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