1 // Deque implementation -*- C++ -*- 2 3 // Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 4 // 2011 Free Software Foundation, Inc. 5 // 6 // This file is part of the GNU ISO C++ Library. This library is free 7 // software; you can redistribute it and/or modify it under the 8 // terms of the GNU General Public License as published by the 9 // Free Software Foundation; either version 3, or (at your option) 10 // any later version. 11 12 // This library is distributed in the hope that it will be useful, 13 // but WITHOUT ANY WARRANTY; without even the implied warranty of 14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 // GNU General Public License for more details. 16 17 // Under Section 7 of GPL version 3, you are granted additional 18 // permissions described in the GCC Runtime Library Exception, version 19 // 3.1, as published by the Free Software Foundation. 20 21 // You should have received a copy of the GNU General Public License and 22 // a copy of the GCC Runtime Library Exception along with this program; 23 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 24 // <http://www.gnu.org/licenses/>. 25 26 /* 27 * 28 * Copyright (c) 1994 29 * Hewlett-Packard Company 30 * 31 * Permission to use, copy, modify, distribute and sell this software 32 * and its documentation for any purpose is hereby granted without fee, 33 * provided that the above copyright notice appear in all copies and 34 * that both that copyright notice and this permission notice appear 35 * in supporting documentation. Hewlett-Packard Company makes no 36 * representations about the suitability of this software for any 37 * purpose. It is provided "as is" without express or implied warranty. 38 * 39 * 40 * Copyright (c) 1997 41 * Silicon Graphics Computer Systems, Inc. 42 * 43 * Permission to use, copy, modify, distribute and sell this software 44 * and its documentation for any purpose is hereby granted without fee, 45 * provided that the above copyright notice appear in all copies and 46 * that both that copyright notice and this permission notice appear 47 * in supporting documentation. Silicon Graphics makes no 48 * representations about the suitability of this software for any 49 * purpose. It is provided "as is" without express or implied warranty. 50 */ 51 52 /** @file bits/stl_deque.h 53 * This is an internal header file, included by other library headers. 54 * Do not attempt to use it directly. @headername{deque} 55 */ 56 57 #ifndef _STL_DEQUE_H 58 #define _STL_DEQUE_H 1 59 60 #include <bits/concept_check.h> 61 #include <bits/stl_iterator_base_types.h> 62 #include <bits/stl_iterator_base_funcs.h> 63 #ifdef __GXX_EXPERIMENTAL_CXX0X__ 64 #include <initializer_list> 65 #endif 66 67 namespace std _GLIBCXX_VISIBILITY(default) 68 { 69 _GLIBCXX_BEGIN_NAMESPACE_CONTAINER 70 71 /** 72 * @brief This function controls the size of memory nodes. 73 * @param __size The size of an element. 74 * @return The number (not byte size) of elements per node. 75 * 76 * This function started off as a compiler kludge from SGI, but 77 * seems to be a useful wrapper around a repeated constant 78 * expression. The @b 512 is tunable (and no other code needs to 79 * change), but no investigation has been done since inheriting the 80 * SGI code. Touch _GLIBCXX_DEQUE_BUF_SIZE only if you know what 81 * you are doing, however: changing it breaks the binary 82 * compatibility!! 83 */ 84 85 #ifndef _GLIBCXX_DEQUE_BUF_SIZE 86 #define _GLIBCXX_DEQUE_BUF_SIZE 512 87 #endif 88 89 inline size_t 90 __deque_buf_size(size_t __size) 91 { return (__size < _GLIBCXX_DEQUE_BUF_SIZE 92 ? size_t(_GLIBCXX_DEQUE_BUF_SIZE / __size) : size_t(1)); } 93 94 95 /** 96 * @brief A deque::iterator. 97 * 98 * Quite a bit of intelligence here. Much of the functionality of 99 * deque is actually passed off to this class. A deque holds two 100 * of these internally, marking its valid range. Access to 101 * elements is done as offsets of either of those two, relying on 102 * operator overloading in this class. 103 * 104 * All the functions are op overloads except for _M_set_node. 105 */ 106 template<typename _Tp, typename _Ref, typename _Ptr> 107 struct _Deque_iterator 108 { 109 typedef _Deque_iterator<_Tp, _Tp&, _Tp*> iterator; 110 typedef _Deque_iterator<_Tp, const _Tp&, const _Tp*> const_iterator; 111 112 static size_t _S_buffer_size() 113 { return __deque_buf_size(sizeof(_Tp)); } 114 115 typedef std::random_access_iterator_tag iterator_category; 116 typedef _Tp value_type; 117 typedef _Ptr pointer; 118 typedef _Ref reference; 119 typedef size_t size_type; 120 typedef ptrdiff_t difference_type; 121 typedef _Tp** _Map_pointer; 122 typedef _Deque_iterator _Self; 123 124 _Tp* _M_cur; 125 _Tp* _M_first; 126 _Tp* _M_last; 127 _Map_pointer _M_node; 128 129 _Deque_iterator(_Tp* __x, _Map_pointer __y) 130 : _M_cur(__x), _M_first(*__y), 131 _M_last(*__y + _S_buffer_size()), _M_node(__y) { } 132 133 _Deque_iterator() 134 : _M_cur(0), _M_first(0), _M_last(0), _M_node(0) { } 135 136 _Deque_iterator(const iterator& __x) 137 : _M_cur(__x._M_cur), _M_first(__x._M_first), 138 _M_last(__x._M_last), _M_node(__x._M_node) { } 139 140 reference 141 operator*() const 142 { return *_M_cur; } 143 144 pointer 145 operator->() const 146 { return _M_cur; } 147 148 _Self& 149 operator++() 150 { 151 ++_M_cur; 152 if (_M_cur == _M_last) 153 { 154 _M_set_node(_M_node + 1); 155 _M_cur = _M_first; 156 } 157 return *this; 158 } 159 160 _Self 161 operator++(int) 162 { 163 _Self __tmp = *this; 164 ++*this; 165 return __tmp; 166 } 167 168 _Self& 169 operator--() 170 { 171 if (_M_cur == _M_first) 172 { 173 _M_set_node(_M_node - 1); 174 _M_cur = _M_last; 175 } 176 --_M_cur; 177 return *this; 178 } 179 180 _Self 181 operator--(int) 182 { 183 _Self __tmp = *this; 184 --*this; 185 return __tmp; 186 } 187 188 _Self& 189 operator+=(difference_type __n) 190 { 191 const difference_type __offset = __n + (_M_cur - _M_first); 192 if (__offset >= 0 && __offset < difference_type(_S_buffer_size())) 193 _M_cur += __n; 194 else 195 { 196 const difference_type __node_offset = 197 __offset > 0 ? __offset / difference_type(_S_buffer_size()) 198 : -difference_type((-__offset - 1) 199 / _S_buffer_size()) - 1; 200 _M_set_node(_M_node + __node_offset); 201 _M_cur = _M_first + (__offset - __node_offset 202 * difference_type(_S_buffer_size())); 203 } 204 return *this; 205 } 206 207 _Self 208 operator+(difference_type __n) const 209 { 210 _Self __tmp = *this; 211 return __tmp += __n; 212 } 213 214 _Self& 215 operator-=(difference_type __n) 216 { return *this += -__n; } 217 218 _Self 219 operator-(difference_type __n) const 220 { 221 _Self __tmp = *this; 222 return __tmp -= __n; 223 } 224 225 reference 226 operator[](difference_type __n) const 227 { return *(*this + __n); } 228 229 /** 230 * Prepares to traverse new_node. Sets everything except 231 * _M_cur, which should therefore be set by the caller 232 * immediately afterwards, based on _M_first and _M_last. 233 */ 234 void 235 _M_set_node(_Map_pointer __new_node) 236 { 237 _M_node = __new_node; 238 _M_first = *__new_node; 239 _M_last = _M_first + difference_type(_S_buffer_size()); 240 } 241 }; 242 243 // Note: we also provide overloads whose operands are of the same type in 244 // order to avoid ambiguous overload resolution when std::rel_ops operators 245 // are in scope (for additional details, see libstdc++/3628) 246 template<typename _Tp, typename _Ref, typename _Ptr> 247 inline bool 248 operator==(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x, 249 const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) 250 { return __x._M_cur == __y._M_cur; } 251 252 template<typename _Tp, typename _RefL, typename _PtrL, 253 typename _RefR, typename _PtrR> 254 inline bool 255 operator==(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x, 256 const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) 257 { return __x._M_cur == __y._M_cur; } 258 259 template<typename _Tp, typename _Ref, typename _Ptr> 260 inline bool 261 operator!=(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x, 262 const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) 263 { return !(__x == __y); } 264 265 template<typename _Tp, typename _RefL, typename _PtrL, 266 typename _RefR, typename _PtrR> 267 inline bool 268 operator!