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/allocate_at_least.h> 21#include <__memory/allocator.h> 22#include <__memory/allocator_traits.h> 23#include <__memory/compressed_pair.h> 24#include <__memory/pointer_traits.h> 25#include <__memory/swap_allocator.h> 26#include <__type_traits/add_lvalue_reference.h> 27#include <__type_traits/enable_if.h> 28#include <__type_traits/integral_constant.h> 29#include <__type_traits/is_nothrow_default_constructible.h> 30#include <__type_traits/is_nothrow_move_assignable.h> 31#include <__type_traits/is_nothrow_move_constructible.h> 32#include <__type_traits/is_swappable.h> 33#include <__type_traits/is_trivially_destructible.h> 34#include <__type_traits/remove_reference.h> 35#include <__utility/forward.h> 36#include <__utility/move.h> 37#include <cstddef> 38 39#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 40# pragma GCC system_header 41#endif 42 43_LIBCPP_PUSH_MACROS 44#include <__undef_macros> 45 46 47_LIBCPP_BEGIN_NAMESPACE_STD 48 49// __split_buffer allocates a contiguous chunk of memory and stores objects in the range [__begin_, __end_). 50// It has uninitialized memory in the ranges [__first_, __begin_) and [__end_, __end_cap_.first()). That allows 51// it to grow both in the front and back without having to move the data. 52 53template <class _Tp, class _Allocator = allocator<_Tp> > 54struct __split_buffer 55{ 56public: 57 using value_type = _Tp; 58 using allocator_type = _Allocator; 59 using __alloc_rr = __libcpp_remove_reference_t<allocator_type>; 60 using __alloc_traits = allocator_traits<__alloc_rr>; 61 using reference = value_type&; 62 using const_reference = const value_type&; 63 using size_type = typename __alloc_traits::size_type; 64 using difference_type = typename __alloc_traits::difference_type; 65 using pointer = typename __alloc_traits::pointer; 66 using const_pointer = typename __alloc_traits::const_pointer; 67 using iterator = pointer; 68 using const_iterator = const_pointer; 69 70 pointer __first_; 71 pointer __begin_; 72 pointer __end_; 73 __compressed_pair<pointer, allocator_type> __end_cap_; 74 75 using __alloc_ref = __add_lvalue_reference_t<allocator_type>; 76 using __alloc_const_ref = __add_lvalue_reference_t<allocator_type>; 77 78 __split_buffer(const __split_buffer&) = delete; 79 __split_buffer& operator=(const __split_buffer&) = delete; 80 81 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI __split_buffer() 82 _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value) 83 : __first_(nullptr), __begin_(nullptr), __end_(nullptr), __end_cap_(nullptr, __default_init_tag()) {} 84 85 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI explicit __split_buffer(__alloc_rr& __a) 86 : __first_(nullptr), __begin_(nullptr), __end_(nullptr), __end_cap_(nullptr, __a) {} 87 88 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI explicit __split_buffer(const __alloc_rr& __a) 89 : __first_(nullptr), __begin_(nullptr), __end_(nullptr), __end_cap_(nullptr, __a) {} 90 91 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI 92 __split_buffer(size_type __cap, size_type __start, __alloc_rr& __a); 93 94 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI __split_buffer(__split_buffer&& __c) 95 _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value); 96 97 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI __split_buffer(__split_buffer&& __c, const __alloc_rr& __a); 98 99 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI __split_buffer& operator=(__split_buffer&& __c) 100 _NOEXCEPT_((__alloc_traits::propagate_on_container_move_assignment::value && 101 is_nothrow_move_assignable<allocator_type>::value) || 102 !