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The C and C++ Include Header Files
/usr/include/c++/13/bits/stl_deque.h
$ cat -n /usr/include/c++/13/bits/stl_deque.h 1 // Deque implementation -*- C++ -*- 2 3 // Copyright (C) 2001-2023 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 _GLIBCXX_NODISCARD 180 reference 181 operator*() const _GLIBCXX_NOEXCEPT 182 { return *_M_cur; } 183 184 _GLIBCXX_NODISCARD 185 pointer 186 operator->() const _GLIBCXX_NOEXCEPT 187 { return _M_cur; } 188 189 _Self& 190 operator++() _GLIBCXX_NOEXCEPT 191 { 192 ++_M_cur; 193 if (_M_cur == _M_last) 194 { 195 _M_set_node(_M_node + 1); 196 _M_cur = _M_first; 197 } 198 return *this; 199 } 200 201 _Self 202 operator++(int) _GLIBCXX_NOEXCEPT 203 { 204 _Self __tmp = *this; 205 ++*this; 206 return __tmp; 207 } 208 209 _Self& 210 operator--() _GLIBCXX_NOEXCEPT 211 { 212 if (_M_cur == _M_first) 213 { 214 _M_set_node(_M_node - 1); 215 _M_cur = _M_last; 216 } 217 --_M_cur; 218 return *this; 219 } 220 221 _Self 222 operator--(int) _GLIBCXX_NOEXCEPT 223 { 224 _Self __tmp = *this; 225 --*this; 226 return __tmp; 227 } 228 229 _Self& 230 operator+=(difference_type __n) _GLIBCXX_NOEXCEPT 231 { 232 const difference_type __offset = __n + (_M_cur - _M_first); 233 if (__offset >= 0 && __offset < difference_type(_S_buffer_size())) 234 _M_cur += __n; 235 else 236 { 237 const difference_type __node_offset = 238 __offset > 0 ? __offset / difference_type(_S_buffer_size()) 239 : -difference_type((-__offset - 1) 240 / _S_buffer_size()) - 1; 241 _M_set_node(_M_node + __node_offset); 242 _M_cur = _M_first + (__offset - __node_offset 243 * difference_type(_S_buffer_size())); 244 } 245 return *this; 246 } 247 248 _Self& 249 operator-=(difference_type __n) _GLIBCXX_NOEXCEPT 250 { return *this += -__n; } 251 252 _GLIBCXX_NODISCARD 253 reference 254 operator[](difference_type __n) const _GLIBCXX_NOEXCEPT 255 { return *(*this + __n); } 256 257 /** 258 * Prepares to traverse new_node. Sets everything except 259 * _M_cur, which should therefore be set by the caller 260 * immediately afterwards, based on _M_first and _M_last. 261 */ 262 void 263 _M_set_node(_Map_pointer __new_node) _GLIBCXX_NOEXCEPT 264 { 265 _M_node = __new_node; 266 _M_first = *__new_node; 267 _M_last = _M_first + difference_type(_S_buffer_size()); 268 } 269 270 _GLIBCXX_NODISCARD 271 friend bool 272 operator==(const _Self& __x, const _Self& __y) _GLIBCXX_NOEXCEPT 273 { return __x._M_cur == __y._M_cur; } 274 275 // Note: we also provide overloads whose operands are of the same type in 276 // order to avoid ambiguous overload resolution when std::rel_ops 277 // operators are in scope (for additional details, see libstdc++/3628) 278 template<typename _RefR, typename _PtrR> 279 _GLIBCXX_NODISCARD 280 friend bool 281 operator==(const _Self& __x, 282 const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) 283 _GLIBCXX_NOEXCEPT 284 { return __x._M_cur == __y._M_cur; } 285 286 #if __cpp_lib_three_way_comparison 287 [[nodiscard]] 288 friend strong_ordering 289 operator<=>(const _Self& __x, const _Self& __y) noexcept 290 { 291 if (const auto __cmp = __x._M_node <=> __y._M_node; __cmp != 0) 292 return __cmp; 293 return __x._M_cur <=> __y._M_cur; 294 } 295 #else 296 _GLIBCXX_NODISCARD 297 friend bool 298 operator!=(const _Self& __x, const _Self& __y) _GLIBCXX_NOEXCEPT 299 { return !(__x == __y); } 300 301 template<typename _RefR, typename _PtrR> 302 _GLIBCXX_NODISCARD 303 friend bool 304 operator!=(const _Self& __x, 305 const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) 306 _GLIBCXX_NOEXCEPT 307 { return !(__x == __y); } 308 309 _GLIBCXX_NODISCARD 310 friend bool 311 operator<(const _Self& __x, const _Self& __y) _GLIBCXX_NOEXCEPT 312 { 313 return (__x._M_node == __y._M_node) 314 ? (__x._M_cur < __y._M_cur) : (__x._M_node < __y._M_node); 315 } 316 317 template<typename _RefR, typename _PtrR> 318 _GLIBCXX_NODISCARD 319 friend bool 320 operator<(const _Self& __x, 321 const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) 322 _GLIBCXX_NOEXCEPT 323 { 324 return (__x._M_node == __y._M_node) 325 ? (__x._M_cur < __y._M_cur) : (__x._M_node < __y._M_node); 326 } 327 328 _GLIBCXX_NODISCARD 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 _GLIBCXX_NODISCARD 335 friend bool 336 operator>(const _Self& __x, 337 const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) 338 _GLIBCXX_NOEXCEPT 339 { return __y < __x; } 340 341 _GLIBCXX_NODISCARD 342 friend bool 343 operator<=(const _Self& __x, const _Self& __y) _GLIBCXX_NOEXCEPT 344 { return !(__y < __x); } 345 346 template<typename _RefR, typename _PtrR> 347 _GLIBCXX_NODISCARD 348 friend bool 349 operator<=(const _Self& __x, 350 const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) 351 _GLIBCXX_NOEXCEPT 352 { return !(__y < __x); } 353 354 _GLIBCXX_NODISCARD 355 friend bool 356 operator>=(const _Self& __x, const _Self& __y) _GLIBCXX_NOEXCEPT 357 { return !(__x < __y); } 358 359 template<typename _RefR, typename _PtrR> 360 _GLIBCXX_NODISCARD 361 friend bool 362 operator>=(const _Self& __x, 363 const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) 364 _GLIBCXX_NOEXCEPT 365 { return !(__x < __y); } 366 #endif // three-way comparison 367 368 _GLIBCXX_NODISCARD 369 friend difference_type 370 operator-(const _Self& __x, const _Self& __y) _GLIBCXX_NOEXCEPT 371 { 372 return difference_type(_S_buffer_size()) 373 * (__x._M_node - __y._M_node - bool(__x._M_node)) 374 + (__x._M_cur - __x._M_first) 375 + (__y._M_last - __y._M_cur); 376 } 377 378 // _GLIBCXX_RESOLVE_LIB_DEFECTS 379 // According to the resolution of DR179 not only the various comparison 380 // operators but also operator- must accept mixed iterator/const_iterator 381 // parameters. 382 template<typename _RefR, typename _PtrR> 383 _GLIBCXX_NODISCARD 384 friend difference_type 385 operator-(const _Self& __x, 386 const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) 387 _GLIBCXX_NOEXCEPT 388 { 389 return difference_type(_S_buffer_size()) 390 * (__x._M_node - __y._M_node - bool(__x._M_node)) 391 + (__x._M_cur - __x._M_first) 392 + (__y._M_last - __y._M_cur); 393 } 394 395 _GLIBCXX_NODISCARD 396 friend _Self 397 operator+(const _Self& __x, difference_type __n) _GLIBCXX_NOEXCEPT 398 { 399 _Self __tmp = __x; 400 __tmp += __n; 401 return __tmp; 402 } 403 404 _GLIBCXX_NODISCARD 405 friend _Self 406 operator-(const _Self& __x, difference_type __n) _GLIBCXX_NOEXCEPT 407 { 408 _Self __tmp = __x; 409 __tmp -= __n; 410 return __tmp; 411 } 412 413 _GLIBCXX_NODISCARD 414 friend _Self 415 operator+(difference_type __n, const _Self& __x) _GLIBCXX_NOEXCEPT 416 { return __x + __n; } 417 }; 418 419 /** 420 * Deque base class. This class provides the unified face for %deque's 421 * allocation. This class's constructor and destructor allocate and 422 * deallocate (but do not initialize) storage. This makes %exception 423 * safety easier. 424 * 425 * Nothing in this class ever constructs or destroys an actual Tp element. 426 * (Deque handles that itself.) Only/All memory management is performed 427 * here. 428 */ 429 template<typename _Tp, typename _Alloc> 430 class _Deque_base 431 { 432 protected: 433 typedef typename __gnu_cxx::__alloc_traits<_Alloc>::template 434 rebind<_Tp>::other _Tp_alloc_type; 435 typedef __gnu_cxx::__alloc_traits<_Tp_alloc_type> _Alloc_traits; 436 437 #if __cplusplus < 201103L 438 typedef _Tp* _Ptr; 439 typedef const _Tp* _Ptr_const; 440 #else 441 typedef typename _Alloc_traits::pointer _Ptr; 442 typedef typename _Alloc_traits::const_pointer _Ptr_const; 443 #endif 444 445 typedef typename _Alloc_traits::template rebind<_Ptr>::other 446 _Map_alloc_type; 447 typedef __gnu_cxx::__alloc_traits<_Map_alloc_type> _Map_alloc_traits; 448 449 typedef _Alloc allocator_type; 450 451 allocator_type 452 get_allocator() const _GLIBCXX_NOEXCEPT 453 { return allocator_type(_M_get_Tp_allocator()); } 454 455 typedef _Deque_iterator<_Tp, _Tp&, _Ptr> iterator; 456 typedef _Deque_iterator<_Tp, const _Tp&, _Ptr_const> const_iterator; 457 458 _Deque_base() 459 : _M_impl() 460 { _M_initialize_map(0); } 461 462 _Deque_base(size_t __num_elements) 463 : _M_impl() 464 { _M_initialize_map(__num_elements); } 465 466 _Deque_base(const allocator_type& __a, size_t __num_elements) 467 : _M_impl(__a) 468 { _M_initialize_map(__num_elements); } 469 470 _Deque_base(const allocator_type& __a) 471 : _M_impl(__a) 472 { /* Caller must initialize map. */ } 473 474 #if __cplusplus >= 201103L 475 _Deque_base(_Deque_base&& __x) 476 : _M_impl(std::move(__x._M_get_Tp_allocator())) 477 { 478 _M_initialize_map(0); 479 if (__x._M_impl._M_map) 480 this->_M_impl._M_swap_data(__x._M_impl); 481 } 482 483 _Deque_base(_Deque_base&& __x, const allocator_type& __a) 484 : _M_impl(std::move(__x._M_impl), _Tp_alloc_type(__a)) 485 { __x._M_initialize_map(0); } 486 487 _Deque_base(_Deque_base&& __x, const allocator_type& __a, size_t __n) 488 : _M_impl(__a) 489 { 490 if (__x.get_allocator() == __a) 491 { 492 if (__x._M_impl._M_map) 493 { 494 _M_initialize_map(0); 495 this->_M_impl._M_swap_data(__x._M_impl); 496 } 497 } 498 else 499 { 500 _M_initialize_map(__n); 501 } 502 } 503 #endif 504 505 ~_Deque_base() _GLIBCXX_NOEXCEPT; 506 507 typedef typename iterator::_Map_pointer _Map_pointer; 508 509 struct _Deque_impl_data 510 { 511 _Map_pointer _M_map; 512 size_t _M_map_size; 513 iterator _M_start; 514 iterator _M_finish; 515 516 _Deque_impl_data() _GLIBCXX_NOEXCEPT 517 : _M_map(), _M_map_size(), _M_start(), _M_finish() 518 { } 519 520 #if __cplusplus >= 201103L 521 _Deque_impl_data(const _Deque_impl_data&) = default; 522 _Deque_impl_data& 523 operator=(const _Deque_impl_data&) = default; 524 525 _Deque_impl_data(_Deque_impl_data&& __x) noexcept 526 : _Deque_impl_data(__x) 527 { __x = _Deque_impl_data(); } 528 #endif 529 530 void 531 _M_swap_data(_Deque_impl_data& __x) _GLIBCXX_NOEXCEPT 532 { 533 // Do not use std::swap(_M_start, __x._M_start), etc as it loses 534 // information used by TBAA. 535 std::swap(*this, __x); 536 } 537 }; 538 539 // This struct encapsulates the implementation of the std::deque 540 // standard container and at the same time makes use of the EBO 541 // for empty allocators. 