=(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x, 269 const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) 270 { return !(__x == __y); } 271 272 template<typename _Tp, typename _Ref, typename _Ptr> 273 inline bool 274 operator<(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x, 275 const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) 276 { return (__x._M_node == __y._M_node) ? (__x._M_cur < __y._M_cur) 277 : (__x._M_node < __y._M_node); } 278 279 template<typename _Tp, typename _RefL, typename _PtrL, 280 typename _RefR, typename _PtrR> 281 inline bool 282 operator<(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x, 283 const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) 284 { return (__x._M_node == __y._M_node) ? (__x._M_cur < __y._M_cur) 285 : (__x._M_node < __y._M_node); } 286 287 template<typename _Tp, typename _Ref, typename _Ptr> 288 inline bool 289 operator>(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x, 290 const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) 291 { return __y < __x; } 292 293 template<typename _Tp, typename _RefL, typename _PtrL, 294 typename _RefR, typename _PtrR> 295 inline bool 296 operator>(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x, 297 const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) 298 { return __y < __x; } 299 300 template<typename _Tp, typename _Ref, typename _Ptr> 301 inline bool 302 operator<=(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x, 303 const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) 304 { return !(__y < __x); } 305 306 template<typename _Tp, typename _RefL, typename _PtrL, 307 typename _RefR, typename _PtrR> 308 inline bool 309 operator<=(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x, 310 const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) 311 { return !(__y < __x); } 312 313 template<typename _Tp, typename _Ref, typename _Ptr> 314 inline bool 315 operator>=(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x, 316 const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) 317 { return !(__x < __y); } 318 319 template<typename _Tp, typename _RefL, typename _PtrL, 320 typename _RefR, typename _PtrR> 321 inline bool 322 operator>=(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x, 323 const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) 324 { return !(__x < __y); } 325 326 // _GLIBCXX_RESOLVE_LIB_DEFECTS 327 // According to the resolution of DR179 not only the various comparison 328 // operators but also operator- must accept mixed iterator/const_iterator 329 // parameters. 330 template<typename _Tp, typename _Ref, typename _Ptr> 331 inline typename _Deque_iterator<_Tp, _Ref, _Ptr>::difference_type 332 operator-(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x, 333 const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) 334 { 335 return typename _Deque_iterator<_Tp, _Ref, _Ptr>::difference_type 336 (_Deque_iterator<_Tp, _Ref, _Ptr>::_S_buffer_size()) 337 * (__x._M_node - __y._M_node - 1) + (__x._M_cur - __x._M_first) 338 + (__y._M_last - __y._M_cur); 339 } 340 341 template<typename _Tp, typename _RefL, typename _PtrL, 342 typename _RefR, typename _PtrR> 343 inline typename _Deque_iterator<_Tp, _RefL, _PtrL>::difference_type 344 operator-(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x, 345 const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) 346 { 347 return typename _Deque_iterator<_Tp, _RefL, _PtrL>::difference_type 348 (_Deque_iterator<_Tp, _RefL, _PtrL>::_S_buffer_size()) 349 * (__x._M_node - __y._M_node - 1) + (__x._M_cur - __x._M_first) 350 + (__y._M_last - __y._M_cur); 351 } 352 353 template<typename _Tp, typename _Ref, typename _Ptr> 354 inline _Deque_iterator<_Tp, _Ref, _Ptr> 355 operator+(ptrdiff_t __n, const _Deque_iterator<_Tp, _Ref, _Ptr>& __x) 356 { return __x + __n; } 357 358 template<typename _Tp> 359 void 360 fill(const _Deque_iterator<_Tp, _Tp&, _Tp*>&, 361 const _Deque_iterator<_Tp, _Tp&, _Tp*>&, const _Tp&); 362 363 template<typename _Tp> 364 _Deque_iterator<_Tp, _Tp&, _Tp*> 365 copy(_Deque_iterator<_Tp, const _Tp&, const _Tp*>, 366 _Deque_iterator<_Tp, const _Tp&, const _Tp*>, 367 _Deque_iterator<_Tp, _Tp&, _Tp*>); 368 369 template<typename _Tp> 370 inline _Deque_iterator<_Tp, _Tp&, _Tp*> 371 copy(_Deque_iterator<_Tp, _Tp&, _Tp*> __first, 372 _Deque_iterator<_Tp, _Tp&, _Tp*> __last, 373 _Deque_iterator<_Tp, _Tp&, _Tp*> __result) 374 { return std::copy(_Deque_iterator<_Tp, const _Tp&, const _Tp*>(__first), 375 _Deque_iterator<_Tp, const _Tp&, const _Tp*>(__last), 376 __result); } 377 378 template<typename _Tp> 379 _Deque_iterator<_Tp, _Tp&, _Tp*> 380 copy_backward(_Deque_iterator<_Tp, const _Tp&, const _Tp*>, 381 _Deque_iterator<_Tp, const _Tp&, const _Tp*>, 382 _Deque_iterator<_Tp, _Tp&, _Tp*>); 383 384 template<typename _Tp> 385 inline _Deque_iterator<_Tp, _Tp&, _Tp*> 386 copy_backward(_Deque_iterator<_Tp, _Tp&, _Tp*> __first, 387 _Deque_iterator<_Tp, _Tp&, _Tp*> __last, 388 _Deque_iterator<_Tp, _Tp&, _Tp*> __result) 389 { return std::copy_backward(_Deque_iterator<_Tp, 390 const _Tp&, const _Tp*>(__first), 391 _Deque_iterator<_Tp, 392 const _Tp&, const _Tp*>(__last), 393 __result); } 394 395 #ifdef __GXX_EXPERIMENTAL_CXX0X__ 396 template<typename _Tp> 397 _Deque_iterator<_Tp, _Tp&, _Tp*> 398 move(_Deque_iterator<_Tp, const _Tp&, const _Tp*>, 399 _Deque_iterator<_Tp, const _Tp&, const _Tp*>, 400 _Deque_iterator<_Tp, _Tp&, _Tp*>); 401 402 template<typename _Tp> 403 inline _Deque_iterator<_Tp, _Tp&, _Tp*> 404 move(_Deque_iterator<_Tp, _Tp&, _Tp*> __first, 405 _Deque_iterator<_Tp, _Tp&, _Tp*> __last, 406 _Deque_iterator<_Tp, _Tp&, _Tp*> __result) 407 { return std::move(_Deque_iterator<_Tp, const _Tp&, const _Tp*>(__first), 408 _Deque_iterator<_Tp, const _Tp&, const _Tp*>(__last), 409 __result); } 410 411 template<typename _Tp> 412 _Deque_iterator<_Tp, _Tp&, _Tp*> 413 move_backward(_Deque_iterator<_Tp, const _Tp&, const _Tp*>, 414 _Deque_iterator<_Tp, const _Tp&, const _Tp*>, 415 _Deque_iterator<_Tp, _Tp&, _Tp*>); 416 417 template<typename _Tp> 418 inline _Deque_iterator<_Tp, _Tp&, _Tp*> 419 move_backward(_Deque_iterator<_Tp, _Tp&, _Tp*> __first, 420 _Deque_iterator<_Tp, _Tp&, _Tp*> __last, 421 _Deque_iterator<_Tp, _Tp&, _Tp*> __result) 422 { return std::move_backward(_Deque_iterator<_Tp, 423 const _Tp&, const _Tp*>(__first), 424 _Deque_iterator<_Tp, 425 const _Tp&, const _Tp*>(__last), 426 __result); } 427 #endif 428 429 /** 430 * Deque base class. This class provides the unified face for %deque's 431 * allocation. This class's constructor and destructor allocate and 432 * deallocate (but do not initialize) storage. This makes %exception 433 * safety easier. 434 * 435 * Nothing in this class ever constructs or destroys an actual Tp element. 436 * (Deque handles that itself.) Only/All memory management is performed 437 * here. 438 */ 439 template<typename _Tp, typename _Alloc> 440 class _Deque_base 441 { 442 public: 443 typedef _Alloc allocator_type; 444 445 allocator_type 446 get_allocator() const _GLIBCXX_NOEXCEPT 447 { return allocator_type(_M_get_Tp_allocator()); } 448 449 typedef _Deque_iterator<_Tp, _Tp&, _Tp*> iterator; 450 typedef _Deque_iterator<_Tp, const _Tp&, const _Tp*> const_iterator; 451 452 _Deque_base() 453 : _M_impl() 454 { _M_initialize_map(0); } 455 456 _Deque_base(size_t __num_elements) 457 : _M_impl() 458 { _M_initialize_map(__num_elements); } 459 460 _Deque_base(const allocator_type& __a, size_t __num_elements) 461 : _M_impl(__a) 462 { _M_initialize_map(__num_elements); } 463 464 _Deque_base(const allocator_type& __a) 465 : _M_impl(__a) 466 { } 467 468 #ifdef __GXX_EXPERIMENTAL_CXX0X__ 469 _Deque_base(_Deque_base&& __x) 470 : _M_impl(std::move(__x._M_get_Tp_allocator())) 471 { 472 _M_initialize_map(0); 473 if (__x._M_impl._M_map) 474 { 475 std::swap(this->_M_impl._M_start, __x._M_impl._M_start); 476 std::swap(this->_M_impl._M_finish, __x._M_impl._M_finish); 477 std::swap(this->_M_impl._M_map, __x._M_impl._M_map); 478 std::swap(this->_M_impl._M_map_size, __x._M_impl._M_map_size); 479 } 480 } 481 #endif 482 483 ~_Deque_base(); 484 485 protected: 486 //This struct encapsulates the implementation of the std::deque 487 //standard container and at the same time makes use of the EBO 488 //for empty allocators. 