1// -*- C++ -*- 2//===----------------------------------------------------------------------===// 3// 4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 5// See https://llvm.org/LICENSE.txt for license information. 6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 7// 8//===----------------------------------------------------------------------===// 9 10#ifndef _LIBCPP___SPLIT_BUFFER 11#define _LIBCPP___SPLIT_BUFFER 12 13#include <__algorithm/max.h> 14#include <__algorithm/move.h> 15#include <__algorithm/move_backward.h> 16#include <__config> 17#include <__iterator/distance.h> 18#include <__iterator/iterator_traits.h> 19#include <__iterator/move_iterator.h> 20#include <__memory/allocator.h> 21#include <__memory/compressed_pair.h> 22#include <__utility/forward.h> 23#include <memory> 24#include <type_traits> 25 26#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 27# pragma GCC system_header 28#endif 29 30_LIBCPP_PUSH_MACROS 31#include <__undef_macros> 32 33 34_LIBCPP_BEGIN_NAMESPACE_STD 35 36template <class _Tp, class _Allocator = allocator<_Tp> > 37struct __split_buffer 38{ 39private: 40 __split_buffer(const __split_buffer&); 41 __split_buffer& operator=(const __split_buffer&); 42public: 43 typedef _Tp value_type; 44 typedef _Allocator allocator_type; 45 typedef typename remove_reference<allocator_type>::type __alloc_rr; 46 typedef allocator_traits<__alloc_rr> __alloc_traits; 47 typedef value_type& reference; 48 typedef const value_type& const_reference; 49 typedef typename __alloc_traits::size_type size_type; 50 typedef typename __alloc_traits::difference_type difference_type; 51 typedef typename __alloc_traits::pointer pointer; 52 typedef typename __alloc_traits::const_pointer const_pointer; 53 typedef pointer iterator; 54 typedef const_pointer const_iterator; 55 56 pointer __first_; 57 pointer __begin_; 58 pointer __end_; 59 __compressed_pair<pointer, allocator_type> __end_cap_; 60 61 typedef typename add_lvalue_reference<allocator_type>::type __alloc_ref; 62 typedef typename add_lvalue_reference<allocator_type>::type __alloc_const_ref; 63 64 _LIBCPP_INLINE_VISIBILITY __alloc_rr& __alloc() _NOEXCEPT {return __end_cap_.second();} 65 _LIBCPP_INLINE_VISIBILITY const __alloc_rr& __alloc() const _NOEXCEPT {return __end_cap_.second();} 66 _LIBCPP_INLINE_VISIBILITY pointer& __end_cap() _NOEXCEPT {return __end_cap_.first();} 67 _LIBCPP_INLINE_VISIBILITY const pointer& __end_cap() const _NOEXCEPT {return __end_cap_.first();} 68 69 _LIBCPP_INLINE_VISIBILITY 70 __split_buffer() 71 _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value); 72 _LIBCPP_INLINE_VISIBILITY 73 explicit __split_buffer(__alloc_rr& __a); 74 _LIBCPP_INLINE_VISIBILITY 75 explicit __split_buffer(const __alloc_rr& __a); 76 __split_buffer(size_type __cap, size_type __start, __alloc_rr& __a); 77 ~__split_buffer(); 78 79 __split_buffer(__split_buffer&& __c) 80 _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value); 81 __split_buffer(__split_buffer&& __c, const __alloc_rr& __a); 82 __split_buffer& operator=(__split_buffer&& __c) 83 _NOEXCEPT_((__alloc_traits::propagate_on_container_move_assignment::value && 84 is_nothrow_move_assignable<allocator_type>::value) || 85 !