542 struct _Deque_impl 543 : public _Tp_alloc_type, public _Deque_impl_data 544 { 545 _Deque_impl() _GLIBCXX_NOEXCEPT_IF( 546 is_nothrow_default_constructible<_Tp_alloc_type>::value) 547 : _Tp_alloc_type() 548 { } 549 550 _Deque_impl(const _Tp_alloc_type& __a) _GLIBCXX_NOEXCEPT 551 : _Tp_alloc_type(__a) 552 { } 553 554 #if __cplusplus >= 201103L 555 _Deque_impl(_Deque_impl&&) = default; 556 557 _Deque_impl(_Tp_alloc_type&& __a) noexcept 558 : _Tp_alloc_type(std::move(__a)) 559 { } 560 561 _Deque_impl(_Deque_impl&& __d, _Tp_alloc_type&& __a) 562 : _Tp_alloc_type(std::move(__a)), _Deque_impl_data(std::move(__d)) 563 { } 564 #endif 565 }; 566 567 _Tp_alloc_type& 568 _M_get_Tp_allocator() _GLIBCXX_NOEXCEPT 569 { return this->_M_impl; } 570 571 const _Tp_alloc_type& 572 _M_get_Tp_allocator() const _GLIBCXX_NOEXCEPT 573 { return this->_M_impl; } 574 575 _Map_alloc_type 576 _M_get_map_allocator() const _GLIBCXX_NOEXCEPT 577 { return _Map_alloc_type(_M_get_Tp_allocator()); } 578 579 _Ptr 580 _M_allocate_node() 581 { 582 typedef __gnu_cxx::__alloc_traits<_Tp_alloc_type> _Traits; 583 return _Traits::allocate(_M_impl, __deque_buf_size(sizeof(_Tp))); 584 } 585 586 void 587 _M_deallocate_node(_Ptr __p) _GLIBCXX_NOEXCEPT 588 { 589 typedef __gnu_cxx::__alloc_traits<_Tp_alloc_type> _Traits; 590 _Traits::deallocate(_M_impl, __p, __deque_buf_size(sizeof(_Tp))); 591 } 592 593 _Map_pointer 594 _M_allocate_map(size_t __n) 595 { 596 _Map_alloc_type __map_alloc = _M_get_map_allocator(); 597 return _Map_alloc_traits::allocate(__map_alloc, __n); 598 } 599 600 void 601 _M_deallocate_map(_Map_pointer __p, size_t __n) _GLIBCXX_NOEXCEPT 602 { 603 _Map_alloc_type __map_alloc = _M_get_map_allocator(); 604 _Map_alloc_traits::deallocate(__map_alloc, __p, __n); 605 } 606 607 void _M_initialize_map(size_t); 608 void _M_create_nodes(_Map_pointer __nstart, _Map_pointer __nfinish); 609 void _M_destroy_nodes(_Map_pointer __nstart, 610 _Map_pointer __nfinish) _GLIBCXX_NOEXCEPT; 611 enum { _S_initial_map_size = 8 }; 612 613 _Deque_impl _M_impl; 614 }; 615 616 template<typename _Tp, typename _Alloc> 617 _Deque_base<_Tp, _Alloc>:: 618 ~_Deque_base() _GLIBCXX_NOEXCEPT 619 { 620 if (this->_M_impl._M_map) 621 { 622 _M_destroy_nodes(this->_M_impl._M_start._M_node, 623 this->_M_impl._M_finish._M_node + 1); 624 _M_deallocate_map(this->_M_impl._M_map, this->_M_impl._M_map_size); 625 } 626 } 627 628 /** 629 * @brief Layout storage. 630 * @param __num_elements The count of T's for which to allocate space 631 * at first. 632 * @return Nothing. 633 * 634 * The initial underlying memory layout is a bit complicated... 635 */ 636 template<typename _Tp, typename _Alloc> 637 void 638 _Deque_base<_Tp, _Alloc>:: 639 _M_initialize_map(size_t __num_elements) 640 { 641 const size_t __num_nodes = (__num_elements / __deque_buf_size(sizeof(_Tp)) 642 + 1); 643 644 this->_M_impl._M_map_size = std::max((size_t) _S_initial_map_size, 645 size_t(__num_nodes + 2)); 646 this->_M_impl._M_map = _M_allocate_map(this->_M_impl._M_map_size); 647 648 // For "small" maps (needing less than _M_map_size nodes), allocation 649 // starts in the middle elements and grows outwards. So nstart may be 650 // the beginning of _M_map, but for small maps it may be as far in as 651 // _M_map+3. 652 653 _Map_pointer __nstart = (this->_M_impl._M_map 654 + (this->_M_impl._M_map_size - __num_nodes) / 2); 655 _Map_pointer __nfinish = __nstart + __num_nodes; 656 657 __try 658 { _M_create_nodes(__nstart, __nfinish); } 659 __catch(...) 660 { 661 _M_deallocate_map(this->_M_impl._M_map, this->_M_impl._M_map_size); 662 this->_M_impl._M_map = _Map_pointer(); 663 this->_M_impl._M_map_size = 0; 664 __throw_exception_again; 665 } 666 667 this->_M_impl._M_start._M_set_node(__nstart); 668 this->_M_impl._M_finish._M_set_node(__nfinish - 1); 669 this->_M_impl._M_start._M_cur = _M_impl._M_start._M_first; 670 this->_M_impl._M_finish._M_cur = (this->_M_impl._M_finish._M_first 671 + __num_elements 672 % __deque_buf_size(sizeof(_Tp))); 673 } 674 675 template<typename _Tp, typename _Alloc> 676 void 677 _Deque_base<_Tp, _Alloc>:: 678 _M_create_nodes(_Map_pointer __nstart, _Map_pointer __nfinish) 679 { 680 _Map_pointer __cur; 681 __try 682 { 683 for (__cur = __nstart; __cur < __nfinish; ++__cur) 684 *__cur = this->_M_allocate_node(); 685 } 686 __catch(...) 687 { 688 _M_destroy_nodes(__nstart, __cur); 689 __throw_exception_again; 690 } 691 } 692 693 template<typename _Tp, typename _Alloc> 694 void 695 _Deque_base<_Tp, _Alloc>:: 696 _M_destroy_nodes(_Map_pointer __nstart, 697 _Map_pointer __nfinish) _GLIBCXX_NOEXCEPT 698 { 699 for (_Map_pointer __n = __nstart; __n < __nfinish; ++__n) 700 _M_deallocate_node(*__n); 701 } 702 703 /** 704 * @brief A standard container using fixed-size memory allocation and 705 * constant-time manipulation of elements at either end. 706 * 707 * @ingroup sequences 708 * 709 * @tparam _Tp Type of element. 710 * @tparam _Alloc Allocator type, defaults to allocator<_Tp>. 711 * 712 * Meets the requirements of a <a href="tables.html#65">container</a>, a 713 * <a href="tables.html#66">reversible container</a>, and a 714 * <a href="tables.html#67">sequence</a>, including the 715 * <a href="tables.html#68">optional sequence requirements</a>. 716 * 717 * In previous HP/SGI versions of deque, there was an extra template 718 * parameter so users could control the node size. This extension turned 719 * out to violate the C++ standard (it can be detected using template 720 * template parameters), and it was removed. 721 * 722 * Here's how a deque<Tp> manages memory. Each deque has 4 members: 723 * 724 * - Tp** _M_map 725 * - size_t _M_map_size 726 * - iterator _M_start, _M_finish 727 * 728 * map_size is at least 8. %map is an array of map_size 729 * pointers-to-@a nodes. (The name %map has nothing to do with the 730 * std::map class, and @b nodes should not be confused with 731 * std::list's usage of @a node.) 732 * 733 * A @a node has no specific type name as such, but it is referred 734 * to as @a node in this file. It is a simple array-of-Tp. If Tp 735 * is very large, there will be one Tp element per node (i.e., an 736 * @a array of one). For non-huge Tp's, node size is inversely 737 * related to Tp size: the larger the Tp, the fewer Tp's will fit 738 * in a node. The goal here is to keep the total size of a node 739 * relatively small and constant over different Tp's, to improve 740 * allocator efficiency. 741 * 742 * Not every pointer in the %map array will point to a node. If 743 * the initial number of elements in the deque is small, the 744 * /middle/ %map pointers will be valid, and the ones at the edges 745 * will be unused. This same situation will arise as the %map 746 * grows: available %map pointers, if any, will be on the ends. As 747 * new nodes are created, only a subset of the %map's pointers need 748 * to be copied @a outward. 749 * 750 * Class invariants: 751 * - For any nonsingular iterator i: 752 * - i.node points to a member of the %map array. (Yes, you read that 753 * correctly: i.node does not actually point to a node.) The member of 754 * the %map array is what actually points to the node. 755 * - i.first == *(i.node) (This points to the node (first Tp element).) 756 * - i.last == i.first + node_size 757 * - i.cur is a pointer in the range [i.first, i.last). NOTE: 758 * the implication of this is that i.cur is always a dereferenceable 759 * pointer, even if i is a past-the-end iterator. 