictly needed within this layer at the moment or as 00382 // requested by an explicit application call to reserve(). 00383 00384 // Many malloc implementations perform quite poorly when an 00385 // application attempts to allocate memory in a stepwise fashion 00386 // growing each allocation size by only 1 char. Additionally, 00387 // it makes little sense to allocate less linear memory than the 00388 // natural blocking size of the malloc implementation. 00389 // Unfortunately, we would need a somewhat low-level calculation 00390 // with tuned parameters to get this perfect for any particular 00391 // malloc implementation. Fortunately, generalizations about 00392 // common features seen among implementations seems to suffice. 00393 00394 // __pagesize need not match the actual VM page size for good 00395 // results in practice, thus we pick a common value on the low 00396 // side. __malloc_header_size is an estimate of the amount of 00397 // overhead per memory allocation (in practice seen N * sizeof 00398 // (void*) where N is 0, 2 or 4). According to folklore, 00399 // picking this value on the high side is better than 00400 // low-balling it (especially when this algorithm is used with 00401 // malloc implementations that allocate memory blocks rounded up 00402 // to a size which is a power of 2). 00403 const size_type __pagesize = 4096; 00404 const size_type __malloc_header_size = 4 * sizeof(void*); 00405 00406 // The below implements an exponential growth policy, necessary to 00407 // meet amortized linear time requirements of the library: see 00408 // http://gcc.gnu.org/ml/libstdc++/2001-07/msg00085.html. 00409 if (__capacity > __old_capacity && __capacity < 2 * __old_capacity) 00410 { 00411 __capacity = 2 * __old_capacity; 00412 // Never allocate a string bigger than _S_max_size. 00413 if (__capacity > size_type(_S_max_size)) 00414 __capacity = size_type(_S_max_size); 00415 } 00416 00417 // NB: Need an array of char_type[__capacity], plus a terminating 00418 // null char_type() element, plus enough for the _Rep data structure, 00419 // plus sizeof(_Rep) - 1 to upper round to a size multiple of 00420 // sizeof(_Rep). 00421 // Whew. Seemingly so needy, yet so elemental. 00422 size_type __size = ((__capacity + 1) * sizeof(_CharT) 00423 + 2 * sizeof(_Rep) - 1); 00424 00425 const size_type __adj_size = __size + __malloc_header_size; 00426 if (__adj_size > __pagesize && __capacity > __old_capacity) 00427 { 00428 const size_type __extra = __pagesize - __adj_size % __pagesize; 00429 __capacity += __extra / sizeof(_CharT); 00430 if (__capacity > size_type(_S_max_size)) 00431 __capacity = size_type(_S_max_size); 00432 __size = (__capacity + 1) * sizeof(_CharT) + 2 * sizeof(_Rep) - 1; 00433 } 00434 00435 // NB: Might throw, but no worries about a leak, mate: _Rep() 00436 // does not throw. 00437 _Rep* __place = _Rep_alloc_type(__alloc).allocate(__size / sizeof(_Rep)); 00438 _Rep* __p = new (__place) _Rep; 00439 __p->_M_info._M_capacity = __capacity; 00440 return __p; 00441 } 00442 00443 template<typename _CharT, typename _Traits, typename _Alloc> 00444 void 00445 __rc_string_base<_CharT, _Traits, _Alloc>::_Rep:: 00446 _M_destroy(const _Alloc& __a) throw () 00447 { 00448 const size_type __size = ((_M_info._M_capacity + 1) * sizeof(_CharT) 00449 + 2 * sizeof(_Rep) - 1); 00450 _Rep_alloc_type(__a).deallocate(this, __size / sizeof(_Rep)); 00451 } 00452 00453 template<typename _CharT, typename _Traits, typename _Alloc> 00454 _CharT* 00455 __rc_string_base<_CharT, _Traits, _Alloc>::_Rep:: 00456 _M_clone(const _Alloc& __alloc, size_type __res) 00457 { 00458 // Requested capacity of the clone. 