__alloc_traits::propagate_on_container_move_assignment::value); 86 87 _LIBCPP_INLINE_VISIBILITY iterator begin() _NOEXCEPT {return __begin_;} 88 _LIBCPP_INLINE_VISIBILITY const_iterator begin() const _NOEXCEPT {return __begin_;} 89 _LIBCPP_INLINE_VISIBILITY iterator end() _NOEXCEPT {return __end_;} 90 _LIBCPP_INLINE_VISIBILITY const_iterator end() const _NOEXCEPT {return __end_;} 91 92 _LIBCPP_INLINE_VISIBILITY 93 void clear() _NOEXCEPT 94 {__destruct_at_end(__begin_);} 95 _LIBCPP_INLINE_VISIBILITY size_type size() const {return static_cast<size_type>(__end_ - __begin_);} 96 _LIBCPP_INLINE_VISIBILITY bool empty() const {return __end_ == __begin_;} 97 _LIBCPP_INLINE_VISIBILITY size_type capacity() const {return static_cast<size_type>(__end_cap() - __first_);} 98 _LIBCPP_INLINE_VISIBILITY size_type __front_spare() const {return static_cast<size_type>(__begin_ - __first_);} 99 _LIBCPP_INLINE_VISIBILITY size_type __back_spare() const {return static_cast<size_type>(__end_cap() - __end_);} 100 101 _LIBCPP_INLINE_VISIBILITY reference front() {return *__begin_;} 102 _LIBCPP_INLINE_VISIBILITY const_reference front() const {return *__begin_;} 103 _LIBCPP_INLINE_VISIBILITY reference back() {return *(__end_ - 1);} 104 _LIBCPP_INLINE_VISIBILITY const_reference back() const {return *(__end_ - 1);} 105 106 void reserve(size_type __n); 107 void shrink_to_fit() _NOEXCEPT; 108 void push_front(const_reference __x); 109 _LIBCPP_INLINE_VISIBILITY void push_back(const_reference __x); 110 void push_front(value_type&& __x); 111 void push_back(value_type&& __x); 112 template <class... _Args> 113 void emplace_back(_Args&&... __args); 114 115 _LIBCPP_INLINE_VISIBILITY void pop_front() {__destruct_at_begin(__begin_+1);} 116 _LIBCPP_INLINE_VISIBILITY void pop_back() {__destruct_at_end(__end_-1);} 117 118 void __construct_at_end(size_type __n); 119 void __construct_at_end(size_type __n, const_reference __x); 120 template <class _InputIter> 121 typename enable_if 122 < 123 __is_cpp17_input_iterator<_InputIter>::value && 124 !__is_cpp17_forward_iterator<_InputIter>::value, 125 void 126 >::type 127 __construct_at_end(_InputIter __first, _InputIter __last); 128 template <class _ForwardIterator> 129 typename enable_if 130 < 131 __is_cpp17_forward_iterator<_ForwardIterator>::value, 132 void 133 >::type 134 __construct_at_end(_ForwardIterator __first, _ForwardIterator __last); 135 136 _LIBCPP_INLINE_VISIBILITY void __destruct_at_begin(pointer __new_begin) 137 {__destruct_at_begin(__new_begin, is_trivially_destructible<value_type>());} 138 _LIBCPP_INLINE_VISIBILITY 139 void __destruct_at_begin(pointer __new_begin, false_type); 140 _LIBCPP_INLINE_VISIBILITY 141 void __destruct_at_begin(pointer __new_begin, true_type); 142 143 _LIBCPP_INLINE_VISIBILITY 144 void __destruct_at_end(pointer __new_last) _NOEXCEPT 145 {__destruct_at_end(__new_last, false_type());} 146 _LIBCPP_INLINE_VISIBILITY 147 void __destruct_at_end(pointer __new_last, false_type) _NOEXCEPT; 148 _LIBCPP_INLINE_VISIBILITY 149 void __destruct_at_end(pointer __new_last, true_type) _NOEXCEPT; 150 151 void swap(__split_buffer& __x) 152 _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value|| 153 __is_nothrow_swappable<__alloc_rr>::value); 154 155 bool __invariants() const; 156 157private: 158 _LIBCPP_INLINE_VISIBILITY 159 void __move_assign_alloc(__split_buffer& __c, true_type) 160 _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value) 161 { 162 __alloc() = _VSTD::move(__c.__alloc()); 163 } 164 165 _LIBCPP_INLINE_VISIBILITY 166 void __move_assign_alloc(__split_buffer&, false_type) _NOEXCEPT 167 {} 168 169 struct _ConstructTransaction { 170 explicit _ConstructTransaction(pointer* __p, size_type __n) _NOEXCEPT 171 : __pos_(*__p), __end_(*__p + __n), __dest_(__p) { 172 } 173 ~_ConstructTransaction() { 174 *__dest_ = __pos_; 175 } 176 pointer __pos_; 177 const pointer __end_; 178 private: 179 pointer *__dest_; 180 }; 181}; 182 183template <class _Tp, class _Allocator> 184bool 185__split_buffer<_Tp, _Allocator>::__invariants() const 186{ 187 if (__first_ == nullptr) 188 { 189 if (__begin_ != nullptr) 190 return false; 191 if (__end_ != nullptr) 192 return false; 193 if (__end_cap() != nullptr) 194 return false; 195 } 196 else 197 { 198 if (__begin_ < __first_) 199 return false; 200 if (__end_ < __begin_) 201 return false; 202 if (__end_cap() < __end_) 203 return false; 204 } 205 return true; 206} 207 208// Default constructs __n objects starting at __end_ 209// throws if construction throws 210// Precondition: __n > 0 211// Precondition: size() + __n <= capacity() 212// Postcondition: size() == size() + __n 213template <class _Tp, class _Allocator> 214void 215__split_buffer<_Tp, _Allocator>::__construct_at_end(size_type __n) 216{ 217 _ConstructTransaction __tx(&this->__end_, __n); 218 for (; __tx.__pos_ != __tx.__end_; ++__tx.__pos_) { 219 __alloc_traits::construct(this->__alloc(), _VSTD::__to_address(__tx.__pos_)); 220 } 221} 222 223// Copy constructs __n objects starting at __end_ from __x 224// throws if construction throws 225// Precondition: __n > 0 226// Precondition: size() + __n <= capacity() 227// Postcondition: size() == old size() + __n 228// Postcondition: [i] == __x for all i in [size() - __n, __n) 229template <class _Tp, class _Allocator> 230void 231__split_buffer<_Tp, _Allocator>::__construct_at_end(size_type __n, const_reference __x) 232{ 233 _ConstructTransaction __tx(&this->__end_, __n); 234 for (; __tx.__pos_ != __tx.__end_; ++__tx.__pos_) { 235 __alloc_traits::construct(this->__alloc(), 236 _VSTD::__to_address(__tx.__pos_), __x); 237 } 238} 239 240template <class _Tp, class _Allocator> 241template <class _InputIter> 242typename enable_if 243< 244 __is_cpp17_input_iterator<_InputIter>::value && 245 !