760 * - Start and Finish are always nonsingular iterators. NOTE: this 761 * means that an empty deque must have one node, a deque with <N 762 * elements (where N is the node buffer size) must have one node, a 763 * deque with N through (2N-1) elements must have two nodes, etc. 764 * - For every node other than start.node and finish.node, every 765 * element in the node is an initialized object. If start.node == 766 * finish.node, then [start.cur, finish.cur) are initialized 767 * objects, and the elements outside that range are uninitialized 768 * storage. Otherwise, [start.cur, start.last) and [finish.first, 769 * finish.cur) are initialized objects, and [start.first, start.cur) 770 * and [finish.cur, finish.last) are uninitialized storage. 771 * - [%map, %map + map_size) is a valid, non-empty range. 772 * - [start.node, finish.node] is a valid range contained within 773 * [%map, %map + map_size). 774 * - A pointer in the range [%map, %map + map_size) points to an allocated 775 * node if and only if the pointer is in the range 776 * [start.node, finish.node]. 777 * 778 * Here's the magic: nothing in deque is @b aware of the discontiguous 779 * storage! 780 * 781 * The memory setup and layout occurs in the parent, _Base, and the iterator 782 * class is entirely responsible for @a leaping from one node to the next. 783 * All the implementation routines for deque itself work only through the 784 * start and finish iterators. This keeps the routines simple and sane, 785 * and we can use other standard algorithms as well. 786 */ 787 template<typename _Tp, typename _Alloc = std::allocator<_Tp> > 788 class deque : protected _Deque_base<_Tp, _Alloc> 789 { 790 #ifdef _GLIBCXX_CONCEPT_CHECKS 791 // concept requirements 792 typedef typename _Alloc::value_type _Alloc_value_type; 793 # if __cplusplus < 201103L 794 __glibcxx_class_requires(_Tp, _SGIAssignableConcept) 795 # endif 796 __glibcxx_class_requires2(_Tp, _Alloc_value_type, _SameTypeConcept) 797 #endif 798 799 #if __cplusplus >= 201103L 800 static_assert(is_same<typename remove_cv<_Tp>::type, _Tp>::value, 801 "std::deque must have a non-const, non-volatile value_type"); 802 # if __cplusplus > 201703L || defined __STRICT_ANSI__ 803 static_assert(is_same<typename _Alloc::value_type, _Tp>::value, 804 "std::deque must have the same value_type as its allocator"); 805 # endif 806 #endif 807 808 typedef _Deque_base<_Tp, _Alloc> _Base; 809 typedef typename _Base::_Tp_alloc_type _Tp_alloc_type; 810 typedef typename _Base::_Alloc_traits _Alloc_traits; 811 typedef typename _Base::_Map_pointer _Map_pointer; 812 813 public: 814 typedef _Tp value_type; 815 typedef typename _Alloc_traits::pointer pointer; 816 typedef typename _Alloc_traits::const_pointer const_pointer; 817 typedef typename _Alloc_traits::reference reference; 818 typedef typename _Alloc_traits::const_reference const_reference; 819 typedef typename _Base::iterator iterator; 820 typedef typename _Base::const_iterator const_iterator; 821 typedef std::reverse_iterator<const_iterator> const_reverse_iterator; 822 typedef std::reverse_iterator<iterator> reverse_iterator; 823 typedef size_t size_type; 824 typedef ptrdiff_t difference_type; 825 typedef _Alloc allocator_type; 826 827 private: 828 static size_t _S_buffer_size() _GLIBCXX_NOEXCEPT 829 { return __deque_buf_size(sizeof(_Tp)); } 830 831 // Functions controlling memory layout, and nothing else. 832 using _Base::_M_initialize_map; 833 using _Base::_M_create_nodes; 834 using _Base::_M_destroy_nodes; 835 using _Base::_M_allocate_node; 836 using _Base::_M_deallocate_node; 837 using _Base::_M_allocate_map; 838 using _Base::_M_deallocate_map; 839 using _Base::_M_get_Tp_allocator; 840 841 /** 842 * A total of four data members accumulated down the hierarchy. 843 * May be accessed via _M_impl.* 844 */ 845 using _Base::_M_impl; 846 847 public: 848 // [23.2.1.1] construct/copy/destroy 849 // (assign() and get_allocator() are also listed in this section) 850 851 /** 852 * @brief Creates a %deque with no elements. 853 */ 854 #if __cplusplus >= 201103L 855 deque() = default; 856 #else 857 deque() { } 858 #endif 859 860 /** 861 * @brief Creates a %deque with no elements. 862 * @param __a An allocator object. 863 */ 864 explicit 865 deque(const allocator_type& __a) 866 : _Base(__a, 0) { } 867 868 #if __cplusplus >= 201103L 869 /** 870 * @brief Creates a %deque with default constructed elements. 871 * @param __n The number of elements to initially create. 872 * @param __a An allocator. 873 * 874 * This constructor fills the %deque with @a n default 875 * constructed elements. 876 */ 877 explicit 878 deque(size_type __n, const allocator_type& __a = allocator_type()) 879 : _Base(__a, _S_check_init_len(__n, __a)) 880 { _M_default_initialize(); } 881 882 /** 883 * @brief Creates a %deque with copies of an exemplar element. 884 * @param __n The number of elements to initially create. 885 * @param __value An element to copy. 886 * @param __a An allocator. 887 * 888 * This constructor fills the %deque with @a __n copies of @a __value. 889 */ 890 deque(size_type __n, const value_type& __value, 891 const allocator_type& __a = allocator_type()) 892 : _Base(__a, _S_check_init_len(__n, __a)) 893 { _M_fill_initialize(__value); } 894 #else 895 /** 896 * @brief Creates a %deque with copies of an exemplar element. 897 * @param __n The number of elements to initially create. 898 * @param __value An element to copy. 899 * @param __a An allocator. 900 * 901 * This constructor fills the %deque with @a __n copies of @a __value. 902 */ 903 explicit 904 deque(size_type __n, const value_type& __value = value_type(), 905 const allocator_type& __a = allocator_type()) 906 : _Base(__a, _S_check_init_len(__n, __a)) 907 { _M_fill_initialize(__value); } 908 #endif 909 910 /** 911 * @brief %Deque copy constructor. 912 * @param __x A %deque of identical element and allocator types. 913 * 914 * The newly-created %deque uses a copy of the allocator object used 915 * by @a __x (unless the allocator traits dictate a different object). 916 */ 917 deque(const deque& __x) 918 : _Base(_Alloc_traits::_S_select_on_copy(__x._M_get_Tp_allocator()), 919 __x.size()) 920 { std::__uninitialized_copy_a(__x.begin(), __x.end(), 921 this->_M_impl._M_start, 922 _M_get_Tp_allocator()); } 923 924 #if __cplusplus >= 201103L 925 /** 926 * @brief %Deque move constructor. 927 * 928 * The newly-created %deque contains the exact contents of the 929 * moved instance. 930 * The contents of the moved instance are a valid, but unspecified 931 * %deque. 932 */ 933 deque(deque&&) = default; 934 935 /// Copy constructor with alternative allocator 936 deque(const deque& __x, const __type_identity_t<allocator_type>& __a) 937 : _Base(__a, __x.size()) 938 { std::__uninitialized_copy_a(__x.begin(), __x.end(), 939 this->_M_impl._M_start, 940 _M_get_Tp_allocator()); } 941 942 /// Move constructor with alternative allocator 943 deque(deque&& __x, const __type_identity_t<allocator_type>& __a) 944 : deque(std::move(__x), __a, typename _Alloc_traits::is_always_equal{}) 945 { } 946 947 private: 948 deque(deque&& __x, const allocator_type& __a, true_type) 949 : _Base(std::move(__x), __a) 950 { } 951 952 deque(deque&& __x, const allocator_type& __a, false_type) 953 : _Base(std::move(__x), __a, __x.size()) 954 { 955 if (__x.get_allocator() != __a && !__x.empty()) 956 { 957 std::__uninitialized_move_a(__x.begin(), __x.end(), 958 this->_M_impl._M_start, 959 _M_get_Tp_allocator()); 960 __x.clear(); 961 } 962 } 963 964 public: 965 /** 966 * @brief Builds a %deque from an initializer list. 967 * @param __l An initializer_list. 968 * @param __a An allocator object. 969 * 970 * Create a %deque consisting of copies of the elements in the 971 * initializer_list @a __l. 972 * 973 * This will call the element type's copy constructor N times 974 * (where N is __l.size()) and do no memory reallocation. 975 */ 976 deque(initializer_list<value_type> __l, 977 const allocator_type& __a = allocator_type()) 978 : _Base(__a) 979 { 980 _M_range_initialize(__l.begin(), __l.end(), 981 random_access_iterator_tag()); 982 } 983 #endif 984 985 /** 986 * @brief Builds a %deque from a range. 987 * @param __first An input iterator. 988 * @param __last An input iterator. 989 * @param __a An allocator object. 990 * 991 * Create a %deque consisting of copies of the elements from [__first, 992 * __last). 993 * 994 * If the iterators are forward, bidirectional, or random-access, then 995 * this will call the elements' copy constructor N times (where N is 996 * distance(__first,__last)) and do no memory reallocation. But if only 997 * input iterators are used, then this will do at most 2N calls to the 998 * copy constructor, and logN memory reallocations. 999 */ 1000 #if __cplusplus >= 201103L 1001 template<typename _InputIterator, 1002 typename = std::_RequireInputIter<_InputIterator>> 1003 deque(_InputIterator __first, _InputIterator __last, 1004 const allocator_type& __a = allocator_type()) 1005 : _Base(__a) 1006 { 1007 _M_range_initialize(__first, __last, 1008 std::__iterator_category(__first)); 1009 } 1010 #else 1011 template<typename _InputIterator> 1012 deque(_InputIterator __first, _InputIterator __last, 1013 const allocator_type& __a = allocator_type()) 1014 : _Base(__a) 1015 { 1016 // Check whether it's an integral type. If so, it's not an iterator. 