489 typedef typename _Alloc::template rebind<_Tp*>::other _Map_alloc_type; 490 491 typedef typename _Alloc::template rebind<_Tp>::other _Tp_alloc_type; 492 493 struct _Deque_impl 494 : public _Tp_alloc_type 495 { 496 _Tp** _M_map; 497 size_t _M_map_size; 498 iterator _M_start; 499 iterator _M_finish; 500 501 _Deque_impl() 502 : _Tp_alloc_type(), _M_map(0), _M_map_size(0), 503 _M_start(), _M_finish() 504 { } 505 506 _Deque_impl(const _Tp_alloc_type& __a) 507 : _Tp_alloc_type(__a), _M_map(0), _M_map_size(0), 508 _M_start(), _M_finish() 509 { } 510 511 #ifdef __GXX_EXPERIMENTAL_CXX0X__ 512 _Deque_impl(_Tp_alloc_type&& __a) 513 : _Tp_alloc_type(std::move(__a)), _M_map(0), _M_map_size(0), 514 _M_start(), _M_finish() 515 { } 516 #endif 517 }; 518 519 _Tp_alloc_type& 520 _M_get_Tp_allocator() _GLIBCXX_NOEXCEPT 521 { return *static_cast<_Tp_alloc_type*>(&this->_M_impl); } 522 523 const _Tp_alloc_type& 524 _M_get_Tp_allocator() const _GLIBCXX_NOEXCEPT 525 { return *static_cast<const _Tp_alloc_type*>(&this->_M_impl); } 526 527 _Map_alloc_type 528 _M_get_map_allocator() const _GLIBCXX_NOEXCEPT 529 { return _Map_alloc_type(_M_get_Tp_allocator()); } 530 531 _Tp* 532 _M_allocate_node() 533 { 534 return _M_impl._Tp_alloc_type::allocate(__deque_buf_size(sizeof(_Tp))); 535 } 536 537 void 538 _M_deallocate_node(_Tp* __p) 539 { 540 _M_impl._Tp_alloc_type::deallocate(__p, __deque_buf_size(sizeof(_Tp))); 541 } 542 543 _Tp** 544 _M_allocate_map(size_t __n) 545 { return _M_get_map_allocator().allocate(__n); } 546 547 void 548 _M_deallocate_map(_Tp** __p, size_t __n) 549 { _M_get_map_allocator().deallocate(__p, __n); } 550 551 protected: 552 void _M_initialize_map(size_t); 553 void _M_create_nodes(_Tp** __nstart, _Tp** __nfinish); 554 void _M_destroy_nodes(_Tp** __nstart, _Tp** __nfinish); 555 enum { _S_initial_map_size = 8 }; 556 557 _Deque_impl _M_impl; 558 }; 559 560 template<typename _Tp, typename _Alloc> 561 _Deque_base<_Tp, _Alloc>:: 562 ~_Deque_base() 563 { 564 if (this->_M_impl._M_map) 565 { 566 _M_destroy_nodes(this->_M_impl._M_start._M_node, 567 this->_M_impl._M_finish._M_node + 1); 568 _M_deallocate_map(this->_M_impl._M_map, this->_M_impl._M_map_size); 569 } 570 } 571 572 /** 573 * @brief Layout storage. 574 * @param __num_elements The count of T's for which to allocate space 575 * at first. 576 * @return Nothing. 577 * 578 * The initial underlying memory layout is a bit complicated... 579 */ 580 template<typename _Tp, typename _Alloc> 581 void 582 _Deque_base<_Tp, _Alloc>:: 583 _M_initialize_map(size_t __num_elements) 584 { 585 const size_t __num_nodes = (__num_elements/ __deque_buf_size(sizeof(_Tp)) 586 + 1); 587 588 this->_M_impl._M_map_size = std::max((size_t) _S_initial_map_size, 589 size_t(__num_nodes + 2)); 590 this->_M_impl._M_map = _M_allocate_map(this->_M_impl._M_map_size); 591 592 // For "small" maps (needing less than _M_map_size nodes), allocation 593 // starts in the middle elements and grows outwards. So nstart may be 594 // the beginning of _M_map, but for small maps it may be as far in as 595 // _M_map+3. 596 597 _Tp** __nstart = (this->_M_impl._M_map 598 + (this->_M_impl._M_map_size - __num_nodes) / 2); 599 _Tp** __nfinish = __nstart + __num_nodes; 600 601 __try 602 { _M_create_nodes(__nstart, __nfinish); } 603 __catch(...) 604 { 605 _M_deallocate_map(this->_M_impl._M_map, this->_M_impl._M_map_size); 606 this->_M_impl._M_map = 0; 607 this->_M_impl._M_map_size = 0; 608 __throw_exception_again; 609 } 610 611 this->_M_impl._M_start._M_set_node(__nstart); 612 this->_M_impl._M_finish._M_set_node(__nfinish - 1); 613 this->_M_impl._M_start._M_cur = _M_impl._M_start._M_first; 614 this->_M_impl._M_finish._M_cur = (this->_M_impl._M_finish._M_first 615 + __num_elements 616 % __deque_buf_size(sizeof(_Tp))); 617 } 618 619 template<typename _Tp, typename _Alloc> 620 void 621 _Deque_base<_Tp, _Alloc>:: 622 _M_create_nodes(_Tp** __nstart, _Tp** __nfinish) 623 { 624 _Tp** __cur; 625 __try 626 { 627 for (__cur = __nstart; __cur < __nfinish; ++__cur) 628 *__cur = this->_M_allocate_node(); 629 } 630 __catch(...) 631 { 632 _M_destroy_nodes(__nstart, __cur); 633 __throw_exception_again; 634 } 635 } 636 637 template<typename _Tp, typename _Alloc> 638 void 639 _Deque_base<_Tp, _Alloc>:: 640 _M_destroy_nodes(_Tp** __nstart, _Tp** __nfinish) 641 { 642 for (_Tp** __n = __nstart; __n < __nfinish; ++__n) 643 _M_deallocate_node(*__n); 644 } 645 646 /** 647 * @brief A standard container using fixed-size memory allocation and 648 * constant-time manipulation of elements at either end. 649 * 650 * @ingroup sequences 651 * 652 * Meets the requirements of a <a href="tables.html#65">container</a>, a 653 * <a href="tables.html#66">reversible container</a>, and a 654 * <a href="tables.html#67">sequence</a>, including the 655 * <a href="tables.html#68">optional sequence requirements</a>. 656 * 657 * In previous HP/SGI versions of deque, there was an extra template 658 * parameter so users could control the node size. This extension turned 659 * out to violate the C++ standard (it can be detected using template 660 * template parameters), and it was removed. 661 * 662 * Here's how a deque<Tp> manages memory. Each deque has 4 members: 663 * 664 * - Tp** _M_map 665 * - size_t _M_map_size 666 * - iterator _M_start, _M_finish 667 * 668 * map_size is at least 8. %map is an array of map_size 669 * pointers-to-@a nodes. (The name %map has nothing to do with the 670 * std::map class, and @b nodes should not be confused with 671 * std::list's usage of @a node.) 672 * 673 * A @a node has no specific type name as such, but it is referred 674 * to as @a node in this file. It is a simple array-of-Tp. If Tp 675 * is very large, there will be one Tp element per node (i.e., an 676 * @a array of one). For non-huge Tp's, node size is inversely 677 * related to Tp size: the larger the Tp, the fewer Tp's will fit 678 * in a node. The goal here is to keep the total size of a node 679 * relatively small and constant over different Tp's, to improve 680 * allocator efficiency. 681 * 682 * Not every pointer in the %map array will point to a node. If 683 * the initial number of elements in the deque is small, the 684 * /middle/ %map pointers will be valid, and the ones at the edges 685 * will be unused. This same situation will arise as the %map 686 * grows: available %map pointers, if any, will be on the ends. As 687 * new nodes are created, only a subset of the %map's pointers need 688 * to be copied @a outward. 689 * 690 * Class invariants: 691 * - For any nonsingular iterator i: 692 * - i.node points to a member of the %map array. (Yes, you read that 693 * correctly: i.node does not actually point to a node.) The member of 694 * the %map array is what actually points to the node. 695 * - i.first == *(i.node) (This points to the node (first Tp element).) 696 * - i.last == i.first + node_size 697 * - i.cur is a pointer in the range [i.first, i.last). NOTE: 698 * the implication of this is that i.cur is always a dereferenceable 699 * pointer, even if i is a past-the-end iterator. 700 * - Start and Finish are always nonsingular iterators. NOTE: this 701 * means that an empty deque must have one node, a deque with <N 702 * elements (where N is the node buffer size) must have one node, a 703 * deque with N through (2N-1) elements must have two nodes, etc. 704 * - For every node other than start.node and finish.node, every 705 * element in the node is an initialized object. If start.node == 706 * finish.node, then [start.cur, finish.cur) are initialized 707 * objects, and the elements outside that range are uninitialized 708 * storage. Otherwise, [start.cur, start.last) and [finish.first, 709 * finish.cur) are initialized objects, and [start.first, start.cur) 710 * and [finish.cur, finish.last) are uninitialized storage. 711 * - [%map, %map + map_size) is a valid, non-empty range. 712 * - [start.node, finish.node] is a valid range contained within 713 * [%map, %map + map_size). 714 * - A pointer in the range [%map, %map + map_size) points to an allocated 715 * node if and only if the pointer is in the range 716 * [start.node, finish.node]. 