Where Online Learning is simpler!
The C and C++ Include Header Files
/usr/include/c++/11/bits/stl_deque.h
$ cat -n /usr/include/c++/11/bits/stl_deque.h 1 // Deque implementation -*- C++ -*- 2 3 // Copyright (C) 2001-2021 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 #include <bits/stl_uninitialized.h> // for __is_bitwise_relocatable 65 #endif 66 #if __cplusplus > 201703L 67 # include <compare> 68 #endif 69 70 #include <debug/assertions.h> 71 72 namespace std _GLIBCXX_VISIBILITY(default) 73 { 74 _GLIBCXX_BEGIN_NAMESPACE_VERSION 75 _GLIBCXX_BEGIN_NAMESPACE_CONTAINER 76 77 /** 78 * @brief This function controls the size of memory nodes. 79 * @param __size The size of an element. 80 * @return The number (not byte size) of elements per node. 81 * 82 * This function started off as a compiler kludge from SGI, but 83 * seems to be a useful wrapper around a repeated constant 84 * expression. The @b 512 is tunable (and no other code needs to 85 * change), but no investigation has been done since inheriting the 86 * SGI code. Touch _GLIBCXX_DEQUE_BUF_SIZE only if you know what 87 * you are doing, however: changing it breaks the binary 88 * compatibility!! 89 */ 90 91 #ifndef _GLIBCXX_DEQUE_BUF_SIZE 92 #define _GLIBCXX_DEQUE_BUF_SIZE 512 93 #endif 94 95 _GLIBCXX_CONSTEXPR inline size_t 96 __deque_buf_size(size_t __size) 97 { return (__size < _GLIBCXX_DEQUE_BUF_SIZE 98 ? size_t(_GLIBCXX_DEQUE_BUF_SIZE / __size) : size_t(1)); } 99 100 101 /** 102 * @brief A deque::iterator. 103 * 104 * Quite a bit of intelligence here. Much of the functionality of 105 * deque is actually passed off to this class. A deque holds two 106 * of these internally, marking its valid range. Access to 107 * elements is done as offsets of either of those two, relying on 108 * operator overloading in this class. 109 * 110 * All the functions are op overloads except for _M_set_node. 111 */ 112 template<typename _Tp, typename _Ref, typename _Ptr> 113 struct _Deque_iterator 114 { 115 #if __cplusplus < 201103L 116 typedef _Deque_iterator<_Tp, _Tp&, _Tp*> iterator; 117 typedef _Deque_iterator<_Tp, const _Tp&, const _Tp*> const_iterator; 118 typedef _Tp* _Elt_pointer; 119 typedef _Tp** _Map_pointer; 120 #else 121 private: 122 template<typename _CvTp> 123 using __iter = _Deque_iterator<_Tp, _CvTp&, __ptr_rebind<_Ptr, _CvTp>>; 124 public: 125 typedef __iter<_Tp> iterator; 126 typedef __iter<const _Tp> const_iterator; 127 typedef __ptr_rebind<_Ptr, _Tp> _Elt_pointer; 128 typedef __ptr_rebind<_Ptr, _Elt_pointer> _Map_pointer; 129 #endif 130 131 static size_t _S_buffer_size() _GLIBCXX_NOEXCEPT 132 { return __deque_buf_size(sizeof(_Tp)); } 133 134 typedef std::random_access_iterator_tag iterator_category; 135 typedef _Tp value_type; 136 typedef _Ptr pointer; 137 typedef _Ref reference; 138 typedef size_t size_type; 139 typedef ptrdiff_t difference_type; 140 typedef _Deque_iterator _Self; 141 142 _Elt_pointer _M_cur; 143 _Elt_pointer _M_first; 144 _Elt_pointer _M_last; 145 _Map_pointer _M_node; 146 147 _Deque_iterator(_Elt_pointer __x, _Map_pointer __y) _GLIBCXX_NOEXCEPT 148 : _M_cur(__x), _M_first(*__y), 149 _M_last(*__y + _S_buffer_size()), _M_node(__y) { } 150 151 _Deque_iterator() _GLIBCXX_NOEXCEPT 152 : _M_cur(), _M_first(), _M_last(), _M_node() { } 153 154 #if __cplusplus < 201103L 155 // Conversion from iterator to const_iterator. 156 _Deque_iterator(const iterator& __x) _GLIBCXX_NOEXCEPT 157 : _M_cur(__x._M_cur), _M_first(__x._M_first), 158 _M_last(__x._M_last), _M_node(__x._M_node) { } 159 #else 160 // Conversion from iterator to const_iterator. 161 template<typename _Iter, 162 typename = _Require<is_same<_Self, const_iterator>, 163 is_same<_Iter, iterator>>> 164 _Deque_iterator(const _Iter& __x) noexcept 165 : _M_cur(__x._M_cur), _M_first(__x._M_first), 166 _M_last(__x._M_last), _M_node(__x._M_node) { } 167 168 _Deque_iterator(const _Deque_iterator& __x) noexcept 169 : _M_cur(__x._M_cur), _M_first(__x._M_first), 170 _M_last(__x._M_last), _M_node(__x._M_node) { } 171 172 _Deque_iterator& operator=(const _Deque_iterator&) = default; 173 #endif 174 175 iterator 176 _M_const_cast() const _GLIBCXX_NOEXCEPT 177 { return iterator(_M_cur, _M_node); } 178 179 reference 180 operator*() const _GLIBCXX_NOEXCEPT 181 { return *_M_cur; } 182 183 pointer 184 operator->() const _GLIBCXX_NOEXCEPT 185 { return _M_cur; } 186 187 _Self& 188 operator++() _GLIBCXX_NOEXCEPT 189 { 190 ++_M_cur; 191 if (_M_cur == _M_last) 192 { 193 _M_set_node(_M_node + 1); 194 _M_cur = _M_first; 195 } 196 return *this; 197 } 198 199 _Self 200 operator++(int) _GLIBCXX_NOEXCEPT 201 { 202 _Self __tmp = *this; 203 ++*this; 204 return __tmp; 205 } 206 207 _Self& 208 operator--() _GLIBCXX_NOEXCEPT 209 { 210 if (_M_cur == _M_first) 211 { 212 _M_set_node(_M_node - 1); 213 _M_cur = _M_last; 214 } 215 --_M_cur; 216 return *this; 217 } 218 219 _Self 220 operator--(int) _GLIBCXX_NOEXCEPT 221 { 222 _Self __tmp = *this; 223 --*this; 224 return __tmp; 225 } 226 227 _Self& 228 operator+=(difference_type __n) _GLIBCXX_NOEXCEPT 229 { 230 const difference_type __offset = __n + (_M_cur - _M_first); 231 if (__offset >= 0 && __offset < difference_type(_S_buffer_size())) 232 _M_cur += __n; 233 else 234 { 235 const difference_type __node_offset = 236 __offset > 0 ? __offset / difference_type(_S_buffer_size()) 237 : -difference_type((-__offset - 1) 238 / _S_buffer_size()) - 1; 239 _M_set_node(_M_node + __node_offset); 240 _M_cur = _M_first + (__offset - __node_offset 241 * difference_type(_S_buffer_size())); 242 } 243 return *this; 244 } 245 246 _Self& 247 operator-=(difference_type __n) _GLIBCXX_NOEXCEPT 248 { return *this += -__n; } 249 250 reference 251 operator[](difference_type __n) const _GLIBCXX_NOEXCEPT 252 { return *(*this + __n); } 253 254 /** 255 * Prepares to traverse new_node. Sets everything except 256 * _M_cur, which should therefore be set by the caller 257 * immediately afterwards, based on _M_first and _M_last. 258 */ 259 void 260 _M_set_node(_Map_pointer __new_node) _GLIBCXX_NOEXCEPT 261 { 262 _M_node = __new_node; 263 _M_first = *__new_node; 264 _M_last = _M_first + difference_type(_S_buffer_size()); 265 } 266 267 friend bool 268 operator==(const _Self& __x, const _Self& __y) _GLIBCXX_NOEXCEPT 269 { return __x._M_cur == __y._M_cur; } 270 271 // Note: we also provide overloads whose operands are of the same type in 272 // order to avoid ambiguous overload resolution when std::rel_ops 273 // operators are in scope (for additional details, see libstdc++/3628) 274 template<typename _RefR, typename _PtrR> 275 friend bool 276 operator==(const _Self& __x, 277 const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) 278 _GLIBCXX_NOEXCEPT 279 { return __x._M_cur == __y._M_cur; } 280 281 #if __cpp_lib_three_way_comparison 282 friend strong_ordering 283 operator<=>(const _Self& __x, const _Self& __y) noexcept 284 { 285 if (const auto __cmp = __x._M_node <=> __y._M_node; __cmp != 0) 286 return __cmp; 287 return __x._M_cur <=> __y._M_cur; 288 } 289 #else 290 friend bool 291 operator!=(const _Self& __x, const _Self& __y) _GLIBCXX_NOEXCEPT 292 { return !(__x == __y); } 293 294 template<typename _RefR, typename _PtrR> 295 friend bool 296 operator!=(const _Self& __x, 297 const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) 298 _GLIBCXX_NOEXCEPT 299 { return !(__x == __y); } 300 301 friend bool 302 operator<(const _Self& __x, const _Self& __y) _GLIBCXX_NOEXCEPT 303 { 304 return (__x._M_node == __y._M_node) 305 ? (__x._M_cur < __y._M_cur) : (__x._M_node < __y._M_node); 306 } 307 308 template<typename _RefR, typename _PtrR> 309 friend bool 310 operator<(const _Self& __x, 311 const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) 312 _GLIBCXX_NOEXCEPT 313 { 314 return (__x._M_node == __y._M_node) 315 ? (__x._M_cur < __y._M_cur) : (__x._M_node < __y._M_node); 316 } 317 318 friend bool 319 operator>(const _Self& __x, const _Self& __y) _GLIBCXX_NOEXCEPT 320 { return __y < __x; } 321 322 template<typename _RefR, typename _PtrR> 323 friend bool 324 operator>(const _Self& __x, 325 const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) 326 _GLIBCXX_NOEXCEPT 327 { return __y < __x; } 328 329 friend bool 330 operator<=(const _Self& __x, const _Self& __y) _GLIBCXX_NOEXCEPT 331 { return !(__y < __x); } 332 333 template<typename _RefR, typename _PtrR> 334 friend bool 335 operator<=(const _Self& __x, 336 const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) 337 _GLIBCXX_NOEXCEPT 338 { return !(__y < __x); } 339 340 friend bool 341 operator>=(const _Self& __x, const _Self& __y) _GLIBCXX_NOEXCEPT 342 { return !(__x < __y); } 343 344 template<typename _RefR, typename _PtrR> 345 friend bool 346 operator>=(const _Self& __x, 347 const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) 348 _GLIBCXX_NOEXCEPT 349 { return !(__x < __y); } 350 #endif // three-way comparison 351 352 friend difference_type 353 operator-(const _Self& __x, const _Self& __y) _GLIBCXX_NOEXCEPT 354 { 355 return difference_type(_S_buffer_size()) 356 * (__x._M_node - __y._M_node - bool(__x._M_node)) 357 + (__x._M_cur - __x._M_first) 358 + (__y._M_last - __y._M_cur); 359 } 360 361 // _GLIBCXX_RESOLVE_LIB_DEFECTS 362 // According to the resolution of DR179 not only the various comparison 363 // operators but also operator- must accept mixed iterator/const_iterator 364 // parameters. 