__is_cpp17_forward_iterator<_InputIter>::value, 246 void 247>::type 248__split_buffer<_Tp, _Allocator>::__construct_at_end(_InputIter __first, _InputIter __last) 249{ 250 __alloc_rr& __a = this->__alloc(); 251 for (; __first != __last; ++__first) 252 { 253 if (__end_ == __end_cap()) 254 { 255 size_type __old_cap = __end_cap() - __first_; 256 size_type __new_cap = _VSTD::max<size_type>(2 * __old_cap, 8); 257 __split_buffer __buf(__new_cap, 0, __a); 258 for (pointer __p = __begin_; __p != __end_; ++__p, (void) ++__buf.__end_) 259 __alloc_traits::construct(__buf.__alloc(), 260 _VSTD::__to_address(__buf.__end_), _VSTD::move(*__p)); 261 swap(__buf); 262 } 263 __alloc_traits::construct(__a, _VSTD::__to_address(this->__end_), *__first); 264 ++this->__end_; 265 } 266} 267 268template <class _Tp, class _Allocator> 269template <class _ForwardIterator> 270typename enable_if 271< 272 __is_cpp17_forward_iterator<_ForwardIterator>::value, 273 void 274>::type 275__split_buffer<_Tp, _Allocator>::__construct_at_end(_ForwardIterator __first, _ForwardIterator __last) 276{ 277 _ConstructTransaction __tx(&this->__end_, _VSTD::distance(__first, __last)); 278 for (; __tx.__pos_ != __tx.__end_; ++__tx.__pos_, (void) ++__first) { 279 __alloc_traits::construct(this->__alloc(), 280 _VSTD::__to_address(__tx.__pos_), *__first); 281 } 282} 283 284template <class _Tp, class _Allocator> 285inline 286void 287__split_buffer<_Tp, _Allocator>::__destruct_at_begin(pointer __new_begin, false_type) 288{ 289 while (__begin_ != __new_begin) 290 __alloc_traits::destroy(__alloc(), _VSTD::__to_address(__begin_++)); 291} 292 293template <class _Tp, class _Allocator> 294inline 295void 296__split_buffer<_Tp, _Allocator>::__destruct_at_begin(pointer __new_begin, true_type) 297{ 298 __begin_ = __new_begin; 299} 300 301template <class _Tp, class _Allocator> 302inline _LIBCPP_INLINE_VISIBILITY 303void 304__split_buffer<_Tp, _Allocator>::__destruct_at_end(pointer __new_last, false_type) _NOEXCEPT 305{ 306 while (__new_last != __end_) 307 __alloc_traits::destroy(__alloc(), _VSTD::__to_address(--__end_)); 308} 309 310template <class _Tp, class _Allocator> 311inline _LIBCPP_INLINE_VISIBILITY 312void 313__split_buffer<_Tp, _Allocator>::__destruct_at_end(pointer __new_last, true_type) _NOEXCEPT 314{ 315 __end_ = __new_last; 316} 317 318template <class _Tp, class _Allocator> 319__split_buffer<_Tp, _Allocator>::__split_buffer(size_type __cap, size_type __start, __alloc_rr& __a) 320 : __end_cap_(nullptr, __a) 321{ 322 if (__cap == 0) { 323 __first_ = nullptr; 324 } else { 325 auto __allocation = std::__allocate_at_least(__alloc(), __cap); 326 __first_ = __allocation.ptr; 327 __cap = __allocation.count; 328 } 329 __begin_ = __end_ = __first_ + __start; 330 __end_cap() = __first_ + __cap; 331} 332 333template <class _Tp, class _Allocator> 334inline 335__split_buffer<_Tp, _Allocator>::__split_buffer() 336 _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value) 337 : __first_(nullptr), __begin_(nullptr), __end_(nullptr), __end_cap_(nullptr, __default_init_tag()) 338{ 339} 340 341template <class _Tp, class _Allocator> 342inline 343__split_buffer<_Tp, _Allocator>::__split_buffer(__alloc_rr& __a) 344 : __first_(nullptr), __begin_(nullptr), __end_(nullptr), __end_cap_(nullptr, __a) 