1 // Deque implementation -*- C++ -*- 2 3 // Copyright (C) 2001-2013 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 /* 26 * 27 * Copyright (c) 1994 28 * Hewlett-Packard Company 29 * 30 * Permission to use, copy, modify, distribute and sell this software 31 * and its documentation for any purpose is hereby granted without fee, 32 * provided that the above copyright notice appear in all copies and 33 * that both that copyright notice and this permission notice appear 34 * in supporting documentation. Hewlett-Packard Company makes no 35 * representations about the suitability of this software for any 36 * purpose. It is provided "as is" without express or implied warranty. 37 * 38 * 39 * Copyright (c) 1997 40 * Silicon Graphics Computer Systems, Inc. 41 * 42 * Permission to use, copy, modify, distribute and sell this software 43 * and its documentation for any purpose is hereby granted without fee, 44 * provided that the above copyright notice appear in all copies and 45 * that both that copyright notice and this permission notice appear 46 * in supporting documentation. Silicon Graphics makes no 47 * representations about the suitability of this software for any 48 * purpose. It is provided "as is" without express or implied warranty. 49 */ 50 51 /** @file bits/stl_deque.h 52 * This is an internal header file, included by other library headers. 53 * Do not attempt to use it directly. @headername{deque} 54 */ 55 56 #ifndef _STL_DEQUE_H 57 #define _STL_DEQUE_H 1 58 59 #include <bits/concept_check.h> 60 #include <bits/stl_iterator_base_types.h> 61 #include <bits/stl_iterator_base_funcs.h> 62 #if __cplusplus >= 201103L 63 #include <initializer_list> 64 #endif 65 66 namespace std _GLIBCXX_VISIBILITY(default) 67 { 68 _GLIBCXX_BEGIN_NAMESPACE_CONTAINER 69 70 /** 71 * @brief This function controls the size of memory nodes. 72 * @param __size The size of an element. 73 * @return The number (not byte size) of elements per node. 74 * 75 * This function started off as a compiler kludge from SGI, but 76 * seems to be a useful wrapper around a repeated constant 77 * expression. The @b 512 is tunable (and no other code needs to 78 * change), but no investigation has been done since inheriting the 79 * SGI code. Touch _GLIBCXX_DEQUE_BUF_SIZE only if you know what 80 * you are doing, however: changing it breaks the binary 81 * compatibility!! 82 */ 83 84 #ifndef _GLIBCXX_DEQUE_BUF_SIZE 85 #define _GLIBCXX_DEQUE_BUF_SIZE 512 86 #endif 87 88 inline size_t 89 __deque_buf_size(size_t __size) 90 { return (__size < _GLIBCXX_DEQUE_BUF_SIZE 91 ? size_t(_GLIBCXX_DEQUE_BUF_SIZE / __size) : size_t(1)); } 92 93 94 /** 95 * @brief A deque::iterator. 96 * 97 * Quite a bit of intelligence here. Much of the functionality of 98 * deque is actually passed off to this class. A deque holds two 99 * of these internally, marking its valid range. Access to 100 * elements is done as offsets of either of those two, relying on 101 * operator overloading in this class. 102 * 103 * All the functions are op overloads except for _M_set_node. 104 */ 105 template<typename _Tp, typename _Ref, typename _Ptr> 106 struct _Deque_iterator 107 { 108 typedef _Deque_iterator<_Tp, _Tp&, _Tp*> iterator; 109 typedef _Deque_iterator<_Tp, const _Tp&, const _Tp*> const_iterator; 110 111 static size_t _S_buffer_size() 112 { return __deque_buf_size(sizeof(_Tp)); } 113 114 typedef std::random_access_iterator_tag iterator_category; 115 typedef _Tp value_type; 116 typedef _Ptr pointer; 117 typedef _Ref reference; 118 typedef size_t size_type; 119 typedef ptrdiff_t difference_type; 120 typedef _Tp** _Map_pointer; 121 typedef _Deque_iterator _Self; 122 123 _Tp* _M_cur; 124 _Tp* _M_first; 125 _Tp* _M_last; 126 _Map_pointer _M_node; 127 128 _Deque_iterator(_Tp* __x, _Map_pointer __y) 129 : _M_cur(__x), _M_first(*__y), 130 _M_last(*__y + _S_buffer_size()), _M_node(__y) { } 131 132 _Deque_iterator() 133 : _M_cur(0), _M_first(0), _M_last(0), _M_node(0) { } 134 135 _Deque_iterator(const iterator& __x) 136 : _M_cur(__x._M_cur), _M_first(__x._M_first), 137 _M_last(__x._M_last), _M_node(__x._M_node) { } 138 139 reference 140 operator*() const 141 { return *_M_cur; } 142 143 pointer 144 operator->() const 145 { return _M_cur; } 146 147 _Self& 148 operator++() 149 { 150 ++_M_cur; 151 if (_M_cur == _M_last) 152 { 153 _M_set_node(_M_node + 1); 154 _M_cur = _M_first; 155 } 156 return *this; 157 } 158 159 _Self 160 operator++(int) 161 { 162 _Self __tmp = *this; 163 ++*this; 164 return __tmp; 165 } 166 167 _Self& 168 operator--() 169 { 170 if (_M_cur == _M_first) 171 { 172 _M_set_node(_M_node - 1); 173 _M_cur = _M_last; 174 } 175 --_M_cur; 176 return *this; 177 } 178 179 _Self 180 operator--(int) 181 { 182 _Self __tmp = *this; 183 --*this; 184 return __tmp; 185 } 186 187 _Self& 188 operator+=(difference_type __n) 189 { 190 const difference_type __offset = __n + (_M_cur - _M_first); 191 if (__offset >= 0 && __offset < difference_type(_S_buffer_size())) 192 _M_cur += __n; 193 else 194 { 195 const difference_type __node_offset = 196 __offset > 0 ? __offset / difference_type(_S_buffer_size()) 197 : -difference_type((-__offset - 1) 198 / _S_buffer_size()) - 1; 199 _M_set_node(_M_node + __node_offset); 200 _M_cur = _M_first + (__offset - __node_offset 201 * difference_type(_S_buffer_size())); 202 } 203 return *this; 204 } 205 206 _Self 207 operator+(difference_type __n) const 208 { 209 _Self __tmp = *this; 210 return __tmp += __n; 211 } 212 213 _Self& 214 operator-=(difference_type __n) 215 { return *this += -__n; } 216 217 _Self 218 operator-(difference_type __n) const 219 { 220 _Self __tmp = *this; 221 return __tmp -= __n; 222 } 223 224 reference 225 operator[](difference_type __n) const 226 { return *(*this + __n); } 227 228 /** 229 * Prepares to traverse new_node. Sets everything except 230 * _M_cur, which should therefore be set by the caller 231 * immediately afterwards, based on _M_first and _M_last. 232 */ 233 void 234 _M_set_node(_Map_pointer __new_node) 235 { 236 _M_node = __new_node; 237 _M_first = *__new_node; 238 _M_last = _M_first + difference_type(_S_buffer_size()); 239 } 240 }; 241 242 // Note: we also provide overloads whose operands are of the same type in 243 // order to avoid ambiguous overload resolution when std::rel_ops operators 244 // are in scope (for additional details, see libstdc++/3628) 245 template<typename _Tp, typename _Ref, typename _Ptr> 246 inline bool 247 operator==(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x, 248 const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) 249 { return __x._M_cur == __y._M_cur; } 250 251 template<typename _Tp, typename _RefL, typename _PtrL, 252 typename _RefR, typename _PtrR> 253 inline bool 254 operator==(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x, 255 const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) 256 { return __x._M_cur == __y._M_cur; } 257 258 template<typename _Tp, typename _Ref, typename _Ptr> 259 inline bool 260 operator!=(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x, 261 const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) 262 { return !(__x == __y); } 263 264 template<typename _Tp, typename _RefL, typename _PtrL, 265 typename _RefR, typename _PtrR> 266 inline bool 267 operator!=(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x, 268 const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) 269 { return !(__x == __y); } 270 271 template<typename _Tp, typename _Ref, typename _Ptr> 272 inline bool 273 operator<(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x, 274 const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) 275 { return (__x._M_node == __y._M_node) ? (__x._M_cur < __y._M_cur) 276 : (__x._M_node < __y._M_node); } 277 278 template<typename _Tp, typename _RefL, typename _PtrL, 279 typename _RefR, typename _PtrR> 280 inline bool 281 operator<(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x, 282 const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) 283 { return (__x._M_node == __y._M_node) ? (__x._M_cur < __y._M_cur) 284 : (__x._M_node < __y._M_node); } 285 286 template<typename _Tp, typename _Ref, typename _Ptr> 287 inline bool 288 operator>(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x, 289 const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) 290 { return __y < __x; } 291 292 template<typename _Tp, typename _RefL, typename _PtrL, 293 typename _RefR, typename _PtrR> 294 inline bool 295 operator>(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x, 296 const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) 297 { return __y < __x; } 298 299 template<typename _Tp, typename _Ref, typename _Ptr> 300 inline bool 301 operator<=(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x, 302 const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) 303 { return !