365 template<typename _RefR, typename _PtrR> 366 friend difference_type 367 operator-(const _Self& __x, 368 const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) 369 _GLIBCXX_NOEXCEPT 370 { 371 return difference_type(_S_buffer_size()) 372 * (__x._M_node - __y._M_node - bool(__x._M_node)) 373 + (__x._M_cur - __x._M_first) 374 + (__y._M_last - __y._M_cur); 375 } 376 377 friend _Self 378 operator+(const _Self& __x, difference_type __n) _GLIBCXX_NOEXCEPT 379 { 380 _Self __tmp = __x; 381 __tmp += __n; 382 return __tmp; 383 } 384 385 friend _Self 386 operator-(const _Self& __x, difference_type __n) _GLIBCXX_NOEXCEPT 387 { 388 _Self __tmp = __x; 389 __tmp -= __n; 390 return __tmp; 391 } 392 393 friend _Self 394 operator+(difference_type __n, const _Self& __x) _GLIBCXX_NOEXCEPT 395 { return __x + __n; } 396 }; 397 398 /** 399 * Deque base class. This class provides the unified face for %deque's 400 * allocation. This class's constructor and destructor allocate and 401 * deallocate (but do not initialize) storage. This makes %exception 402 * safety easier. 403 * 404 * Nothing in this class ever constructs or destroys an actual Tp element. 405 * (Deque handles that itself.) Only/All memory management is performed 406 * here. 407 */ 408 template<typename _Tp, typename _Alloc> 409 class _Deque_base 410 { 411 protected: 412 typedef typename __gnu_cxx::__alloc_traits<_Alloc>::template 413 rebind<_Tp>::other _Tp_alloc_type; 414 typedef __gnu_cxx::__alloc_traits<_Tp_alloc_type> _Alloc_traits; 415 416 #if __cplusplus < 201103L 417 typedef _Tp* _Ptr; 418 typedef const _Tp* _Ptr_const; 419 #else 420 typedef typename _Alloc_traits::pointer _Ptr; 421 typedef typename _Alloc_traits::const_pointer _Ptr_const; 422 #endif 423 424 typedef typename _Alloc_traits::template rebind<_Ptr>::other 425 _Map_alloc_type; 426 typedef __gnu_cxx::__alloc_traits<_Map_alloc_type> _Map_alloc_traits; 427 428 typedef _Alloc allocator_type; 429 430 allocator_type 431 get_allocator() const _GLIBCXX_NOEXCEPT 432 { return allocator_type(_M_get_Tp_allocator()); } 433 434 typedef _Deque_iterator<_Tp, _Tp&, _Ptr> iterator; 435 typedef _Deque_iterator<_Tp, const _Tp&, _Ptr_const> const_iterator; 436 437 _Deque_base() 438 : _M_impl() 439 { _M_initialize_map(0); } 440 441 _Deque_base(size_t __num_elements) 442 : _M_impl() 443 { _M_initialize_map(__num_elements); } 444 445 _Deque_base(const allocator_type& __a, size_t __num_elements) 446 : _M_impl(__a) 447 { _M_initialize_map(__num_elements); } 448 449 _Deque_base(const allocator_type& __a) 450 : _M_impl(__a) 451 { /* Caller must initialize map. */ } 452 453 #if __cplusplus >= 201103L 454 _Deque_base(_Deque_base&& __x) 455 : _M_impl(std::move(__x._M_get_Tp_allocator())) 456 { 457 _M_initialize_map(0); 458 if (__x._M_impl._M_map) 459 this->_M_impl._M_swap_data(__x._M_impl); 460 } 461 462 _Deque_base(_Deque_base&& __x, const allocator_type& __a) 463 : _M_impl(std::move(__x._M_impl), _Tp_alloc_type(__a)) 464 { __x._M_initialize_map(0); } 465 466 _Deque_base(_Deque_base&& __x, const allocator_type& __a, size_t __n) 467 : _M_impl(__a) 468 { 469 if (__x.get_allocator() == __a) 470 { 471 if (__x._M_impl._M_map) 472 { 473 _M_initialize_map(0); 474 this->_M_impl._M_swap_data(__x._M_impl); 475 } 476 } 477 else 478 { 479 _M_initialize_map(__n); 480 } 481 } 482 #endif 483 484 ~_Deque_base() _GLIBCXX_NOEXCEPT; 485 486 typedef typename iterator::_Map_pointer _Map_pointer; 487 488 struct _Deque_impl_data 489 { 490 _Map_pointer _M_map; 491 size_t _M_map_size; 492 iterator _M_start; 493 iterator _M_finish; 494 495 _Deque_impl_data() _GLIBCXX_NOEXCEPT 496 : _M_map(), _M_map_size(), _M_start(), _M_finish() 497 { } 498 499 #if __cplusplus >= 201103L 500 _Deque_impl_data(const _Deque_impl_data&) = default; 501 _Deque_impl_data& 502 operator=(const _Deque_impl_data&) = default; 503 504 _Deque_impl_data(_Deque_impl_data&& __x) noexcept 505 : _Deque_impl_data(__x) 506 { __x = _Deque_impl_data(); } 507 #endif 508 509 void 510 _M_swap_data(_Deque_impl_data& __x) _GLIBCXX_NOEXCEPT 511 { 512 // Do not use std::swap(_M_start, __x._M_start), etc as it loses 513 // information used by TBAA. 514 std::swap(*this, __x); 515 } 516 }; 517 518 // This struct encapsulates the implementation of the std::deque 519 // standard container and at the same time makes use of the EBO 520 // for empty allocators. 521 struct _Deque_impl 522 : public _Tp_alloc_type, public _Deque_impl_data 523 { 524 _Deque_impl() _GLIBCXX_NOEXCEPT_IF( 525 is_nothrow_default_constructible<_Tp_alloc_type>::value) 526 : _Tp_alloc_type() 527 { } 528 529 _Deque_impl(const _Tp_alloc_type& __a) _GLIBCXX_NOEXCEPT 530 : _Tp_alloc_type(__a) 531 { } 532 533 #if __cplusplus >= 201103L 534 _Deque_impl(_Deque_impl&&) = default; 535 536 _Deque_impl(_Tp_alloc_type&& __a) noexcept 537 : _Tp_alloc_type(std::move(__a)) 538 { } 539 540 _Deque_impl(_Deque_impl&& __d, _Tp_alloc_type&& __a) 541 : _Tp_alloc_type(std::move(__a)), _Deque_impl_data(std::move(__d)) 542 { } 543 #endif 544 }; 545 546 _Tp_alloc_type& 547 _M_get_Tp_allocator() _GLIBCXX_NOEXCEPT 548 { return this->_M_impl; } 549 550 const _Tp_alloc_type& 551 _M_get_Tp_allocator() const _GLIBCXX_NOEXCEPT 552 { return this->_M_impl; } 553 554 _Map_alloc_type 555 _M_get_map_allocator() const _GLIBCXX_NOEXCEPT 556 { return _Map_alloc_type(_M_get_Tp_allocator()); } 557 558 _Ptr 559 _M_allocate_node() 560 { 561 typedef __gnu_cxx::__alloc_traits<_Tp_alloc_type> _Traits; 562 return _Traits::allocate(_M_impl, __deque_buf_size(sizeof(_Tp))); 563 } 564 565 void 566 _M_deallocate_node(_Ptr __p) _GLIBCXX_NOEXCEPT 567 { 568 typedef __gnu_cxx::__alloc_traits<_Tp_alloc_type> _Traits; 569 _Traits::deallocate(_M_impl, __p, __deque_buf_size(sizeof(_Tp))); 570 } 571 572 _Map_pointer 573 _M_allocate_map(size_t __n) 574 { 575 _Map_alloc_type __map_alloc = _M_get_map_allocator(); 576 return _Map_alloc_traits::allocate(__map_alloc, __n); 577 } 578 579 void 580 _M_deallocate_map(_Map_pointer __p, size_t __n) _GLIBCXX_NOEXCEPT 581 { 582 _Map_alloc_type __map_alloc = _M_get_map_allocator(); 583 _Map_alloc_traits::deallocate(__map_alloc, __p, __n); 584 } 585 586 void _M_initialize_map(size_t); 587 void _M_create_nodes(_Map_pointer __nstart, _Map_pointer __nfinish); 588 void _M_destroy_nodes(_Map_pointer __nstart, 589 _Map_pointer __nfinish) _GLIBCXX_NOEXCEPT; 590 enum { _S_initial_map_size = 8 }; 591 592 _Deque_impl _M_impl; 593 }; 594 595 template<typename _Tp, typename _Alloc> 596 _Deque_base<_Tp, _Alloc>:: 597 ~_Deque_base() _GLIBCXX_NOEXCEPT 598 { 599 if (this->_M_impl._M_map) 600 { 601 _M_destroy_nodes(this->_M_impl._M_start._M_node, 602 this->_M_impl._M_finish._M_node + 1); 603 _M_deallocate_map(this->_M_impl._M_map, this->_M_impl._M_map_size); 604 } 605 } 606 607 /** 608 * @brief Layout storage. 609 * @param __num_elements The count of T's for which to allocate space 610 * at first. 611 * @return Nothing. 612 * 613 * The initial underlying memory layout is a bit complicated... 614 */ 615 template<typename _Tp, typename _Alloc> 616 void 617 _Deque_base<_Tp, _Alloc>:: 618 _M_initialize_map(size_t __num_elements) 619 { 620 const size_t __num_nodes = (__num_elements / __deque_buf_size(sizeof(_Tp)) 621 + 1); 622 623 this->_M_impl._M_map_size = std::max((size_t) _S_initial_map_size, 624 size_t(__num_nodes + 2)); 625 this->_M_impl._M_map = _M_allocate_map(this->_M_impl._M_map_size); 626 627 // For "small" maps (needing less than _M_map_size nodes), allocation 628 // starts in the middle elements and grows outwards. So nstart may be 629 // the beginning of _M_map, but for small maps it may be as far in as 630 // _M_map+3. 631 632 _Map_pointer __nstart = (this->_M_impl._M_map 633 + (this->_M_impl._M_map_size - __num_nodes) / 2); 634 _Map_pointer __nfinish = __nstart + __num_nodes; 635 636 __try 637 { _M_create_nodes(__nstart, __nfinish); } 638 __catch(...) 639 { 640 _M_deallocate_map(this->_M_impl._M_map, this->_M_impl._M_map_size); 641 this->_M_impl._M_map = _Map_pointer(); 642 this->_M_impl._M_map_size = 0; 643 __throw_exception_again; 644 } 645 646 this->_M_impl._M_start._M_set_node(__nstart); 647 this->_M_impl._M_finish._M_set_node(__nfinish - 1); 648 this->_M_impl._M_start._M_cur = _M_impl._M_start._M_first; 649 this->_M_impl._M_finish._M_cur = (this->_M_impl._M_finish._M_first 650 + __num_elements 651 % __deque_buf_size(sizeof(_Tp))); 652 } 653 654 template<typename _Tp, typename _Alloc> 655 void 656 _Deque_base<_Tp, _Alloc>:: 657 _M_create_nodes(_Map_pointer __nstart, _Map_pointer __nfinish) 658 { 659 _Map_pointer __cur; 660 __try 661 { 662 for (__cur = __nstart; __cur < __nfinish; ++__cur) 663 *__cur = this->_M_allocate_node(); 664 } 665 __catch(...) 666 { 667 _M_destroy_nodes(__nstart, __cur); 668 __throw_exception_again; 669 } 670 } 671 672 template<typename _Tp, typename _Alloc> 673 void 674 _Deque_base<_Tp, _Alloc>:: 675 _M_destroy_nodes(_Map_pointer __nstart, 676 _Map_pointer __nfinish) _GLIBCXX_NOEXCEPT 677 { 678 for (_Map_pointer __n = __nstart; __n < __nfinish; ++__n) 679 _M_deallocate_node(*__n); 680 } 681 682 /** 683 * @brief A standard container using fixed-size memory allocation and 684 * constant-time manipulation of elements at either end. 685 * 686 * @ingroup sequences 687 * 688 * @tparam _Tp Type of element. 689 * @tparam _Alloc Allocator type, defaults to allocator<_Tp>. 