__alloc_traits::propagate_on_container_move_assignment::value); 103 104 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI ~__split_buffer(); 105 106 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI __alloc_rr& __alloc() _NOEXCEPT { return __end_cap_.second(); } 107 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI const __alloc_rr& __alloc() const _NOEXCEPT { 108 return __end_cap_.second(); 109 } 110 111 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI pointer& __end_cap() _NOEXCEPT { return __end_cap_.first(); } 112 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI const pointer& __end_cap() const _NOEXCEPT { 113 return __end_cap_.first(); 114 } 115 116 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI iterator begin() _NOEXCEPT { return __begin_; } 117 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI const_iterator begin() const _NOEXCEPT { return __begin_; } 118 119 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI iterator end() _NOEXCEPT { return __end_; } 120 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI const_iterator end() const _NOEXCEPT { return __end_; } 121 122 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void clear() _NOEXCEPT { __destruct_at_end(__begin_); } 123 124 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI size_type size() const { 125 return static_cast<size_type>(__end_ - __begin_); 126 } 127 128 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI bool empty() const { return __end_ == __begin_; } 129 130 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI size_type capacity() const { 131 return static_cast<size_type>(__end_cap() - __first_); 132 } 133 134 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI size_type __front_spare() const { 135 return static_cast<size_type>(__begin_ - __first_); 136 } 137 138 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI size_type __back_spare() const { 139 return static_cast<size_type>(__end_cap() - __end_); 140 } 141 142 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI reference front() { return *__begin_; } 143 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI const_reference front() const { return *__begin_; } 144 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI reference back() { return *(__end_ - 1); } 145 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI const_reference back() const { return *(__end_ - 1); } 146 147 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void reserve(size_type __n); 148 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void shrink_to_fit() _NOEXCEPT; 149 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void push_front(const_reference __x); 150 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void push_back(const_reference __x); 151 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void push_front(value_type&& __x); 152 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void push_back(value_type&& __x); 153 154 template <class... _Args> 155 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void emplace_back(_Args&&... __args); 156 157 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void pop_front() { __destruct_at_begin(__begin_ + 1); } 158 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void pop_back() { __destruct_at_end(__end_ - 1); } 159 160 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __construct_at_end(size_type __n); 161 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __construct_at_end(size_type __n, const_reference __x); 162 163 template <class _InputIter> 164 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI 165 __enable_if_t<__is_exactly_cpp17_input_iterator<_InputIter>::value> 166 __construct_at_end(_InputIter __first, _InputIter __last); 167 168 template <class _ForwardIterator> 169 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI 170 __enable_if_t<__is_cpp17_forward_iterator<_ForwardIterator>::value> 171 __construct_at_end(_ForwardIterator __first, _ForwardIterator __last); 172 173 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __destruct_at_begin(pointer __new_begin) { 174 __destruct_at_begin(__new_begin, is_trivially_destructible<value_type>()); 175 } 176 177 