(__y < __x); } 304 305 template<typename _Tp, typename _RefL, typename _PtrL, 306 typename _RefR, typename _PtrR> 307 inline bool 308 operator<=(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x, 309 const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) 310 { return !(__y < __x); } 311 312 template<typename _Tp, typename _Ref, typename _Ptr> 313 inline bool 314 operator>=(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x, 315 const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) 316 { return !(__x < __y); } 317 318 template<typename _Tp, typename _RefL, typename _PtrL, 319 typename _RefR, typename _PtrR> 320 inline bool 321 operator>=(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x, 322 const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) 323 { return !(__x < __y); } 324 325 // _GLIBCXX_RESOLVE_LIB_DEFECTS 326 // According to the resolution of DR179 not only the various comparison 327 // operators but also operator- must accept mixed iterator/const_iterator 328 // parameters. 329 template<typename _Tp, typename _Ref, typename _Ptr> 330 inline typename _Deque_iterator<_Tp, _Ref, _Ptr>::difference_type 331 operator-(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x, 332 const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) 333 { 334 return typename _Deque_iterator<_Tp, _Ref, _Ptr>::difference_type 335 (_Deque_iterator<_Tp, _Ref, _Ptr>::_S_buffer_size()) 336 * (__x._M_node - __y._M_node - 1) + (__x._M_cur - __x._M_first) 337 + (__y._M_last - __y._M_cur); 338 } 339 340 template<typename _Tp, typename _RefL, typename _PtrL, 341 typename _RefR, typename _PtrR> 342 inline typename _Deque_iterator<_Tp, _RefL, _PtrL>::difference_type 343 operator-(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x, 344 const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) 345 { 346 return typename _Deque_iterator<_Tp, _RefL, _PtrL>::difference_type 347 (_Deque_iterator<_Tp, _RefL, _PtrL>::_S_buffer_size()) 348 * (__x._M_node - __y._M_node - 1) + (__x._M_cur - __x._M_first) 349 + (__y._M_last - __y._M_cur); 350 } 351 352 template<typename _Tp, typename _Ref, typename _Ptr> 353 inline _Deque_iterator<_Tp, _Ref, _Ptr> 354 operator+(ptrdiff_t __n, const _Deque_iterator<_Tp, _Ref, _Ptr>& __x) 355 { return __x + __n; } 356 357 template<typename _Tp> 358 void 359 fill(const _Deque_iterator<_Tp, _Tp&, _Tp*>&, 360 const _Deque_iterator<_Tp, _Tp&, _Tp*>&, const _Tp&); 361 362 template<typename _Tp> 363 _Deque_iterator<_Tp, _Tp&, _Tp*> 364 copy(_Deque_iterator<_Tp, const _Tp&, const _Tp*>, 365 _Deque_iterator<_Tp, const _Tp&, const _Tp*>, 366 _Deque_iterator<_Tp, _Tp&, _Tp*>); 367 368 template<typename _Tp> 369 inline _Deque_iterator<_Tp, _Tp&, _Tp*> 370 copy(_Deque_iterator<_Tp, _Tp&, _Tp*> __first, 371 _Deque_iterator<_Tp, _Tp&, _Tp*> __last, 372 _Deque_iterator<_Tp, _Tp&, _Tp*> __result) 373 { return std::copy(_Deque_iterator<_Tp, const _Tp&, const _Tp*>(__first), 374 _Deque_iterator<_Tp, const _Tp&, const _Tp*>(__last), 375 __result); } 376 377 template<typename _Tp> 378 _Deque_iterator<_Tp, _Tp&, _Tp*> 379 copy_backward(_Deque_iterator<_Tp, const _Tp&, const _Tp*>, 380 _Deque_iterator<_Tp, const _Tp&, const _Tp*>, 381 _Deque_iterator<_Tp, _Tp&, _Tp*>); 382 383 template<typename _Tp> 384 inline _Deque_iterator<_Tp, _Tp&, _Tp*> 385 copy_backward(_Deque_iterator<_Tp, _Tp&, _Tp*> __first, 386 _Deque_iterator<_Tp, _Tp&, _Tp*> __last, 387 _Deque_iterator<_Tp, _Tp&, _Tp*> __result) 388 { return std::copy_backward(_Deque_iterator<_Tp, 389 const _Tp&, const _Tp*>(__first), 390 _Deque_iterator<_Tp, 391 const _Tp&, const _Tp*>(__last), 392 __result); } 393 394 #if __cplusplus >= 201103L 395 template<typename _Tp> 396 _Deque_iterator<_Tp, _Tp&, _Tp*> 397 move(_Deque_iterator<_Tp, const _Tp&, const _Tp*>, 398 _Deque_iterator<_Tp, const _Tp&, const _Tp*>, 399 _Deque_iterator<_Tp, _Tp&, _Tp*>); 400 401 template<typename _Tp> 402 inline _Deque_iterator<_Tp, _Tp&, _Tp*> 403 move(_Deque_iterator<_Tp, _Tp&, _Tp*> __first, 404 _Deque_iterator<_Tp, _Tp&, _Tp*> __last, 405 _Deque_iterator<_Tp, _Tp&, _Tp*> __result) 406 { return std::move(_Deque_iterator<_Tp, const _Tp&, const _Tp*>(__first), 407 _Deque_iterator<_Tp, const _Tp&, const _Tp*>(__last), 408 __result); } 409 410 template<typename _Tp> 411 _Deque_iterator<_Tp, _Tp&, _Tp*> 412 move_backward(_Deque_iterator<_Tp, const _Tp&, const _Tp*>, 413 _Deque_iterator<_Tp, const _Tp&, const _Tp*>, 414 _Deque_iterator<_Tp, _Tp&, _Tp*>); 415 416 template<typename _Tp> 417 inline _Deque_iterator<_Tp, _Tp&, _Tp*> 418 move_backward(_Deque_iterator<_Tp, _Tp&, _Tp*> __first, 419 _Deque_iterator<_Tp, _Tp&, _Tp*> __last, 420 _Deque_iterator<_Tp, _Tp&, _Tp*> __result) 421 { return std::move_backward(_Deque_iterator<_Tp, 422 const _Tp&, const _Tp*>(__first), 423 _Deque_iterator<_Tp, 424 const _Tp&, const _Tp*>(__last), 425 __result); } 426 #endif 427 428 /** 429 * Deque base class. This class provides the unified face for %deque's 430 * allocation. This class's constructor and destructor allocate and 431 * deallocate (but do not initialize) storage. This makes %exception 432 * safety easier. 433 * 434 * Nothing in this class ever constructs or destroys an actual Tp element. 435 * (Deque handles that itself.) Only/All memory management is performed 436 * here. 437 */ 438 template<typename _Tp, typename _Alloc> 439 class _Deque_base 440 { 441 public: 442 typedef _Alloc allocator_type; 443 444 allocator_type 445 get_allocator() const _GLIBCXX_NOEXCEPT 446 { return allocator_type(_M_get_Tp_allocator()); } 447 448 typedef _Deque_iterator<_Tp, _Tp&, _Tp*> iterator; 449 typedef _Deque_iterator<_Tp, const _Tp&, const _Tp*> const_iterator; 450 451 _Deque_base() 452 : _M_impl() 453 { _M_initialize_map(0); } 454 455 _Deque_base(size_t __num_elements) 456 : _M_impl() 457 { _M_initialize_map(__num_elements); } 458 459 _Deque_base(const allocator_type& __a, size_t __num_elements) 460 : _M_impl(__a) 461 { _M_initialize_map(__num_elements); } 462 463 _Deque_base(const allocator_type& __a) 464 : _M_impl(__a) 465 { } 466 467 #if __cplusplus >= 201103L 468 _Deque_base(_Deque_base&& __x) 469 : _M_impl(std::move(__x._M_get_Tp_allocator())) 470 { 471 _M_initialize_map(0); 472 if (__x._M_impl._M_map) 473 { 474 std::swap(this->_M_impl._M_start, __x._M_impl._M_start); 475 std::swap(this->_M_impl._M_finish, __x._M_impl._M_finish); 476 std::swap(this->_M_impl._M_map, __x._M_impl._M_map); 477 std::swap(this->_M_impl._M_map_size, __x._M_impl._M_map_size); 478 } 479 } 480 #endif 481 482 ~_Deque_base(); 483 484 protected: 485 //This struct encapsulates the implementation of the std::deque 486 //standard container and at the same time makes use of the EBO 487 //for empty allocators. 