690 * 691 * Meets the requirements of a <a href="tables.html#65">container</a>, a 692 * <a href="tables.html#66">reversible container</a>, and a 693 * <a href="tables.html#67">sequence</a>, including the 694 * <a href="tables.html#68">optional sequence requirements</a>. 695 * 696 * In previous HP/SGI versions of deque, there was an extra template 697 * parameter so users could control the node size. This extension turned 698 * out to violate the C++ standard (it can be detected using template 699 * template parameters), and it was removed. 700 * 701 * Here's how a deque<Tp> manages memory. Each deque has 4 members: 702 * 703 * - Tp** _M_map 704 * - size_t _M_map_size 705 * - iterator _M_start, _M_finish 706 * 707 * map_size is at least 8. %map is an array of map_size 708 * pointers-to-@a nodes. (The name %map has nothing to do with the 709 * std::map class, and @b nodes should not be confused with 710 * std::list's usage of @a node.) 711 * 712 * A @a node has no specific type name as such, but it is referred 713 * to as @a node in this file. It is a simple array-of-Tp. If Tp 714 * is very large, there will be one Tp element per node (i.e., an 715 * @a array of one). For non-huge Tp's, node size is inversely 716 * related to Tp size: the larger the Tp, the fewer Tp's will fit 717 * in a node. The goal here is to keep the total size of a node 718 * relatively small and constant over different Tp's, to improve 719 * allocator efficiency. 720 * 721 * Not every pointer in the %map array will point to a node. If 722 * the initial number of elements in the deque is small, the 723 * /middle/ %map pointers will be valid, and the ones at the edges 724 * will be unused. This same situation will arise as the %map 725 * grows: available %map pointers, if any, will be on the ends. As 726 * new nodes are created, only a subset of the %map's pointers need 727 * to be copied @a outward. 728 * 729 * Class invariants: 730 * - For any nonsingular iterator i: 731 * - i.node points to a member of the %map array. (Yes, you read that 732 * correctly: i.node does not actually point to a node.) The member of 733 * the %map array is what actually points to the node. 734 * - i.first == *(i.node) (This points to the node (first Tp element).) 735 * - i.last == i.first + node_size 736 * - i.cur is a pointer in the range [i.first, i.last). NOTE: 737 * the implication of this is that i.cur is always a dereferenceable 738 * pointer, even if i is a past-the-end iterator. 739 * - Start and Finish are always nonsingular iterators. NOTE: this 740 * means that an empty deque must have one node, a deque with <N 741 * elements (where N is the node buffer size) must have one node, a 742 * deque with N through (2N-1) elements must have two nodes, etc. 743 * - For every node other than start.node and finish.node, every 744 * element in the node is an initialized object. If start.node == 745 * finish.node, then [start.cur, finish.cur) are initialized 746 * objects, and the elements outside that range are uninitialized 747 * storage. Otherwise, [start.cur, start.last) and [finish.first, 748 * finish.cur) are initialized objects, and [start.first, start.cur) 749 * and [finish.cur, finish.last) are uninitialized storage. 750 * - [%map, %map + map_size) is a valid, non-empty range. 751 * - [start.node, finish.node] is a valid range contained within 752 * [%map, %map + map_size). 753 * - A pointer in the range [%map, %map + map_size) points to an allocated 754 * node if and only if the pointer is in the range 755 * [start.node, finish.node]. 756 * 757 * Here's the magic: nothing in deque is @b aware of the discontiguous 758 * storage! 759 * 760 * The memory setup and layout occurs in the parent, _Base, and the iterator 761 * class is entirely responsible for @a leaping from one node to the next. 762 * All the implementation routines for deque itself work only through the 763 * start and finish iterators. This keeps the routines simple and sane, 764 * and we can use other standard algorithms as well. 765 */ 766 template<typename _Tp, typename _Alloc = std::allocator<_Tp> > 767 class deque : protected _Deque_base<_Tp, _Alloc> 768 { 769 #ifdef _GLIBCXX_CONCEPT_CHECKS 770 // concept requirements 771 typedef typename _Alloc::value_type _Alloc_value_type; 772 # if __cplusplus < 201103L 773 __glibcxx_class_requires(_Tp, _SGIAssignableConcept) 774 # endif 775 __glibcxx_class_requires2(_Tp, _Alloc_value_type, _SameTypeConcept) 776 #endif 777 778 #if __cplusplus >= 201103L 779 static_assert(is_same<typename remove_cv<_Tp>::type, _Tp>::value, 780 "std::deque must have a non-const, non-volatile value_type"); 781 # if __cplusplus > 201703L || defined __STRICT_ANSI__ 782 static_assert(is_same<typename _Alloc::value_type, _Tp>::value, 783 "std::deque must have the same value_type as its allocator"); 784 # endif 785 #endif 786 787 typedef _Deque_base<_Tp, _Alloc> _Base; 788 typedef typename _Base::_Tp_alloc_type _Tp_alloc_type; 789 typedef typename _Base::_Alloc_traits _Alloc_traits; 790 typedef typename _Base::_Map_pointer _Map_pointer; 791 792 public: 793 typedef _Tp value_type; 794 typedef typename _Alloc_traits::pointer pointer; 795 typedef typename _Alloc_traits::const_pointer const_pointer; 796 typedef typename _Alloc_traits::reference reference; 797 typedef typename _Alloc_traits::const_reference const_reference; 798 typedef typename _Base::iterator iterator; 799 typedef typename _Base::const_iterator const_iterator; 800 typedef std::reverse_iterator<const_iterator> const_reverse_iterator; 801 typedef std::reverse_iterator<iterator> reverse_iterator; 802 typedef size_t size_type; 803 typedef ptrdiff_t difference_type; 804 typedef _Alloc allocator_type; 805 806 private: 807 static size_t _S_buffer_size() _GLIBCXX_NOEXCEPT 808 { return __deque_buf_size(sizeof(_Tp)); } 809 810 // Functions controlling memory layout, and nothing else. 811 using _Base::_M_initialize_map; 812 using _Base::_M_create_nodes; 813 using _Base::_M_destroy_nodes; 814 using _Base::_M_allocate_node; 815 using _Base::_M_deallocate_node; 816 using _Base::_M_allocate_map; 817 using _Base::_M_deallocate_map; 818 using _Base::_M_get_Tp_allocator; 819 820 /** 821 * A total of four data members accumulated down the hierarchy. 822 * May be accessed via _M_impl.* 823 */ 824 using _Base::_M_impl; 825 826 public: 827 // [23.2.1.1] construct/copy/destroy 828 // (assign() and get_allocator() are also listed in this section) 829 830 /** 831 * @brief Creates a %deque with no elements. 832 */ 833 #if __cplusplus >= 201103L 834 deque() = default; 835 #else 836 deque() { } 837 #endif 838 839 /** 840 * @brief Creates a %deque with no elements. 841 * @param __a An allocator object. 842 */ 843 explicit 844 deque(const allocator_type& __a) 845 : _Base(__a, 0) { } 846 847 #if __cplusplus >= 201103L 848 /** 849 * @brief Creates a %deque with default constructed elements. 850 * @param __n The number of elements to initially create. 851 * @param __a An allocator. 852 * 853 * This constructor fills the %deque with @a n default 854 * constructed elements. 855 */ 856 explicit 857 deque(size_type __n, const allocator_type& __a = allocator_type()) 858 : _Base(__a, _S_check_init_len(__n, __a)) 859 { _M_default_initialize(); } 860 861 /** 862 * @brief Creates a %deque with copies of an exemplar element. 863 * @param __n The number of elements to initially create. 864 * @param __value An element to copy. 865 * @param __a An allocator. 866 * 867 * This constructor fills the %deque with @a __n copies of @a __value. 868 */ 869 deque(size_type __n, const value_type& __value, 870 const allocator_type& __a = allocator_type()) 871 : _Base(__a, _S_check_init_len(__n, __a)) 872 { _M_fill_initialize(__value); } 873 #else 874 /** 875 * @brief Creates a %deque with copies of an exemplar element. 876 * @param __n The number of elements to initially create. 877 * @param __value An element to copy. 878 * @param __a An allocator. 879 * 880 * This constructor fills the %deque with @a __n copies of @a __value. 881 */ 882 explicit 883 deque(size_type __n, const value_type& __value = value_type(), 884 const allocator_type& __a = allocator_type()) 885 : _Base(__a, _S_check_init_len(__n, __a)) 886 { _M_fill_initialize(__value); } 887 #endif 888 889 /** 890 * @brief %Deque copy constructor. 891 * @param __x A %deque of identical element and allocator types. 892 * 893 * The newly-created %deque uses a copy of the allocator object used 894 * by @a __x (unless the allocator traits dictate a different object). 895 */ 896 deque(const deque& __x) 897 : _Base(_Alloc_traits::_S_select_on_copy(__x._M_get_Tp_allocator()), 898 __x.size()) 899 { std::__uninitialized_copy_a(__x.begin(), __x.end(), 900 this->_M_impl._M_start, 901 _M_get_Tp_allocator()); } 902 903 #if __cplusplus >= 201103L 904 /** 905 * @brief %Deque move constructor. 906 * 907 * The newly-created %deque contains the exact contents of the 908 * moved instance. 909 * The contents of the moved instance are a valid, but unspecified 910 * %deque. 