345{ 346} 347 348template <class _Tp, class _Allocator> 349inline 350__split_buffer<_Tp, _Allocator>::__split_buffer(const __alloc_rr& __a) 351 : __first_(nullptr), __begin_(nullptr), __end_(nullptr), __end_cap_(nullptr, __a) 352{ 353} 354 355template <class _Tp, class _Allocator> 356__split_buffer<_Tp, _Allocator>::~__split_buffer() 357{ 358 clear(); 359 if (__first_) 360 __alloc_traits::deallocate(__alloc(), __first_, capacity()); 361} 362 363template <class _Tp, class _Allocator> 364__split_buffer<_Tp, _Allocator>::__split_buffer(__split_buffer&& __c) 365 _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value) 366 : __first_(_VSTD::move(__c.__first_)), 367 __begin_(_VSTD::move(__c.__begin_)), 368 __end_(_VSTD::move(__c.__end_)), 369 __end_cap_(_VSTD::move(__c.__end_cap_)) 370{ 371 __c.__first_ = nullptr; 372 __c.__begin_ = nullptr; 373 __c.__end_ = nullptr; 374 __c.__end_cap() = nullptr; 375} 376 377template <class _Tp, class _Allocator> 378__split_buffer<_Tp, _Allocator>::__split_buffer(__split_buffer&& __c, const __alloc_rr& __a) 379 : __end_cap_(nullptr, __a) 380{ 381 if (__a == __c.__alloc()) 382 { 383 __first_ = __c.__first_; 384 __begin_ = __c.__begin_; 385 __end_ = __c.__end_; 386 __end_cap() = __c.__end_cap(); 387 __c.__first_ = nullptr; 388 __c.__begin_ = nullptr; 389 __c.__end_ = nullptr; 390 __c.__end_cap() = nullptr; 391 } 392 else 393 { 394 auto __allocation = std::__allocate_at_least(__alloc(), __c.size()); 395 __first_ = __allocation.ptr; 396 __begin_ = __end_ = __first_; 397 __end_cap() = __first_ + __allocation.count; 398 typedef move_iterator<iterator> _Ip; 399 __construct_at_end(_Ip(__c.begin()), _Ip(__c.end())); 400 } 401} 402 403template <class _Tp, class _Allocator> 404__split_buffer<_Tp, _Allocator>& 405__split_buffer<_Tp, _Allocator>::operator=(__split_buffer&& __c) 406 _NOEXCEPT_((__alloc_traits::propagate_on_container_move_assignment::value && 407 is_nothrow_move_assignable<allocator_type>::value) || 408 !__alloc_traits::propagate_on_container_move_assignment::value) 409{ 410 clear(); 411 shrink_to_fit(); 412 __first_ = __c.__first_; 413 __begin_ = __c.__begin_; 414 __end_ = __c.__end_; 415 __end_cap() = __c.__end_cap(); 416 __move_assign_alloc(__c, 417 integral_constant<bool, 418 __alloc_traits::propagate_on_container_move_assignment::value>()); 419 __c.__first_ = __c.__begin_ = __c.__end_ = __c.__end_cap() = nullptr; 420 return *this; 421} 422 423template <class _Tp, class _Allocator> 424void 425__split_buffer<_Tp, _Allocator>::swap(__split_buffer& __x) 426 _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value|| 427 __is_nothrow_swappable<__alloc_rr>::value) 428{ 429 _VSTD::swap(__first_, __x.__first_); 430 _VSTD::swap(__begin_, __x.__begin_); 431 _VSTD::swap(__end_, __x.__end_); 432 _VSTD::swap(__end_cap(), __x.__end_cap()); 433 _VSTD::__swap_allocator(__alloc(), __x.__alloc()); 434} 435 436template <class _Tp, class _Allocator> 437void 438__split_buffer<_Tp, _Allocator>::reserve(size_type __n) 439{ 440 if (__n < capacity()) 441 { 442 __split_buffer<value_type, __alloc_rr&> __t(__n, 0, __alloc()); 443 __t.