1017 typedef typename std::__is_integer<_InputIterator>::__type _Integral; 1018 _M_initialize_dispatch(__first, __last, _Integral()); 1019 } 1020 #endif 1021 1022 /** 1023 * The dtor only erases the elements, and note that if the elements 1024 * themselves are pointers, the pointed-to memory is not touched in any 1025 * way. Managing the pointer is the user's responsibility. 1026 */ 1027 ~deque() 1028 { _M_destroy_data(begin(), end(), _M_get_Tp_allocator()); } 1029 1030 /** 1031 * @brief %Deque assignment operator. 1032 * @param __x A %deque of identical element and allocator types. 1033 * 1034 * All the elements of @a x are copied. 1035 * 1036 * The newly-created %deque uses a copy of the allocator object used 1037 * by @a __x (unless the allocator traits dictate a different object). 1038 */ 1039 deque& 1040 operator=(const deque& __x); 1041 1042 #if __cplusplus >= 201103L 1043 /** 1044 * @brief %Deque move assignment operator. 1045 * @param __x A %deque of identical element and allocator types. 1046 * 1047 * The contents of @a __x are moved into this deque (without copying, 1048 * if the allocators permit it). 1049 * @a __x is a valid, but unspecified %deque. 1050 */ 1051 deque& 1052 operator=(deque&& __x) noexcept(_Alloc_traits::_S_always_equal()) 1053 { 1054 using __always_equal = typename _Alloc_traits::is_always_equal; 1055 _M_move_assign1(std::move(__x), __always_equal{}); 1056 return *this; 1057 } 1058 1059 /** 1060 * @brief Assigns an initializer list to a %deque. 1061 * @param __l An initializer_list. 1062 * 1063 * This function fills a %deque with copies of the elements in the 1064 * initializer_list @a __l. 1065 * 1066 * Note that the assignment completely changes the %deque and that the 1067 * resulting %deque's size is the same as the number of elements 1068 * assigned. 1069 */ 1070 deque& 1071 operator=(initializer_list<value_type> __l) 1072 { 1073 _M_assign_aux(__l.begin(), __l.end(), 1074 random_access_iterator_tag()); 1075 return *this; 1076 } 1077 #endif 1078 1079 /** 1080 * @brief Assigns a given value to a %deque. 1081 * @param __n Number of elements to be assigned. 1082 * @param __val Value to be assigned. 1083 * 1084 * This function fills a %deque with @a n copies of the given 1085 * value. Note that the assignment completely changes the 1086 * %deque and that the resulting %deque's size is the same as 1087 * the number of elements assigned. 1088 */ 1089 void 1090 assign(size_type __n, const value_type& __val) 1091 { _M_fill_assign(__n, __val); } 1092 1093 /** 1094 * @brief Assigns a range to a %deque. 1095 * @param __first An input iterator. 1096 * @param __last An input iterator. 1097 * 1098 * This function fills a %deque with copies of the elements in the 1099 * range [__first,__last). 1100 * 1101 * Note that the assignment completely changes the %deque and that the 1102 * resulting %deque's size is the same as the number of elements 1103 * assigned. 1104 */ 1105 #if __cplusplus >= 201103L 1106 template<typename _InputIterator, 1107 typename = std::_RequireInputIter<_InputIterator>> 1108 void 1109 assign(_InputIterator __first, _InputIterator __last) 1110 { _M_assign_aux(__first, __last, std::__iterator_category(__first)); } 1111 #else 1112 template<typename _InputIterator> 1113 void 1114 assign(_InputIterator __first, _InputIterator __last) 1115 { 1116 typedef typename std::__is_integer<_InputIterator>::__type _Integral; 1117 _M_assign_dispatch(__first, __last, _Integral()); 1118 } 1119 #endif 1120 1121 #if __cplusplus >= 201103L 1122 /** 1123 * @brief Assigns an initializer list to a %deque. 1124 * @param __l An initializer_list. 1125 * 1126 * This function fills a %deque with copies of the elements in the 1127 * initializer_list @a __l. 1128 * 1129 * Note that the assignment completely changes the %deque and that the 1130 * resulting %deque's size is the same as the number of elements 1131 * assigned. 1132 */ 1133 void 1134 assign(initializer_list<value_type> __l) 1135 { _M_assign_aux(__l.begin(), __l.end(), random_access_iterator_tag()); } 1136 #endif 1137 1138 /// Get a copy of the memory allocation object. 1139 _GLIBCXX_NODISCARD 1140 allocator_type 1141 get_allocator() const _GLIBCXX_NOEXCEPT 1142 { return _Base::get_allocator(); } 1143 1144 // iterators 1145 /** 1146 * Returns a read/write iterator that points to the first element in the 1147 * %deque. Iteration is done in ordinary element order. 1148 */ 1149 _GLIBCXX_NODISCARD 1150 iterator 1151 begin() _GLIBCXX_NOEXCEPT 1152 { return this->_M_impl._M_start; } 1153 1154 /** 1155 * Returns a read-only (constant) iterator that points to the first 1156 * element in the %deque. Iteration is done in ordinary element order. 1157 */ 1158 _GLIBCXX_NODISCARD 1159 const_iterator 1160 begin() const _GLIBCXX_NOEXCEPT 1161 { return this->_M_impl._M_start; } 1162 1163 /** 1164 * Returns a read/write iterator that points one past the last 1165 * element in the %deque. Iteration is done in ordinary 1166 * element order. 1167 */ 1168 _GLIBCXX_NODISCARD 1169 iterator 1170 end() _GLIBCXX_NOEXCEPT 1171 { return this->_M_impl._M_finish; } 1172 1173 /** 1174 * Returns a read-only (constant) iterator that points one past 1175 * the last element in the %deque. Iteration is done in 1176 * ordinary element order. 1177 */ 1178 _GLIBCXX_NODISCARD 1179 const_iterator 1180 end() const _GLIBCXX_NOEXCEPT 1181 { return this->_M_impl._M_finish; } 1182 1183 /** 1184 * Returns a read/write reverse iterator that points to the 1185 * last element in the %deque. Iteration is done in reverse 1186 * element order. 1187 */ 1188 _GLIBCXX_NODISCARD 1189 reverse_iterator 1190 rbegin() _GLIBCXX_NOEXCEPT 1191 { return reverse_iterator(this->_M_impl._M_finish); } 1192 1193 /** 1194 * Returns a read-only (constant) reverse iterator that points 1195 * to the last element in the %deque. Iteration is done in 1196 * reverse element order. 1197 */ 1198 _GLIBCXX_NODISCARD 1199 const_reverse_iterator 1200 rbegin() const _GLIBCXX_NOEXCEPT 1201 { return const_reverse_iterator(this->_M_impl._M_finish); } 1202 1203 /** 1204 * Returns a read/write reverse iterator that points to one 1205 * before the first element in the %deque. Iteration is done 1206 * in reverse element order. 1207 */ 1208 _GLIBCXX_NODISCARD 1209 reverse_iterator 1210 rend() _GLIBCXX_NOEXCEPT 1211 { return reverse_iterator(this->_M_impl._M_start); } 1212 1213 /** 1214 * Returns a read-only (constant) reverse iterator that points 1215 * to one before the first element in the %deque. Iteration is 1216 * done in reverse element order. 1217 */ 1218 _GLIBCXX_NODISCARD 1219 const_reverse_iterator 1220 rend() const _GLIBCXX_NOEXCEPT 1221 { return const_reverse_iterator(this->_M_impl._M_start); } 1222 1223 #if __cplusplus >= 201103L 1224 /** 1225 * Returns a read-only (constant) iterator that points to the first 1226 * element in the %deque. Iteration is done in ordinary element order. 1227 */ 1228 [[__nodiscard__]] 1229 const_iterator 1230 cbegin() const noexcept 1231 { return this->_M_impl._M_start; } 1232 1233 /** 1234 * Returns a read-only (constant) iterator that points one past 1235 * the last element in the %deque. Iteration is done in 1236 * ordinary element order. 1237 */ 1238 [[__nodiscard__]] 1239 const_iterator 1240 cend() const noexcept 1241 { return this->_M_impl._M_finish; } 1242 1243 /** 1244 * Returns a read-only (constant) reverse iterator that points 1245 * to the last element in the %deque. Iteration is done in 1246 * reverse element order. 1247 */ 1248 [[__nodiscard__]] 1249 const_reverse_iterator 1250 crbegin() const noexcept 1251 { return const_reverse_iterator(this->_M_impl._M_finish); } 1252 1253 /** 1254 * Returns a read-only (constant) reverse iterator that points 1255 * to one before the first element in the %deque. Iteration is 1256 * done in reverse element order. 1257 */ 1258 [[__nodiscard__]] 1259 const_reverse_iterator 1260 crend() const noexcept 1261 { return const_reverse_iterator(this->_M_impl._M_start); } 1262 #endif 1263 1264 // [23.2.1.2] capacity 1265 /** Returns the number of elements in the %deque. */ 1266 _GLIBCXX_NODISCARD 1267 size_type 1268 size() const _GLIBCXX_NOEXCEPT 1269 { return this->_M_impl._M_finish - this->_M_impl._M_start; } 1270 1271 /** Returns the size() of the largest possible %deque. */ 1272 _GLIBCXX_NODISCARD 1273 size_type 1274 max_size() const _GLIBCXX_NOEXCEPT 1275 { return _S_max_size(_M_get_Tp_allocator()); } 1276 1277 #if __cplusplus >= 201103L 1278 /** 1279 * @brief Resizes the %deque to the specified number of elements. 1280 * @param __new_size Number of elements the %deque should contain. 1281 * 1282 * This function will %resize the %deque to the specified 1283 * number of elements. If the number is smaller than the 1284 * %deque's current size the %deque is truncated, otherwise 1285 * default constructed elements are appended. 