717 * 718 * Here's the magic: nothing in deque is @b aware of the discontiguous 719 * storage! 720 * 721 * The memory setup and layout occurs in the parent, _Base, and the iterator 722 * class is entirely responsible for @a leaping from one node to the next. 723 * All the implementation routines for deque itself work only through the 724 * start and finish iterators. This keeps the routines simple and sane, 725 * and we can use other standard algorithms as well. 726 */ 727 template<typename _Tp, typename _Alloc = std::allocator<_Tp> > 728 class deque : protected _Deque_base<_Tp, _Alloc> 729 { 730 // concept requirements 731 typedef typename _Alloc::value_type _Alloc_value_type; 732 __glibcxx_class_requires(_Tp, _SGIAssignableConcept) 733 __glibcxx_class_requires2(_Tp, _Alloc_value_type, _SameTypeConcept) 734 735 typedef _Deque_base<_Tp, _Alloc> _Base; 736 typedef typename _Base::_Tp_alloc_type _Tp_alloc_type; 737 738 public: 739 typedef _Tp value_type; 740 typedef typename _Tp_alloc_type::pointer pointer; 741 typedef typename _Tp_alloc_type::const_pointer const_pointer; 742 typedef typename _Tp_alloc_type::reference reference; 743 typedef typename _Tp_alloc_type::const_reference const_reference; 744 typedef typename _Base::iterator iterator; 745 typedef typename _Base::const_iterator const_iterator; 746 typedef std::reverse_iterator<const_iterator> const_reverse_iterator; 747 typedef std::reverse_iterator<iterator> reverse_iterator; 748 typedef size_t size_type; 749 typedef ptrdiff_t difference_type; 750 typedef _Alloc allocator_type; 751 752 protected: 753 typedef pointer* _Map_pointer; 754 755 static size_t _S_buffer_size() 756 { return __deque_buf_size(sizeof(_Tp)); } 757 758 // Functions controlling memory layout, and nothing else. 759 using _Base::_M_initialize_map; 760 using _Base::_M_create_nodes; 761 using _Base::_M_destroy_nodes; 762 using _Base::_M_allocate_node; 763 using _Base::_M_deallocate_node; 764 using _Base::_M_allocate_map; 765 using _Base::_M_deallocate_map; 766 using _Base::_M_get_Tp_allocator; 767 768 /** 769 * A total of four data members accumulated down the hierarchy. 770 * May be accessed via _M_impl.* 771 */ 772 using _Base::_M_impl; 773 774 public: 775 // [23.2.1.1] construct/copy/destroy 776 // (assign() and get_allocator() are also listed in this section) 777 /** 778 * @brief Default constructor creates no elements. 779 */ 780 deque() 781 : _Base() { } 782 783 /** 784 * @brief Creates a %deque with no elements. 785 * @param __a An allocator object. 786 */ 787 explicit 788 deque(const allocator_type& __a) 789 : _Base(__a, 0) { } 790 791 #ifdef __GXX_EXPERIMENTAL_CXX0X__ 792 /** 793 * @brief Creates a %deque with default constructed elements. 794 * @param __n The number of elements to initially create. 795 * 796 * This constructor fills the %deque with @a n default 797 * constructed elements. 798 */ 799 explicit 800 deque(size_type __n) 801 : _Base(__n) 802 { _M_default_initialize(); } 803 804 /** 805 * @brief Creates a %deque with copies of an exemplar element. 806 * @param __n The number of elements to initially create. 807 * @param __value An element to copy. 808 * @param __a An allocator. 809 * 810 * This constructor fills the %deque with @a __n copies of @a __value. 811 */ 812 deque(size_type __n, const value_type& __value, 813 const allocator_type& __a = allocator_type()) 814 : _Base(__a, __n) 815 { _M_fill_initialize(__value); } 816 #else 817 /** 818 * @brief Creates a %deque with copies of an exemplar element. 819 * @param __n The number of elements to initially create. 820 * @param __value An element to copy. 821 * @param __a An allocator. 822 * 823 * This constructor fills the %deque with @a __n copies of @a __value. 824 */ 825 explicit 826 deque(size_type __n, const value_type& __value = value_type(), 827 const allocator_type& __a = allocator_type()) 828 : _Base(__a, __n) 829 { _M_fill_initialize(__value); } 830 #endif 831 832 /** 833 * @brief %Deque copy constructor. 834 * @param __x A %deque of identical element and allocator types. 835 * 836 * The newly-created %deque uses a copy of the allocation object used 837 * by @a __x. 838 */ 839 deque(const deque& __x) 840 : _Base(__x._M_get_Tp_allocator(), __x.size()) 841 { std::__uninitialized_copy_a(__x.begin(), __x.end(), 842 this->_M_impl._M_start, 843 _M_get_Tp_allocator()); } 844 845 #ifdef __GXX_EXPERIMENTAL_CXX0X__ 846 /** 847 * @brief %Deque move constructor. 848 * @param __x A %deque of identical element and allocator types. 849 * 850 * The newly-created %deque contains the exact contents of @a __x. 851 * The contents of @a __x are a valid, but unspecified %deque. 852 */ 853 deque(deque&& __x) 854 : _Base(std::move(__x)) { } 855 856 /** 857 * @brief Builds a %deque from an initializer list. 858 * @param __l An initializer_list. 859 * @param __a An allocator object. 860 * 861 * Create a %deque consisting of copies of the elements in the 862 * initializer_list @a __l. 863 * 864 * This will call the element type's copy constructor N times 865 * (where N is __l.size()) and do no memory reallocation. 866 */ 867 deque(initializer_list<value_type> __l, 868 const allocator_type& __a = allocator_type()) 869 : _Base(__a) 870 { 871 _M_range_initialize(__l.begin(), __l.end(), 872 random_access_iterator_tag()); 873 } 874 #endif 875 876 /** 877 * @brief Builds a %deque from a range. 878 * @param __first An input iterator. 879 * @param __last An input iterator. 880 * @param __a An allocator object. 881 * 882 * Create a %deque consisting of copies of the elements from [__first, 883 * __last). 884 * 885 * If the iterators are forward, bidirectional, or random-access, then 886 * this will call the elements' copy constructor N times (where N is 887 * distance(__first,__last)) and do no memory reallocation. But if only 888 * input iterators are used, then this will do at most 2N calls to the 889 * copy constructor, and logN memory reallocations. 890 */ 891 template<typename _InputIterator> 892 deque(_InputIterator __first, _InputIterator __last, 893 const allocator_type& __a = allocator_type()) 894 : _Base(__a) 895 { 896 // Check whether it's an integral type. If so, it's not an iterator. 897 typedef typename std::__is_integer<_InputIterator>::__type _Integral; 898 _M_initialize_dispatch(__first, __last, _Integral()); 899 } 900 901 /** 902 * The dtor only erases the elements, and note that if the elements 903 * themselves are pointers, the pointed-to memory is not touched in any 904 * way. Managing the pointer is the user's responsibility. 905 */ 906 ~deque() _GLIBCXX_NOEXCEPT 907 { _M_destroy_data(begin(), end(), _M_get_Tp_allocator()); } 908 909 /** 910 * @brief %Deque assignment operator. 911 * @param __x A %deque of identical element and allocator types. 912 * 913 * All the elements of @a x are copied, but unlike the copy constructor, 914 * the allocator object is not copied. 915 */ 916 deque& 917 operator=(const deque& __x); 918 919 #ifdef __GXX_EXPERIMENTAL_CXX0X__ 920 /** 921 * @brief %Deque move assignment operator. 922 * @param __x A %deque of identical element and allocator types. 923 * 924 * The contents of @a __x are moved into this deque (without copying). 925 * @a __x is a valid, but unspecified %deque. 926 */ 927 deque& 928 operator=(deque&& __x) 929 { 930 // NB: DR 1204. 931 // NB: DR 675. 932 this->clear(); 933 this->swap(__x); 934 return *this; 935 } 936 937 /** 938 * @brief Assigns an initializer list to a %deque. 939 * @param __l An initializer_list. 940 * 941 * This function fills a %deque with copies of the elements in the 942 * initializer_list @a __l. 943 * 944 * Note that the assignment completely changes the %deque and that the 945 * resulting %deque's size is the same as the number of elements 946 * assigned. Old data may be lost. 947 */ 948 deque& 949 operator=(initializer_list<value_type> __l) 950 { 951 this->assign(__l.begin(), __l.end()); 952 return *this; 953 } 954 #endif 955 956 /** 957 * @brief Assigns a given value to a %deque. 958 * @param __n Number of elements to be assigned. 959 * @param __val Value to be assigned. 