488 typedef typename _Alloc::template rebind<_Tp*>::other _Map_alloc_type; 489 490 typedef typename _Alloc::template rebind<_Tp>::other _Tp_alloc_type; 491 492 struct _Deque_impl 493 : public _Tp_alloc_type 494 { 495 _Tp** _M_map; 496 size_t _M_map_size; 497 iterator _M_start; 498 iterator _M_finish; 499 500 _Deque_impl() 501 : _Tp_alloc_type(), _M_map(0), _M_map_size(0), 502 _M_start(), _M_finish() 503 { } 504 505 _Deque_impl(const _Tp_alloc_type& __a) 506 : _Tp_alloc_type(__a), _M_map(0), _M_map_size(0), 507 _M_start(), _M_finish() 508 { } 509 510 #if __cplusplus >= 201103L 511 _Deque_impl(_Tp_alloc_type&& __a) 512 : _Tp_alloc_type(std::move(__a)), _M_map(0), _M_map_size(0), 513 _M_start(), _M_finish() 514 { } 515 #endif 516 }; 517 518 _Tp_alloc_type& 519 _M_get_Tp_allocator() _GLIBCXX_NOEXCEPT 520 { return *static_cast<_Tp_alloc_type*>(&this->_M_impl); } 521 522 const _Tp_alloc_type& 523 _M_get_Tp_allocator() const _GLIBCXX_NOEXCEPT 524 { return *static_cast<const _Tp_alloc_type*>(&this->_M_impl); } 525 526 _Map_alloc_type 527 _M_get_map_allocator() const _GLIBCXX_NOEXCEPT 528 { return _Map_alloc_type(_M_get_Tp_allocator()); } 529 530 _Tp* 531 _M_allocate_node() 532 { 533 return _M_impl._Tp_alloc_type::allocate(__deque_buf_size(sizeof(_Tp))); 534 } 535 536 void 537 _M_deallocate_node(_Tp* __p) 538 { 539 _M_impl._Tp_alloc_type::deallocate(__p, __deque_buf_size(sizeof(_Tp))); 540 } 541 542 _Tp** 543 _M_allocate_map(size_t __n) 544 { return _M_get_map_allocator().allocate(__n); } 545 546 void 547 _M_deallocate_map(_Tp** __p, size_t __n) 548 { _M_get_map_allocator().deallocate(__p, __n); } 549 550 protected: 551 void _M_initialize_map(size_t); 552 void _M_create_nodes(_Tp** __nstart, _Tp** __nfinish); 553 void _M_destroy_nodes(_Tp** __nstart, _Tp** __nfinish); 554 enum { _S_initial_map_size = 8 }; 555 556 _Deque_impl _M_impl; 557 }; 558 559 template<typename _Tp, typename _Alloc> 560 _Deque_base<_Tp, _Alloc>:: 561 ~_Deque_base() 562 { 563 if (this->_M_impl._M_map) 564 { 565 _M_destroy_nodes(this->_M_impl._M_start._M_node, 566 this->_M_impl._M_finish._M_node + 1); 567 _M_deallocate_map(this->_M_impl._M_map, this->_M_impl._M_map_size); 568 } 569 } 570 571 /** 572 * @brief Layout storage. 573 * @param __num_elements The count of T's for which to allocate space 574 * at first. 575 * @return Nothing. 576 * 577 * The initial underlying memory layout is a bit complicated... 578 */ 579 template<typename _Tp, typename _Alloc> 580 void 581 _Deque_base<_Tp, _Alloc>:: 582 _M_initialize_map(size_t __num_elements) 583 { 584 const size_t __num_nodes = (__num_elements/ __deque_buf_size(sizeof(_Tp)) 585 + 1); 586 587 this->_M_impl._M_map_size = std::max((size_t) _S_initial_map_size, 588 size_t(__num_nodes + 2)); 589 this->_M_impl._M_map = _M_allocate_map(this->_M_impl._M_map_size); 590 591 // For "small" maps (needing less than _M_map_size nodes), allocation 592 // starts in the middle elements and grows outwards. So nstart may be 593 // the beginning of _M_map, but for small maps it may be as far in as 594 // _M_map+3. 595 596 _Tp** __nstart = (this->_M_impl._M_map 597 + (this->_M_impl._M_map_size - __num_nodes) / 2); 598 _Tp** __nfinish = __nstart + __num_nodes; 599 600 __try 601 { _M_create_nodes(__nstart, __nfinish); } 602 __catch(...) 603 { 604 _M_deallocate_map(this->_M_impl._M_map, this->_M_impl._M_map_size); 605 this->_M_impl._M_map = 0; 606 this->_M_impl._M_map_size = 0; 607 __throw_exception_again; 608 } 609 610 this->_M_impl._M_start._M_set_node(__nstart); 611 this->_M_impl._M_finish._M_set_node(__nfinish - 1); 612 this->_M_impl._M_start._M_cur = _M_impl._M_start._M_first; 613 this->_M_impl._M_finish._M_cur = (this->_M_impl._M_finish._M_first 614 + __num_elements 615 % __deque_buf_size(sizeof(_Tp))); 616 } 617 618 template<typename _Tp, typename _Alloc> 619 void 620 _Deque_base<_Tp, _Alloc>:: 621 _M_create_nodes(_Tp** __nstart, _Tp** __nfinish) 622 { 623 _Tp** __cur; 624 __try 625 { 626 for (__cur = __nstart; __cur < __nfinish; ++__cur) 627 *__cur = this->_M_allocate_node(); 628 } 629 __catch(...) 630 { 631 _M_destroy_nodes(__nstart, __cur); 632 __throw_exception_again; 633 } 634 } 635 636 template<typename _Tp, typename _Alloc> 637 void 638 _Deque_base<_Tp, _Alloc>:: 639 _M_destroy_nodes(_Tp** __nstart, _Tp** __nfinish) 640 { 641 for (_Tp** __n = __nstart; __n < __nfinish; ++__n) 642 _M_deallocate_node(*__n); 643 } 644 645 /** 646 * @brief A standard container using fixed-size memory allocation and 647 * constant-time manipulation of elements at either end. 648 * 649 * @ingroup sequences 650 * 651 * @tparam _Tp Type of element. 652 * @tparam _Alloc Allocator type, defaults to allocator<_Tp>. 653 * 654 * Meets the requirements of a <a href="tables.html#65">container</a>, a 655 * <a href="tables.html#66">reversible container</a>, and a 656 * <a href="tables.html#67">sequence</a>, including the 657 * <a href="tables.html#68">optional sequence requirements</a>. 658 * 659 * In previous HP/SGI versions of deque, there was an extra template 660 * parameter so users could control the node size. This extension turned 661 * out to violate the C++ standard (it can be detected using template 662 * template parameters), and it was removed. 663 * 664 * Here's how a deque<Tp> manages memory. Each deque has 4 members: 665 * 666 * - Tp** _M_map 667 * - size_t _M_map_size 668 * - iterator _M_start, _M_finish 669 * 670 * map_size is at least 8. %map is an array of map_size 671 * pointers-to-@a nodes. (The name %map has nothing to do with the 672 * std::map class, and @b nodes should not be confused with 673 * std::list's usage of @a node.) 674 * 675 * A @a node has no specific type name as such, but it is referred 676 * to as @a node in this file. It is a simple array-of-Tp. If Tp 677 * is very large, there will be one Tp element per node (i.e., an 678 * @a array of one). For non-huge Tp's, node size is inversely 679 * related to Tp size: the larger the Tp, the fewer Tp's will fit 680 * in a node. The goal here is to keep the total size of a node 681 * relatively small and constant over different Tp's, to improve 682 * allocator efficiency. 683 * 684 * Not every pointer in the %map array will point to a node. If 685 * the initial number of elements in the deque is small, the 686 * /middle/ %map pointers will be valid, and the ones at the edges 687 * will be unused. This same situation will arise as the %map 688 * grows: available %map pointers, if any, will be on the ends. As 689 * new nodes are created, only a subset of the %map's pointers need 690 * to be copied @a outward. 691 * 692 * Class invariants: 693 * - For any nonsingular iterator i: 694 * - i.node points to a member of the %map array. (Yes, you read that 695 * correctly: i.node does not actually point to a node.) The member of 696 * the %map array is what actually points to the node. 697 * - i.first == *(i.node) (This points to the node (first Tp element).) 698 * - i.last == i.first + node_size 699 * - i.cur is a pointer in the range [i.first, i.last). NOTE: 700 * the implication of this is that i.cur is always a dereferenceable 701 * pointer, even if i is a past-the-end iterator. 702 * - Start and Finish are always nonsingular iterators. NOTE: this 703 * means that an empty deque must have one node, a deque with <N 704 * elements (where N is the node buffer size) must have one node, a 705 * deque with N through (2N-1) elements must have two nodes, etc. 706 * - For every node other than start.node and finish.node, every 707 * element in the node is an initialized object. If start.node == 708 * finish.node, then [start.cur, finish.cur) are initialized 709 * objects, and the elements outside that range are uninitialized 710 * storage. Otherwise, [start.cur, start.last) and [finish.first, 711 * finish.cur) are initialized objects, and [start.first, start.cur) 712 * and [finish.cur, finish.last) are uninitialized storage. 713 * - [%map, %map + map_size) is a valid, non-empty range. 714 * - [start.node, finish.node] is a valid range contained within 715 * [%map, %map + map_size). 716 * - A pointer in the range [%map, %map + map_size) points to an allocated 717 * node if and only if the pointer is in the range 718 * [start.node, finish.node]. 719 * 720 * Here's the magic: nothing in deque is @b aware of the discontiguous 721 * storage! 