911 */ 912 deque(deque&&) = default; 913 914 /// Copy constructor with alternative allocator 915 deque(const deque& __x, const allocator_type& __a) 916 : _Base(__a, __x.size()) 917 { std::__uninitialized_copy_a(__x.begin(), __x.end(), 918 this->_M_impl._M_start, 919 _M_get_Tp_allocator()); } 920 921 /// Move constructor with alternative allocator 922 deque(deque&& __x, const allocator_type& __a) 923 : deque(std::move(__x), __a, typename _Alloc_traits::is_always_equal{}) 924 { } 925 926 private: 927 deque(deque&& __x, const allocator_type& __a, true_type) 928 : _Base(std::move(__x), __a) 929 { } 930 931 deque(deque&& __x, const allocator_type& __a, false_type) 932 : _Base(std::move(__x), __a, __x.size()) 933 { 934 if (__x.get_allocator() != __a && !__x.empty()) 935 { 936 std::__uninitialized_move_a(__x.begin(), __x.end(), 937 this->_M_impl._M_start, 938 _M_get_Tp_allocator()); 939 __x.clear(); 940 } 941 } 942 943 public: 944 /** 945 * @brief Builds a %deque from an initializer list. 946 * @param __l An initializer_list. 947 * @param __a An allocator object. 948 * 949 * Create a %deque consisting of copies of the elements in the 950 * initializer_list @a __l. 951 * 952 * This will call the element type's copy constructor N times 953 * (where N is __l.size()) and do no memory reallocation. 954 */ 955 deque(initializer_list<value_type> __l, 956 const allocator_type& __a = allocator_type()) 957 : _Base(__a) 958 { 959 _M_range_initialize(__l.begin(), __l.end(), 960 random_access_iterator_tag()); 961 } 962 #endif 963 964 /** 965 * @brief Builds a %deque from a range. 966 * @param __first An input iterator. 967 * @param __last An input iterator. 968 * @param __a An allocator object. 969 * 970 * Create a %deque consisting of copies of the elements from [__first, 971 * __last). 972 * 973 * If the iterators are forward, bidirectional, or random-access, then 974 * this will call the elements' copy constructor N times (where N is 975 * distance(__first,__last)) and do no memory reallocation. But if only 976 * input iterators are used, then this will do at most 2N calls to the 977 * copy constructor, and logN memory reallocations. 978 */ 979 #if __cplusplus >= 201103L 980 template<typename _InputIterator, 981 typename = std::_RequireInputIter<_InputIterator>> 982 deque(_InputIterator __first, _InputIterator __last, 983 const allocator_type& __a = allocator_type()) 984 : _Base(__a) 985 { 986 _M_range_initialize(__first, __last, 987 std::__iterator_category(__first)); 988 } 989 #else 990 template<typename _InputIterator> 991 deque(_InputIterator __first, _InputIterator __last, 992 const allocator_type& __a = allocator_type()) 993 : _Base(__a) 994 { 995 // Check whether it's an integral type. If so, it's not an iterator. 996 typedef typename std::__is_integer<_InputIterator>::__type _Integral; 997 _M_initialize_dispatch(__first, __last, _Integral()); 998 } 999 #endif 1000 1001 /** 1002 * The dtor only erases the elements, and note that if the elements 1003 * themselves are pointers, the pointed-to memory is not touched in any 1004 * way. Managing the pointer is the user's responsibility. 1005 */ 1006 ~deque() 1007 { _M_destroy_data(begin(), end(), _M_get_Tp_allocator()); } 1008 1009 /** 1010 * @brief %Deque assignment operator. 1011 * @param __x A %deque of identical element and allocator types. 1012 * 1013 * All the elements of @a x are copied. 1014 * 1015 * The newly-created %deque uses a copy of the allocator object used 1016 * by @a __x (unless the allocator traits dictate a different object). 1017 */ 1018 deque& 1019 operator=(const deque& __x); 1020 1021 #if __cplusplus >= 201103L 1022 /** 1023 * @brief %Deque move assignment operator. 1024 * @param __x A %deque of identical element and allocator types. 1025 * 1026 * The contents of @a __x are moved into this deque (without copying, 1027 * if the allocators permit it). 1028 * @a __x is a valid, but unspecified %deque. 1029 */ 1030 deque& 1031 operator=(deque&& __x) noexcept(_Alloc_traits::_S_always_equal()) 1032 { 1033 using __always_equal = typename _Alloc_traits::is_always_equal; 1034 _M_move_assign1(std::move(__x), __always_equal{}); 1035 return *this; 1036 } 1037 1038 /** 1039 * @brief Assigns an initializer list to a %deque. 1040 * @param __l An initializer_list. 1041 * 1042 * This function fills a %deque with copies of the elements in the 1043 * initializer_list @a __l. 1044 * 1045 * Note that the assignment completely changes the %deque and that the 1046 * resulting %deque's size is the same as the number of elements 1047 * assigned. 1048 */ 1049 deque& 1050 operator=(initializer_list<value_type> __l) 1051 { 1052 _M_assign_aux(__l.begin(), __l.end(), 1053 random_access_iterator_tag()); 1054 return *this; 1055 } 1056 #endif 1057 1058 /** 1059 * @brief Assigns a given value to a %deque. 1060 * @param __n Number of elements to be assigned. 1061 * @param __val Value to be assigned. 1062 * 1063 * This function fills a %deque with @a n copies of the given 1064 * value. Note that the assignment completely changes the 1065 * %deque and that the resulting %deque's size is the same as 1066 * the number of elements assigned. 1067 */ 1068 void 1069 assign(size_type __n, const value_type& __val) 1070 { _M_fill_assign(__n, __val); } 1071 1072 /** 1073 * @brief Assigns a range to a %deque. 1074 * @param __first An input iterator. 1075 * @param __last An input iterator. 1076 * 1077 * This function fills a %deque with copies of the elements in the 1078 * range [__first,__last). 1079 * 1080 * Note that the assignment completely changes the %deque and that the 1081 * resulting %deque's size is the same as the number of elements 1082 * assigned. 1083 */ 1084 #if __cplusplus >= 201103L 1085 template<typename _InputIterator, 1086 typename = std::_RequireInputIter<_InputIterator>> 1087 void 1088 assign(_InputIterator __first, _InputIterator __last) 1089 { _M_assign_aux(__first, __last, std::__iterator_category(__first)); } 1090 #else 1091 template<typename _InputIterator> 1092 void 1093 assign(_InputIterator __first, _InputIterator __last) 1094 { 1095 typedef typename std::__is_integer<_InputIterator>::__type _Integral; 1096 _M_assign_dispatch(__first, __last, _Integral()); 1097 } 1098 #endif 1099 1100 #if __cplusplus >= 201103L 1101 /** 1102 * @brief Assigns an initializer list to a %deque. 1103 * @param __l An initializer_list. 1104 * 1105 * This function fills a %deque with copies of the elements in the 1106 * initializer_list @a __l. 1107 * 1108 * Note that the assignment completely changes the %deque and that the 1109 * resulting %deque's size is the same as the number of elements 1110 * assigned. 1111 */ 1112 void 1113 assign(initializer_list<value_type> __l) 1114 { _M_assign_aux(__l.begin(), __l.end(), random_access_iterator_tag()); } 1115 #endif 1116 1117 /// Get a copy of the memory allocation object. 1118 allocator_type 1119 get_allocator() const _GLIBCXX_NOEXCEPT 1120 { return _Base::get_allocator(); } 1121 1122 // iterators 1123 /** 1124 * Returns a read/write iterator that points to the first element in the 1125 * %deque. Iteration is done in ordinary element order. 1126 */ 1127 iterator 1128 begin() _GLIBCXX_NOEXCEPT 1129 { return this->_M_impl._M_start; } 1130 1131 /** 1132 * Returns a read-only (constant) iterator that points to the first 1133 * element in the %deque. Iteration is done in ordinary element order. 1134 */ 1135 const_iterator 1136 begin() const _GLIBCXX_NOEXCEPT 1137 { return this->_M_impl._M_start; } 1138 1139 /** 1140 * Returns a read/write iterator that points one past the last 1141 * element in the %deque. Iteration is done in ordinary 1142 * element order. 1143 */ 1144 iterator 1145 end() _GLIBCXX_NOEXCEPT 1146 { return this->_M_impl._M_finish; } 1147 1148 /** 1149 * Returns a read-only (constant) iterator that points one past 1150 * the last element in the %deque. Iteration is done in 1151 * ordinary element order. 1152 */ 1153 const_iterator 1154 end() const _GLIBCXX_NOEXCEPT 1155 { return this->_M_impl._M_finish; } 1156 1157 /** 1158 * Returns a read/write reverse iterator that points to the 1159 * last element in the %deque. Iteration is done in reverse 1160 * element order. 1161 */ 1162 reverse_iterator 1163 rbegin() _GLIBCXX_NOEXCEPT 1164 { return reverse_iterator(this->_M_impl._M_finish); } 1165 1166 /** 1167 * Returns a read-only (constant) reverse iterator that points 1168 * to the last element in the %deque. Iteration is done in 1169 * reverse element order. 1170 */ 1171 const_reverse_iterator 1172 rbegin() const _GLIBCXX_NOEXCEPT 1173 { return const_reverse_iterator(this->_M_impl._M_finish); } 1174 1175 /** 1176 * Returns a read/write reverse iterator that points to one 1177 * before the first element in the %deque. Iteration is done 1178 * in reverse element order. 1179 */ 1180 reverse_iterator 1181 rend() _GLIBCXX_NOEXCEPT 1182 { return reverse_iterator(this->_M_impl._M_start); } 1183 1184 /** 1185 * Returns a read-only (constant) reverse iterator that points 1186 * to one before the first element in the %deque. Iteration is 1187 * done in reverse element order. 1188 */ 1189 const_reverse_iterator 1190 rend() const _GLIBCXX_NOEXCEPT 1191 { return const_reverse_iterator(this->_M_impl._M_start); } 1192 1193 #if __cplusplus >= 201103L 1194 /** 1195 * Returns a read-only (constant) iterator that points to the first 1196 * element in the %deque. Iteration is done in ordinary element order. 1197 */ 1198 const_iterator 1199 cbegin() const noexcept 1200 { return this->_M_impl._M_start; } 1201 1202 /** 1203 * Returns a read-only (constant) iterator that points one past 1204 * the last element in the %deque. Iteration is done in 1205 * ordinary element order. 