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __destruct_at_begin(pointer __new_begin, false_type); 178 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __destruct_at_begin(pointer __new_begin, true_type); 179 180 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __destruct_at_end(pointer __new_last) _NOEXCEPT { 181 __destruct_at_end(__new_last, false_type()); 182 } 183 184 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __destruct_at_end(pointer __new_last, false_type) _NOEXCEPT; 185 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __destruct_at_end(pointer __new_last, true_type) _NOEXCEPT; 186 187 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void swap(__split_buffer& __x) 188 _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value || __is_nothrow_swappable<__alloc_rr>::value); 189 190 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI bool __invariants() const; 191 192private: 193 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __move_assign_alloc(__split_buffer& __c, true_type) 194 _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value) { 195 __alloc() = _VSTD::move(__c.__alloc()); 196 } 197 198 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __move_assign_alloc(__split_buffer&, false_type) _NOEXCEPT {} 199 200 struct _ConstructTransaction { 201 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI explicit _ConstructTransaction( 202 pointer* __p, size_type __n) _NOEXCEPT 203 : __pos_(*__p), 204 __end_(*__p + __n), 205 __dest_(__p) {} 206 207 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI ~_ConstructTransaction() { *__dest_ = __pos_; } 208 209 pointer __pos_; 210 const pointer __end_; 211 212 private: 213 pointer* __dest_; 214 }; 215}; 216 217template <class _Tp, class _Allocator> 218_LIBCPP_CONSTEXPR_SINCE_CXX20 219bool 220__split_buffer<_Tp, _Allocator>::__invariants() const 221{ 222 if (__first_ == nullptr) 223 { 224 if (__begin_ != nullptr) 225 return false; 226 if (__end_ != nullptr) 227 return false; 228 if (__end_cap() != nullptr) 229 return false; 230 } 231 else 232 { 233 if (__begin_ < __first_) 234 return false; 235 if (__end_ < __begin_) 236 return false; 237 if (__end_cap() < __end_) 238 return false; 239 } 240 return true; 241} 242 243// Default constructs __n objects starting at __end_ 244// throws if construction throws 245// Precondition: __n > 0 246// Precondition: size() + __n <= capacity() 247// Postcondition: size() == size() + __n 248template <class _Tp, class _Allocator> 249_LIBCPP_CONSTEXPR_SINCE_CXX20 250void 251__split_buffer<_Tp, _Allocator>::__construct_at_end(size_type __n) 252{ 253 _ConstructTransaction __tx(&this->__end_, __n); 254 for (; __tx.__pos_ != __tx.__end_; ++__tx.__pos_) { 255 __alloc_traits::construct(this->__alloc(), _VSTD::__to_address(__tx.__pos_)); 256 } 257} 258 259// Copy constructs __n objects starting at __end_ from __x 260// throws if construction throws 261// Precondition: __n > 0 262// Precondition: size() + __n <= capacity() 263// Postcondition: size() == old size() + __n 264// Postcondition: [i] == __x for all i in [size() - __n, __n) 265template <class _Tp, class _Allocator> 266_LIBCPP_CONSTEXPR_SINCE_CXX20 267void 268__split_buffer<_Tp, _Allocator>::__construct_at_end(size_type __n, const_reference __x) 269{ 270 _ConstructTransaction __tx(&this->__end_, __n); 271 for (; __tx.__pos_ != __tx.__end_; ++__tx.__pos_) { 272 __alloc_traits::construct(this->__alloc(), 273 _VSTD::__to_address(__tx.__pos_), __x); 274 } 275} 276 277template <class _Tp, class _Allocator> 278template <class _InputIter> 279_LIBCPP_CONSTEXPR_SINCE_CXX20 __enable_if_t<__is_exactly_cpp17_input_iterator<_InputIter>::value> 280__split_buffer<_Tp, _Allocator>::__construct_at_end(_InputIter __first, _InputIter __last) 281{ 282 __alloc_rr& __a = this->__alloc(); 283 for (; __first != __last; ++__first) 284 { 285 if (__end_ == __end_cap()) 286 { 287 size_type __old_cap = __end_cap() - __first_; 288 size_type __new_cap = _VSTD::max<size_type>(2 * __old_cap, 8); 289 __split_buffer __buf(__new_cap, 0, __a); 290 for (pointer __p = __begin_; __p != __end_; ++__p, (void) ++__buf.