722 * 723 * The memory setup and layout occurs in the parent, _Base, and the iterator 724 * class is entirely responsible for @a leaping from one node to the next. 725 * All the implementation routines for deque itself work only through the 726 * start and finish iterators. This keeps the routines simple and sane, 727 * and we can use other standard algorithms as well. 728 */ 729 template<typename _Tp, typename _Alloc = std::allocator<_Tp> > 730 class deque : protected _Deque_base<_Tp, _Alloc> 731 { 732 // concept requirements 733 typedef typename _Alloc::value_type _Alloc_value_type; 734 __glibcxx_class_requires(_Tp, _SGIAssignableConcept) 735 __glibcxx_class_requires2(_Tp, _Alloc_value_type, _SameTypeConcept) 736 737 typedef _Deque_base<_Tp, _Alloc> _Base; 738 typedef typename _Base::_Tp_alloc_type _Tp_alloc_type; 739 740 public: 741 typedef _Tp value_type; 742 typedef typename _Tp_alloc_type::pointer pointer; 743 typedef typename _Tp_alloc_type::const_pointer const_pointer; 744 typedef typename _Tp_alloc_type::reference reference; 745 typedef typename _Tp_alloc_type::const_reference const_reference; 746 typedef typename _Base::iterator iterator; 747 typedef typename _Base::const_iterator const_iterator; 748 typedef std::reverse_iterator<const_iterator> const_reverse_iterator; 749 typedef std::reverse_iterator<iterator> reverse_iterator; 750 typedef size_t size_type; 751 typedef ptrdiff_t difference_type; 752 typedef _Alloc allocator_type; 753 754 protected: 755 typedef pointer* _Map_pointer; 756 757 static size_t _S_buffer_size() 758 { return __deque_buf_size(sizeof(_Tp)); } 759 760 // Functions controlling memory layout, and nothing else. 761 using _Base::_M_initialize_map; 762 using _Base::_M_create_nodes; 763 using _Base::_M_destroy_nodes; 764 using _Base::_M_allocate_node; 765 using _Base::_M_deallocate_node; 766 using _Base::_M_allocate_map; 767 using _Base::_M_deallocate_map; 768 using _Base::_M_get_Tp_allocator; 769 770 /** 771 * A total of four data members accumulated down the hierarchy. 772 * May be accessed via _M_impl.* 773 */ 774 using _Base::_M_impl; 775 776 public: 777 // [23.2.1.1] construct/copy/destroy 778 // (assign() and get_allocator() are also listed in this section) 779 /** 780 * @brief Default constructor creates no elements. 781 */ 782 deque() 783 : _Base() { } 784 785 /** 786 * @brief Creates a %deque with no elements. 787 * @param __a An allocator object. 788 */ 789 explicit 790 deque(const allocator_type& __a) 791 : _Base(__a, 0) { } 792 793 #if __cplusplus >= 201103L 794 /** 795 * @brief Creates a %deque with default constructed elements. 796 * @param __n The number of elements to initially create. 797 * 798 * This constructor fills the %deque with @a n default 799 * constructed elements. 800 */ 801 explicit 802 deque(size_type __n) 803 : _Base(__n) 804 { _M_default_initialize(); } 805 806 /** 807 * @brief Creates a %deque with copies of an exemplar element. 808 * @param __n The number of elements to initially create. 809 * @param __value An element to copy. 810 * @param __a An allocator. 811 * 812 * This constructor fills the %deque with @a __n copies of @a __value. 813 */ 814 deque(size_type __n, const value_type& __value, 815 const allocator_type& __a = allocator_type()) 816 : _Base(__a, __n) 817 { _M_fill_initialize(__value); } 818 #else 819 /** 820 * @brief Creates a %deque with copies of an exemplar element. 821 * @param __n The number of elements to initially create. 822 * @param __value An element to copy. 823 * @param __a An allocator. 824 * 825 * This constructor fills the %deque with @a __n copies of @a __value. 826 */ 827 explicit 828 deque(size_type __n, const value_type& __value = value_type(), 829 const allocator_type& __a = allocator_type()) 830 : _Base(__a, __n) 831 { _M_fill_initialize(__value); } 832 #endif 833 834 /** 835 * @brief %Deque copy constructor. 836 * @param __x A %deque of identical element and allocator types. 837 * 838 * The newly-created %deque uses a copy of the allocation object used 839 * by @a __x. 840 */ 841 deque(const deque& __x) 842 : _Base(__x._M_get_Tp_allocator(), __x.size()) 843 { std::__uninitialized_copy_a(__x.begin(), __x.end(), 844 this->_M_impl._M_start, 845 _M_get_Tp_allocator()); } 846 847 #if __cplusplus >= 201103L 848 /** 849 * @brief %Deque move constructor. 850 * @param __x A %deque of identical element and allocator types. 851 * 852 * The newly-created %deque contains the exact contents of @a __x. 853 * The contents of @a __x are a valid, but unspecified %deque. 854 */ 855 deque(deque&& __x) 856 : _Base(std::move(__x)) { } 857 858 /** 859 * @brief Builds a %deque from an initializer list. 860 * @param __l An initializer_list. 861 * @param __a An allocator object. 862 * 863 * Create a %deque consisting of copies of the elements in the 864 * initializer_list @a __l. 865 * 866 * This will call the element type's copy constructor N times 867 * (where N is __l.size()) and do no memory reallocation. 868 */ 869 deque(initializer_list<value_type> __l, 870 const allocator_type& __a = allocator_type()) 871 : _Base(__a) 872 { 873 _M_range_initialize(__l.begin(), __l.end(), 874 random_access_iterator_tag()); 875 } 876 #endif 877 878 /** 879 * @brief Builds a %deque from a range. 880 * @param __first An input iterator. 881 * @param __last An input iterator. 882 * @param __a An allocator object. 883 * 884 * Create a %deque consisting of copies of the elements from [__first, 885 * __last). 886 * 887 * If the iterators are forward, bidirectional, or random-access, then 888 * this will call the elements' copy constructor N times (where N is 889 * distance(__first,__last)) and do no memory reallocation. But if only 890 * input iterators are used, then this will do at most 2N calls to the 891 * copy constructor, and logN memory reallocations. 892 */ 893 #if __cplusplus >= 201103L 894 template<typename _InputIterator, 895 typename = std::_RequireInputIter<_InputIterator>> 896 deque(_InputIterator __first, _InputIterator __last, 897 const allocator_type& __a = allocator_type()) 898 : _Base(__a) 899 { _M_initialize_dispatch(__first, __last, __false_type()); } 900 #else 901 template<typename _InputIterator> 902 deque(_InputIterator __first, _InputIterator __last, 903 const allocator_type& __a = allocator_type()) 904 : _Base(__a) 905 { 906 // Check whether it's an integral type. If so, it's not an iterator. 907 typedef typename std::__is_integer<_InputIterator>::__type _Integral; 908 _M_initialize_dispatch(__first, __last, _Integral()); 909 } 910 #endif 911 912 /** 913 * The dtor only erases the elements, and note that if the elements 914 * themselves are pointers, the pointed-to memory is not touched in any 915 * way. Managing the pointer is the user's responsibility. 916 */ 917 ~deque() _GLIBCXX_NOEXCEPT 918 { _M_destroy_data(begin(), end(), _M_get_Tp_allocator()); } 919 920 /** 921 * @brief %Deque assignment operator. 922 * @param __x A %deque of identical element and allocator types. 923 * 924 * All the elements of @a x are copied, but unlike the copy constructor, 925 * the allocator object is not copied. 926 */ 927 deque& 928 operator=(const deque& __x); 929 930 #if __cplusplus >= 201103L 931 /** 932 * @brief %Deque move assignment operator. 933 * @param __x A %deque of identical element and allocator types. 934 * 935 * The contents of @a __x are moved into this deque (without copying). 936 * @a __x is a valid, but unspecified %deque. 937 */ 938 deque& 939 operator=(deque&& __x) 940 { 941 // NB: DR 1204. 942 // NB: DR 675. 943 this->clear(); 944 this->swap(__x); 945 return *this; 946 } 947 948 /** 949 * @brief Assigns an initializer list to a %deque. 950 * @param __l An initializer_list. 951 * 952 * This function fills a %deque with copies of the elements in the 953 * initializer_list @a __l. 954 * 955 * Note that the assignment completely changes the %deque and that the 956 * resulting %deque's size is the same as the number of elements 957 * assigned. Old data may be lost. 958 */ 959 deque& 960 operator=(initializer_list<value_type> __l) 961 { 962 this->assign(__l.begin(), __l.end()); 963 return *this; 964 } 965 #endif 966 967 /** 968 * @brief Assigns a given value to a %deque. 969 * @param __n Number of elements to be assigned. 970 * @param __val Value to be assigned. 971 * 972 * This function fills a %deque with @a n copies of the given 973 * value. Note that the assignment completely changes the 974 * %deque and that the resulting %deque's size is the same as 975 * the number of elements assigned. Old data may be lost. 976 */ 977 void 978 assign(size_type __n, const value_type& __val) 979 { _M_fill_assign(__n, __val); } 980 981 /** 982 * @brief Assigns a range to a %deque. 983 * @param __first An input iterator. 984 * @param __last An input iterator. 985 * 986 * This function fills a %deque with copies of the elements in the 987 * range [__first,__last). 