1206 */ 1207 const_iterator 1208 cend() const noexcept 1209 { return this->_M_impl._M_finish; } 1210 1211 /** 1212 * Returns a read-only (constant) reverse iterator that points 1213 * to the last element in the %deque. Iteration is done in 1214 * reverse element order. 1215 */ 1216 const_reverse_iterator 1217 crbegin() const noexcept 1218 { return const_reverse_iterator(this->_M_impl._M_finish); } 1219 1220 /** 1221 * Returns a read-only (constant) reverse iterator that points 1222 * to one before the first element in the %deque. Iteration is 1223 * done in reverse element order. 1224 */ 1225 const_reverse_iterator 1226 crend() const noexcept 1227 { return const_reverse_iterator(this->_M_impl._M_start); } 1228 #endif 1229 1230 // [23.2.1.2] capacity 1231 /** Returns the number of elements in the %deque. */ 1232 size_type 1233 size() const _GLIBCXX_NOEXCEPT 1234 { return this->_M_impl._M_finish - this->_M_impl._M_start; } 1235 1236 /** Returns the size() of the largest possible %deque. */ 1237 size_type 1238 max_size() const _GLIBCXX_NOEXCEPT 1239 { return _S_max_size(_M_get_Tp_allocator()); } 1240 1241 #if __cplusplus >= 201103L 1242 /** 1243 * @brief Resizes the %deque to the specified number of elements. 1244 * @param __new_size Number of elements the %deque should contain. 1245 * 1246 * This function will %resize the %deque to the specified 1247 * number of elements. If the number is smaller than the 1248 * %deque's current size the %deque is truncated, otherwise 1249 * default constructed elements are appended. 1250 */ 1251 void 1252 resize(size_type __new_size) 1253 { 1254 const size_type __len = size(); 1255 if (__new_size > __len) 1256 _M_default_append(__new_size - __len); 1257 else if (__new_size < __len) 1258 _M_erase_at_end(this->_M_impl._M_start 1259 + difference_type(__new_size)); 1260 } 1261 1262 /** 1263 * @brief Resizes the %deque to the specified number of elements. 1264 * @param __new_size Number of elements the %deque should contain. 1265 * @param __x Data with which new elements should be populated. 1266 * 1267 * This function will %resize the %deque to the specified 1268 * number of elements. If the number is smaller than the 1269 * %deque's current size the %deque is truncated, otherwise the 1270 * %deque is extended and new elements are populated with given 1271 * data. 1272 */ 1273 void 1274 resize(size_type __new_size, const value_type& __x) 1275 #else 1276 /** 1277 * @brief Resizes the %deque to the specified number of elements. 1278 * @param __new_size Number of elements the %deque should contain. 1279 * @param __x Data with which new elements should be populated. 1280 * 1281 * This function will %resize the %deque to the specified 1282 * number of elements. If the number is smaller than the 1283 * %deque's current size the %deque is truncated, otherwise the 1284 * %deque is extended and new elements are populated with given 1285 * data. 1286 */ 1287 void 1288 resize(size_type __new_size, value_type __x = value_type()) 1289 #endif 1290 { 1291 const size_type __len = size(); 1292 if (__new_size > __len) 1293 _M_fill_insert(this->_M_impl._M_finish, __new_size - __len, __x); 1294 else if (__new_size < __len) 1295 _M_erase_at_end(this->_M_impl._M_start 1296 + difference_type(__new_size)); 1297 } 1298 1299 #if __cplusplus >= 201103L 1300 /** A non-binding request to reduce memory use. */ 1301 void 1302 shrink_to_fit() noexcept 1303 { _M_shrink_to_fit(); } 1304 #endif 1305 1306 /** 1307 * Returns true if the %deque is empty. (Thus begin() would 1308 * equal end().) 1309 */ 1310 _GLIBCXX_NODISCARD bool 1311 empty() const _GLIBCXX_NOEXCEPT 1312 { return this->_M_impl._M_finish == this->_M_impl._M_start; } 1313 1314 // element access 1315 /** 1316 * @brief Subscript access to the data contained in the %deque. 1317 * @param __n The index of the element for which data should be 1318 * accessed. 1319 * @return Read/write reference to data. 1320 * 1321 * This operator allows for easy, array-style, data access. 1322 * Note that data access with this operator is unchecked and 1323 * out_of_range lookups are not defined. (For checked lookups 1324 * see at().) 1325 */ 1326 reference 1327 operator[](size_type __n) _GLIBCXX_NOEXCEPT 1328 { 1329 __glibcxx_requires_subscript(__n); 1330 return this->_M_impl._M_start[difference_type(__n)]; 1331 } 1332 1333 /** 1334 * @brief Subscript access to the data contained in the %deque. 1335 * @param __n The index of the element for which data should be 1336 * accessed. 1337 * @return Read-only (constant) reference to data. 1338 * 1339 * This operator allows for easy, array-style, data access. 1340 * Note that data access with this operator is unchecked and 1341 * out_of_range lookups are not defined. (For checked lookups 1342 * see at().) 1343 */ 1344 const_reference 1345 operator[](size_type __n) const _GLIBCXX_NOEXCEPT 1346 { 1347 __glibcxx_requires_subscript(__n); 1348 return this->_M_impl._M_start[difference_type(__n)]; 1349 } 1350 1351 protected: 1352 /// Safety check used only from at(). 1353 void 1354 _M_range_check(size_type __n) const 1355 { 1356 if (__n >= this->size()) 1357 __throw_out_of_range_fmt(__N("deque::_M_range_check: __n " 1358 "(which is %zu)>= this->size() " 1359 "(which is %zu)"), 1360 __n, this->size()); 1361 } 1362 1363 public: 1364 /** 1365 * @brief Provides access to the data contained in the %deque. 1366 * @param __n The index of the element for which data should be 1367 * accessed. 1368 * @return Read/write reference to data. 1369 * @throw std::out_of_range If @a __n is an invalid index. 1370 * 1371 * This function provides for safer data access. The parameter 1372 * is first checked that it is in the range of the deque. The 1373 * function throws out_of_range if the check fails. 1374 */ 1375 reference 1376 at(size_type __n) 1377 { 1378 _M_range_check(__n); 1379 return (*this)[__n]; 1380 } 1381 1382 /** 1383 * @brief Provides access to the data contained in the %deque. 1384 * @param __n The index of the element for which data should be 1385 * accessed. 1386 * @return Read-only (constant) reference to data. 1387 * @throw std::out_of_range If @a __n is an invalid index. 1388 * 1389 * This function provides for safer data access. The parameter is first 1390 * checked that it is in the range of the deque. The function throws 1391 * out_of_range if the check fails. 1392 */ 1393 const_reference 1394 at(size_type __n) const 1395 { 1396 _M_range_check(__n); 1397 return (*this)[__n]; 1398 } 1399 1400 /** 1401 * Returns a read/write reference to the data at the first 1402 * element of the %deque. 1403 */ 1404 reference 1405 front() _GLIBCXX_NOEXCEPT 1406 { 1407 __glibcxx_requires_nonempty(); 1408 return *begin(); 1409 } 1410 1411 /** 1412 * Returns a read-only (constant) reference to the data at the first 1413 * element of the %deque. 1414 */ 1415 const_reference 1416 front() const _GLIBCXX_NOEXCEPT 1417 { 1418 __glibcxx_requires_nonempty(); 1419 return *begin(); 1420 } 1421 1422 /** 1423 * Returns a read/write reference to the data at the last element of the 1424 * %deque. 1425 */ 1426 reference 1427 back() _GLIBCXX_NOEXCEPT 1428 { 1429 __glibcxx_requires_nonempty(); 1430 iterator __tmp = end(); 1431 --__tmp; 1432 return *__tmp; 1433 } 1434 1435 /** 1436 * Returns a read-only (constant) reference to the data at the last 1437 * element of the %deque. 1438 */ 1439 const_reference 1440 back() const _GLIBCXX_NOEXCEPT 1441 { 1442 __glibcxx_requires_nonempty(); 1443 const_iterator __tmp = end(); 1444 --__tmp; 1445 return *__tmp; 1446 } 1447 1448 // [23.2.1.2] modifiers 1449 /** 1450 * @brief Add data to the front of the %deque. 1451 * @param __x Data to be added. 1452 * 1453 * This is a typical stack operation. The function creates an 1454 * element at the front of the %deque and assigns the given 1455 * data to it. Due to the nature of a %deque this operation 1456 * can be done in constant time. 1457 */ 1458 void 1459 push_front(const value_type& __x) 1460 { 1461 if (this->_M_impl._M_start._M_cur != this->_M_impl._M_start._M_first) 1462 { 1463 _Alloc_traits::construct(this->_M_impl, 1464 this->_M_impl._M_start._M_cur - 1, 1465 __x); 1466 --this->_M_impl._M_start._M_cur; 1467 } 1468 else 1469 _M_push_front_aux(__x); 1470 } 1471 1472 #if __cplusplus >= 201103L 1473 void 1474 push_front(value_type&& __x) 1475 { emplace_front(std::move(__x)); } 1476 1477 template<typename... _Args> 1478 #if __cplusplus > 201402L 1479 reference 1480 #else 1481 void 1482 #endif 1483 emplace_front(_Args&&... __args); 1484 #endif 1485 1486 /** 1487 * @brief Add data to the end of the %deque. 1488 * @param __x Data to be added. 1489 * 1490 * This is a typical stack operation. The function creates an 1491 * element at the end of the %deque and assigns the given data 1492 * to it. Due to the nature of a %deque this operation can be 1493 * done in constant time. 1494 */ 1495 void 1496 push_back(const value_type& __x) 1497 { 1498 if (this->_M_impl._M_finish._M_cur 1499 != this->_M_impl._M_finish._M_last - 1) 1500 { 1501 _Alloc_traits::construct(this->_M_impl, 1502 this->_M_impl._M_finish._M_cur, __x); 1503 ++this->_M_impl._M_finish._M_cur; 1504 } 1505 else 1506 _M_push_back_aux(__x); 1507 } 1508 1509 #if __cplusplus >= 201103L 1510 void 1511 push_back(value_type&& __x) 1512 { emplace_back(std::move(__x)); } 1513 1514 template<typename... _Args> 1515 #if __cplusplus > 201402L 1516 reference 1517 #else 1518 void 1519 #endif 1520 emplace_back(_Args&&... __args); 1521 #endif 1522 1523 /** 1524 * @brief Removes first element. 