1286 */ 1287 void 1288 resize(size_type __new_size) 1289 { 1290 const size_type __len = size(); 1291 if (__new_size > __len) 1292 _M_default_append(__new_size - __len); 1293 else if (__new_size < __len) 1294 _M_erase_at_end(this->_M_impl._M_start 1295 + difference_type(__new_size)); 1296 } 1297 1298 /** 1299 * @brief Resizes the %deque to the specified number of elements. 1300 * @param __new_size Number of elements the %deque should contain. 1301 * @param __x Data with which new elements should be populated. 1302 * 1303 * This function will %resize the %deque to the specified 1304 * number of elements. If the number is smaller than the 1305 * %deque's current size the %deque is truncated, otherwise the 1306 * %deque is extended and new elements are populated with given 1307 * data. 1308 */ 1309 void 1310 resize(size_type __new_size, const value_type& __x) 1311 #else 1312 /** 1313 * @brief Resizes the %deque to the specified number of elements. 1314 * @param __new_size Number of elements the %deque should contain. 1315 * @param __x Data with which new elements should be populated. 1316 * 1317 * This function will %resize the %deque to the specified 1318 * number of elements. If the number is smaller than the 1319 * %deque's current size the %deque is truncated, otherwise the 1320 * %deque is extended and new elements are populated with given 1321 * data. 1322 */ 1323 void 1324 resize(size_type __new_size, value_type __x = value_type()) 1325 #endif 1326 { 1327 const size_type __len = size(); 1328 if (__new_size > __len) 1329 _M_fill_insert(this->_M_impl._M_finish, __new_size - __len, __x); 1330 else if (__new_size < __len) 1331 _M_erase_at_end(this->_M_impl._M_start 1332 + difference_type(__new_size)); 1333 } 1334 1335 #if __cplusplus >= 201103L 1336 /** A non-binding request to reduce memory use. */ 1337 void 1338 shrink_to_fit() noexcept 1339 { _M_shrink_to_fit(); } 1340 #endif 1341 1342 /** 1343 * Returns true if the %deque is empty. (Thus begin() would 1344 * equal end().) 1345 */ 1346 _GLIBCXX_NODISCARD bool 1347 empty() const _GLIBCXX_NOEXCEPT 1348 { return this->_M_impl._M_finish == this->_M_impl._M_start; } 1349 1350 // element access 1351 /** 1352 * @brief Subscript access to the data contained in the %deque. 1353 * @param __n The index of the element for which data should be 1354 * accessed. 1355 * @return Read/write reference to data. 1356 * 1357 * This operator allows for easy, array-style, data access. 1358 * Note that data access with this operator is unchecked and 1359 * out_of_range lookups are not defined. (For checked lookups 1360 * see at().) 1361 */ 1362 _GLIBCXX_NODISCARD 1363 reference 1364 operator[](size_type __n) _GLIBCXX_NOEXCEPT 1365 { 1366 __glibcxx_requires_subscript(__n); 1367 return this->_M_impl._M_start[difference_type(__n)]; 1368 } 1369 1370 /** 1371 * @brief Subscript access to the data contained in the %deque. 1372 * @param __n The index of the element for which data should be 1373 * accessed. 1374 * @return Read-only (constant) reference to data. 1375 * 1376 * This operator allows for easy, array-style, data access. 1377 * Note that data access with this operator is unchecked and 1378 * out_of_range lookups are not defined. (For checked lookups 1379 * see at().) 1380 */ 1381 _GLIBCXX_NODISCARD 1382 const_reference 1383 operator[](size_type __n) const _GLIBCXX_NOEXCEPT 1384 { 1385 __glibcxx_requires_subscript(__n); 1386 return this->_M_impl._M_start[difference_type(__n)]; 1387 } 1388 1389 protected: 1390 /// Safety check used only from at(). 1391 void 1392 _M_range_check(size_type __n) const 1393 { 1394 if (__n >= this->size()) 1395 __throw_out_of_range_fmt(__N("deque::_M_range_check: __n " 1396 "(which is %zu)>= this->size() " 1397 "(which is %zu)"), 1398 __n, this->size()); 1399 } 1400 1401 public: 1402 /** 1403 * @brief Provides access to the data contained in the %deque. 1404 * @param __n The index of the element for which data should be 1405 * accessed. 1406 * @return Read/write reference to data. 1407 * @throw std::out_of_range If @a __n is an invalid index. 1408 * 1409 * This function provides for safer data access. The parameter 1410 * is first checked that it is in the range of the deque. The 1411 * function throws out_of_range if the check fails. 1412 */ 1413 reference 1414 at(size_type __n) 1415 { 1416 _M_range_check(__n); 1417 return (*this)[__n]; 1418 } 1419 1420 /** 1421 * @brief Provides access to the data contained in the %deque. 1422 * @param __n The index of the element for which data should be 1423 * accessed. 1424 * @return Read-only (constant) reference to data. 1425 * @throw std::out_of_range If @a __n is an invalid index. 1426 * 1427 * This function provides for safer data access. The parameter is first 1428 * checked that it is in the range of the deque. The function throws 1429 * out_of_range if the check fails. 1430 */ 1431 const_reference 1432 at(size_type __n) const 1433 { 1434 _M_range_check(__n); 1435 return (*this)[__n]; 1436 } 1437 1438 /** 1439 * Returns a read/write reference to the data at the first 1440 * element of the %deque. 1441 */ 1442 _GLIBCXX_NODISCARD 1443 reference 1444 front() _GLIBCXX_NOEXCEPT 1445 { 1446 __glibcxx_requires_nonempty(); 1447 return *begin(); 1448 } 1449 1450 /** 1451 * Returns a read-only (constant) reference to the data at the first 1452 * element of the %deque. 1453 */ 1454 _GLIBCXX_NODISCARD 1455 const_reference 1456 front() const _GLIBCXX_NOEXCEPT 1457 { 1458 __glibcxx_requires_nonempty(); 1459 return *begin(); 1460 } 1461 1462 /** 1463 * Returns a read/write reference to the data at the last element of the 1464 * %deque. 1465 */ 1466 _GLIBCXX_NODISCARD 1467 reference 1468 back() _GLIBCXX_NOEXCEPT 1469 { 1470 __glibcxx_requires_nonempty(); 1471 iterator __tmp = end(); 1472 --__tmp; 1473 return *__tmp; 1474 } 1475 1476 /** 1477 * Returns a read-only (constant) reference to the data at the last 1478 * element of the %deque. 1479 */ 1480 _GLIBCXX_NODISCARD 1481 const_reference 1482 back() const _GLIBCXX_NOEXCEPT 1483 { 1484 __glibcxx_requires_nonempty(); 1485 const_iterator __tmp = end(); 1486 --__tmp; 1487 return *__tmp; 1488 } 1489 1490 // [23.2.1.2] modifiers 1491 /** 1492 * @brief Add data to the front of the %deque. 1493 * @param __x Data to be added. 1494 * 1495 * This is a typical stack operation. The function creates an 1496 * element at the front of the %deque and assigns the given 1497 * data to it. Due to the nature of a %deque this operation 1498 * can be done in constant time. 1499 */ 1500 void 1501 push_front(const value_type& __x) 1502 { 1503 if (this->_M_impl._M_start._M_cur != this->_M_impl._M_start._M_first) 1504 { 1505 _Alloc_traits::construct(this->_M_impl, 1506 this->_M_impl._M_start._M_cur - 1, 1507 __x); 1508 --this->_M_impl._M_start._M_cur; 1509 } 1510 else 1511 _M_push_front_aux(__x); 1512 } 1513 1514 #if __cplusplus >= 201103L 1515 void 1516 push_front(value_type&& __x) 1517 { emplace_front(std::move(__x)); } 1518 1519 template<typename... _Args> 1520 #if __cplusplus > 201402L 1521 reference 1522 #else 1523 void 1524 #endif 1525 emplace_front(_Args&&... __args); 1526 #endif 1527 1528 /** 1529 * @brief Add data to the end of the %deque. 1530 * @param __x Data to be added. 1531 * 1532 * This is a typical stack operation. The function creates an 1533 * element at the end of the %deque and assigns the given data 1534 * to it. Due to the nature of a %deque this operation can be 1535 * done in constant time. 1536 */ 1537 void 1538 push_back(const value_type& __x) 1539 { 1540 if (this->_M_impl._M_finish._M_cur 1541 != this->_M_impl._M_finish._M_last - 1) 1542 { 1543 _Alloc_traits::construct(this->_M_impl, 1544 this->_M_impl._M_finish._M_cur, __x); 1545 ++this->_M_impl._M_finish._M_cur; 1546 } 1547 else 1548 _M_push_back_aux(__x); 1549 } 1550 1551 #if __cplusplus >= 201103L 1552 void 1553 push_back(value_type&& __x) 1554 { emplace_back(std::move(__x)); } 1555 1556 template<typename... _Args> 1557 #if __cplusplus > 201402L 1558 reference 1559 #else 1560 void 1561 #endif 1562 emplace_back(_Args&&... __args); 1563 #endif 1564 1565 /** 1566 * @brief Removes first element. 1567 * 1568 * This is a typical stack operation. It shrinks the %deque by one. 1569 * 1570 * Note that no data is returned, and if the first element's data is 1571 * needed, it should be retrieved before pop_front() is called. 1572 */ 1573 void 1574 pop_front() _GLIBCXX_NOEXCEPT 1575 { 1576 __glibcxx_requires_nonempty(); 1577 if (this->_M_impl._M_start._M_cur 1578 != this->_M_impl._M_start._M_last - 1) 1579 { 1580 _Alloc_traits::destroy(_M_get_Tp_allocator(), 1581 this->_M_impl._M_start._M_cur); 1582 ++this->_M_impl._M_start._M_cur; 1583 } 1584 else 1585 _M_pop_front_aux(); 1586 } 1587 1588 /** 1589 * @brief Removes last element. 1590 * 1591 * This is a typical stack operation. It shrinks the %deque by one. 1592 * 1593 * Note that no data is returned, and if the last element's data is 1594 * needed, it should be retrieved before pop_back() is called. 