__construct_at_end(move_iterator<pointer>(__begin_), 444 move_iterator<pointer>(__end_)); 445 _VSTD::swap(__first_, __t.__first_); 446 _VSTD::swap(__begin_, __t.__begin_); 447 _VSTD::swap(__end_, __t.__end_); 448 _VSTD::swap(__end_cap(), __t.__end_cap()); 449 } 450} 451 452template <class _Tp, class _Allocator> 453void 454__split_buffer<_Tp, _Allocator>::shrink_to_fit() _NOEXCEPT 455{ 456 if (capacity() > size()) 457 { 458#ifndef _LIBCPP_NO_EXCEPTIONS 459 try 460 { 461#endif // _LIBCPP_NO_EXCEPTIONS 462 __split_buffer<value_type, __alloc_rr&> __t(size(), 0, __alloc()); 463 __t.__construct_at_end(move_iterator<pointer>(__begin_), 464 move_iterator<pointer>(__end_)); 465 __t.__end_ = __t.__begin_ + (__end_ - __begin_); 466 _VSTD::swap(__first_, __t.__first_); 467 _VSTD::swap(__begin_, __t.__begin_); 468 _VSTD::swap(__end_, __t.__end_); 469 _VSTD::swap(__end_cap(), __t.__end_cap()); 470#ifndef _LIBCPP_NO_EXCEPTIONS 471 } 472 catch (...) 473 { 474 } 475#endif // _LIBCPP_NO_EXCEPTIONS 476 } 477} 478 479template <class _Tp, class _Allocator> 480void 481__split_buffer<_Tp, _Allocator>::push_front(const_reference __x) 482{ 483 if (__begin_ == __first_) 484 { 485 if (__end_ < __end_cap()) 486 { 487 difference_type __d = __end_cap() - __end_; 488 __d = (__d + 1) / 2; 489 __begin_ = _VSTD::move_backward(__begin_, __end_, __end_ + __d); 490 __end_ += __d; 491 } 492 else 493 { 494 size_type __c = max<size_type>(2 * static_cast<size_t>(__end_cap() - __first_), 1); 495 __split_buffer<value_type, __alloc_rr&> __t(__c, (__c + 3) / 4, __alloc()); 496 __t.__construct_at_end(move_iterator<pointer>(__begin_), 497 move_iterator<pointer>(__end_)); 498 _VSTD::swap(__first_, __t.__first_); 499 _VSTD::swap(__begin_, __t.__begin_); 500 _VSTD::swap(__end_, __t.__end_); 501 _VSTD::swap(__end_cap(), __t.__end_cap()); 502 } 503 } 504 __alloc_traits::construct(__alloc(), _VSTD::__to_address(__begin_-1), __x); 505 --__begin_; 506} 507 508template <class _Tp, class _Allocator> 509void 510__split_buffer<_Tp, _Allocator>::push_front(value_type&& __x) 511{ 512 if (__begin_ == __first_) 513 { 514 if (__end_ < __end_cap()) 515 { 516 difference_type __d = __end_cap() - __end_; 517 __d = (__d + 1) / 2; 518 __begin_ = _VSTD::move_backward(__begin_, __end_, __end_ + __d); 519 __end_ += __d; 520 } 521 else 522 { 523 size_type __c = max<size_type>(2 * static_cast<size_t>(__end_cap() - __first_), 1); 524 __split_buffer<value_type, __alloc_rr&> __t(__c, (__c + 3) / 4, __alloc()); 525 __t.__construct_at_end(move_iterator<pointer>(__begin_), 526 move_iterator<pointer>(__end_)); 527 _VSTD::swap(__first_, __t.__first_); 528 _VSTD::swap(__begin_, __t.__begin_); 529 _VSTD::swap(__end_, __t.__end_); 530 _VSTD::swap(__end_cap(), __t.