1525 * 1526 * This is a typical stack operation. It shrinks the %deque by one. 1527 * 1528 * Note that no data is returned, and if the first element's data is 1529 * needed, it should be retrieved before pop_front() is called. 1530 */ 1531 void 1532 pop_front() _GLIBCXX_NOEXCEPT 1533 { 1534 __glibcxx_requires_nonempty(); 1535 if (this->_M_impl._M_start._M_cur 1536 != this->_M_impl._M_start._M_last - 1) 1537 { 1538 _Alloc_traits::destroy(_M_get_Tp_allocator(), 1539 this->_M_impl._M_start._M_cur); 1540 ++this->_M_impl._M_start._M_cur; 1541 } 1542 else 1543 _M_pop_front_aux(); 1544 } 1545 1546 /** 1547 * @brief Removes last element. 1548 * 1549 * This is a typical stack operation. It shrinks the %deque by one. 1550 * 1551 * Note that no data is returned, and if the last element's data is 1552 * needed, it should be retrieved before pop_back() is called. 1553 */ 1554 void 1555 pop_back() _GLIBCXX_NOEXCEPT 1556 { 1557 __glibcxx_requires_nonempty(); 1558 if (this->_M_impl._M_finish._M_cur 1559 != this->_M_impl._M_finish._M_first) 1560 { 1561 --this->_M_impl._M_finish._M_cur; 1562 _Alloc_traits::destroy(_M_get_Tp_allocator(), 1563 this->_M_impl._M_finish._M_cur); 1564 } 1565 else 1566 _M_pop_back_aux(); 1567 } 1568 1569 #if __cplusplus >= 201103L 1570 /** 1571 * @brief Inserts an object in %deque before specified iterator. 1572 * @param __position A const_iterator into the %deque. 1573 * @param __args Arguments. 1574 * @return An iterator that points to the inserted data. 1575 * 1576 * This function will insert an object of type T constructed 1577 * with T(std::forward<Args>(args)...) before the specified location. 1578 */ 1579 template<typename... _Args> 1580 iterator 1581 emplace(const_iterator __position, _Args&&... __args); 1582 1583 /** 1584 * @brief Inserts given value into %deque before specified iterator. 1585 * @param __position A const_iterator into the %deque. 1586 * @param __x Data to be inserted. 1587 * @return An iterator that points to the inserted data. 1588 * 1589 * This function will insert a copy of the given value before the 1590 * specified location. 1591 */ 1592 iterator 1593 insert(const_iterator __position, const value_type& __x); 1594 #else 1595 /** 1596 * @brief Inserts given value into %deque before specified iterator. 1597 * @param __position An iterator into the %deque. 1598 * @param __x Data to be inserted. 1599 * @return An iterator that points to the inserted data. 1600 * 1601 * This function will insert a copy of the given value before the 1602 * specified location. 1603 */ 1604 iterator 1605 insert(iterator __position, const value_type& __x); 1606 #endif 1607 1608 #if __cplusplus >= 201103L 1609 /** 1610 * @brief Inserts given rvalue into %deque before specified iterator. 1611 * @param __position A const_iterator into the %deque. 1612 * @param __x Data to be inserted. 1613 * @return An iterator that points to the inserted data. 1614 * 1615 * This function will insert a copy of the given rvalue before the 1616 * specified location. 1617 */ 1618 iterator 1619 insert(const_iterator __position, value_type&& __x) 1620 { return emplace(__position, std::move(__x)); } 1621 1622 /** 1623 * @brief Inserts an initializer list into the %deque. 1624 * @param __p An iterator into the %deque. 1625 * @param __l An initializer_list. 1626 * @return An iterator that points to the inserted data. 1627 * 1628 * This function will insert copies of the data in the 1629 * initializer_list @a __l into the %deque before the location 1630 * specified by @a __p. This is known as <em>list insert</em>. 1631 */ 1632 iterator 1633 insert(const_iterator __p, initializer_list<value_type> __l) 1634 { 1635 auto __offset = __p - cbegin(); 1636 _M_range_insert_aux(__p._M_const_cast(), __l.begin(), __l.end(), 1637 std::random_access_iterator_tag()); 1638 return begin() + __offset; 1639 } 1640 1641 /** 1642 * @brief Inserts a number of copies of given data into the %deque. 1643 * @param __position A const_iterator into the %deque. 1644 * @param __n Number of elements to be inserted. 1645 * @param __x Data to be inserted. 1646 * @return An iterator that points to the inserted data. 1647 * 1648 * This function will insert a specified number of copies of the given 1649 * data before the location specified by @a __position. 1650 */ 1651 iterator 1652 insert(const_iterator __position, size_type __n, const value_type& __x) 1653 { 1654 difference_type __offset = __position - cbegin(); 1655 _M_fill_insert(__position._M_const_cast(), __n, __x); 1656 return begin() + __offset; 1657 } 1658 #else 1659 /** 1660 * @brief Inserts a number of copies of given data into the %deque. 1661 * @param __position An iterator into the %deque. 1662 * @param __n Number of elements to be inserted. 1663 * @param __x Data to be inserted. 1664 * 1665 * This function will insert a specified number of copies of the given 1666 * data before the location specified by @a __position. 1667 */ 1668 void 1669 insert(iterator __position, size_type __n, const value_type& __x) 1670 { _M_fill_insert(__position, __n, __x); } 1671 #endif 1672 1673 #if __cplusplus >= 201103L 1674 /** 1675 * @brief Inserts a range into the %deque. 1676 * @param __position A const_iterator into the %deque. 1677 * @param __first An input iterator. 1678 * @param __last An input iterator. 1679 * @return An iterator that points to the inserted data. 1680 * 1681 * This function will insert copies of the data in the range 1682 * [__first,__last) into the %deque before the location specified 1683 * by @a __position. This is known as <em>range insert</em>. 1684 */ 1685 template<typename _InputIterator, 1686 typename = std::_RequireInputIter<_InputIterator>> 1687 iterator 1688 insert(const_iterator __position, _InputIterator __first, 1689 _InputIterator __last) 1690 { 1691 difference_type __offset = __position - cbegin(); 1692 _M_range_insert_aux(__position._M_const_cast(), __first, __last, 1693 std::__iterator_category(__first)); 1694 return begin() + __offset; 1695 } 1696 #else 1697 /** 1698 * @brief Inserts a range into the %deque. 1699 * @param __position An iterator into the %deque. 1700 * @param __first An input iterator. 1701 * @param __last An input iterator. 1702 * 1703 * This function will insert copies of the data in the range 1704 * [__first,__last) into the %deque before the location specified 1705 * by @a __position. This is known as <em>range insert</em>. 1706 */ 1707 template<typename _InputIterator> 1708 void 1709 insert(iterator __position, _InputIterator __first, 1710 _InputIterator __last) 1711 { 1712 // Check whether it's an integral type. If so, it's not an iterator. 1713 typedef typename std::__is_integer<_InputIterator>::__type _Integral; 1714 _M_insert_dispatch(__position, __first, __last, _Integral()); 1715 } 1716 #endif 1717 1718 /** 1719 * @brief Remove element at given position. 1720 * @param __position Iterator pointing to element to be erased. 1721 * @return An iterator pointing to the next element (or end()). 1722 * 1723 * This function will erase the element at the given position and thus 1724 * shorten the %deque by one. 1725 * 1726 * The user is cautioned that 1727 * this function only erases the element, and that if the element is 1728 * itself a pointer, the pointed-to memory is not touched in any way. 1729 * Managing the pointer is the user's responsibility. 1730 */ 1731 iterator 1732 #if __cplusplus >= 201103L 1733 erase(const_iterator __position) 1734 #else 1735 erase(iterator __position) 1736 #endif 1737 { return _M_erase(__position._M_const_cast()); } 1738 1739 /** 1740 * @brief Remove a range of elements. 1741 * @param __first Iterator pointing to the first element to be erased. 1742 * @param __last Iterator pointing to one past the last element to be 1743 * erased. 1744 * @return An iterator pointing to the element pointed to by @a last 1745 * prior to erasing (or end()). 1746 * 1747 * This function will erase the elements in the range 1748 * [__first,__last) and shorten the %deque accordingly. 1749 * 1750 * The user is cautioned that 1751 * this function only erases the elements, and that if the elements 1752 * themselves are pointers, the pointed-to memory is not touched in any 1753 * way. Managing the pointer is the user's responsibility. 1754 */ 1755 iterator 1756 #if __cplusplus >= 201103L 1757 erase(const_iterator __first, const_iterator __last) 1758 #else 1759 erase(iterator __first, iterator __last) 1760 #endif 1761 { return _M_erase(__first._M_const_cast(), __last._M_const_cast()); } 1762 1763 /** 1764 * @brief Swaps data with another %deque. 1765 * @param __x A %deque of the same element and allocator types. 1766 * 1767 * This exchanges the elements between two deques in constant time. 1768 * (Four pointers, so it should be quite fast.) 1769 * Note that the global std::swap() function is specialized such that 1770 * std::swap(d1,d2) will feed to this function. 1771 * 1772 * Whether the allocators are swapped depends on the allocator traits. 