988 * 989 * Note that the assignment completely changes the %deque and that the 990 * resulting %deque's size is the same as the number of elements 991 * assigned. Old data may be lost. 992 */ 993 #if __cplusplus >= 201103L 994 template<typename _InputIterator, 995 typename = std::_RequireInputIter<_InputIterator>> 996 void 997 assign(_InputIterator __first, _InputIterator __last) 998 { _M_assign_dispatch(__first, __last, __false_type()); } 999 #else 1000 template<typename _InputIterator> 1001 void 1002 assign(_InputIterator __first, _InputIterator __last) 1003 { 1004 typedef typename std::__is_integer<_InputIterator>::__type _Integral; 1005 _M_assign_dispatch(__first, __last, _Integral()); 1006 } 1007 #endif 1008 1009 #if __cplusplus >= 201103L 1010 /** 1011 * @brief Assigns an initializer list to a %deque. 1012 * @param __l An initializer_list. 1013 * 1014 * This function fills a %deque with copies of the elements in the 1015 * initializer_list @a __l. 1016 * 1017 * Note that the assignment completely changes the %deque and that the 1018 * resulting %deque's size is the same as the number of elements 1019 * assigned. Old data may be lost. 1020 */ 1021 void 1022 assign(initializer_list<value_type> __l) 1023 { this->assign(__l.begin(), __l.end()); } 1024 #endif 1025 1026 /// Get a copy of the memory allocation object. 1027 allocator_type 1028 get_allocator() const _GLIBCXX_NOEXCEPT 1029 { return _Base::get_allocator(); } 1030 1031 // iterators 1032 /** 1033 * Returns a read/write iterator that points to the first element in the 1034 * %deque. Iteration is done in ordinary element order. 1035 */ 1036 iterator 1037 begin() _GLIBCXX_NOEXCEPT 1038 { return this->_M_impl._M_start; } 1039 1040 /** 1041 * Returns a read-only (constant) iterator that points to the first 1042 * element in the %deque. Iteration is done in ordinary element order. 1043 */ 1044 const_iterator 1045 begin() const _GLIBCXX_NOEXCEPT 1046 { return this->_M_impl._M_start; } 1047 1048 /** 1049 * Returns a read/write iterator that points one past the last 1050 * element in the %deque. Iteration is done in ordinary 1051 * element order. 1052 */ 1053 iterator 1054 end() _GLIBCXX_NOEXCEPT 1055 { return this->_M_impl._M_finish; } 1056 1057 /** 1058 * Returns a read-only (constant) iterator that points one past 1059 * the last element in the %deque. Iteration is done in 1060 * ordinary element order. 1061 */ 1062 const_iterator 1063 end() const _GLIBCXX_NOEXCEPT 1064 { return this->_M_impl._M_finish; } 1065 1066 /** 1067 * Returns a read/write reverse iterator that points to the 1068 * last element in the %deque. Iteration is done in reverse 1069 * element order. 1070 */ 1071 reverse_iterator 1072 rbegin() _GLIBCXX_NOEXCEPT 1073 { return reverse_iterator(this->_M_impl._M_finish); } 1074 1075 /** 1076 * Returns a read-only (constant) reverse iterator that points 1077 * to the last element in the %deque. Iteration is done in 1078 * reverse element order. 1079 */ 1080 const_reverse_iterator 1081 rbegin() const _GLIBCXX_NOEXCEPT 1082 { return const_reverse_iterator(this->_M_impl._M_finish); } 1083 1084 /** 1085 * Returns a read/write reverse iterator that points to one 1086 * before the first element in the %deque. Iteration is done 1087 * in reverse element order. 1088 */ 1089 reverse_iterator 1090 rend() _GLIBCXX_NOEXCEPT 1091 { return reverse_iterator(this->_M_impl._M_start); } 1092 1093 /** 1094 * Returns a read-only (constant) reverse iterator that points 1095 * to one before the first element in the %deque. Iteration is 1096 * done in reverse element order. 1097 */ 1098 const_reverse_iterator 1099 rend() const _GLIBCXX_NOEXCEPT 1100 { return const_reverse_iterator(this->_M_impl._M_start); } 1101 1102 #if __cplusplus >= 201103L 1103 /** 1104 * Returns a read-only (constant) iterator that points to the first 1105 * element in the %deque. Iteration is done in ordinary element order. 1106 */ 1107 const_iterator 1108 cbegin() const noexcept 1109 { return this->_M_impl._M_start; } 1110 1111 /** 1112 * Returns a read-only (constant) iterator that points one past 1113 * the last element in the %deque. Iteration is done in 1114 * ordinary element order. 1115 */ 1116 const_iterator 1117 cend() const noexcept 1118 { return this->_M_impl._M_finish; } 1119 1120 /** 1121 * Returns a read-only (constant) reverse iterator that points 1122 * to the last element in the %deque. Iteration is done in 1123 * reverse element order. 1124 */ 1125 const_reverse_iterator 1126 crbegin() const noexcept 1127 { return const_reverse_iterator(this->_M_impl._M_finish); } 1128 1129 /** 1130 * Returns a read-only (constant) reverse iterator that points 1131 * to one before the first element in the %deque. Iteration is 1132 * done in reverse element order. 1133 */ 1134 const_reverse_iterator 1135 crend() const noexcept 1136 { return const_reverse_iterator(this->_M_impl._M_start); } 1137 #endif 1138 1139 // [23.2.1.2] capacity 1140 /** Returns the number of elements in the %deque. */ 1141 size_type 1142 size() const _GLIBCXX_NOEXCEPT 1143 { return this->_M_impl._M_finish - this->_M_impl._M_start; } 1144 1145 /** Returns the size() of the largest possible %deque. */ 1146 size_type 1147 max_size() const _GLIBCXX_NOEXCEPT 1148 { return _M_get_Tp_allocator().max_size(); } 1149 1150 #if __cplusplus >= 201103L 1151 /** 1152 * @brief Resizes the %deque to the specified number of elements. 1153 * @param __new_size Number of elements the %deque should contain. 1154 * 1155 * This function will %resize the %deque to the specified 1156 * number of elements. If the number is smaller than the 1157 * %deque's current size the %deque is truncated, otherwise 1158 * default constructed elements are appended. 1159 */ 1160 void 1161 resize(size_type __new_size) 1162 { 1163 const size_type __len = size(); 1164 if (__new_size > __len) 1165 _M_default_append(__new_size - __len); 1166 else if (__new_size < __len) 1167 _M_erase_at_end(this->_M_impl._M_start 1168 + difference_type(__new_size)); 1169 } 1170 1171 /** 1172 * @brief Resizes the %deque to the specified number of elements. 1173 * @param __new_size Number of elements the %deque should contain. 1174 * @param __x Data with which new elements should be populated. 1175 * 1176 * This function will %resize the %deque to the specified 1177 * number of elements. If the number is smaller than the 1178 * %deque's current size the %deque is truncated, otherwise the 1179 * %deque is extended and new elements are populated with given 1180 * data. 1181 */ 1182 void 1183 resize(size_type __new_size, const value_type& __x) 1184 { 1185 const size_type __len = size(); 1186 if (__new_size > __len) 1187 insert(this->_M_impl._M_finish, __new_size - __len, __x); 1188 else if (__new_size < __len) 1189 _M_erase_at_end(this->_M_impl._M_start 1190 + difference_type(__new_size)); 1191 } 1192 #else 1193 /** 1194 * @brief Resizes the %deque to the specified number of elements. 1195 * @param __new_size Number of elements the %deque should contain. 1196 * @param __x Data with which new elements should be populated. 1197 * 1198 * This function will %resize the %deque to the specified 1199 * number of elements. If the number is smaller than the 1200 * %deque's current size the %deque is truncated, otherwise the 1201 * %deque is extended and new elements are populated with given 1202 * data. 1203 */ 1204 void 1205 resize(size_type __new_size, value_type __x = value_type()) 1206 { 1207 const size_type __len = size(); 1208 if (__new_size > __len) 1209 insert(this->_M_impl._M_finish, __new_size - __len, __x); 1210 else if (__new_size < __len) 1211 _M_erase_at_end(this->_M_impl._M_start 1212 + difference_type(__new_size)); 1213 } 1214 #endif 1215 1216 #if __cplusplus >= 201103L 1217 /** A non-binding request to reduce memory use. */ 1218 void 1219 shrink_to_fit() 1220 { _M_shrink_to_fit(); } 1221 #endif 1222 1223 /** 1224 * Returns true if the %deque is empty. (Thus begin() would 1225 * equal end().) 1226 */ 1227 bool 1228 empty() const _GLIBCXX_NOEXCEPT 1229 { return this->_M_impl._M_finish == this->_M_impl._M_start; } 1230 1231 // element access 1232 /** 1233 * @brief Subscript access to the data contained in the %deque. 1234 * @param __n The index of the element for which data should be 1235 * accessed. 1236 * @return Read/write reference to data. 1237 * 1238 * This operator allows for easy, array-style, data access. 