1595 */ 1596 void 1597 pop_back() _GLIBCXX_NOEXCEPT 1598 { 1599 __glibcxx_requires_nonempty(); 1600 if (this->_M_impl._M_finish._M_cur 1601 != this->_M_impl._M_finish._M_first) 1602 { 1603 --this->_M_impl._M_finish._M_cur; 1604 _Alloc_traits::destroy(_M_get_Tp_allocator(), 1605 this->_M_impl._M_finish._M_cur); 1606 } 1607 else 1608 _M_pop_back_aux(); 1609 } 1610 1611 #if __cplusplus >= 201103L 1612 /** 1613 * @brief Inserts an object in %deque before specified iterator. 1614 * @param __position A const_iterator into the %deque. 1615 * @param __args Arguments. 1616 * @return An iterator that points to the inserted data. 1617 * 1618 * This function will insert an object of type T constructed 1619 * with T(std::forward<Args>(args)...) before the specified location. 1620 */ 1621 template<typename... _Args> 1622 iterator 1623 emplace(const_iterator __position, _Args&&... __args); 1624 1625 /** 1626 * @brief Inserts given value into %deque before specified iterator. 1627 * @param __position A const_iterator into the %deque. 1628 * @param __x Data to be inserted. 1629 * @return An iterator that points to the inserted data. 1630 * 1631 * This function will insert a copy of the given value before the 1632 * specified location. 1633 */ 1634 iterator 1635 insert(const_iterator __position, const value_type& __x); 1636 #else 1637 /** 1638 * @brief Inserts given value into %deque before specified iterator. 1639 * @param __position An iterator into the %deque. 1640 * @param __x Data to be inserted. 1641 * @return An iterator that points to the inserted data. 1642 * 1643 * This function will insert a copy of the given value before the 1644 * specified location. 1645 */ 1646 iterator 1647 insert(iterator __position, const value_type& __x); 1648 #endif 1649 1650 #if __cplusplus >= 201103L 1651 /** 1652 * @brief Inserts given rvalue into %deque before specified iterator. 1653 * @param __position A const_iterator into the %deque. 1654 * @param __x Data to be inserted. 1655 * @return An iterator that points to the inserted data. 1656 * 1657 * This function will insert a copy of the given rvalue before the 1658 * specified location. 1659 */ 1660 iterator 1661 insert(const_iterator __position, value_type&& __x) 1662 { return emplace(__position, std::move(__x)); } 1663 1664 /** 1665 * @brief Inserts an initializer list into the %deque. 1666 * @param __p An iterator into the %deque. 1667 * @param __l An initializer_list. 1668 * @return An iterator that points to the inserted data. 1669 * 1670 * This function will insert copies of the data in the 1671 * initializer_list @a __l into the %deque before the location 1672 * specified by @a __p. This is known as <em>list insert</em>. 1673 */ 1674 iterator 1675 insert(const_iterator __p, initializer_list<value_type> __l) 1676 { 1677 auto __offset = __p - cbegin(); 1678 _M_range_insert_aux(__p._M_const_cast(), __l.begin(), __l.end(), 1679 std::random_access_iterator_tag()); 1680 return begin() + __offset; 1681 } 1682 1683 /** 1684 * @brief Inserts a number of copies of given data into the %deque. 1685 * @param __position A const_iterator into the %deque. 1686 * @param __n Number of elements to be inserted. 1687 * @param __x Data to be inserted. 1688 * @return An iterator that points to the inserted data. 1689 * 1690 * This function will insert a specified number of copies of the given 1691 * data before the location specified by @a __position. 1692 */ 1693 iterator 1694 insert(const_iterator __position, size_type __n, const value_type& __x) 1695 { 1696 difference_type __offset = __position - cbegin(); 1697 _M_fill_insert(__position._M_const_cast(), __n, __x); 1698 return begin() + __offset; 1699 } 1700 #else 1701 /** 1702 * @brief Inserts a number of copies of given data into the %deque. 1703 * @param __position An iterator into the %deque. 1704 * @param __n Number of elements to be inserted. 1705 * @param __x Data to be inserted. 1706 * 1707 * This function will insert a specified number of copies of the given 1708 * data before the location specified by @a __position. 1709 */ 1710 void 1711 insert(iterator __position, size_type __n, const value_type& __x) 1712 { _M_fill_insert(__position, __n, __x); } 1713 #endif 1714 1715 #if __cplusplus >= 201103L 1716 /** 1717 * @brief Inserts a range into the %deque. 1718 * @param __position A const_iterator into the %deque. 1719 * @param __first An input iterator. 1720 * @param __last An input iterator. 1721 * @return An iterator that points to the inserted data. 1722 * 1723 * This function will insert copies of the data in the range 1724 * [__first,__last) into the %deque before the location specified 1725 * by @a __position. This is known as <em>range insert</em>. 1726 */ 1727 template<typename _InputIterator, 1728 typename = std::_RequireInputIter<_InputIterator>> 1729 iterator 1730 insert(const_iterator __position, _InputIterator __first, 1731 _InputIterator __last) 1732 { 1733 difference_type __offset = __position - cbegin(); 1734 _M_range_insert_aux(__position._M_const_cast(), __first, __last, 1735 std::__iterator_category(__first)); 1736 return begin() + __offset; 1737 } 1738 #else 1739 /** 1740 * @brief Inserts a range into the %deque. 1741 * @param __position An iterator into the %deque. 1742 * @param __first An input iterator. 1743 * @param __last An input iterator. 1744 * 1745 * This function will insert copies of the data in the range 1746 * [__first,__last) into the %deque before the location specified 1747 * by @a __position. This is known as <em>range insert</em>. 1748 */ 1749 template<typename _InputIterator> 1750 void 1751 insert(iterator __position, _InputIterator __first, 1752 _InputIterator __last) 1753 { 1754 // Check whether it's an integral type. If so, it's not an iterator. 1755 typedef typename std::__is_integer<_InputIterator>::__type _Integral; 1756 _M_insert_dispatch(__position, __first, __last, _Integral()); 1757 } 1758 #endif 1759 1760 /** 1761 * @brief Remove element at given position. 1762 * @param __position Iterator pointing to element to be erased. 1763 * @return An iterator pointing to the next element (or end()). 1764 * 1765 * This function will erase the element at the given position and thus 1766 * shorten the %deque by one. 1767 * 1768 * The user is cautioned that 1769 * this function only erases the element, and that if the element is 1770 * itself a pointer, the pointed-to memory is not touched in any way. 1771 * Managing the pointer is the user's responsibility. 1772 */ 1773 iterator 1774 #if __cplusplus >= 201103L 1775 erase(const_iterator __position) 1776 #else 1777 erase(iterator __position) 1778 #endif 1779 { return _M_erase(__position._M_const_cast()); } 1780 1781 /** 1782 * @brief Remove a range of elements. 1783 * @param __first Iterator pointing to the first element to be erased. 1784 * @param __last Iterator pointing to one past the last element to be 1785 * erased. 1786 * @return An iterator pointing to the element pointed to by @a last 1787 * prior to erasing (or end()). 1788 * 1789 * This function will erase the elements in the range 1790 * [__first,__last) and shorten the %deque accordingly. 1791 * 1792 * The user is cautioned that 1793 * this function only erases the elements, and that if the elements 1794 * themselves are pointers, the pointed-to memory is not touched in any 1795 * way. Managing the pointer is the user's responsibility. 1796 */ 1797 iterator 1798 #if __cplusplus >= 201103L 1799 erase(const_iterator __first, const_iterator __last) 1800 #else 1801 erase(iterator __first, iterator __last) 1802 #endif 1803 { return _M_erase(__first._M_const_cast(), __last._M_const_cast()); } 1804 1805 /** 1806 * @brief Swaps data with another %deque. 1807 * @param __x A %deque of the same element and allocator types. 1808 * 1809 * This exchanges the elements between two deques in constant time. 1810 * (Four pointers, so it should be quite fast.) 1811 * Note that the global std::swap() function is specialized such that 1812 * std::swap(d1,d2) will feed to this function. 1813 * 1814 * Whether the allocators are swapped depends on the allocator traits. 1815 */ 1816 void 1817 swap(deque& __x) _GLIBCXX_NOEXCEPT 1818 { 1819 #if __cplusplus >= 201103L 1820 __glibcxx_assert(_Alloc_traits::propagate_on_container_swap::value 1821 || _M_get_Tp_allocator() == __x._M_get_Tp_allocator()); 1822 #endif 1823 _M_impl._M_swap_data(__x._M_impl); 1824 _Alloc_traits::_S_on_swap(_M_get_Tp_allocator(), 1825 __x._M_get_Tp_allocator()); 1826 } 1827 1828 /** 1829 * Erases all the elements. Note that this function only erases the 1830 * elements, and that if the elements themselves are pointers, the 1831 * pointed-to memory is not touched in any way. Managing the pointer is 1832 * the user's responsibility. 1833 */ 1834 void 1835 clear() _GLIBCXX_NOEXCEPT 1836 { _M_erase_at_end(begin()); } 1837 1838 protected: 1839 // Internal constructor functions follow. 