__end_cap()); 531 } 532 } 533 __alloc_traits::construct(__alloc(), _VSTD::__to_address(__begin_-1), 534 _VSTD::move(__x)); 535 --__begin_; 536} 537 538template <class _Tp, class _Allocator> 539inline _LIBCPP_INLINE_VISIBILITY 540void 541__split_buffer<_Tp, _Allocator>::push_back(const_reference __x) 542{ 543 if (__end_ == __end_cap()) 544 { 545 if (__begin_ > __first_) 546 { 547 difference_type __d = __begin_ - __first_; 548 __d = (__d + 1) / 2; 549 __end_ = _VSTD::move(__begin_, __end_, __begin_ - __d); 550 __begin_ -= __d; 551 } 552 else 553 { 554 size_type __c = max<size_type>(2 * static_cast<size_t>(__end_cap() - __first_), 1); 555 __split_buffer<value_type, __alloc_rr&> __t(__c, __c / 4, __alloc()); 556 __t.__construct_at_end(move_iterator<pointer>(__begin_), 557 move_iterator<pointer>(__end_)); 558 _VSTD::swap(__first_, __t.__first_); 559 _VSTD::swap(__begin_, __t.__begin_); 560 _VSTD::swap(__end_, __t.__end_); 561 _VSTD::swap(__end_cap(), __t.__end_cap()); 562 } 563 } 564 __alloc_traits::construct(__alloc(), _VSTD::__to_address(__end_), __x); 565 ++__end_; 566} 567 568template <class _Tp, class _Allocator> 569void 570__split_buffer<_Tp, _Allocator>::push_back(value_type&& __x) 571{ 572 if (__end_ == __end_cap()) 573 { 574 if (__begin_ > __first_) 575 { 576 difference_type __d = __begin_ - __first_; 577 __d = (__d + 1) / 2; 578 __end_ = _VSTD::move(__begin_, __end_, __begin_ - __d); 579 __begin_ -= __d; 580 } 581 else 582 { 583 size_type __c = max<size_type>(2 * static_cast<size_t>(__end_cap() - __first_), 1); 584 __split_buffer<value_type, __alloc_rr&> __t(__c, __c / 4, __alloc()); 585 __t.__construct_at_end(move_iterator<pointer>(__begin_), 586 move_iterator<pointer>(__end_)); 587 _VSTD::swap(__first_, __t.__first_); 588 _VSTD::swap(__begin_, __t.__begin_); 589 _VSTD::swap(__end_, __t.__end_); 590 _VSTD::swap(__end_cap(), __t.__end_cap()); 591 } 592 } 593 __alloc_traits::construct(__alloc(), _VSTD::__to_address(__end_), 594 _VSTD::move(__x)); 595 ++__end_; 596} 597 598template <class _Tp, class _Allocator> 599template <class... _Args> 600void 601__split_buffer<_Tp, _Allocator>::emplace_back(_Args&&... __args) 602{ 603 if (__end_ == __end_cap()) 604 { 605 if (__begin_ > __first_) 606 { 607 difference_type __d = __begin_ - __first_; 608 __d = (__d + 1) / 2; 609 __end_ = _VSTD::move(__begin_, __end_, __begin_ - __d); 610 __begin_ -= __d; 611 } 612 else 613 { 614 size_type __c = max<size_type>(2 * static_cast<size_t>(__end_cap() - __first_), 1); 615 __split_buffer<value_type, __alloc_rr&> __t(__c, __c / 4, __alloc()); 616 __t.__construct_at_end(move_iterator<pointer>(__begin_), 617 move_iterator<pointer>(__end_)); 618 _VSTD::swap(__first_, __t.__first_); 619 _VSTD::swap(__begin_, __t.__begin_); 620 _VSTD::swap(__end_, __t.__end_); 621 _VSTD::swap(__end_cap(), __t.__end_cap()); 622 } 623 } 624 __alloc_traits::construct(__alloc(), _VSTD::__to_address(__end_), 625 _VSTD::forward<_Args>(__args)...); 626 ++__end_; 627} 628 629template <class _Tp, class _Allocator> 630inline _LIBCPP_INLINE_VISIBILITY 631void 632swap(__split_buffer<_Tp, _Allocator>& __x, __split_buffer<_Tp, _Allocator>& __y) 633 _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y))) 634{ 635 __x.swap(__y); 636} 637 638_LIBCPP_END_NAMESPACE_STD 639 640_LIBCPP_POP_MACROS 641 642#endif // _LIBCPP___SPLIT_BUFFER 643