1239 * Note that data access with this operator is unchecked and 1240 * out_of_range lookups are not defined. (For checked lookups 1241 * see at().) 1242 */ 1243 reference 1244 operator[](size_type __n) 1245 { return this->_M_impl._M_start[difference_type(__n)]; } 1246 1247 /** 1248 * @brief Subscript access to the data contained in the %deque. 1249 * @param __n The index of the element for which data should be 1250 * accessed. 1251 * @return Read-only (constant) reference to data. 1252 * 1253 * This operator allows for easy, array-style, data access. 1254 * Note that data access with this operator is unchecked and 1255 * out_of_range lookups are not defined. (For checked lookups 1256 * see at().) 1257 */ 1258 const_reference 1259 operator[](size_type __n) const 1260 { return this->_M_impl._M_start[difference_type(__n)]; } 1261 1262 protected: 1263 /// Safety check used only from at(). 1264 void 1265 _M_range_check(size_type __n) const 1266 { 1267 if (__n >= this->size()) 1268 __throw_out_of_range(__N("deque::_M_range_check")); 1269 } 1270 1271 public: 1272 /** 1273 * @brief Provides access to the data contained in the %deque. 1274 * @param __n The index of the element for which data should be 1275 * accessed. 1276 * @return Read/write reference to data. 1277 * @throw std::out_of_range If @a __n is an invalid index. 1278 * 1279 * This function provides for safer data access. The parameter 1280 * is first checked that it is in the range of the deque. The 1281 * function throws out_of_range if the check fails. 1282 */ 1283 reference 1284 at(size_type __n) 1285 { 1286 _M_range_check(__n); 1287 return (*this)[__n]; 1288 } 1289 1290 /** 1291 * @brief Provides access to the data contained in the %deque. 1292 * @param __n The index of the element for which data should be 1293 * accessed. 1294 * @return Read-only (constant) reference to data. 1295 * @throw std::out_of_range If @a __n is an invalid index. 1296 * 1297 * This function provides for safer data access. The parameter is first 1298 * checked that it is in the range of the deque. The function throws 1299 * out_of_range if the check fails. 1300 */ 1301 const_reference 1302 at(size_type __n) const 1303 { 1304 _M_range_check(__n); 1305 return (*this)[__n]; 1306 } 1307 1308 /** 1309 * Returns a read/write reference to the data at the first 1310 * element of the %deque. 1311 */ 1312 reference 1313 front() 1314 { return *begin(); } 1315 1316 /** 1317 * Returns a read-only (constant) reference to the data at the first 1318 * element of the %deque. 1319 */ 1320 const_reference 1321 front() const 1322 { return *begin(); } 1323 1324 /** 1325 * Returns a read/write reference to the data at the last element of the 1326 * %deque. 1327 */ 1328 reference 1329 back() 1330 { 1331 iterator __tmp = end(); 1332 --__tmp; 1333 return *__tmp; 1334 } 1335 1336 /** 1337 * Returns a read-only (constant) reference to the data at the last 1338 * element of the %deque. 1339 */ 1340 const_reference 1341 back() const 1342 { 1343 const_iterator __tmp = end(); 1344 --__tmp; 1345 return *__tmp; 1346 } 1347 1348 // [23.2.1.2] modifiers 1349 /** 1350 * @brief Add data to the front of the %deque. 1351 * @param __x Data to be added. 1352 * 1353 * This is a typical stack operation. The function creates an 1354 * element at the front of the %deque and assigns the given 1355 * data to it. Due to the nature of a %deque this operation 1356 * can be done in constant time. 1357 */ 1358 void 1359 push_front(const value_type& __x) 1360 { 1361 if (this->_M_impl._M_start._M_cur != this->_M_impl._M_start._M_first) 1362 { 1363 this->_M_impl.construct(this->_M_impl._M_start._M_cur - 1, __x); 1364 --this->_M_impl._M_start._M_cur; 1365 } 1366 else 1367 _M_push_front_aux(__x); 1368 } 1369 1370 #if __cplusplus >= 201103L 1371 void 1372 push_front(value_type&& __x) 1373 { emplace_front(std::move(__x)); } 1374 1375 template<typename... _Args> 1376 void 1377 emplace_front(_Args&&... __args); 1378 #endif 1379 1380 /** 1381 * @brief Add data to the end of the %deque. 1382 * @param __x Data to be added. 1383 * 1384 * This is a typical stack operation. The function creates an 1385 * element at the end of the %deque and assigns the given data 1386 * to it. Due to the nature of a %deque this operation can be 1387 * done in constant time. 1388 */ 1389 void 1390 push_back(const value_type& __x) 1391 { 1392 if (this->_M_impl._M_finish._M_cur 1393 != this->_M_impl._M_finish._M_last - 1) 1394 { 1395 this->_M_impl.construct(this->_M_impl._M_finish._M_cur, __x); 1396 ++this->_M_impl._M_finish._M_cur; 1397 } 1398 else 1399 _M_push_back_aux(__x); 1400 } 1401 1402 #if __cplusplus >= 201103L 1403 void 1404 push_back(value_type&& __x) 1405 { emplace_back(std::move(__x)); } 1406 1407 template<typename... _Args> 1408 void 1409 emplace_back(_Args&&... __args); 1410 #endif 1411 1412 /** 1413 * @brief Removes first element. 1414 * 1415 * This is a typical stack operation. It shrinks the %deque by one. 1416 * 1417 * Note that no data is returned, and if the first element's data is 1418 * needed, it should be retrieved before pop_front() is called. 1419 */ 1420 void 1421 pop_front() 1422 { 1423 if (this->_M_impl._M_start._M_cur 1424 != this->_M_impl._M_start._M_last - 1) 1425 { 1426 this->_M_impl.destroy(this->_M_impl._M_start._M_cur); 1427 ++this->_M_impl._M_start._M_cur; 1428 } 1429 else 1430 _M_pop_front_aux(); 1431 } 1432 1433 /** 1434 * @brief Removes last element. 1435 * 1436 * This is a typical stack operation. It shrinks the %deque by one. 1437 * 1438 * Note that no data is returned, and if the last element's data is 1439 * needed, it should be retrieved before pop_back() is called. 1440 */ 1441 void 1442 pop_back() 1443 { 1444 if (this->_M_impl._M_finish._M_cur 1445 != this->_M_impl._M_finish._M_first) 1446 { 1447 --this->_M_impl._M_finish._M_cur; 1448 this->_M_impl.destroy(this->_M_impl._M_finish._M_cur); 1449 } 1450 else 1451 _M_pop_back_aux(); 1452 } 1453 1454 #if __cplusplus >= 201103L 1455 /** 1456 * @brief Inserts an object in %deque before specified iterator. 1457 * @param __position An iterator into the %deque. 1458 * @param __args Arguments. 1459 * @return An iterator that points to the inserted data. 1460 * 1461 * This function will insert an object of type T constructed 1462 * with T(std::forward<Args>(args)...) before the specified location. 1463 */ 1464 template<typename... _Args> 1465 iterator 1466 emplace(iterator __position, _Args&&... __args); 1467 #endif 1468 1469 /** 1470 * @brief Inserts given value into %deque before specified iterator. 1471 * @param __position An iterator into the %deque. 1472 * @param __x Data to be inserted. 1473 * @return An iterator that points to the inserted data. 1474 * 1475 * This function will insert a copy of the given value before the 1476 * specified location. 1477 */ 1478 iterator 1479 insert(iterator __position, const value_type& __x); 1480 1481 #if __cplusplus >= 201103L 1482 /** 1483 * @brief Inserts given rvalue into %deque before specified iterator. 1484 * @param __position An iterator into the %deque. 1485 * @param __x Data to be inserted. 1486 * @return An iterator that points to the inserted data. 1487 * 1488 * This function will insert a copy of the given rvalue before the 1489 * specified location. 1490 */ 1491 iterator 1492 insert(iterator __position, value_type&& __x) 1493 { return emplace(__position, std::move(__x)); } 1494 1495 /** 1496 * @brief Inserts an initializer list into the %deque. 1497 * @param __p An iterator into the %deque. 1498 * @param __l An initializer_list. 1499 * 1500 * This function will insert copies of the data in the 1501 * initializer_list @a __l into the %deque before the location 1502 * specified by @a __p. This is known as <em>list insert</em>. 1503 */ 1504 void 1505 insert(iterator __p, initializer_list<value_type> __l) 1506 { this->insert(__p, __l.begin(), __l.end()); } 1507 #endif 1508 1509 /** 1510 * @brief Inserts a number of copies of given data into the %deque. 1511 * @param __position An iterator into the %deque. 1512 * @param __n Number of elements to be inserted. 1513 * @param __x Data to be inserted. 1514 * 1515 * This function will insert a specified number of copies of the given 1516 * data before the location specified by @a __position. 