1840 1841 #if __cplusplus < 201103L 1842 // called by the range constructor to implement [23.1.1]/9 1843 1844 // _GLIBCXX_RESOLVE_LIB_DEFECTS 1845 // 438. Ambiguity in the "do the right thing" clause 1846 template<typename _Integer> 1847 void 1848 _M_initialize_dispatch(_Integer __n, _Integer __x, __true_type) 1849 { 1850 _M_initialize_map(_S_check_init_len(static_cast<size_type>(__n), 1851 _M_get_Tp_allocator())); 1852 _M_fill_initialize(__x); 1853 } 1854 1855 // called by the range constructor to implement [23.1.1]/9 1856 template<typename _InputIterator> 1857 void 1858 _M_initialize_dispatch(_InputIterator __first, _InputIterator __last, 1859 __false_type) 1860 { 1861 _M_range_initialize(__first, __last, 1862 std::__iterator_category(__first)); 1863 } 1864 #endif 1865 1866 static size_t 1867 _S_check_init_len(size_t __n, const allocator_type& __a) 1868 { 1869 if (__n > _S_max_size(__a)) 1870 __throw_length_error( 1871 __N("cannot create std::deque larger than max_size()")); 1872 return __n; 1873 } 1874 1875 static size_type 1876 _S_max_size(const _Tp_alloc_type& __a) _GLIBCXX_NOEXCEPT 1877 { 1878 const size_t __diffmax = __gnu_cxx::__numeric_traits<ptrdiff_t>::__max; 1879 const size_t __allocmax = _Alloc_traits::max_size(__a); 1880 return (std::min)(__diffmax, __allocmax); 1881 } 1882 1883 // called by the second initialize_dispatch above 1884 ///@{ 1885 /** 1886 * @brief Fills the deque with whatever is in [first,last). 1887 * @param __first An input iterator. 1888 * @param __last An input iterator. 1889 * @return Nothing. 1890 * 1891 * If the iterators are actually forward iterators (or better), then the 1892 * memory layout can be done all at once. Else we move forward using 1893 * push_back on each value from the iterator. 1894 */ 1895 template<typename _InputIterator> 1896 void 1897 _M_range_initialize(_InputIterator __first, _InputIterator __last, 1898 std::input_iterator_tag); 1899 1900 // called by the second initialize_dispatch above 1901 template<typename _ForwardIterator> 1902 void 1903 _M_range_initialize(_ForwardIterator __first, _ForwardIterator __last, 1904 std::forward_iterator_tag); 1905 ///@} 1906 1907 /** 1908 * @brief Fills the %deque with copies of value. 1909 * @param __value Initial value. 1910 * @return Nothing. 1911 * @pre _M_start and _M_finish have already been initialized, 1912 * but none of the %deque's elements have yet been constructed. 1913 * 1914 * This function is called only when the user provides an explicit size 1915 * (with or without an explicit exemplar value). 1916 */ 1917 void 1918 _M_fill_initialize(const value_type& __value); 1919 1920 #if __cplusplus >= 201103L 1921 // called by deque(n). 1922 void 1923 _M_default_initialize(); 1924 #endif 1925 1926 // Internal assign functions follow. The *_aux functions do the actual 1927 // assignment work for the range versions. 1928 1929 #if __cplusplus < 201103L 1930 // called by the range assign to implement [23.1.1]/9 1931 1932 // _GLIBCXX_RESOLVE_LIB_DEFECTS 1933 // 438. Ambiguity in the "do the right thing" clause 1934 template<typename _Integer> 1935 void 1936 _M_assign_dispatch(_Integer __n, _Integer __val, __true_type) 1937 { _M_fill_assign(__n, __val); } 1938 1939 // called by the range assign to implement [23.1.1]/9 1940 template<typename _InputIterator> 1941 void 1942 _M_assign_dispatch(_InputIterator __first, _InputIterator __last, 1943 __false_type) 1944 { _M_assign_aux(__first, __last, std::__iterator_category(__first)); } 1945 #endif 1946 1947 // called by the second assign_dispatch above 1948 template<typename _InputIterator> 1949 void 1950 _M_assign_aux(_InputIterator __first, _InputIterator __last, 1951 std::input_iterator_tag); 1952 1953 // called by the second assign_dispatch above 1954 template<typename _ForwardIterator> 1955 void 1956 _M_assign_aux(_ForwardIterator __first, _ForwardIterator __last, 1957 std::forward_iterator_tag) 1958 { 1959 const size_type __len = std::distance(__first, __last); 1960 if (__len > size()) 1961 { 1962 _ForwardIterator __mid = __first; 1963 std::advance(__mid, size()); 1964 std::copy(__first, __mid, begin()); 1965 _M_range_insert_aux(end(), __mid, __last, 1966 std::__iterator_category(__first)); 1967 } 1968 else 1969 _M_erase_at_end(std::copy(__first, __last, begin())); 1970 } 1971 1972 // Called by assign(n,t), and the range assign when it turns out 1973 // to be the same thing. 1974 void 1975 _M_fill_assign(size_type __n, const value_type& __val) 1976 { 1977 if (__n > size()) 1978 { 1979 std::fill(begin(), end(), __val); 1980 _M_fill_insert(end(), __n - size(), __val); 1981 } 1982 else 1983 { 1984 _M_erase_at_end(begin() + difference_type(__n)); 1985 std::fill(begin(), end(), __val); 1986 } 1987 } 1988 1989 ///@{ 1990 /// Helper functions for push_* and pop_*. 1991 #if __cplusplus < 201103L 1992 void _M_push_back_aux(const value_type&); 1993 1994 void _M_push_front_aux(const value_type&); 1995 #else 1996 template<typename... _Args> 1997 void _M_push_back_aux(_Args&&... __args); 1998 1999 template<typename... _Args> 2000 void _M_push_front_aux(_Args&&... __args); 2001 #endif 2002 2003 void _M_pop_back_aux(); 2004 2005 void _M_pop_front_aux(); 2006 ///@} 2007 2008 // Internal insert functions follow. The *_aux functions do the actual 2009 // insertion work when all shortcuts fail. 2010 2011 #if __cplusplus < 201103L 2012 // called by the range insert to implement [23.1.1]/9 2013 2014 // _GLIBCXX_RESOLVE_LIB_DEFECTS 2015 // 438. Ambiguity in the "do the right thing" clause 2016 template<typename _Integer> 2017 void 2018 _M_insert_dispatch(iterator __pos, 2019 _Integer __n, _Integer __x, __true_type) 2020 { _M_fill_insert(__pos, __n, __x); } 2021 2022 // called by the range insert to implement [23.1.1]/9 2023 template<typename _InputIterator> 2024 void 2025 _M_insert_dispatch(iterator __pos, 2026 _InputIterator __first, _InputIterator __last, 2027 __false_type) 2028 { 2029 _M_range_insert_aux(__pos, __first, __last, 2030 std::__iterator_category(__first)); 2031 } 2032 #endif 2033 2034 // called by the second insert_dispatch above 2035 template<typename _InputIterator> 2036 void 2037 _M_range_insert_aux(iterator __pos, _InputIterator __first, 2038 _InputIterator __last, std::input_iterator_tag); 2039 2040 // called by the second insert_dispatch above 2041 template<typename _ForwardIterator> 2042 void 2043 _M_range_insert_aux(iterator __pos, _ForwardIterator __first, 2044 _ForwardIterator __last, std::forward_iterator_tag); 2045 2046 // Called by insert(p,n,x), and the range insert when it turns out to be 2047 // the same thing. Can use fill functions in optimal situations, 2048 // otherwise passes off to insert_aux(p,n,x). 2049 void 2050 _M_fill_insert(iterator __pos, size_type __n, const value_type& __x); 2051 2052 // called by insert(p,x) 2053 #if __cplusplus < 201103L 2054 iterator 2055 _M_insert_aux(iterator __pos, const value_type& __x); 2056 #else 2057 template<typename... _Args> 2058 iterator 2059 _M_insert_aux(iterator __pos, _Args&&... __args); 2060 #endif 2061 2062 // called by insert(p,n,x) via fill_insert 2063 void 2064 _M_insert_aux(iterator __pos, size_type __n, const value_type& __x); 2065 2066 // called by range_insert_aux for forward iterators 2067 template<typename _ForwardIterator> 2068 void 2069 _M_insert_aux(iterator __pos, 2070 _ForwardIterator __first, _ForwardIterator __last, 2071 size_type __n); 2072 2073 2074 // Internal erase functions follow. 2075 2076 void 2077 _M_destroy_data_aux(iterator __first, iterator __last); 2078 2079 // Called by ~deque(). 2080 // NB: Doesn't deallocate the nodes. 2081 template<typename _Alloc1> 2082 void 2083 _M_destroy_data(iterator __first, iterator __last, const _Alloc1&) 2084 { _M_destroy_data_aux(__first, __last); } 2085 2086 void 2087 _M_destroy_data(iterator __first, iterator __last, 2088 const std::allocator<_Tp>&) 2089 { 2090 if (!__has_trivial_destructor(value_type)) 2091 _M_destroy_data_aux(__first, __last); 2092 } 2093 2094 // Called by erase(q1, q2). 2095 void 2096 _M_erase_at_begin(iterator __pos) 2097 { 2098 _M_destroy_data(begin(), __pos, _M_get_Tp_allocator()); 2099 _M_destroy_nodes(this->_M_impl._M_start._M_node, __pos._M_node); 2100 this->_M_impl._M_start = __pos; 2101 } 2102 2103 // Called by erase(q1, q2), resize(), clear(), _M_assign_aux, 2104 // _M_fill_assign, operator=. 2105 void 2106 _M_erase_at_end(iterator __pos) 2107 { 2108 _M_destroy_data(__pos, end(), _M_get_Tp_allocator()); 2109 _M_destroy_nodes(__pos._M_node + 1, 2110 this->_M_impl._M_finish._M_node + 1); 2111 this->_M_impl._M_finish = __pos; 2112 } 2113 2114 iterator 2115 _M_erase(iterator __pos); 2116 2117 iterator 2118 _M_erase(iterator __first, iterator __last); 2119 2120 #if __cplusplus >= 201103L 2121 // Called by resize(sz). 2122 void 2123 _M_default_append(size_type __n); 2124 2125 bool 2126 _M_shrink_to_fit(); 2127 #endif 2128 2129 ///@{ 2130 /// Memory-handling helpers for the previous internal insert functions. 