__end_) 291 __alloc_traits::construct(__buf.__alloc(), 292 _VSTD::__to_address(__buf.__end_), _VSTD::move(*__p)); 293 swap(__buf); 294 } 295 __alloc_traits::construct(__a, _VSTD::__to_address(this->__end_), *__first); 296 ++this->__end_; 297 } 298} 299 300template <class _Tp, class _Allocator> 301template <class _ForwardIterator> 302_LIBCPP_CONSTEXPR_SINCE_CXX20 __enable_if_t<__is_cpp17_forward_iterator<_ForwardIterator>::value> 303__split_buffer<_Tp, _Allocator>::__construct_at_end(_ForwardIterator __first, _ForwardIterator __last) 304{ 305 _ConstructTransaction __tx(&this->__end_, _VSTD::distance(__first, __last)); 306 for (; __tx.__pos_ != __tx.__end_; ++__tx.__pos_, (void) ++__first) { 307 __alloc_traits::construct(this->__alloc(), 308 _VSTD::__to_address(__tx.__pos_), *__first); 309 } 310} 311 312template <class _Tp, class _Allocator> 313_LIBCPP_CONSTEXPR_SINCE_CXX20 314inline 315void 316__split_buffer<_Tp, _Allocator>::__destruct_at_begin(pointer __new_begin, false_type) 317{ 318 while (__begin_ != __new_begin) 319 __alloc_traits::destroy(__alloc(), _VSTD::__to_address(__begin_++)); 320} 321 322template <class _Tp, class _Allocator> 323_LIBCPP_CONSTEXPR_SINCE_CXX20 324inline 325void 326__split_buffer<_Tp, _Allocator>::__destruct_at_begin(pointer __new_begin, true_type) 327{ 328 __begin_ = __new_begin; 329} 330 331template <class _Tp, class _Allocator> 332_LIBCPP_CONSTEXPR_SINCE_CXX20 333inline _LIBCPP_HIDE_FROM_ABI 334void 335__split_buffer<_Tp, _Allocator>::__destruct_at_end(pointer __new_last, false_type) _NOEXCEPT 336{ 337 while (__new_last != __end_) 338 __alloc_traits::destroy(__alloc(), _VSTD::__to_address(--__end_)); 339} 340 341template <class _Tp, class _Allocator> 342_LIBCPP_CONSTEXPR_SINCE_CXX20 343inline _LIBCPP_HIDE_FROM_ABI 344void 345__split_buffer<_Tp, _Allocator>::__destruct_at_end(pointer __new_last, true_type) _NOEXCEPT 346{ 347 __end_ = __new_last; 348} 349 350template <class _Tp, class _Allocator> 351_LIBCPP_CONSTEXPR_SINCE_CXX20 352__split_buffer<_Tp, _Allocator>::__split_buffer(size_type __cap, size_type __start, __alloc_rr& __a) 353 : __end_cap_(nullptr, __a) 354{ 355 if (__cap == 0) { 356 __first_ = nullptr; 357 } else { 358 auto __allocation = std::__allocate_at_least(__alloc(), __cap); 359 __first_ = __allocation.ptr; 360 __cap = __allocation.count; 361 } 362 __begin_ = __end_ = __first_ + __start; 363 __end_cap() = __first_ + __cap; 364} 365 366template <class _Tp, class _Allocator> 367_LIBCPP_CONSTEXPR_SINCE_CXX20 368__split_buffer<_Tp, _Allocator>::~__split_buffer() 369{ 370 clear(); 371 if (__first_) 372 __alloc_traits::deallocate(__alloc(), __first_, capacity()); 373} 374 375template <class _Tp, class _Allocator> 376_LIBCPP_CONSTEXPR_SINCE_CXX20 377__split_buffer<_Tp, _Allocator>::__split_buffer(__split_buffer&& __c) 378 _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value) 379 : __first_(_VSTD::move(__c.__first_)), 380 __begin_(_VSTD::move(__c.__begin_)), 381 __end_(_VSTD::move(__c.__end_)), 382 __end_cap_(_VSTD::move(__c.__end_cap_)) 383{ 384 __c.__first_ = nullptr; 385 __c.__begin_ = nullptr; 386 __c.__end_ = nullptr; 387 __c.__end_cap() = nullptr; 388} 389 390template <class _Tp, class _Allocator> 391_LIBCPP_CONSTEXPR_SINCE_CXX20 392__split_buffer<_Tp, _Allocator>::__split_buffer(__split_buffer&& __c, const __alloc_rr& __a) 393 : __end_cap_(nullptr, __a) 394{ 395 if (__a == __c.__alloc()) 396 { 397 __first_ = __c.__first_; 398 __begin_ = __c.__begin_; 399 __end_ = __c.__end_; 400 __end_cap() = __c.__end_cap(); 401 __c.__first_ = nullptr; 402 __c.__begin_ = nullptr; 403 __c.__end_ = nullptr; 404 __c.