960 * 961 * This function fills a %deque with @a n copies of the given 962 * value. Note that the assignment completely changes the 963 * %deque and that the resulting %deque's size is the same as 964 * the number of elements assigned. Old data may be lost. 965 */ 966 void 967 assign(size_type __n, const value_type& __val) 968 { _M_fill_assign(__n, __val); } 969 970 /** 971 * @brief Assigns a range to a %deque. 972 * @param __first An input iterator. 973 * @param __last An input iterator. 974 * 975 * This function fills a %deque with copies of the elements in the 976 * range [__first,__last). 977 * 978 * Note that the assignment completely changes the %deque and that the 979 * resulting %deque's size is the same as the number of elements 980 * assigned. Old data may be lost. 981 */ 982 template<typename _InputIterator> 983 void 984 assign(_InputIterator __first, _InputIterator __last) 985 { 986 typedef typename std::__is_integer<_InputIterator>::__type _Integral; 987 _M_assign_dispatch(__first, __last, _Integral()); 988 } 989 990 #ifdef __GXX_EXPERIMENTAL_CXX0X__ 991 /** 992 * @brief Assigns an initializer list to a %deque. 993 * @param __l An initializer_list. 994 * 995 * This function fills a %deque with copies of the elements in the 996 * initializer_list @a __l. 997 * 998 * Note that the assignment completely changes the %deque and that the 999 * resulting %deque's size is the same as the number of elements 1000 * assigned. Old data may be lost. 1001 */ 1002 void 1003 assign(initializer_list<value_type> __l) 1004 { this->assign(__l.begin(), __l.end()); } 1005 #endif 1006 1007 /// Get a copy of the memory allocation object. 1008 allocator_type 1009 get_allocator() const _GLIBCXX_NOEXCEPT 1010 { return _Base::get_allocator(); } 1011 1012 // iterators 1013 /** 1014 * Returns a read/write iterator that points to the first element in the 1015 * %deque. Iteration is done in ordinary element order. 1016 */ 1017 iterator 1018 begin() _GLIBCXX_NOEXCEPT 1019 { return this->_M_impl._M_start; } 1020 1021 /** 1022 * Returns a read-only (constant) iterator that points to the first 1023 * element in the %deque. Iteration is done in ordinary element order. 1024 */ 1025 const_iterator 1026 begin() const _GLIBCXX_NOEXCEPT 1027 { return this->_M_impl._M_start; } 1028 1029 /** 1030 * Returns a read/write iterator that points one past the last 1031 * element in the %deque. Iteration is done in ordinary 1032 * element order. 1033 */ 1034 iterator 1035 end() _GLIBCXX_NOEXCEPT 1036 { return this->_M_impl._M_finish; } 1037 1038 /** 1039 * Returns a read-only (constant) iterator that points one past 1040 * the last element in the %deque. Iteration is done in 1041 * ordinary element order. 1042 */ 1043 const_iterator 1044 end() const _GLIBCXX_NOEXCEPT 1045 { return this->_M_impl._M_finish; } 1046 1047 /** 1048 * Returns a read/write reverse iterator that points to the 1049 * last element in the %deque. Iteration is done in reverse 1050 * element order. 1051 */ 1052 reverse_iterator 1053 rbegin() _GLIBCXX_NOEXCEPT 1054 { return reverse_iterator(this->_M_impl._M_finish); } 1055 1056 /** 1057 * Returns a read-only (constant) reverse iterator that points 1058 * to the last element in the %deque. Iteration is done in 1059 * reverse element order. 1060 */ 1061 const_reverse_iterator 1062 rbegin() const _GLIBCXX_NOEXCEPT 1063 { return const_reverse_iterator(this->_M_impl._M_finish); } 1064 1065 /** 1066 * Returns a read/write reverse iterator that points to one 1067 * before the first element in the %deque. Iteration is done 1068 * in reverse element order. 1069 */ 1070 reverse_iterator 1071 rend() _GLIBCXX_NOEXCEPT 1072 { return reverse_iterator(this->_M_impl._M_start); } 1073 1074 /** 1075 * Returns a read-only (constant) reverse iterator that points 1076 * to one before the first element in the %deque. Iteration is 1077 * done in reverse element order. 1078 */ 1079 const_reverse_iterator 1080 rend() const _GLIBCXX_NOEXCEPT 1081 { return const_reverse_iterator(this->_M_impl._M_start); } 1082 1083 #ifdef __GXX_EXPERIMENTAL_CXX0X__ 1084 /** 1085 * Returns a read-only (constant) iterator that points to the first 1086 * element in the %deque. Iteration is done in ordinary element order. 1087 */ 1088 const_iterator 1089 cbegin() const noexcept 1090 { return this->_M_impl._M_start; } 1091 1092 /** 1093 * Returns a read-only (constant) iterator that points one past 1094 * the last element in the %deque. Iteration is done in 1095 * ordinary element order. 1096 */ 1097 const_iterator 1098 cend() const noexcept 1099 { return this->_M_impl._M_finish; } 1100 1101 /** 1102 * Returns a read-only (constant) reverse iterator that points 1103 * to the last element in the %deque. Iteration is done in 1104 * reverse element order. 1105 */ 1106 const_reverse_iterator 1107 crbegin() const noexcept 1108 { return const_reverse_iterator(this->_M_impl._M_finish); } 1109 1110 /** 1111 * Returns a read-only (constant) reverse iterator that points 1112 * to one before the first element in the %deque. Iteration is 1113 * done in reverse element order. 1114 */ 1115 const_reverse_iterator 1116 crend() const noexcept 1117 { return const_reverse_iterator(this->_M_impl._M_start); } 1118 #endif 1119 1120 // [23.2.1.2] capacity 1121 /** Returns the number of elements in the %deque. */ 1122 size_type 1123 size() const _GLIBCXX_NOEXCEPT 1124 { return this->_M_impl._M_finish - this->_M_impl._M_start; } 1125 1126 /** Returns the size() of the largest possible %deque. */ 1127 size_type 1128 max_size() const _GLIBCXX_NOEXCEPT 1129 { return _M_get_Tp_allocator().max_size(); } 1130 1131 #ifdef __GXX_EXPERIMENTAL_CXX0X__ 1132 /** 1133 * @brief Resizes the %deque to the specified number of elements. 1134 * @param __new_size Number of elements the %deque should contain. 1135 * 1136 * This function will %resize the %deque to the specified 1137 * number of elements. If the number is smaller than the 1138 * %deque's current size the %deque is truncated, otherwise 1139 * default constructed elements are appended. 1140 */ 1141 void 1142 resize(size_type __new_size) 1143 { 1144 const size_type __len = size(); 1145 if (__new_size > __len) 1146 _M_default_append(__new_size - __len); 1147 else if (__new_size < __len) 1148 _M_erase_at_end(this->_M_impl._M_start 1149 + difference_type(__new_size)); 1150 } 1151 1152 /** 1153 * @brief Resizes the %deque to the specified number of elements. 1154 * @param __new_size Number of elements the %deque should contain. 1155 * @param __x Data with which new elements should be populated. 1156 * 1157 * This function will %resize the %deque to the specified 1158 * number of elements. If the number is smaller than the 1159 * %deque's current size the %deque is truncated, otherwise the 1160 * %deque is extended and new elements are populated with given 1161 * data. 1162 */ 1163 void 1164 resize(size_type __new_size, const value_type& __x) 1165 { 1166 const size_type __len = size(); 1167 if (__new_size > __len) 1168 insert(this->_M_impl._M_finish, __new_size - __len, __x); 1169 else if (__new_size < __len) 1170 _M_erase_at_end(this->_M_impl._M_start 1171 + difference_type(__new_size)); 1172 } 1173 #else 1174 /** 1175 * @brief Resizes the %deque to the specified number of elements. 1176 * @param __new_size Number of elements the %deque should contain. 1177 * @param __x Data with which new elements should be populated. 1178 * 1179 * This function will %resize the %deque to the specified 1180 * number of elements. If the number is smaller than the 1181 * %deque's current size the %deque is truncated, otherwise the 1182 * %deque is extended and new elements are populated with given 1183 * data. 1184 */ 1185 void 1186 resize(size_type __new_size, value_type __x = value_type()) 1187 { 1188 const size_type __len = size(); 1189 if (__new_size > __len) 1190 insert(this->_M_impl._M_finish, __new_size - __len, __x); 1191 else if (__new_size < __len) 1192 _M_erase_at_end(this->_M_impl._M_start 1193 + difference_type(__new_size)); 1194 } 1195 #endif 1196 1197 #ifdef __GXX_EXPERIMENTAL_CXX0X__ 1198 /** A non-binding request to reduce memory use. */ 1199 void 1200 shrink_to_fit() 1201 { _M_shrink_to_fit(); } 1202 #endif 1203 1204 /** 1205 * Returns true if the %deque is empty. (Thus begin() would 1206 * equal end().) 1207 */ 1208 bool 1209 empty() const _GLIBCXX_NOEXCEPT 1210 { return this->_M_impl._M_finish == this->_M_impl._M_start; } 1211 1212 // element access 1213 /** 1214 * @brief Subscript access to the data contained in the %deque. 