1517 */ 1518 void 1519 insert(iterator __position, size_type __n, const value_type& __x) 1520 { _M_fill_insert(__position, __n, __x); } 1521 1522 /** 1523 * @brief Inserts a range into the %deque. 1524 * @param __position An iterator into the %deque. 1525 * @param __first An input iterator. 1526 * @param __last An input iterator. 1527 * 1528 * This function will insert copies of the data in the range 1529 * [__first,__last) into the %deque before the location specified 1530 * by @a __position. This is known as <em>range insert</em>. 1531 */ 1532 #if __cplusplus >= 201103L 1533 template<typename _InputIterator, 1534 typename = std::_RequireInputIter<_InputIterator>> 1535 void 1536 insert(iterator __position, _InputIterator __first, 1537 _InputIterator __last) 1538 { _M_insert_dispatch(__position, __first, __last, __false_type()); } 1539 #else 1540 template<typename _InputIterator> 1541 void 1542 insert(iterator __position, _InputIterator __first, 1543 _InputIterator __last) 1544 { 1545 // Check whether it's an integral type. If so, it's not an iterator. 1546 typedef typename std::__is_integer<_InputIterator>::__type _Integral; 1547 _M_insert_dispatch(__position, __first, __last, _Integral()); 1548 } 1549 #endif 1550 1551 /** 1552 * @brief Remove element at given position. 1553 * @param __position Iterator pointing to element to be erased. 1554 * @return An iterator pointing to the next element (or end()). 1555 * 1556 * This function will erase the element at the given position and thus 1557 * shorten the %deque by one. 1558 * 1559 * The user is cautioned that 1560 * this function only erases the element, and that if the element is 1561 * itself a pointer, the pointed-to memory is not touched in any way. 1562 * Managing the pointer is the user's responsibility. 1563 */ 1564 iterator 1565 erase(iterator __position); 1566 1567 /** 1568 * @brief Remove a range of elements. 1569 * @param __first Iterator pointing to the first element to be erased. 1570 * @param __last Iterator pointing to one past the last element to be 1571 * erased. 1572 * @return An iterator pointing to the element pointed to by @a last 1573 * prior to erasing (or end()). 1574 * 1575 * This function will erase the elements in the range 1576 * [__first,__last) and shorten the %deque accordingly. 1577 * 1578 * The user is cautioned that 1579 * this function only erases the elements, and that if the elements 1580 * themselves are pointers, the pointed-to memory is not touched in any 1581 * way. Managing the pointer is the user's responsibility. 1582 */ 1583 iterator 1584 erase(iterator __first, iterator __last); 1585 1586 /** 1587 * @brief Swaps data with another %deque. 1588 * @param __x A %deque of the same element and allocator types. 1589 * 1590 * This exchanges the elements between two deques in constant time. 1591 * (Four pointers, so it should be quite fast.) 1592 * Note that the global std::swap() function is specialized such that 1593 * std::swap(d1,d2) will feed to this function. 1594 */ 1595 void 1596 swap(deque& __x) 1597 { 1598 std::swap(this->_M_impl._M_start, __x._M_impl._M_start); 1599 std::swap(this->_M_impl._M_finish, __x._M_impl._M_finish); 1600 std::swap(this->_M_impl._M_map, __x._M_impl._M_map); 1601 std::swap(this->_M_impl._M_map_size, __x._M_impl._M_map_size); 1602 1603 // _GLIBCXX_RESOLVE_LIB_DEFECTS 1604 // 431. Swapping containers with unequal allocators. 1605 std::__alloc_swap<_Tp_alloc_type>::_S_do_it(_M_get_Tp_allocator(), 1606 __x._M_get_Tp_allocator()); 1607 } 1608 1609 /** 1610 * Erases all the elements. Note that this function only erases the 1611 * elements, and that if the elements themselves are pointers, the 1612 * pointed-to memory is not touched in any way. Managing the pointer is 1613 * the user's responsibility. 1614 */ 1615 void 1616 clear() _GLIBCXX_NOEXCEPT 1617 { _M_erase_at_end(begin()); } 1618 1619 protected: 1620 // Internal constructor functions follow. 1621 1622 // called by the range constructor to implement [23.1.1]/9 1623 1624 // _GLIBCXX_RESOLVE_LIB_DEFECTS 1625 // 438. Ambiguity in the "do the right thing" clause 1626 template<typename _Integer> 1627 void 1628 _M_initialize_dispatch(_Integer __n, _Integer __x, __true_type) 1629 { 1630 _M_initialize_map(static_cast<size_type>(__n)); 1631 _M_fill_initialize(__x); 1632 } 1633 1634 // called by the range constructor to implement [23.1.1]/9 1635 template<typename _InputIterator> 1636 void 1637 _M_initialize_dispatch(_InputIterator __first, _InputIterator __last, 1638 __false_type) 1639 { 1640 typedef typename std::iterator_traits<_InputIterator>:: 1641 iterator_category _IterCategory; 1642 _M_range_initialize(__first, __last, _IterCategory()); 1643 } 1644 1645 // called by the second initialize_dispatch above 1646 //@{ 1647 /** 1648 * @brief Fills the deque with whatever is in [first,last). 1649 * @param __first An input iterator. 1650 * @param __last An input iterator. 1651 * @return Nothing. 1652 * 1653 * If the iterators are actually forward iterators (or better), then the 1654 * memory layout can be done all at once. Else we move forward using 1655 * push_back on each value from the iterator. 1656 */ 1657 template<typename _InputIterator> 1658 void 1659 _M_range_initialize(_InputIterator __first, _InputIterator __last, 1660 std::input_iterator_tag); 1661 1662 // called by the second initialize_dispatch above 1663 template<typename _ForwardIterator> 1664 void 1665 _M_range_initialize(_ForwardIterator __first, _ForwardIterator __last, 1666 std::forward_iterator_tag); 1667 //@} 1668 1669 /** 1670 * @brief Fills the %deque with copies of value. 1671 * @param __value Initial value. 1672 * @return Nothing. 1673 * @pre _M_start and _M_finish have already been initialized, 1674 * but none of the %deque's elements have yet been constructed. 1675 * 1676 * This function is called only when the user provides an explicit size 1677 * (with or without an explicit exemplar value). 1678 */ 1679 void 1680 _M_fill_initialize(const value_type& __value); 1681 1682 #if __cplusplus >= 201103L 1683 // called by deque(n). 1684 void 1685 _M_default_initialize(); 1686 #endif 1687 1688 // Internal assign functions follow. The *_aux functions do the actual 1689 // assignment work for the range versions. 1690 1691 // called by the range assign to implement [23.1.1]/9 1692 1693 // _GLIBCXX_RESOLVE_LIB_DEFECTS 1694 // 438. Ambiguity in the "do the right thing" clause 1695 template<typename _Integer> 1696 void 1697 _M_assign_dispatch(_Integer __n, _Integer __val, __true_type) 1698 { _M_fill_assign(__n, __val); } 1699 1700 // called by the range assign to implement [23.1.1]/9 1701 template<typename _InputIterator> 1702 void 1703 _M_assign_dispatch(_InputIterator __first, _InputIterator __last, 1704 __false_type) 1705 { 1706 typedef typename std::iterator_traits<_InputIterator>:: 1707 iterator_category _IterCategory; 1708 _M_assign_aux(__first, __last, _IterCategory()); 1709 } 1710 1711 // called by the second assign_dispatch above 1712 template<typename _InputIterator> 1713 void 1714 _M_assign_aux(_InputIterator __first, _InputIterator __last, 1715 std::input_iterator_tag); 1716 1717 // called by the second assign_dispatch above 1718 template<typename _ForwardIterator> 1719 void 1720 _M_assign_aux(_ForwardIterator __first, _ForwardIterator __last, 1721 std::forward_iterator_tag) 1722 { 1723 const size_type __len = std::distance(__first, __last); 1724 if (__len > size()) 1725 { 1726 _ForwardIterator __mid = __first; 1727 std::advance(__mid, size()); 1728 std::copy(__first, __mid, begin()); 1729 insert(end(), __mid, __last); 1730 } 1731 else 1732 _M_erase_at_end(std::copy(__first, __last, begin())); 1733 } 1734 1735 // Called by assign(n,t), and the range assign when it turns out 1736 // to be the same thing. 1737 void 1738 _M_fill_assign(size_type __n, const value_type& __val) 1739 { 1740 if (__n > size()) 1741 { 1742 std::fill(begin(), end(), __val); 1743 insert(end(), __n - size(), __val); 1744 } 1745 else 1746 { 1747 _M_erase_at_end(begin() + difference_type(__n)); 1748 std::fill(begin(), end(), __val); 1749 } 1750 } 1751 1752 //@{ 1753 /// Helper functions for push_* and pop_*. 