__end_cap() = nullptr; 405 } 406 else 407 { 408 auto __allocation = std::__allocate_at_least(__alloc(), __c.size()); 409 __first_ = __allocation.ptr; 410 __begin_ = __end_ = __first_; 411 __end_cap() = __first_ + __allocation.count; 412 typedef move_iterator<iterator> _Ip; 413 __construct_at_end(_Ip(__c.begin()), _Ip(__c.end())); 414 } 415} 416 417template <class _Tp, class _Allocator> 418_LIBCPP_CONSTEXPR_SINCE_CXX20 419__split_buffer<_Tp, _Allocator>& 420__split_buffer<_Tp, _Allocator>::operator=(__split_buffer&& __c) 421 _NOEXCEPT_((__alloc_traits::propagate_on_container_move_assignment::value && 422 is_nothrow_move_assignable<allocator_type>::value) || 423 !__alloc_traits::propagate_on_container_move_assignment::value) 424{ 425 clear(); 426 shrink_to_fit(); 427 __first_ = __c.__first_; 428 __begin_ = __c.__begin_; 429 __end_ = __c.__end_; 430 __end_cap() = __c.__end_cap(); 431 __move_assign_alloc(__c, 432 integral_constant<bool, 433 __alloc_traits::propagate_on_container_move_assignment::value>()); 434 __c.__first_ = __c.__begin_ = __c.__end_ = __c.__end_cap() = nullptr; 435 return *this; 436} 437 438template <class _Tp, class _Allocator> 439_LIBCPP_CONSTEXPR_SINCE_CXX20 440void 441__split_buffer<_Tp, _Allocator>::swap(__split_buffer& __x) 442 _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value|| 443 __is_nothrow_swappable<__alloc_rr>::value) 444{ 445 _VSTD::swap(__first_, __x.__first_); 446 _VSTD::swap(__begin_, __x.__begin_); 447 _VSTD::swap(__end_, __x.__end_); 448 _VSTD::swap(__end_cap(), __x.__end_cap()); 449 _VSTD::__swap_allocator(__alloc(), __x.__alloc()); 450} 451 452template <class _Tp, class _Allocator> 453_LIBCPP_CONSTEXPR_SINCE_CXX20 454void 455__split_buffer<_Tp, _Allocator>::reserve(size_type __n) 456{ 457 if (__n < capacity()) 458 { 459 __split_buffer<value_type, __alloc_rr&> __t(__n, 0, __alloc()); 460 __t.__construct_at_end(move_iterator<pointer>(__begin_), 461 move_iterator<pointer>(__end_)); 462 _VSTD::swap(__first_, __t.__first_); 463 _VSTD::swap(__begin_, __t.__begin_); 464 _VSTD::swap(__end_, __t.__end_); 465 _VSTD::swap(__end_cap(), __t.__end_cap()); 466 } 467} 468 469template <class _Tp, class _Allocator> 470_LIBCPP_CONSTEXPR_SINCE_CXX20 471void 472__split_buffer<_Tp, _Allocator>::shrink_to_fit() _NOEXCEPT 473{ 474 if (capacity() > size()) 475 { 476#ifndef _LIBCPP_HAS_NO_EXCEPTIONS 477 try 478 { 479#endif // _LIBCPP_HAS_NO_EXCEPTIONS 480 __split_buffer<value_type, __alloc_rr&> __t(size(), 0, __alloc()); 481 __t.__construct_at_end(move_iterator<pointer>(__begin_), 482 move_iterator<pointer>(__end_)); 483 __t.__end_ = __t.__begin_ + (__end_ - __begin_); 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#ifndef _LIBCPP_HAS_NO_EXCEPTIONS 489 } 490 catch (...) 491 { 492 } 493#endif // _LIBCPP_HAS_NO_EXCEPTIONS 494 } 495} 496 497template <class _Tp, class _Allocator> 498_LIBCPP_CONSTEXPR_SINCE_CXX20 499void 500__split_buffer<_Tp, _Allocator>::push_front(const_reference __x) 501{ 502 if (__begin_ == __first_) 503 { 504 if (__end_ < __end_cap()) 505 { 506 difference_type __d = __end_cap() - __end_; 507 __d = (__d + 1) / 2; 508 __begin_ = _VSTD::move_backward(__begin_, __end_, __end_ + __d); 509 __end_ += __d; 510 } 511 else 512 { 513 size_type __c = std::max<size_type>(2 * static_cast<size_t>(__end_cap() - __first_), 1); 514 __split_buffer<value_type, __alloc_rr&> __t(__c, (__c + 3) / 4, __alloc()); 515 __t.__construct_at_end(move_iterator<pointer>(__begin_), 516 move_iterator<pointer>(__end_)); 517 _VSTD::swap(__first_, __t.__first_); 518 _VSTD::swap(__begin_, __t.__begin_); 519 _VSTD::swap(__end_, __t.__end_); 520 _VSTD::swap(__end_cap(), __t.__end_cap()); 521 } 522 } 523 __alloc_traits::construct(__alloc(), _VSTD::__to_address(__begin_-1), __x); 524 --__begin_; 525} 526 527template <class _Tp, class _Allocator> 528_LIBCPP_CONSTEXPR_SINCE_CXX20 529void 530__split_buffer<_Tp, _Allocator>::push_front(value_type&& __x) 531{ 532 if (__begin_ == __first_) 533 { 534 if (__end_ < __end_cap()) 535 { 536 difference_type __d = __end_cap() - __end_; 537 __d = (__d + 1) / 2; 538 __begin_ = _VSTD::move_backward(__begin_, __end_, __end_ + __d); 539 __end_ += __d; 540 } 541 else 542 { 543 size_type __c = std::max<size_type>(2 * static_cast<size_t>(__end_cap() - __first_), 1); 544 __split_buffer<value_type, __alloc_rr&> __t(__c, (__c + 3) / 4, __alloc()); 545 __t.