1215 * @param __n The index of the element for which data should be 1216 * accessed. 1217 * @return Read/write reference to data. 1218 * 1219 * This operator allows for easy, array-style, data access. 1220 * Note that data access with this operator is unchecked and 1221 * out_of_range lookups are not defined. (For checked lookups 1222 * see at().) 1223 */ 1224 reference 1225 operator[](size_type __n) 1226 { return this->_M_impl._M_start[difference_type(__n)]; } 1227 1228 /** 1229 * @brief Subscript access to the data contained in the %deque. 1230 * @param __n The index of the element for which data should be 1231 * accessed. 1232 * @return Read-only (constant) reference to data. 1233 * 1234 * This operator allows for easy, array-style, data access. 1235 * Note that data access with this operator is unchecked and 1236 * out_of_range lookups are not defined. (For checked lookups 1237 * see at().) 1238 */ 1239 const_reference 1240 operator[](size_type __n) const 1241 { return this->_M_impl._M_start[difference_type(__n)]; } 1242 1243 protected: 1244 /// Safety check used only from at(). 1245 void 1246 _M_range_check(size_type __n) const 1247 { 1248 if (__n >= this->size()) 1249 __throw_out_of_range(__N("deque::_M_range_check")); 1250 } 1251 1252 public: 1253 /** 1254 * @brief Provides access to the data contained in the %deque. 1255 * @param __n The index of the element for which data should be 1256 * accessed. 1257 * @return Read/write reference to data. 1258 * @throw std::out_of_range If @a __n is an invalid index. 1259 * 1260 * This function provides for safer data access. The parameter 1261 * is first checked that it is in the range of the deque. The 1262 * function throws out_of_range if the check fails. 1263 */ 1264 reference 1265 at(size_type __n) 1266 { 1267 _M_range_check(__n); 1268 return (*this)[__n]; 1269 } 1270 1271 /** 1272 * @brief Provides access to the data contained in the %deque. 1273 * @param __n The index of the element for which data should be 1274 * accessed. 1275 * @return Read-only (constant) reference to data. 1276 * @throw std::out_of_range If @a __n is an invalid index. 1277 * 1278 * This function provides for safer data access. The parameter is first 1279 * checked that it is in the range of the deque. The function throws 1280 * out_of_range if the check fails. 1281 */ 1282 const_reference 1283 at(size_type __n) const 1284 { 1285 _M_range_check(__n); 1286 return (*this)[__n]; 1287 } 1288 1289 /** 1290 * Returns a read/write reference to the data at the first 1291 * element of the %deque. 1292 */ 1293 reference 1294 front() 1295 { return *begin(); } 1296 1297 /** 1298 * Returns a read-only (constant) reference to the data at the first 1299 * element of the %deque. 1300 */ 1301 const_reference 1302 front() const 1303 { return *begin(); } 1304 1305 /** 1306 * Returns a read/write reference to the data at the last element of the 1307 * %deque. 1308 */ 1309 reference 1310 back() 1311 { 1312 iterator __tmp = end(); 1313 --__tmp; 1314 return *__tmp; 1315 } 1316 1317 /** 1318 * Returns a read-only (constant) reference to the data at the last 1319 * element of the %deque. 1320 */ 1321 const_reference 1322 back() const 1323 { 1324 const_iterator __tmp = end(); 1325 --__tmp; 1326 return *__tmp; 1327 } 1328 1329 // [23.2.1.2] modifiers 1330 /** 1331 * @brief Add data to the front of the %deque. 1332 * @param __x Data to be added. 1333 * 1334 * This is a typical stack operation. The function creates an 1335 * element at the front of the %deque and assigns the given 1336 * data to it. Due to the nature of a %deque this operation 1337 * can be done in constant time. 1338 */ 1339 void 1340 push_front(const value_type& __x) 1341 { 1342 if (this->_M_impl._M_start._M_cur != this->_M_impl._M_start._M_first) 1343 { 1344 this->_M_impl.construct(this->_M_impl._M_start._M_cur - 1, __x); 1345 --this->_M_impl._M_start._M_cur; 1346 } 1347 else 1348 _M_push_front_aux(__x); 1349 } 1350 1351 #ifdef __GXX_EXPERIMENTAL_CXX0X__ 1352 void 1353 push_front(value_type&& __x) 1354 { emplace_front(std::move(__x)); } 1355 1356 template<typename... _Args> 1357 void 1358 emplace_front(_Args&&... __args); 1359 #endif 1360 1361 /** 1362 * @brief Add data to the end of the %deque. 1363 * @param __x Data to be added. 1364 * 1365 * This is a typical stack operation. The function creates an 1366 * element at the end of the %deque and assigns the given data 1367 * to it. Due to the nature of a %deque this operation can be 1368 * done in constant time. 1369 */ 1370 void 1371 push_back(const value_type& __x) 1372 { 1373 if (this->_M_impl._M_finish._M_cur 1374 != this->_M_impl._M_finish._M_last - 1) 1375 { 1376 this->_M_impl.construct(this->_M_impl._M_finish._M_cur, __x); 1377 ++this->_M_impl._M_finish._M_cur; 1378 } 1379 else 1380 _M_push_back_aux(__x); 1381 } 1382 1383 #ifdef __GXX_EXPERIMENTAL_CXX0X__ 1384 void 1385 push_back(value_type&& __x) 1386 { emplace_back(std::move(__x)); } 1387 1388 template<typename... _Args> 1389 void 1390 emplace_back(_Args&&... __args); 1391 #endif 1392 1393 /** 1394 * @brief Removes first element. 1395 * 1396 * This is a typical stack operation. It shrinks the %deque by one. 1397 * 1398 * Note that no data is returned, and if the first element's data is 1399 * needed, it should be retrieved before pop_front() is called. 1400 */ 1401 void 1402 pop_front() 1403 { 1404 if (this->_M_impl._M_start._M_cur 1405 != this->_M_impl._M_start._M_last - 1) 1406 { 1407 this->_M_impl.destroy(this->_M_impl._M_start._M_cur); 1408 ++this->_M_impl._M_start._M_cur; 1409 } 1410 else 1411 _M_pop_front_aux(); 1412 } 1413 1414 /** 1415 * @brief Removes last element. 1416 * 1417 * This is a typical stack operation. It shrinks the %deque by one. 1418 * 1419 * Note that no data is returned, and if the last element's data is 1420 * needed, it should be retrieved before pop_back() is called. 1421 */ 1422 void 1423 pop_back() 1424 { 1425 if (this->_M_impl._M_finish._M_cur 1426 != this->_M_impl._M_finish._M_first) 1427 { 1428 --this->_M_impl._M_finish._M_cur; 1429 this->_M_impl.destroy(this->_M_impl._M_finish._M_cur); 1430 } 1431 else 1432 _M_pop_back_aux(); 1433 } 1434 1435 #ifdef __GXX_EXPERIMENTAL_CXX0X__ 1436 /** 1437 * @brief Inserts an object in %deque before specified iterator. 1438 * @param __position An iterator into the %deque. 1439 * @param __args Arguments. 1440 * @return An iterator that points to the inserted data. 1441 * 1442 * This function will insert an object of type T constructed 1443 * with T(std::forward<Args>(args)...) before the specified location. 1444 */ 1445 template<typename... _Args> 1446 iterator 1447 emplace(iterator __position, _Args&&... __args); 1448 #endif 1449 1450 /** 1451 * @brief Inserts given value into %deque before specified iterator. 1452 * @param __position An iterator into the %deque. 1453 * @param __x Data to be inserted. 1454 * @return An iterator that points to the inserted data. 1455 * 1456 * This function will insert a copy of the given value before the 1457 * specified location. 1458 */ 1459 iterator 1460 insert(iterator __position, const value_type& __x); 1461 1462 #ifdef __GXX_EXPERIMENTAL_CXX0X__ 1463 /** 1464 * @brief Inserts given rvalue into %deque before specified iterator. 1465 * @param __position An iterator into the %deque. 1466 * @param __x Data to be inserted. 1467 * @return An iterator that points to the inserted data. 1468 * 1469 * This function will insert a copy of the given rvalue before the 1470 * specified location. 1471 */ 1472 iterator 1473 insert(iterator __position, value_type&& __x) 1474 { return emplace(__position, std::move(__x)); } 1475 1476 /** 1477 * @brief Inserts an initializer list into the %deque. 1478 * @param __p An iterator into the %deque. 1479 * @param __l An initializer_list. 1480 * 1481 * This function will insert copies of the data in the 1482 * initializer_list @a __l into the %deque before the location 1483 * specified by @a __p. This is known as <em>list insert</em>. 1484 */ 1485 void 1486 insert(iterator __p, initializer_list<value_type> __l) 1487 { this->insert(__p, __l.begin(), __l.end()); } 1488 #endif 1489 1490 /** 1491 * @brief Inserts a number of copies of given data into the %deque. 