00459 const size_type __requested_cap = _M_info._M_length + __res; 00460 _Rep* __r = _Rep::_S_create(__requested_cap, _M_info._M_capacity, 00461 __alloc); 00462 00463 if (_M_info._M_length) 00464 __rc_string_base::_S_copy(__r->_M_refdata(), _M_refdata(), _M_info._M_length); 00465 00466 __r->_M_set_length(_M_info._M_length); 00467 return __r->_M_refdata(); 00468 } 00469 00470 template<typename _CharT, typename _Traits, typename _Alloc> 00471 __rc_string_base<_CharT, _Traits, _Alloc>:: 00472 __rc_string_base(const _Alloc& __a) 00473 : _M_dataplus(__a, _S_construct(size_type(), _CharT(), __a)) { } 00474 00475 template<typename _CharT, typename _Traits, typename _Alloc> 00476 __rc_string_base<_CharT, _Traits, _Alloc>:: 00477 __rc_string_base(const __rc_string_base& __rcs) 00478 : _M_dataplus(__rcs._M_get_allocator(), 00479 __rcs._M_grab(__rcs._M_get_allocator())) { } 00480 00481 template<typename _CharT, typename _Traits, typename _Alloc> 00482 __rc_string_base<_CharT, _Traits, _Alloc>:: 00483 __rc_string_base(size_type __n, _CharT __c, const _Alloc& __a) 00484 : _M_dataplus(__a, _S_construct(__n, __c, __a)) { } 00485 00486 template<typename _CharT, typename _Traits, typename _Alloc> 00487 template<typename _InputIterator> 00488 __rc_string_base<_CharT, _Traits, _Alloc>:: 00489 __rc_string_base(_InputIterator __beg, _InputIterator __end, 00490 const _Alloc& __a) 00491 : _M_dataplus(__a, _S_construct(__beg, __end, __a)) { } 00492 00493 template<typename _CharT, typename _Traits, typename _Alloc> 00494 void 00495 __rc_string_base<_CharT, _Traits, _Alloc>:: 00496 _M_leak_hard() 00497 { 00498 if (_M_is_shared()) 00499 _M_erase(0, 0); 00500 _M_set_leaked(); 00501 } 00502 00503 // NB: This is the special case for Input Iterators, used in 00504 // istreambuf_iterators, etc. 00505 // Input Iterators have a cost structure very different from 00506 // pointers, calling for a different coding style. 00507 template<typename _CharT, typename _Traits, typename _Alloc> 00508 template<typename _InIterator> 00509 _CharT* 00510 __rc_string_base<_CharT, _Traits, _Alloc>:: 00511 _S_construct(_InIterator __beg, _InIterator __end, const _Alloc& __a, 00512 std::input_iterator_tag) 00513 { 00514 if (__beg == __end && __a == _Alloc()) 00515 return _S_empty_rep._M_refcopy(); 00516 00517 // Avoid reallocation for common case. 00518 _CharT __buf[128]; 00519 size_type __len = 0; 00520 while (__beg != __end && __len < sizeof(__buf) / sizeof(_CharT)) 00521 { 00522 __buf[__len++] = *__beg; 00523 ++__beg; 00524 } 00525 _Rep* __r = _Rep::_S_create(__len, size_type(0), __a); 00526 _S_copy(__r->_M_refdata(), __buf, __len); 00527 __try 00528 { 00529 while (__beg != __end) 00530 { 00531 if (__len == __r->_M_info._M_capacity) 00532 { 00533 // Allocate more space. 00534 _Rep* __another = _Rep::_S_create(__len + 1, __len, __a); 00535 _S_copy(__another->_M_refdata(), __r->_M_refdata(), __len); 00536 __r->_M_destroy(__a); 00537 __r = __another; 00538 } 00539 __r->_M_refdata()[__len++] = *__beg; 00540 ++__beg; 00541 } 00542 } 00543 __catch(...) 00544 { 00545 __r->_M_destroy(__a); 00546 __throw_exception_again; 00547 } 00548 __r->_M_set_length(__len); 00549 return __r->_M_refdata(); 00550 } 00551 00552 template<typename _CharT, typename _Traits, typename _Alloc> 00553 template<typename _InIterator> 00554 _CharT* 00555 __rc_string_base<_CharT, _Traits, _Alloc>:: 00556 _S_construct(_InIterator __beg, _InIterator __end, const _Alloc& __a, 00557 std::forward_iterator_tag) 00558 { 00559 if (__beg == __end && __a == _Alloc()) 00560 return _S_empty_rep._M_refcopy(); 00561 00562 // NB: Not required, but considered best practice. 00563 if (__is_null_pointer(__beg) && __beg != __end) 00564 std::__throw_logic_error(__N("__rc_string_base::" 00565 "_S_construct null not valid")); 00566 00567 const size_type __dnew = static_cast<size_type>(std::distance(__beg, 00568 __end)); 00569 // Check for out_of_range and length_error exceptions. 00570 _Rep* __r = _Rep::_S_create(__dnew, size_type(0), __a); 00571 __try 00572 { __rc_string_base::_S_copy_chars(__r->_M_refdata(), __beg, __end); } 00573 __catch(...) 00574 { 00575 __r->_M_destroy(__a); 00576 __throw_exception_again; 00577 } 00578 __r->_M_set_length(__dnew); 00579 return __r->_M_refdata(); 00580 } 00581 00582 template<typename _CharT, typename _Traits, typename _Alloc> 00583 _CharT* 00584 __rc_string_base<_CharT, _Traits, _Alloc>:: 00585 _S_construct(size_type __n, _CharT __c, const _Alloc& __a) 00586 { 00587 if (__n == 0 && __a == _Alloc()) 00588 return _S_empty_rep._M_refcopy(); 00589 00590 // Check for out_of_range and length_error exceptions. 