1773 */ 1774 void 1775 swap(deque& __x) _GLIBCXX_NOEXCEPT 1776 { 1777 #if __cplusplus >= 201103L 1778 __glibcxx_assert(_Alloc_traits::propagate_on_container_swap::value 1779 || _M_get_Tp_allocator() == __x._M_get_Tp_allocator()); 1780 #endif 1781 _M_impl._M_swap_data(__x._M_impl); 1782 _Alloc_traits::_S_on_swap(_M_get_Tp_allocator(), 1783 __x._M_get_Tp_allocator()); 1784 } 1785 1786 /** 1787 * Erases all the elements. Note that this function only erases the 1788 * elements, and that if the elements themselves are pointers, the 1789 * pointed-to memory is not touched in any way. Managing the pointer is 1790 * the user's responsibility. 1791 */ 1792 void 1793 clear() _GLIBCXX_NOEXCEPT 1794 { _M_erase_at_end(begin()); } 1795 1796 protected: 1797 // Internal constructor functions follow. 1798 1799 #if __cplusplus < 201103L 1800 // called by the range constructor to implement [23.1.1]/9 1801 1802 // _GLIBCXX_RESOLVE_LIB_DEFECTS 1803 // 438. Ambiguity in the "do the right thing" clause 1804 template<typename _Integer> 1805 void 1806 _M_initialize_dispatch(_Integer __n, _Integer __x, __true_type) 1807 { 1808 _M_initialize_map(_S_check_init_len(static_cast<size_type>(__n), 1809 _M_get_Tp_allocator())); 1810 _M_fill_initialize(__x); 1811 } 1812 1813 // called by the range constructor to implement [23.1.1]/9 1814 template<typename _InputIterator> 1815 void 1816 _M_initialize_dispatch(_InputIterator __first, _InputIterator __last, 1817 __false_type) 1818 { 1819 _M_range_initialize(__first, __last, 1820 std::__iterator_category(__first)); 1821 } 1822 #endif 1823 1824 static size_t 1825 _S_check_init_len(size_t __n, const allocator_type& __a) 1826 { 1827 if (__n > _S_max_size(__a)) 1828 __throw_length_error( 1829 __N("cannot create std::deque larger than max_size()")); 1830 return __n; 1831 } 1832 1833 static size_type 1834 _S_max_size(const _Tp_alloc_type& __a) _GLIBCXX_NOEXCEPT 1835 { 1836 const size_t __diffmax = __gnu_cxx::__numeric_traits<ptrdiff_t>::__max; 1837 const size_t __allocmax = _Alloc_traits::max_size(__a); 1838 return (std::min)(__diffmax, __allocmax); 1839 } 1840 1841 // called by the second initialize_dispatch above 1842 ///@{ 1843 /** 1844 * @brief Fills the deque with whatever is in [first,last). 1845 * @param __first An input iterator. 1846 * @param __last An input iterator. 1847 * @return Nothing. 1848 * 1849 * If the iterators are actually forward iterators (or better), then the 1850 * memory layout can be done all at once. Else we move forward using 1851 * push_back on each value from the iterator. 1852 */ 1853 template<typename _InputIterator> 1854 void 1855 _M_range_initialize(_InputIterator __first, _InputIterator __last, 1856 std::input_iterator_tag); 1857 1858 // called by the second initialize_dispatch above 1859 template<typename _ForwardIterator> 1860 void 1861 _M_range_initialize(_ForwardIterator __first, _ForwardIterator __last, 1862 std::forward_iterator_tag); 1863 ///@} 1864 1865 /** 1866 * @brief Fills the %deque with copies of value. 1867 * @param __value Initial value. 1868 * @return Nothing. 1869 * @pre _M_start and _M_finish have already been initialized, 1870 * but none of the %deque's elements have yet been constructed. 1871 * 1872 * This function is called only when the user provides an explicit size 1873 * (with or without an explicit exemplar value). 1874 */ 1875 void 1876 _M_fill_initialize(const value_type& __value); 1877 1878 #if __cplusplus >= 201103L 1879 // called by deque(n). 1880 void 1881 _M_default_initialize(); 1882 #endif 1883 1884 // Internal assign functions follow. The *_aux functions do the actual 1885 // assignment work for the range versions. 1886 1887 #if __cplusplus < 201103L 1888 // called by the range assign to implement [23.1.1]/9 1889 1890 // _GLIBCXX_RESOLVE_LIB_DEFECTS 1891 // 438. Ambiguity in the "do the right thing" clause 1892 template<typename _Integer> 1893 void 1894 _M_assign_dispatch(_Integer __n, _Integer __val, __true_type) 1895 { _M_fill_assign(__n, __val); } 1896 1897 // called by the range assign to implement [23.1.1]/9 1898 template<typename _InputIterator> 1899 void 1900 _M_assign_dispatch(_InputIterator __first, _InputIterator __last, 1901 __false_type) 1902 { _M_assign_aux(__first, __last, std::__iterator_category(__first)); } 1903 #endif 1904 1905 // called by the second assign_dispatch above 1906 template<typename _InputIterator> 1907 void 1908 _M_assign_aux(_InputIterator __first, _InputIterator __last, 1909 std::input_iterator_tag); 1910 1911 // called by the second assign_dispatch above 1912 template<typename _ForwardIterator> 1913 void 1914 _M_assign_aux(_ForwardIterator __first, _ForwardIterator __last, 1915 std::forward_iterator_tag) 1916 { 1917 const size_type __len = std::distance(__first, __last); 1918 if (__len > size()) 1919 { 1920 _ForwardIterator __mid = __first; 1921 std::advance(__mid, size()); 1922 std::copy(__first, __mid, begin()); 1923 _M_range_insert_aux(end(), __mid, __last, 1924 std::__iterator_category(__first)); 1925 } 1926 else 1927 _M_erase_at_end(std::copy(__first, __last, begin())); 1928 } 1929 1930 // Called by assign(n,t), and the range assign when it turns out 1931 // to be the same thing. 1932 void 1933 _M_fill_assign(size_type __n, const value_type& __val) 1934 { 1935 if (__n > size()) 1936 { 1937 std::fill(begin(), end(), __val); 1938 _M_fill_insert(end(), __n - size(), __val); 1939 } 1940 else 1941 { 1942 _M_erase_at_end(begin() + difference_type(__n)); 1943 std::fill(begin(), end(), __val); 1944 } 1945 } 1946 1947 ///@{ 1948 /// Helper functions for push_* and pop_*. 1949 #if __cplusplus < 201103L 1950 void _M_push_back_aux(const value_type&); 1951 1952 void _M_push_front_aux(const value_type&); 1953 #else 1954 template<typename... _Args> 1955 void _M_push_back_aux(_Args&&... __args); 1956 1957 template<typename... _Args> 1958 void _M_push_front_aux(_Args&&... __args); 1959 #endif 1960 1961 void _M_pop_back_aux(); 1962 1963 void _M_pop_front_aux(); 1964 ///@} 1965 1966 // Internal insert functions follow. The *_aux functions do the actual 1967 // insertion work when all shortcuts fail. 1968 1969 #if __cplusplus < 201103L 1970 // called by the range insert to implement [23.1.1]/9 1971 1972 // _GLIBCXX_RESOLVE_LIB_DEFECTS 1973 // 438. Ambiguity in the "do the right thing" clause 1974 template<typename _Integer> 1975 void 1976 _M_insert_dispatch(iterator __pos, 1977 _Integer __n, _Integer __x, __true_type) 1978 { _M_fill_insert(__pos, __n, __x); } 1979 1980 // called by the range insert to implement [23.1.1]/9 1981 template<typename _InputIterator> 1982 void 1983 _M_insert_dispatch(iterator __pos, 1984 _InputIterator __first, _InputIterator __last, 1985 __false_type) 1986 { 1987 _M_range_insert_aux(__pos, __first, __last, 1988 std::__iterator_category(__first)); 1989 } 1990 #endif 1991 1992 // called by the second insert_dispatch above 1993 template<typename _InputIterator> 1994 void 1995 _M_range_insert_aux(iterator __pos, _InputIterator __first, 1996 _InputIterator __last, std::input_iterator_tag); 1997 1998 // called by the second insert_dispatch above 1999 template<typename _ForwardIterator> 2000 void 2001 _M_range_insert_aux(iterator __pos, _ForwardIterator __first, 2002 _ForwardIterator __last, std::forward_iterator_tag); 2003 2004 // Called by insert(p,n,x), and the range insert when it turns out to be 2005 // the same thing. Can use fill functions in optimal situations, 2006 // otherwise passes off to insert_aux(p,n,x). 2007 void 2008 _M_fill_insert(iterator __pos, size_type __n, const value_type& __x); 2009 2010 // called by insert(p,x) 2011 #if __cplusplus < 201103L 2012 iterator 2013 _M_insert_aux(iterator __pos, const value_type& __x); 2014 #else 2015 template<typename... _Args> 2016 iterator 2017 _M_insert_aux(iterator __pos, _Args&&... __args); 2018 #endif 2019 2020 // called by insert(p,n,x) via fill_insert 2021 void 2022 _M_insert_aux(iterator __pos, size_type __n, const value_type& __x); 2023 2024 // called by range_insert_aux for forward iterators 2025 template<typename _ForwardIterator> 2026 void 2027 _M_insert_aux(iterator __pos, 2028 _ForwardIterator __first, _ForwardIterator __last, 2029 size_type __n); 2030 2031 2032 // Internal erase functions follow. 2033 2034 void 2035 _M_destroy_data_aux(iterator __first, iterator __last); 2036 2037 // Called by ~deque(). 2038 // NB: Doesn't deallocate the nodes. 2039 template<typename _Alloc1> 2040 void 2041 _M_destroy_data(iterator __first, iterator __last, const _Alloc1&) 2042 { _M_destroy_data_aux(__first, __last); } 2043 2044 void 2045 _M_destroy_data(iterator __first, iterator __last, 2046 const std::allocator<_Tp>&) 2047 { 2048 if (!__has_trivial_destructor(value_type)) 2049 _M_destroy_data_aux(__first, __last); 2050 } 2051 2052 // Called by erase(q1, q2). 2053 void 2054 _M_erase_at_begin(iterator __pos) 2055 { 2056 _M_destroy_data(begin(), __pos, _M_get_Tp_allocator()); 2057 _M_destroy_nodes(this->_M_impl._M_start._M_node, __pos._M_node); 2058 this->_M_impl._M_start = __pos; 2059 } 2060 2061 // Called by erase(q1, q2), resize(), clear(), _M_assign_aux, 2062 // _M_fill_assign, operator=. 