1754 #if __cplusplus < 201103L 1755 void _M_push_back_aux(const value_type&); 1756 1757 void _M_push_front_aux(const value_type&); 1758 #else 1759 template<typename... _Args> 1760 void _M_push_back_aux(_Args&&... __args); 1761 1762 template<typename... _Args> 1763 void _M_push_front_aux(_Args&&... __args); 1764 #endif 1765 1766 void _M_pop_back_aux(); 1767 1768 void _M_pop_front_aux(); 1769 //@} 1770 1771 // Internal insert functions follow. The *_aux functions do the actual 1772 // insertion work when all shortcuts fail. 1773 1774 // called by the range insert to implement [23.1.1]/9 1775 1776 // _GLIBCXX_RESOLVE_LIB_DEFECTS 1777 // 438. Ambiguity in the "do the right thing" clause 1778 template<typename _Integer> 1779 void 1780 _M_insert_dispatch(iterator __pos, 1781 _Integer __n, _Integer __x, __true_type) 1782 { _M_fill_insert(__pos, __n, __x); } 1783 1784 // called by the range insert to implement [23.1.1]/9 1785 template<typename _InputIterator> 1786 void 1787 _M_insert_dispatch(iterator __pos, 1788 _InputIterator __first, _InputIterator __last, 1789 __false_type) 1790 { 1791 typedef typename std::iterator_traits<_InputIterator>:: 1792 iterator_category _IterCategory; 1793 _M_range_insert_aux(__pos, __first, __last, _IterCategory()); 1794 } 1795 1796 // called by the second insert_dispatch above 1797 template<typename _InputIterator> 1798 void 1799 _M_range_insert_aux(iterator __pos, _InputIterator __first, 1800 _InputIterator __last, std::input_iterator_tag); 1801 1802 // called by the second insert_dispatch above 1803 template<typename _ForwardIterator> 1804 void 1805 _M_range_insert_aux(iterator __pos, _ForwardIterator __first, 1806 _ForwardIterator __last, std::forward_iterator_tag); 1807 1808 // Called by insert(p,n,x), and the range insert when it turns out to be 1809 // the same thing. Can use fill functions in optimal situations, 1810 // otherwise passes off to insert_aux(p,n,x). 1811 void 1812 _M_fill_insert(iterator __pos, size_type __n, const value_type& __x); 1813 1814 // called by insert(p,x) 1815 #if __cplusplus < 201103L 1816 iterator 1817 _M_insert_aux(iterator __pos, const value_type& __x); 1818 #else 1819 template<typename... _Args> 1820 iterator 1821 _M_insert_aux(iterator __pos, _Args&&... __args); 1822 #endif 1823 1824 // called by insert(p,n,x) via fill_insert 1825 void 1826 _M_insert_aux(iterator __pos, size_type __n, const value_type& __x); 1827 1828 // called by range_insert_aux for forward iterators 1829 template<typename _ForwardIterator> 1830 void 1831 _M_insert_aux(iterator __pos, 1832 _ForwardIterator __first, _ForwardIterator __last, 1833 size_type __n); 1834 1835 1836 // Internal erase functions follow. 1837 1838 void 1839 _M_destroy_data_aux(iterator __first, iterator __last); 1840 1841 // Called by ~deque(). 1842 // NB: Doesn't deallocate the nodes. 1843 template<typename _Alloc1> 1844 void 1845 _M_destroy_data(iterator __first, iterator __last, const _Alloc1&) 1846 { _M_destroy_data_aux(__first, __last); } 1847 1848 void 1849 _M_destroy_data(iterator __first, iterator __last, 1850 const std::allocator<_Tp>&) 1851 { 1852 if (!__has_trivial_destructor(value_type)) 1853 _M_destroy_data_aux(__first, __last); 1854 } 1855 1856 // Called by erase(q1, q2). 1857 void 1858 _M_erase_at_begin(iterator __pos) 1859 { 1860 _M_destroy_data(begin(), __pos, _M_get_Tp_allocator()); 1861 _M_destroy_nodes(this->_M_impl._M_start._M_node, __pos._M_node); 1862 this->_M_impl._M_start = __pos; 1863 } 1864 1865 // Called by erase(q1, q2), resize(), clear(), _M_assign_aux, 1866 // _M_fill_assign, operator=. 1867 void 1868 _M_erase_at_end(iterator __pos) 1869 { 1870 _M_destroy_data(__pos, end(), _M_get_Tp_allocator()); 1871 _M_destroy_nodes(__pos._M_node + 1, 1872 this->_M_impl._M_finish._M_node + 1); 1873 this->_M_impl._M_finish = __pos; 1874 } 1875 1876 #if __cplusplus >= 201103L 1877 // Called by resize(sz). 1878 void 1879 _M_default_append(size_type __n); 1880 1881 bool 1882 _M_shrink_to_fit(); 1883 #endif 1884 1885 //@{ 1886 /// Memory-handling helpers for the previous internal insert functions. 1887 iterator 1888 _M_reserve_elements_at_front(size_type __n) 1889 { 1890 const size_type __vacancies = this->_M_impl._M_start._M_cur 1891 - this->_M_impl._M_start._M_first; 1892 if (__n > __vacancies) 1893 _M_new_elements_at_front(__n - __vacancies); 1894 return this->_M_impl._M_start - difference_type(__n); 1895 } 1896 1897 iterator 1898 _M_reserve_elements_at_back(size_type __n) 1899 { 1900 const size_type __vacancies = (this->_M_impl._M_finish._M_last 1901 - this->_M_impl._M_finish._M_cur) - 1; 1902 if (__n > __vacancies) 1903 _M_new_elements_at_back(__n - __vacancies); 1904 return this->_M_impl._M_finish + difference_type(__n); 1905 } 1906 1907 void 1908 _M_new_elements_at_front(size_type __new_elements); 1909 1910 void 1911 _M_new_elements_at_back(size_type __new_elements); 1912 //@} 1913 1914 1915 //@{ 1916 /** 1917 * @brief Memory-handling helpers for the major %map. 1918 * 1919 * Makes sure the _M_map has space for new nodes. Does not 1920 * actually add the nodes. Can invalidate _M_map pointers. 1921 * (And consequently, %deque iterators.) 1922 */ 1923 void 1924 _M_reserve_map_at_back(size_type __nodes_to_add = 1) 1925 { 1926 if (__nodes_to_add + 1 > this->_M_impl._M_map_size 1927 - (this->_M_impl._M_finish._M_node - this->_M_impl._M_map)) 1928 _M_reallocate_map(__nodes_to_add, false); 1929 } 1930 1931 void 1932 _M_reserve_map_at_front(size_type __nodes_to_add = 1) 1933 { 1934 if (__nodes_to_add > size_type(this->_M_impl._M_start._M_node 1935 - this->_M_impl._M_map)) 1936 _M_reallocate_map(__nodes_to_add, true); 1937 } 1938 1939 void 1940 _M_reallocate_map(size_type __nodes_to_add, bool __add_at_front); 1941 //@} 1942 }; 1943 1944 1945 /** 1946 * @brief Deque equality comparison. 1947 * @param __x A %deque. 1948 * @param __y A %deque of the same type as @a __x. 1949 * @return True iff the size and elements of the deques are equal. 1950 * 1951 * This is an equivalence relation. It is linear in the size of the 1952 * deques. Deques are considered equivalent if their sizes are equal, 1953 * and if corresponding elements compare equal. 1954 */ 1955 template<typename _Tp, typename _Alloc> 1956 inline bool 1957 operator==(const deque<_Tp, _Alloc>& __x, 1958 const deque<_Tp, _Alloc>& __y) 1959 { return __x.size() == __y.size() 1960 && std::equal(__x.begin(), __x.end(), __y.begin()); } 1961 1962 /** 1963 * @brief Deque ordering relation. 1964 * @param __x A %deque. 1965 * @param __y A %deque of the same type as @a __x. 1966 * @return True iff @a x is lexicographically less than @a __y. 1967 * 1968 * This is a total ordering relation. It is linear in the size of the 1969 * deques. The elements must be comparable with @c <. 1970 * 1971 * See std::lexicographical_compare() for how the determination is made. 1972 */ 1973 template<typename _Tp, typename _Alloc> 1974 inline bool 1975 operator<(const deque<_Tp, _Alloc>& __x, 1976 const deque<_Tp, _Alloc>& __y) 1977 { return std::lexicographical_compare(__x.begin(), __x.end(), 1978 __y.begin(), __y.end()); } 1979 1980 /// Based on operator== 1981 template<typename _Tp, typename _Alloc> 1982 inline bool 1983 operator!=(const deque<_Tp, _Alloc>& __x, 1984 const deque<_Tp, _Alloc>& __y) 1985 { return !(__x == __y); } 1986 1987 /// Based on operator< 1988 template<typename _Tp, typename _Alloc> 1989 inline bool 1990 operator>(const deque<_Tp, _Alloc>& __x, 1991 const deque<_Tp, _Alloc>& __y) 1992 { return __y < __x; } 1993 1994 /// Based on operator< 1995 template<typename _Tp, typename _Alloc> 1996 inline bool 1997 operator<=(const deque<_Tp, _Alloc>& __x, 1998 const deque<_Tp, _Alloc>& __y) 1999 { return !(__y < __x); } 2000 2001 /// Based on operator< 2002 template<typename _Tp, typename _Alloc> 2003 inline bool 2004 operator>=(const deque<_Tp, _Alloc>& __x, 2005 const deque<_Tp, _Alloc>& __y) 2006 { return !(__x < __y); } 2007 2008 /// See std::deque::swap(). 2009 template<typename _Tp, typename _Alloc> 2010 inline void 2011 swap(deque<_Tp,_Alloc>& __x, deque<_Tp,_Alloc>& __y) 2012 { __x.swap(__y); } 2013 2014 #undef _GLIBCXX_DEQUE_BUF_SIZE 2015 2016 _GLIBCXX_END_NAMESPACE_CONTAINER 2017 } // namespace std 2018 2019 #endif /* _STL_DEQUE_H */ 2020