1492 * @param __position An iterator into the %deque. 1493 * @param __n Number of elements to be inserted. 1494 * @param __x Data to be inserted. 1495 * 1496 * This function will insert a specified number of copies of the given 1497 * data before the location specified by @a __position. 1498 */ 1499 void 1500 insert(iterator __position, size_type __n, const value_type& __x) 1501 { _M_fill_insert(__position, __n, __x); } 1502 1503 /** 1504 * @brief Inserts a range into the %deque. 1505 * @param __position An iterator into the %deque. 1506 * @param __first An input iterator. 1507 * @param __last An input iterator. 1508 * 1509 * This function will insert copies of the data in the range 1510 * [__first,__last) into the %deque before the location specified 1511 * by @a __position. This is known as <em>range insert</em>. 1512 */ 1513 template<typename _InputIterator> 1514 void 1515 insert(iterator __position, _InputIterator __first, 1516 _InputIterator __last) 1517 { 1518 // Check whether it's an integral type. If so, it's not an iterator. 1519 typedef typename std::__is_integer<_InputIterator>::__type _Integral; 1520 _M_insert_dispatch(__position, __first, __last, _Integral()); 1521 } 1522 1523 /** 1524 * @brief Remove element at given position. 1525 * @param __position Iterator pointing to element to be erased. 1526 * @return An iterator pointing to the next element (or end()). 1527 * 1528 * This function will erase the element at the given position and thus 1529 * shorten the %deque by one. 1530 * 1531 * The user is cautioned that 1532 * this function only erases the element, and that if the element is 1533 * itself a pointer, the pointed-to memory is not touched in any way. 1534 * Managing the pointer is the user's responsibility. 1535 */ 1536 iterator 1537 erase(iterator __position); 1538 1539 /** 1540 * @brief Remove a range of elements. 1541 * @param __first Iterator pointing to the first element to be erased. 1542 * @param __last Iterator pointing to one past the last element to be 1543 * erased. 1544 * @return An iterator pointing to the element pointed to by @a last 1545 * prior to erasing (or end()). 1546 * 1547 * This function will erase the elements in the range 1548 * [__first,__last) and shorten the %deque accordingly. 1549 * 1550 * The user is cautioned that 1551 * this function only erases the elements, and that if the elements 1552 * themselves are pointers, the pointed-to memory is not touched in any 1553 * way. Managing the pointer is the user's responsibility. 1554 */ 1555 iterator 1556 erase(iterator __first, iterator __last); 1557 1558 /** 1559 * @brief Swaps data with another %deque. 1560 * @param __x A %deque of the same element and allocator types. 1561 * 1562 * This exchanges the elements between two deques in constant time. 1563 * (Four pointers, so it should be quite fast.) 1564 * Note that the global std::swap() function is specialized such that 1565 * std::swap(d1,d2) will feed to this function. 1566 */ 1567 void 1568 swap(deque& __x) 1569 { 1570 std::swap(this->_M_impl._M_start, __x._M_impl._M_start); 1571 std::swap(this->_M_impl._M_finish, __x._M_impl._M_finish); 1572 std::swap(this->_M_impl._M_map, __x._M_impl._M_map); 1573 std::swap(this->_M_impl._M_map_size, __x._M_impl._M_map_size); 1574 1575 // _GLIBCXX_RESOLVE_LIB_DEFECTS 1576 // 431. Swapping containers with unequal allocators. 1577 std::__alloc_swap<_Tp_alloc_type>::_S_do_it(_M_get_Tp_allocator(), 1578 __x._M_get_Tp_allocator()); 1579 } 1580 1581 /** 1582 * Erases all the elements. Note that this function only erases the 1583 * elements, and that if the elements themselves are pointers, the 1584 * pointed-to memory is not touched in any way. Managing the pointer is 1585 * the user's responsibility. 1586 */ 1587 void 1588 clear() _GLIBCXX_NOEXCEPT 1589 { _M_erase_at_end(begin()); } 1590 1591 protected: 1592 // Internal constructor functions follow. 1593 1594 // called by the range constructor to implement [23.1.1]/9 1595 1596 // _GLIBCXX_RESOLVE_LIB_DEFECTS 1597 // 438. Ambiguity in the "do the right thing" clause 1598 template<typename _Integer> 1599 void 1600 _M_initialize_dispatch(_Integer __n, _Integer __x, __true_type) 1601 { 1602 _M_initialize_map(static_cast<size_type>(__n)); 1603 _M_fill_initialize(__x); 1604 } 1605 1606 // called by the range constructor to implement [23.1.1]/9 1607 template<typename _InputIterator> 1608 void 1609 _M_initialize_dispatch(_InputIterator __first, _InputIterator __last, 1610 __false_type) 1611 { 1612 typedef typename std::iterator_traits<_InputIterator>:: 1613 iterator_category _IterCategory; 1614 _M_range_initialize(__first, __last, _IterCategory()); 1615 } 1616 1617 // called by the second initialize_dispatch above 1618 //@{ 1619 /** 1620 * @brief Fills the deque with whatever is in [first,last). 1621 * @param __first An input iterator. 1622 * @param __last An input iterator. 1623 * @return Nothing. 1624 * 1625 * If the iterators are actually forward iterators (or better), then the 1626 * memory layout can be done all at once. Else we move forward using 1627 * push_back on each value from the iterator. 1628 */ 1629 template<typename _InputIterator> 1630 void 1631 _M_range_initialize(_InputIterator __first, _InputIterator __last, 1632 std::input_iterator_tag); 1633 1634 // called by the second initialize_dispatch above 1635 template<typename _ForwardIterator> 1636 void 1637 _M_range_initialize(_ForwardIterator __first, _ForwardIterator __last, 1638 std::forward_iterator_tag); 1639 //@} 1640 1641 /** 1642 * @brief Fills the %deque with copies of value. 1643 * @param __value Initial value. 1644 * @return Nothing. 1645 * @pre _M_start and _M_finish have already been initialized, 1646 * but none of the %deque's elements have yet been constructed. 1647 * 1648 * This function is called only when the user provides an explicit size 1649 * (with or without an explicit exemplar value). 1650 */ 1651 void 1652 _M_fill_initialize(const value_type& __value); 1653 1654 #ifdef __GXX_EXPERIMENTAL_CXX0X__ 1655 // called by deque(n). 1656 void 1657 _M_default_initialize(); 1658 #endif 1659 1660 // Internal assign functions follow. The *_aux functions do the actual 1661 // assignment work for the range versions. 1662 1663 // called by the range assign to implement [23.1.1]/9 1664 1665 // _GLIBCXX_RESOLVE_LIB_DEFECTS 1666 // 438. Ambiguity in the "do the right thing" clause 1667 template<typename _Integer> 1668 void 1669 _M_assign_dispatch(_Integer __n, _Integer __val, __true_type) 1670 { _M_fill_assign(__n, __val); } 1671 1672 // called by the range assign to implement [23.1.1]/9 1673 template<typename _InputIterator> 1674 void 1675 _M_assign_dispatch(_InputIterator __first, _InputIterator __last, 1676 __false_type) 1677 { 1678 typedef typename std::iterator_traits<_InputIterator>:: 1679 iterator_category _IterCategory; 1680 _M_assign_aux(__first, __last, _IterCategory()); 1681 } 1682 1683 // called by the second assign_dispatch above 1684 template<typename _InputIterator> 1685 void 1686 _M_assign_aux(_InputIterator __first, _InputIterator __last, 1687 std::input_iterator_tag); 1688 1689 // called by the second assign_dispatch above 1690 template<typename _ForwardIterator> 1691 void 1692 _M_assign_aux(_ForwardIterator __first, _ForwardIterator __last, 1693 std::forward_iterator_tag) 1694 { 1695 const size_type __len = std::distance(__first, __last); 1696 if (__len > size()) 1697 { 1698 _ForwardIterator __mid = __first; 1699 std::advance(__mid, size()); 1700 std::copy(__first, __mid, begin()); 1701 insert(end(), __mid, __last); 1702 } 1703 else 1704 _M_erase_at_end(std::copy(__first, __last, begin())); 1705 } 1706 1707 // Called by assign(n,t), and the range assign when it turns out 1708 // to be the same thing. 1709 void 1710 _M_fill_assign(size_type __n, const value_type& __val) 1711 { 1712 if (__n > size()) 1713 { 1714 std::fill(begin(), end(), __val); 1715 insert(end(), __n - size(), __val); 1716 } 1717 else 1718 { 1719 _M_erase_at_end(begin() + difference_type(__n)); 1720 std::fill(begin(), end(), __val); 1721 } 1722 } 1723 1724 //@{ 1725 /// Helper functions for push_* and pop_*. 