2063 void 2064 _M_erase_at_end(iterator __pos) 2065 { 2066 _M_destroy_data(__pos, end(), _M_get_Tp_allocator()); 2067 _M_destroy_nodes(__pos._M_node + 1, 2068 this->_M_impl._M_finish._M_node + 1); 2069 this->_M_impl._M_finish = __pos; 2070 } 2071 2072 iterator 2073 _M_erase(iterator __pos); 2074 2075 iterator 2076 _M_erase(iterator __first, iterator __last); 2077 2078 #if __cplusplus >= 201103L 2079 // Called by resize(sz). 2080 void 2081 _M_default_append(size_type __n); 2082 2083 bool 2084 _M_shrink_to_fit(); 2085 #endif 2086 2087 ///@{ 2088 /// Memory-handling helpers for the previous internal insert functions. 2089 iterator 2090 _M_reserve_elements_at_front(size_type __n) 2091 { 2092 const size_type __vacancies = this->_M_impl._M_start._M_cur 2093 - this->_M_impl._M_start._M_first; 2094 if (__n > __vacancies) 2095 _M_new_elements_at_front(__n - __vacancies); 2096 return this->_M_impl._M_start - difference_type(__n); 2097 } 2098 2099 iterator 2100 _M_reserve_elements_at_back(size_type __n) 2101 { 2102 const size_type __vacancies = (this->_M_impl._M_finish._M_last 2103 - this->_M_impl._M_finish._M_cur) - 1; 2104 if (__n > __vacancies) 2105 _M_new_elements_at_back(__n - __vacancies); 2106 return this->_M_impl._M_finish + difference_type(__n); 2107 } 2108 2109 void 2110 _M_new_elements_at_front(size_type __new_elements); 2111 2112 void 2113 _M_new_elements_at_back(size_type __new_elements); 2114 ///@} 2115 2116 2117 ///@{ 2118 /** 2119 * @brief Memory-handling helpers for the major %map. 2120 * 2121 * Makes sure the _M_map has space for new nodes. Does not 2122 * actually add the nodes. Can invalidate _M_map pointers. 2123 * (And consequently, %deque iterators.) 2124 */ 2125 void 2126 _M_reserve_map_at_back(size_type __nodes_to_add = 1) 2127 { 2128 if (__nodes_to_add + 1 > this->_M_impl._M_map_size 2129 - (this->_M_impl._M_finish._M_node - this->_M_impl._M_map)) 2130 _M_reallocate_map(__nodes_to_add, false); 2131 } 2132 2133 void 2134 _M_reserve_map_at_front(size_type __nodes_to_add = 1) 2135 { 2136 if (__nodes_to_add > size_type(this->_M_impl._M_start._M_node 2137 - this->_M_impl._M_map)) 2138 _M_reallocate_map(__nodes_to_add, true); 2139 } 2140 2141 void 2142 _M_reallocate_map(size_type __nodes_to_add, bool __add_at_front); 2143 ///@} 2144 2145 #if __cplusplus >= 201103L 2146 // Constant-time, nothrow move assignment when source object's memory 2147 // can be moved because the allocators are equal. 2148 void 2149 _M_move_assign1(deque&& __x, /* always equal: */ true_type) noexcept 2150 { 2151 this->_M_impl._M_swap_data(__x._M_impl); 2152 __x.clear(); 2153 std::__alloc_on_move(_M_get_Tp_allocator(), __x._M_get_Tp_allocator()); 2154 } 2155 2156 // When the allocators are not equal the operation could throw, because 2157 // we might need to allocate a new map for __x after moving from it 2158 // or we might need to allocate new elements for *this. 2159 void 2160 _M_move_assign1(deque&& __x, /* always equal: */ false_type) 2161 { 2162 if (_M_get_Tp_allocator() == __x._M_get_Tp_allocator()) 2163 return _M_move_assign1(std::move(__x), true_type()); 2164 2165 constexpr bool __move_storage = 2166 _Alloc_traits::_S_propagate_on_move_assign(); 2167 _M_move_assign2(std::move(__x), __bool_constant<__move_storage>()); 2168 } 2169 2170 // Destroy all elements and deallocate all memory, then replace 2171 // with elements created from __args. 2172 template<typename... _Args> 2173 void 2174 _M_replace_map(_Args&&... __args) 2175 { 2176 // Create new data first, so if allocation fails there are no effects. 2177 deque __newobj(std::forward<_Args>(__args)...); 2178 // Free existing storage using existing allocator. 2179 clear(); 2180 _M_deallocate_node(*begin()._M_node); // one node left after clear() 2181 _M_deallocate_map(this->_M_impl._M_map, this->_M_impl._M_map_size); 2182 this->_M_impl._M_map = nullptr; 2183 this->_M_impl._M_map_size = 0; 2184 // Take ownership of replacement memory. 2185 this->_M_impl._M_swap_data(__newobj._M_impl); 2186 } 2187 2188 // Do move assignment when the allocator propagates. 2189 void 2190 _M_move_assign2(deque&& __x, /* propagate: */ true_type) 2191 { 2192 // Make a copy of the original allocator state. 2193 auto __alloc = __x._M_get_Tp_allocator(); 2194 // The allocator propagates so storage can be moved from __x, 2195 // leaving __x in a valid empty state with a moved-from allocator. 2196 _M_replace_map(std::move(__x)); 2197 // Move the corresponding allocator state too. 2198 _M_get_Tp_allocator() = std::move(__alloc); 2199 } 2200 2201 // Do move assignment when it may not be possible to move source 2202 // object's memory, resulting in a linear-time operation. 2203 void 2204 _M_move_assign2(deque&& __x, /* propagate: */ false_type) 2205 { 2206 if (__x._M_get_Tp_allocator() == this->_M_get_Tp_allocator()) 2207 { 2208 // The allocators are equal so storage can be moved from __x, 2209 // leaving __x in a valid empty state with its current allocator. 2210 _M_replace_map(std::move(__x), __x.get_allocator()); 2211 } 2212 else 2213 { 2214 // The rvalue's allocator cannot be moved and is not equal, 2215 // so we need to individually move each element. 2216 _M_assign_aux(std::make_move_iterator(__x.begin()), 2217 std::make_move_iterator(__x.end()), 2218 std::random_access_iterator_tag()); 2219 __x.clear(); 2220 } 2221 } 2222 #endif 2223 }; 2224 2225 #if __cpp_deduction_guides >= 201606 2226 template<typename _InputIterator, typename _ValT 2227 = typename iterator_traits<_InputIterator>::value_type, 2228 typename _Allocator = allocator<_ValT>, 2229 typename = _RequireInputIter<_InputIterator>, 2230 typename = _RequireAllocator<_Allocator>> 2231 deque(_InputIterator, _InputIterator, _Allocator = _Allocator()) 2232 -> deque<_ValT, _Allocator>; 2233 #endif 2234 2235 /** 2236 * @brief Deque equality comparison. 2237 * @param __x A %deque. 2238 * @param __y A %deque of the same type as @a __x. 2239 * @return True iff the size and elements of the deques are equal. 2240 * 2241 * This is an equivalence relation. It is linear in the size of the 2242 * deques. Deques are considered equivalent if their sizes are equal, 2243 * and if corresponding elements compare equal. 2244 */ 2245 template<typename _Tp, typename _Alloc> 2246 inline bool 2247 operator==(const deque<_Tp, _Alloc>& __x, const deque<_Tp, _Alloc>& __y) 2248 { return __x.size() == __y.size() 2249 && std::equal(__x.begin(), __x.end(), __y.begin()); } 2250 2251 #if __cpp_lib_three_way_comparison 2252 /** 2253 * @brief Deque ordering relation. 2254 * @param __x A `deque`. 2255 * @param __y A `deque` of the same type as `__x`. 2256 * @return A value indicating whether `__x` is less than, equal to, 2257 * greater than, or incomparable with `__y`. 2258 * 2259 * See `std::lexicographical_compare_three_way()` for how the determination 2260 * is made. This operator is used to synthesize relational operators like 2261 * `<` and `>=` etc. 2262 */ 2263 template<typename _Tp, typename _Alloc> 2264 inline __detail::__synth3way_t<_Tp> 2265 operator<=>(const deque<_Tp, _Alloc>& __x, const deque<_Tp, _Alloc>& __y) 2266 { 2267 return std::lexicographical_compare_three_way(__x.begin(), __x.end(), 2268 __y.begin(), __y.end(), 2269 __detail::__synth3way); 2270 } 2271 #else 2272 /** 2273 * @brief Deque ordering relation. 2274 * @param __x A %deque. 2275 * @param __y A %deque of the same type as @a __x. 2276 * @return True iff @a x is lexicographically less than @a __y. 2277 * 2278 * This is a total ordering relation. It is linear in the size of the 2279 * deques. The elements must be comparable with @c <. 2280 * 2281 * See std::lexicographical_compare() for how the determination is made. 2282 */ 2283 template<typename _Tp, typename _Alloc> 2284 inline bool 2285 operator<(const deque<_Tp, _Alloc>& __x, const deque<_Tp, _Alloc>& __y) 2286 { return std::lexicographical_compare(__x.begin(), __x.end(), 2287 __y.begin(), __y.end()); } 2288 2289 /// Based on operator== 2290 template<typename _Tp, typename _Alloc> 2291 inline bool 2292 operator!=(const deque<_Tp, _Alloc>& __x, const deque<_Tp, _Alloc>& __y) 2293 { return !(__x == __y); } 2294 2295 /// Based on operator< 2296 template<typename _Tp, typename _Alloc> 2297 inline bool 2298 operator>(const deque<_Tp, _Alloc>& __x, const deque<_Tp, _Alloc>& __y) 2299 { return __y < __x; } 2300 2301 /// Based on operator< 2302 template<typename _Tp, typename _Alloc> 2303 inline bool 2304 operator<=(const deque<_Tp, _Alloc>& __x, const deque<_Tp, _Alloc>& __y) 2305 { return !(__y < __x); } 2306 2307 /// Based on operator< 2308 template<typename _Tp, typename _Alloc> 2309 inline bool 2310 operator>=(const deque<_Tp, _Alloc>& __x, const deque<_Tp, _Alloc>& __y) 2311 { return !(__x < __y); } 2312 #endif // three-way comparison 2313 2314 /// See std::deque::swap(). 2315 template<typename _Tp, typename _Alloc> 2316 inline void 2317 swap(deque<_Tp,_Alloc>& __x, deque<_Tp,_Alloc>& __y) 2318 _GLIBCXX_NOEXCEPT_IF(noexcept(__x.swap(__y))) 2319 { __x.swap(__y); } 2320 2321 #undef _GLIBCXX_DEQUE_BUF_SIZE 2322 2323 _GLIBCXX_END_NAMESPACE_CONTAINER 2324 2325 #if __cplusplus >= 201103L 2326 // std::allocator is safe, but it is not the only allocator 2327 // for which this is valid. 2328 template<class _Tp> 2329 struct __is_bitwise_relocatable<_GLIBCXX_STD_C::deque<_Tp>> 2330 : true_type { }; 2331 #endif 2332 2333 _GLIBCXX_END_NAMESPACE_VERSION 2334 } // namespace std 2335 2336 #endif /* _STL_DEQUE_H */
Contact us
|
About us
|
Term of use
|
Copyright © 2000-2025 MyWebUniversity.com ™
