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_LIBCPP_BEGIN_NAMESPACE_STD 47 48// __split_buffer allocates a contiguous chunk of memory and stores objects in the range [__begin_, __end_). 49// It has uninitialized memory in the ranges [__first_, __begin_) and [__end_, __end_cap_.first()). That allows 50// it to grow both in the front and back without having to move the data. 51 52template <class _Tp, class _Allocator = allocator<_Tp> > 53struct __split_buffer { 54public: 55 using value_type = _Tp; 56 using allocator_type = _Allocator; 57 using __alloc_rr = __libcpp_remove_reference_t<allocator_type>; 58 using __alloc_traits = allocator_traits<__alloc_rr>; 59 using reference = value_type&; 60 using const_reference = const value_type&; 61 using size_type = typename __alloc_traits::size_type; 62 using difference_type = typename __alloc_traits::difference_type; 63 using pointer = typename __alloc_traits::pointer; 64 using const_pointer = typename __alloc_traits::const_pointer; 65 using iterator = pointer; 66 using const_iterator = const_pointer; 67 68 pointer __first_; 69 pointer __begin_; 70 pointer __end_; 71 __compressed_pair<pointer, allocator_type> __end_cap_; 72 73 using __alloc_ref = __add_lvalue_reference_t<allocator_type>; 74 using __alloc_const_ref = __add_lvalue_reference_t<allocator_type>; 75 76 __split_buffer(const __split_buffer&) = delete; 77 __split_buffer& operator=(const __split_buffer&) = delete; 78 79 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI __split_buffer() 80 _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value) 81 : __first_(nullptr), __begin_(nullptr), __end_(nullptr), __end_cap_(nullptr, __default_init_tag()) {} 82 83 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI explicit __split_buffer(__alloc_rr& __a) 84 : __first_(nullptr), __begin_(nullptr), __end_(nullptr), __end_cap_(nullptr, __a) {} 85 86 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI explicit __split_buffer(const __alloc_rr& __a) 87 : __first_(nullptr), __begin_(nullptr), __end_(nullptr), __end_cap_(nullptr, __a) {} 88 89 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI 90 __split_buffer(size_type __cap, size_type __start, __alloc_rr& __a); 91 92 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI __split_buffer(__split_buffer&& __c) 93 _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value); 94 95 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI __split_buffer(__split_buffer&& __c, const __alloc_rr& __a); 96 97 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI __split_buffer& operator=(__split_buffer&& __c) 98 _NOEXCEPT_((__alloc_traits::propagate_on_container_move_assignment::value && 99 is_nothrow_move_assignable<allocator_type>::value) || 100 !__alloc_traits::propagate_on_container_move_assignment::value); 101 102 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI ~__split_buffer(); 103 104 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI __alloc_rr& __alloc() _NOEXCEPT { return __end_cap_.second(); } 105 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI const __alloc_rr& __alloc() const _NOEXCEPT { 106 return __end_cap_.second(); 107 } 108 109 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI pointer& __end_cap() _NOEXCEPT { return __end_cap_.first(); } 110 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI const pointer& __end_cap() const _NOEXCEPT { 111 return __end_cap_.first(); 112 } 113 114 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI iterator begin() _NOEXCEPT { return __begin_; } 115 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI const_iterator begin() const _NOEXCEPT { return __begin_; } 116 117 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI iterator end() _NOEXCEPT { return __end_; } 118 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI const_iterator end() const _NOEXCEPT { return __end_; } 119 120 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void clear() _NOEXCEPT { __destruct_at_end(__begin_); } 121 122 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI size_type size() const { 123 return static_cast<size_type>(__end_ - __begin_); 124 } 125 126 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI bool empty() const { return __end_ == __begin_; } 127 128 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI size_type capacity() const { 129 return static_cast<size_type>(__end_cap() - __first_); 130 } 131 132 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI size_type __front_spare() const { 133 return static_cast<size_type>(__begin_ - __first_); 134 } 135 136 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI size_type __back_spare() const { 137 return static_cast<size_type>(__end_cap() - __end_); 138 } 139 140 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI reference front() { return *__begin_; } 141 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI const_reference front() const { return *__begin_; } 142 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI reference back() { return *(__end_ - 1); } 143 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI const_reference back() const { return *(__end_ - 1); } 144 145 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void reserve(size_type __n); 146 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void shrink_to_fit() _NOEXCEPT; 147 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void push_front(const_reference __x); 148 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void push_back(const_reference __x); 149 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void push_front(value_type&& __x); 150 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void push_back(value_type&& __x); 151 152 template <class... _Args> 153 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void emplace_back(_Args&&... __args); 154 155 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void pop_front() { __destruct_at_begin(__begin_ + 1); } 156 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void pop_back() { __destruct_at_end(__end_ - 1); } 157 158 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __construct_at_end(size_type __n); 159 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __construct_at_end(size_type __n, const_reference __x); 160 161 template <class _InputIter, __enable_if_t<__has_exactly_input_iterator_category<_InputIter>::value, int> = 0> 162 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __construct_at_end(_InputIter __first, _InputIter __last); 163 164 template <class _ForwardIterator, __enable_if_t<__has_forward_iterator_category<_ForwardIterator>::value, int> = 0> 165 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void 166 __construct_at_end(_ForwardIterator __first, _ForwardIterator __last); 167 168 template <class _Iterator, class _Sentinel> 169 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void 170 __construct_at_end_with_sentinel(_Iterator __first, _Sentinel __last); 171 172 template <class _Iterator> 173 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void 174 __construct_at_end_with_size(_Iterator __first, size_type __n); 175 176 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __destruct_at_begin(pointer __new_begin) { 177 __destruct_at_begin(__new_begin, is_trivially_destructible<value_type>()); 178 } 179 180 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __destruct_at_begin(pointer __new_begin, false_type); 181 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __destruct_at_begin(pointer __new_begin, true_type); 182 183 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __destruct_at_end(pointer __new_last) _NOEXCEPT { 184 __destruct_at_end(__new_last, false_type()); 185 } 186 187 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __destruct_at_end(pointer __new_last, false_type) _NOEXCEPT; 188 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __destruct_at_end(pointer __new_last, true_type) _NOEXCEPT; 189 190 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void swap(__split_buffer& __x) 191 _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value || __is_nothrow_swappable<__alloc_rr>::value); 192 193 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI bool __invariants() const; 194 195private: 196 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __move_assign_alloc(__split_buffer& __c, true_type) 197 _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value) { 198 __alloc() = std::move(__c.