1726 #ifndef __GXX_EXPERIMENTAL_CXX0X__ 1727 void _M_push_back_aux(const value_type&); 1728 1729 void _M_push_front_aux(const value_type&); 1730 #else 1731 template<typename... _Args> 1732 void _M_push_back_aux(_Args&&... __args); 1733 1734 template<typename... _Args> 1735 void _M_push_front_aux(_Args&&... __args); 1736 #endif 1737 1738 void _M_pop_back_aux(); 1739 1740 void _M_pop_front_aux(); 1741 //@} 1742 1743 // Internal insert functions follow. The *_aux functions do the actual 1744 // insertion work when all shortcuts fail. 1745 1746 // called by the range insert to implement [23.1.1]/9 1747 1748 // _GLIBCXX_RESOLVE_LIB_DEFECTS 1749 // 438. Ambiguity in the "do the right thing" clause 1750 template<typename _Integer> 1751 void 1752 _M_insert_dispatch(iterator __pos, 1753 _Integer __n, _Integer __x, __true_type) 1754 { _M_fill_insert(__pos, __n, __x); } 1755 1756 // called by the range insert to implement [23.1.1]/9 1757 template<typename _InputIterator> 1758 void 1759 _M_insert_dispatch(iterator __pos, 1760 _InputIterator __first, _InputIterator __last, 1761 __false_type) 1762 { 1763 typedef typename std::iterator_traits<_InputIterator>:: 1764 iterator_category _IterCategory; 1765 _M_range_insert_aux(__pos, __first, __last, _IterCategory()); 1766 } 1767 1768 // called by the second insert_dispatch above 1769 template<typename _InputIterator> 1770 void 1771 _M_range_insert_aux(iterator __pos, _InputIterator __first, 1772 _InputIterator __last, std::input_iterator_tag); 1773 1774 // called by the second insert_dispatch above 1775 template<typename _ForwardIterator> 1776 void 1777 _M_range_insert_aux(iterator __pos, _ForwardIterator __first, 1778 _ForwardIterator __last, std::forward_iterator_tag); 1779 1780 // Called by insert(p,n,x), and the range insert when it turns out to be 1781 // the same thing. Can use fill functions in optimal situations, 1782 // otherwise passes off to insert_aux(p,n,x). 1783 void 1784 _M_fill_insert(iterator __pos, size_type __n, const value_type& __x); 1785 1786 // called by insert(p,x) 1787 #ifndef __GXX_EXPERIMENTAL_CXX0X__ 1788 iterator 1789 _M_insert_aux(iterator __pos, const value_type& __x); 1790 #else 1791 template<typename... _Args> 1792 iterator 1793 _M_insert_aux(iterator __pos, _Args&&... __args); 1794 #endif 1795 1796 // called by insert(p,n,x) via fill_insert 1797 void 1798 _M_insert_aux(iterator __pos, size_type __n, const value_type& __x); 1799 1800 // called by range_insert_aux for forward iterators 1801 template<typename _ForwardIterator> 1802 void 1803 _M_insert_aux(iterator __pos, 1804 _ForwardIterator __first, _ForwardIterator __last, 1805 size_type __n); 1806 1807 1808 // Internal erase functions follow. 1809 1810 void 1811 _M_destroy_data_aux(iterator __first, iterator __last); 1812 1813 // Called by ~deque(). 1814 // NB: Doesn't deallocate the nodes. 1815 template<typename _Alloc1> 1816 void 1817 _M_destroy_data(iterator __first, iterator __last, const _Alloc1&) 1818 { _M_destroy_data_aux(__first, __last); } 1819 1820 void 1821 _M_destroy_data(iterator __first, iterator __last, 1822 const std::allocator<_Tp>&) 1823 { 1824 if (!__has_trivial_destructor(value_type)) 1825 _M_destroy_data_aux(__first, __last); 1826 } 1827 1828 // Called by erase(q1, q2). 1829 void 1830 _M_erase_at_begin(iterator __pos) 1831 { 1832 _M_destroy_data(begin(), __pos, _M_get_Tp_allocator()); 1833 _M_destroy_nodes(this->_M_impl._M_start._M_node, __pos._M_node); 1834 this->_M_impl._M_start = __pos; 1835 } 1836 1837 // Called by erase(q1, q2), resize(), clear(), _M_assign_aux, 1838 // _M_fill_assign, operator=. 1839 void 1840 _M_erase_at_end(iterator __pos) 1841 { 1842 _M_destroy_data(__pos, end(), _M_get_Tp_allocator()); 1843 _M_destroy_nodes(__pos._M_node + 1, 1844 this->_M_impl._M_finish._M_node + 1); 1845 this->_M_impl._M_finish = __pos; 1846 } 1847 1848 #ifdef __GXX_EXPERIMENTAL_CXX0X__ 1849 // Called by resize(sz). 1850 void 1851 _M_default_append(size_type __n); 1852 1853 bool 1854 _M_shrink_to_fit(); 1855 #endif 1856 1857 //@{ 1858 /// Memory-handling helpers for the previous internal insert functions. 1859 iterator 1860 _M_reserve_elements_at_front(size_type __n) 1861 { 1862 const size_type __vacancies = this->_M_impl._M_start._M_cur 1863 - this->_M_impl._M_start._M_first; 1864 if (__n > __vacancies) 1865 _M_new_elements_at_front(__n - __vacancies); 1866 return this->_M_impl._M_start - difference_type(__n); 1867 } 1868 1869 iterator 1870 _M_reserve_elements_at_back(size_type __n) 1871 { 1872 const size_type __vacancies = (this->_M_impl._M_finish._M_last 1873 - this->_M_impl._M_finish._M_cur) - 1; 1874 if (__n > __vacancies) 1875 _M_new_elements_at_back(__n - __vacancies); 1876 return this->_M_impl._M_finish + difference_type(__n); 1877 } 1878 1879 void 1880 _M_new_elements_at_front(size_type __new_elements); 1881 1882 void 1883 _M_new_elements_at_back(size_type __new_elements); 1884 //@} 1885 1886 1887 //@{ 1888 /** 1889 * @brief Memory-handling helpers for the major %map. 1890 * 1891 * Makes sure the _M_map has space for new nodes. Does not 1892 * actually add the nodes. Can invalidate _M_map pointers. 1893 * (And consequently, %deque iterators.) 1894 */ 1895 void 1896 _M_reserve_map_at_back(size_type __nodes_to_add = 1) 1897 { 1898 if (__nodes_to_add + 1 > this->_M_impl._M_map_size 1899 - (this->_M_impl._M_finish._M_node - this->_M_impl._M_map)) 1900 _M_reallocate_map(__nodes_to_add, false); 1901 } 1902 1903 void 1904 _M_reserve_map_at_front(size_type __nodes_to_add = 1) 1905 { 1906 if (__nodes_to_add > size_type(this->_M_impl._M_start._M_node 1907 - this->_M_impl._M_map)) 1908 _M_reallocate_map(__nodes_to_add, true); 1909 } 1910 1911 void 1912 _M_reallocate_map(size_type __nodes_to_add, bool __add_at_front); 1913 //@} 1914 }; 1915 1916 1917 /** 1918 * @brief Deque equality comparison. 1919 * @param __x A %deque. 1920 * @param __y A %deque of the same type as @a __x. 1921 * @return True iff the size and elements of the deques are equal. 1922 * 1923 * This is an equivalence relation. It is linear in the size of the 1924 * deques. Deques are considered equivalent if their sizes are equal, 1925 * and if corresponding elements compare equal. 1926 */ 1927 template<typename _Tp, typename _Alloc> 1928 inline bool 1929 operator==(const deque<_Tp, _Alloc>& __x, 1930 const deque<_Tp, _Alloc>& __y) 1931 { return __x.size() == __y.size() 1932 && std::equal(__x.begin(), __x.end(), __y.begin()); } 1933 1934 /** 1935 * @brief Deque ordering relation. 1936 * @param __x A %deque. 1937 * @param __y A %deque of the same type as @a __x. 1938 * @return True iff @a x is lexicographically less than @a __y. 1939 * 1940 * This is a total ordering relation. It is linear in the size of the 1941 * deques. The elements must be comparable with @c <. 1942 * 1943 * See std::lexicographical_compare() for how the determination is made. 1944 */ 1945 template<typename _Tp, typename _Alloc> 1946 inline bool 1947 operator<(const deque<_Tp, _Alloc>& __x, 1948 const deque<_Tp, _Alloc>& __y) 1949 { return std::lexicographical_compare(__x.begin(), __x.end(), 1950 __y.begin(), __y.end()); } 1951 1952 /// Based on operator== 1953 template<typename _Tp, typename _Alloc> 1954 inline bool 1955 operator!=(const deque<_Tp, _Alloc>& __x, 1956 const deque<_Tp, _Alloc>& __y) 1957 { return !(__x == __y); } 1958 1959 /// Based on operator< 1960 template<typename _Tp, typename _Alloc> 1961 inline bool 1962 operator>(const deque<_Tp, _Alloc>& __x, 1963 const deque<_Tp, _Alloc>& __y) 1964 { return __y < __x; } 1965 1966 /// Based on operator< 1967 template<typename _Tp, typename _Alloc> 1968 inline bool 1969 operator<=(const deque<_Tp, _Alloc>& __x, 1970 const deque<_Tp, _Alloc>& __y) 1971 { return !(__y < __x); } 1972 1973 /// Based on operator< 1974 template<typename _Tp, typename _Alloc> 1975 inline bool 1976 operator>=(const deque<_Tp, _Alloc>& __x, 1977 const deque<_Tp, _Alloc>& __y) 1978 { return !(__x < __y); } 1979 1980 /// See std::deque::swap(). 1981 template<typename _Tp, typename _Alloc> 1982 inline void 1983 swap(deque<_Tp,_Alloc>& __x, deque<_Tp,_Alloc>& __y) 1984 { __x.swap(__y); } 1985 1986 #undef _GLIBCXX_DEQUE_BUF_SIZE 1987 1988 _GLIBCXX_END_NAMESPACE_CONTAINER 1989 } // namespace std 1990 1991 #endif /* _STL_DEQUE_H */ 1992