00591 _Rep* __r = _Rep::_S_create(__n, size_type(0), __a); 00592 if (__n) 00593 __rc_string_base::_S_assign(__r->_M_refdata(), __n, __c); 00594 00595 __r->_M_set_length(__n); 00596 return __r->_M_refdata(); 00597 } 00598 00599 template<typename _CharT, typename _Traits, typename _Alloc> 00600 void 00601 __rc_string_base<_CharT, _Traits, _Alloc>:: 00602 _M_swap(__rc_string_base& __rcs) 00603 { 00604 if (_M_is_leaked()) 00605 _M_set_sharable(); 00606 if (__rcs._M_is_leaked()) 00607 __rcs._M_set_sharable(); 00608 00609 _CharT* __tmp = _M_data(); 00610 _M_data(__rcs._M_data()); 00611 __rcs._M_data(__tmp); 00612 00613 // _GLIBCXX_RESOLVE_LIB_DEFECTS 00614 // 431. Swapping containers with unequal allocators. 00615 std::__alloc_swap<allocator_type>::_S_do_it(_M_get_allocator(), 00616 __rcs._M_get_allocator()); 00617 } 00618 00619 template<typename _CharT, typename _Traits, typename _Alloc> 00620 void 00621 __rc_string_base<_CharT, _Traits, _Alloc>:: 00622 _M_assign(const __rc_string_base& __rcs) 00623 { 00624 if (_M_rep() != __rcs._M_rep()) 00625 { 00626 _CharT* __tmp = __rcs._M_grab(_M_get_allocator()); 00627 _M_dispose(); 00628 _M_data(__tmp); 00629 } 00630 } 00631 00632 template<typename _CharT, typename _Traits, typename _Alloc> 00633 void 00634 __rc_string_base<_CharT, _Traits, _Alloc>:: 00635 _M_reserve(size_type __res) 00636 { 00637 // Make sure we don't shrink below the current size. 00638 if (__res < _M_length()) 00639 __res = _M_length(); 00640 00641 if (__res != _M_capacity() || _M_is_shared()) 00642 { 00643 _CharT* __tmp = _M_rep()->_M_clone(_M_get_allocator(), 00644 __res - _M_length()); 00645 _M_dispose(); 00646 _M_data(__tmp); 00647 } 00648 } 00649 00650 template<typename _CharT, typename _Traits, typename _Alloc> 00651 void 00652 __rc_string_base<_CharT, _Traits, _Alloc>:: 00653 _M_mutate(size_type __pos, size_type __len1, const _CharT* __s, 00654 size_type __len2) 00655 { 00656 const size_type __how_much = _M_length() - __pos - __len1; 00657 00658 _Rep* __r = _Rep::_S_create(_M_length() + __len2 - __len1, 00659 _M_capacity(), _M_get_allocator()); 00660 00661 if (__pos) 00662 this->_S_copy(__r->_M_refdata(), _M_data(), __pos); 00663 if (__s && __len2) 00664 this->_S_copy(__r->_M_refdata() + __pos, __s, __len2); 00665 if (__how_much) 00666 this->_S_copy(__r->_M_refdata() + __pos + __len2, 00667 _M_data() + __pos + __len1, __how_much); 00668 00669 _M_dispose(); 00670 _M_data(__r->_M_refdata()); 00671 } 00672 00673 template<typename _CharT, typename _Traits, typename _Alloc> 00674 void 00675 __rc_string_base<_CharT, _Traits, _Alloc>:: 00676 _M_erase(size_type __pos, size_type __n) 00677 { 00678 const size_type __new_size = _M_length() - __n; 00679 const size_type __how_much = _M_length() - __pos - __n; 00680 00681 if (_M_is_shared()) 00682 { 00683 // Must reallocate. 00684 _Rep* __r = _Rep::_S_create(__new_size, _M_capacity(), 00685 _M_get_allocator()); 00686 00687 if (__pos) 00688 this->_S_copy(__r->_M_refdata(), _M_data(), __pos); 00689 if (__how_much) 00690 this->_S_copy(__r->_M_refdata() + __pos, 00691 _M_data() + __pos + __n, __how_much); 00692 00693 _M_dispose(); 00694 _M_data(__r->_M_refdata()); 00695 } 00696 else if (__how_much && __n) 00697 { 00698 // Work in-place. 00699 this->_S_move(_M_data() + __pos, 00700 _M_data() + __pos + __n, __how_much); 00701 } 00702 00703 _M_rep()->_M_set_length(__new_size); 00704 } 00705 00706 template<> 00707 inline bool 00708 __rc_string_base<char, std::char_traits<char>, 00709 std::allocator<char> >:: 00710 _M_compare(const __rc_string_base& __rcs) const 00711 { 00712 if (_M_rep() == __rcs._M_rep()) 00713 return true; 00714 return false; 00715 } 00716 00717 #ifdef _GLIBCXX_USE_WCHAR_T 00718 template<> 00719 inline bool 00720 __rc_string_base<wchar_t, std::char_traits<wchar_t>, 00721 std::allocator<wchar_t> >:: 00722 _M_compare(const __rc_string_base& __rcs) const 00723 { 00724 if (_M_rep() == __rcs._M_rep()) 00725 return true; 00726 return false; 00727 } 00728 #endif 00729 00730 _GLIBCXX_END_NAMESPACE_VERSION 00731 } // namespace 00732 00733 #endif /* _RC_STRING_BASE_H */