2131 iterator 2132 _M_reserve_elements_at_front(size_type __n) 2133 { 2134 const size_type __vacancies = this->_M_impl._M_start._M_cur 2135 - this->_M_impl._M_start._M_first; 2136 if (__n > __vacancies) 2137 _M_new_elements_at_front(__n - __vacancies); 2138 return this->_M_impl._M_start - difference_type(__n); 2139 } 2140 2141 iterator 2142 _M_reserve_elements_at_back(size_type __n) 2143 { 2144 const size_type __vacancies = (this->_M_impl._M_finish._M_last 2145 - this->_M_impl._M_finish._M_cur) - 1; 2146 if (__n > __vacancies) 2147 _M_new_elements_at_back(__n - __vacancies); 2148 return this->_M_impl._M_finish + difference_type(__n); 2149 } 2150 2151 void 2152 _M_new_elements_at_front(size_type __new_elements); 2153 2154 void 2155 _M_new_elements_at_back(size_type __new_elements); 2156 ///@} 2157 2158 2159 ///@{ 2160 /** 2161 * @brief Memory-handling helpers for the major %map. 2162 * 2163 * Makes sure the _M_map has space for new nodes. Does not 2164 * actually add the nodes. Can invalidate _M_map pointers. 2165 * (And consequently, %deque iterators.) 2166 */ 2167 void 2168 _M_reserve_map_at_back(size_type __nodes_to_add = 1) 2169 { 2170 if (__nodes_to_add + 1 > this->_M_impl._M_map_size 2171 - (this->_M_impl._M_finish._M_node - this->_M_impl._M_map)) 2172 _M_reallocate_map(__nodes_to_add, false); 2173 } 2174 2175 void 2176 _M_reserve_map_at_front(size_type __nodes_to_add = 1) 2177 { 2178 if (__nodes_to_add > size_type(this->_M_impl._M_start._M_node 2179 - this->_M_impl._M_map)) 2180 _M_reallocate_map(__nodes_to_add, true); 2181 } 2182 2183 void 2184 _M_reallocate_map(size_type __nodes_to_add, bool __add_at_front); 2185 ///@} 2186 2187 #if __cplusplus >= 201103L 2188 // Constant-time, nothrow move assignment when source object's memory 2189 // can be moved because the allocators are equal. 2190 void 2191 _M_move_assign1(deque&& __x, /* always equal: */ true_type) noexcept 2192 { 2193 this->_M_impl._M_swap_data(__x._M_impl); 2194 __x.clear(); 2195 std::__alloc_on_move(_M_get_Tp_allocator(), __x._M_get_Tp_allocator()); 2196 } 2197 2198 // When the allocators are not equal the operation could throw, because 2199 // we might need to allocate a new map for __x after moving from it 2200 // or we might need to allocate new elements for *this. 2201 void 2202 _M_move_assign1(deque&& __x, /* always equal: */ false_type) 2203 { 2204 if (_M_get_Tp_allocator() == __x._M_get_Tp_allocator()) 2205 return _M_move_assign1(std::move(__x), true_type()); 2206 2207 constexpr bool __move_storage = 2208 _Alloc_traits::_S_propagate_on_move_assign(); 2209 _M_move_assign2(std::move(__x), __bool_constant<__move_storage>()); 2210 } 2211 2212 // Destroy all elements and deallocate all memory, then replace 2213 // with elements created from __args. 2214 template<typename... _Args> 2215 void 2216 _M_replace_map(_Args&&... __args) 2217 { 2218 // Create new data first, so if allocation fails there are no effects. 2219 deque __newobj(std::forward<_Args>(__args)...); 2220 // Free existing storage using existing allocator. 2221 clear(); 2222 _M_deallocate_node(*begin()._M_node); // one node left after clear() 2223 _M_deallocate_map(this->_M_impl._M_map, this->_M_impl._M_map_size); 2224 this->_M_impl._M_map = nullptr; 2225 this->_M_impl._M_map_size = 0; 2226 // Take ownership of replacement memory. 2227 this->_M_impl._M_swap_data(__newobj._M_impl); 2228 } 2229 2230 // Do move assignment when the allocator propagates. 2231 void 2232 _M_move_assign2(deque&& __x, /* propagate: */ true_type) 2233 { 2234 // Make a copy of the original allocator state. 2235 auto __alloc = __x._M_get_Tp_allocator(); 2236 // The allocator propagates so storage can be moved from __x, 2237 // leaving __x in a valid empty state with a moved-from allocator. 2238 _M_replace_map(std::move(__x)); 2239 // Move the corresponding allocator state too. 2240 _M_get_Tp_allocator() = std::move(__alloc); 2241 } 2242 2243 // Do move assignment when it may not be possible to move source 2244 // object's memory, resulting in a linear-time operation. 2245 void 2246 _M_move_assign2(deque&& __x, /* propagate: */ false_type) 2247 { 2248 if (__x._M_get_Tp_allocator() == this->_M_get_Tp_allocator()) 2249 { 2250 // The allocators are equal so storage can be moved from __x, 2251 // leaving __x in a valid empty state with its current allocator. 2252 _M_replace_map(std::move(__x), __x.get_allocator()); 2253 } 2254 else 2255 { 2256 // The rvalue's allocator cannot be moved and is not equal, 2257 // so we need to individually move each element. 2258 _M_assign_aux(std::make_move_iterator(__x.begin()), 2259 std::make_move_iterator(__x.end()), 2260 std::random_access_iterator_tag()); 2261 __x.clear(); 2262 } 2263 } 2264 #endif 2265 }; 2266 2267 #if __cpp_deduction_guides >= 201606 2268 template<typename _InputIterator, typename _ValT 2269 = typename iterator_traits<_InputIterator>::value_type, 2270 typename _Allocator = allocator<_ValT>, 2271 typename = _RequireInputIter<_InputIterator>, 2272 typename = _RequireAllocator<_Allocator>> 2273 deque(_InputIterator, _InputIterator, _Allocator = _Allocator()) 2274 -> deque<_ValT, _Allocator>; 2275 #endif 2276 2277 /** 2278 * @brief Deque equality comparison. 2279 * @param __x A %deque. 2280 * @param __y A %deque of the same type as @a __x. 2281 * @return True iff the size and elements of the deques are equal. 2282 * 2283 * This is an equivalence relation. It is linear in the size of the 2284 * deques. Deques are considered equivalent if their sizes are equal, 2285 * and if corresponding elements compare equal. 2286 */ 2287 template<typename _Tp, typename _Alloc> 2288 _GLIBCXX_NODISCARD 2289 inline bool 2290 operator==(const deque<_Tp, _Alloc>& __x, const deque<_Tp, _Alloc>& __y) 2291 { return __x.size() == __y.size() 2292 && std::equal(__x.begin(), __x.end(), __y.begin()); } 2293 2294 #if __cpp_lib_three_way_comparison 2295 /** 2296 * @brief Deque ordering relation. 2297 * @param __x A `deque`. 2298 * @param __y A `deque` of the same type as `__x`. 2299 * @return A value indicating whether `__x` is less than, equal to, 2300 * greater than, or incomparable with `__y`. 2301 * 2302 * See `std::lexicographical_compare_three_way()` for how the determination 2303 * is made. This operator is used to synthesize relational operators like 2304 * `<` and `>=` etc. 2305 */ 2306 template<typename _Tp, typename _Alloc> 2307 [[nodiscard]] 2308 inline __detail::__synth3way_t<_Tp> 2309 operator<=>(const deque<_Tp, _Alloc>& __x, const deque<_Tp, _Alloc>& __y) 2310 { 2311 return std::lexicographical_compare_three_way(__x.begin(), __x.end(), 2312 __y.begin(), __y.end(), 2313 __detail::__synth3way); 2314 } 2315 #else 2316 /** 2317 * @brief Deque ordering relation. 2318 * @param __x A %deque. 2319 * @param __y A %deque of the same type as @a __x. 2320 * @return True iff @a x is lexicographically less than @a __y. 2321 * 2322 * This is a total ordering relation. It is linear in the size of the 2323 * deques. The elements must be comparable with @c <. 2324 * 2325 * See std::lexicographical_compare() for how the determination is made. 2326 */ 2327 template<typename _Tp, typename _Alloc> 2328 _GLIBCXX_NODISCARD 2329 inline bool 2330 operator<(const deque<_Tp, _Alloc>& __x, const deque<_Tp, _Alloc>& __y) 2331 { return std::lexicographical_compare(__x.begin(), __x.end(), 2332 __y.begin(), __y.end()); } 2333 2334 /// Based on operator== 2335 template<typename _Tp, typename _Alloc> 2336 _GLIBCXX_NODISCARD 2337 inline bool 2338 operator!=(const deque<_Tp, _Alloc>& __x, const deque<_Tp, _Alloc>& __y) 2339 { return !(__x == __y); } 2340 2341 /// Based on operator< 2342 template<typename _Tp, typename _Alloc> 2343 _GLIBCXX_NODISCARD 2344 inline bool 2345 operator>(const deque<_Tp, _Alloc>& __x, const deque<_Tp, _Alloc>& __y) 2346 { return __y < __x; } 2347 2348 /// Based on operator< 2349 template<typename _Tp, typename _Alloc> 2350 _GLIBCXX_NODISCARD 2351 inline bool 2352 operator<=(const deque<_Tp, _Alloc>& __x, const deque<_Tp, _Alloc>& __y) 2353 { return !(__y < __x); } 2354 2355 /// Based on operator< 2356 template<typename _Tp, typename _Alloc> 2357 _GLIBCXX_NODISCARD 2358 inline bool 2359 operator>=(const deque<_Tp, _Alloc>& __x, const deque<_Tp, _Alloc>& __y) 2360 { return !(__x < __y); } 2361 #endif // three-way comparison 2362 2363 /// See std::deque::swap(). 2364 template<typename _Tp, typename _Alloc> 2365 inline void 2366 swap(deque<_Tp,_Alloc>& __x, deque<_Tp,_Alloc>& __y) 2367 _GLIBCXX_NOEXCEPT_IF(noexcept(__x.swap(__y))) 2368 { __x.swap(__y); } 2369 2370 #undef _GLIBCXX_DEQUE_BUF_SIZE 2371 2372 _GLIBCXX_END_NAMESPACE_CONTAINER 2373 2374 #if __cplusplus >= 201103L 2375 // std::allocator is safe, but it is not the only allocator 2376 // for which this is valid. 2377 template<class _Tp> 2378 struct __is_bitwise_relocatable<_GLIBCXX_STD_C::deque<_Tp>> 2379 : true_type { }; 2380 #endif 2381 2382 _GLIBCXX_END_NAMESPACE_VERSION 2383 } // namespace std 2384 2385 #endif /* _STL_DEQUE_H */
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