__construct_at_end(move_iterator<pointer>(__begin_), 546 move_iterator<pointer>(__end_)); 547 _VSTD::swap(__first_, __t.__first_); 548 _VSTD::swap(__begin_, __t.__begin_); 549 _VSTD::swap(__end_, __t.__end_); 550 _VSTD::swap(__end_cap(), __t.__end_cap()); 551 } 552 } 553 __alloc_traits::construct(__alloc(), _VSTD::__to_address(__begin_-1), 554 _VSTD::move(__x)); 555 --__begin_; 556} 557 558template <class _Tp, class _Allocator> 559_LIBCPP_CONSTEXPR_SINCE_CXX20 560inline _LIBCPP_HIDE_FROM_ABI 561void 562__split_buffer<_Tp, _Allocator>::push_back(const_reference __x) 563{ 564 if (__end_ == __end_cap()) 565 { 566 if (__begin_ > __first_) 567 { 568 difference_type __d = __begin_ - __first_; 569 __d = (__d + 1) / 2; 570 __end_ = _VSTD::move(__begin_, __end_, __begin_ - __d); 571 __begin_ -= __d; 572 } 573 else 574 { 575 size_type __c = std::max<size_type>(2 * static_cast<size_t>(__end_cap() - __first_), 1); 576 __split_buffer<value_type, __alloc_rr&> __t(__c, __c / 4, __alloc()); 577 __t.__construct_at_end(move_iterator<pointer>(__begin_), 578 move_iterator<pointer>(__end_)); 579 _VSTD::swap(__first_, __t.__first_); 580 _VSTD::swap(__begin_, __t.__begin_); 581 _VSTD::swap(__end_, __t.__end_); 582 _VSTD::swap(__end_cap(), __t.__end_cap()); 583 } 584 } 585 __alloc_traits::construct(__alloc(), _VSTD::__to_address(__end_), __x); 586 ++__end_; 587} 588 589template <class _Tp, class _Allocator> 590_LIBCPP_CONSTEXPR_SINCE_CXX20 591void 592__split_buffer<_Tp, _Allocator>::push_back(value_type&& __x) 593{ 594 if (__end_ == __end_cap()) 595 { 596 if (__begin_ > __first_) 597 { 598 difference_type __d = __begin_ - __first_; 599 __d = (__d + 1) / 2; 600 __end_ = _VSTD::move(__begin_, __end_, __begin_ - __d); 601 __begin_ -= __d; 602 } 603 else 604 { 605 size_type __c = std::max<size_type>(2 * static_cast<size_t>(__end_cap() - __first_), 1); 606 __split_buffer<value_type, __alloc_rr&> __t(__c, __c / 4, __alloc()); 607 __t.__construct_at_end(move_iterator<pointer>(__begin_), 608 move_iterator<pointer>(__end_)); 609 _VSTD::swap(__first_, __t.__first_); 610 _VSTD::swap(__begin_, __t.__begin_); 611 _VSTD::swap(__end_, __t.__end_); 612 _VSTD::swap(__end_cap(), __t.__end_cap()); 613 } 614 } 615 __alloc_traits::construct(__alloc(), _VSTD::__to_address(__end_), 616 _VSTD::move(__x)); 617 ++__end_; 618} 619 620template <class _Tp, class _Allocator> 621template <class... _Args> 622_LIBCPP_CONSTEXPR_SINCE_CXX20 623void 624__split_buffer<_Tp, _Allocator>::emplace_back(_Args&&... __args) 625{ 626 if (__end_ == __end_cap()) 627 { 628 if (__begin_ > __first_) 629 { 630 difference_type __d = __begin_ - __first_; 631 __d = (__d + 1) / 2; 632 __end_ = _VSTD::move(__begin_, __end_, __begin_ - __d); 633 __begin_ -= __d; 634 } 635 else 636 { 637 size_type __c = std::max<size_type>(2 * static_cast<size_t>(__end_cap() - __first_), 1); 638 __split_buffer<value_type, __alloc_rr&> __t(__c, __c / 4, __alloc()); 639 __t.__construct_at_end(move_iterator<pointer>(__begin_), 640 move_iterator<pointer>(__end_)); 641 _VSTD::swap(__first_, __t.__first_); 642 _VSTD::swap(__begin_, __t.__begin_); 643 _VSTD::swap(__end_, __t.__end_); 644 _VSTD::swap(__end_cap(), __t.__end_cap()); 645 } 646 } 647 __alloc_traits::construct(__alloc(), _VSTD::__to_address(__end_), 648 _VSTD::forward<_Args>(__args)...); 649 ++__end_; 650} 651 652template <class _Tp, class _Allocator> 653_LIBCPP_CONSTEXPR_SINCE_CXX20 654inline _LIBCPP_HIDE_FROM_ABI 655void 656swap(__split_buffer<_Tp, _Allocator>& __x, __split_buffer<_Tp, _Allocator>& __y) 657 _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y))) 658{ 659 __x.swap(__y); 660} 661 662_LIBCPP_END_NAMESPACE_STD 663 664_LIBCPP_POP_MACROS 665 666#endif // _LIBCPP___SPLIT_BUFFER 667