__alloc()); 199 } 200 201 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __move_assign_alloc(__split_buffer&, false_type) _NOEXCEPT {} 202 203 struct _ConstructTransaction { 204 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI explicit _ConstructTransaction( 205 pointer* __p, size_type __n) _NOEXCEPT 206 : __pos_(*__p), 207 __end_(*__p + __n), 208 __dest_(__p) {} 209 210 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI ~_ConstructTransaction() { *__dest_ = __pos_; } 211 212 pointer __pos_; 213 const pointer __end_; 214 215 private: 216 pointer* __dest_; 217 }; 218}; 219 220template <class _Tp, class _Allocator> 221_LIBCPP_CONSTEXPR_SINCE_CXX20 bool __split_buffer<_Tp, _Allocator>::__invariants() const { 222 if (__first_ == nullptr) { 223 if (__begin_ != nullptr) 224 return false; 225 if (__end_ != nullptr) 226 return false; 227 if (__end_cap() != nullptr) 228 return false; 229 } else { 230 if (__begin_ < __first_) 231 return false; 232 if (__end_ < __begin_) 233 return false; 234 if (__end_cap() < __end_) 235 return false; 236 } 237 return true; 238} 239 240// Default constructs __n objects starting at __end_ 241// throws if construction throws 242// Precondition: __n > 0 243// Precondition: size() + __n <= capacity() 244// Postcondition: size() == size() + __n 245template <class _Tp, class _Allocator> 246_LIBCPP_CONSTEXPR_SINCE_CXX20 void __split_buffer<_Tp, _Allocator>::__construct_at_end(size_type __n) { 247 _ConstructTransaction __tx(&this->__end_, __n); 248 for (; __tx.__pos_ != __tx.__end_; ++__tx.__pos_) { 249 __alloc_traits::construct(this->__alloc(), std::__to_address(__tx.__pos_)); 250 } 251} 252 253// Copy constructs __n objects starting at __end_ from __x 254// throws if construction throws 255// Precondition: __n > 0 256// Precondition: size() + __n <= capacity() 257// Postcondition: size() == old size() + __n 258// Postcondition: [i] == __x for all i in [size() - __n, __n) 259template <class _Tp, class _Allocator> 260_LIBCPP_CONSTEXPR_SINCE_CXX20 void 261__split_buffer<_Tp, _Allocator>::__construct_at_end(size_type __n, const_reference __x) { 262 _ConstructTransaction __tx(&this->__end_, __n); 263 for (; __tx.__pos_ != __tx.__end_; ++__tx.__pos_) { 264 __alloc_traits::construct(this->__alloc(), std::__to_address(__tx.__pos_), __x); 265 } 266} 267 268template <class _Tp, class _Allocator> 269template <class _InputIter, __enable_if_t<__has_exactly_input_iterator_category<_InputIter>::value, int> > 270_LIBCPP_CONSTEXPR_SINCE_CXX20 void 271__split_buffer<_Tp, _Allocator>::__construct_at_end(_InputIter __first, _InputIter __last) { 272 __construct_at_end_with_sentinel(__first, __last); 273} 274 275template <class _Tp, class _Allocator> 276template <class _Iterator, class _Sentinel> 277_LIBCPP_CONSTEXPR_SINCE_CXX20 void 278__split_buffer<_Tp, _Allocator>::__construct_at_end_with_sentinel(_Iterator __first, _Sentinel __last) { 279 __alloc_rr& __a = this->__alloc(); 280 for (; __first != __last; ++__first) { 281 if (__end_ == __end_cap()) { 282 size_type __old_cap = __end_cap() - __first_; 283 size_type __new_cap = std::max<size_type>(2 * __old_cap, 8); 284 __split_buffer __buf(__new_cap, 0, __a); 285 for (pointer __p = __begin_; __p != __end_; ++__p, (void)++__buf.__end_) 286 __alloc_traits::construct(__buf.__alloc(), std::__to_address(__buf.__end_), std::move(*__p)); 287 swap(__buf); 288 } 289 __alloc_traits::construct(__a, std::__to_address(this->__end_), *__first); 290 ++this->__end_; 291 } 292} 293template <class _Tp, class _Allocator> 294template <class _ForwardIterator, __enable_if_t<__has_forward_iterator_category<_ForwardIterator>::value, int> > 295_LIBCPP_CONSTEXPR_SINCE_CXX20 void 296__split_buffer<_Tp, _Allocator>::__construct_at_end(_ForwardIterator __first, _ForwardIterator __last) { 297 __construct_at_end_with_size(__first, std::distance(__first, __last)); 298} 299 300template <class _Tp, class _Allocator> 301template <class _ForwardIterator> 302_LIBCPP_CONSTEXPR_SINCE_CXX20 void 303__split_buffer<_Tp, _Allocator>::__construct_at_end_with_size(_ForwardIterator __first, size_type __n) { 304 _ConstructTransaction __tx(&this->__end_, __n); 305 for (; __tx.__pos_ != __tx.__end_; ++__tx.__pos_, (void)++__first) { 306 __alloc_traits::construct(this->__alloc(), std::__to_address(__tx.__pos_), *__first); 307 } 308} 309 310template <class _Tp, class _Allocator> 311_LIBCPP_CONSTEXPR_SINCE_CXX20 inline void 312__split_buffer<_Tp, _Allocator>::__destruct_at_begin(pointer __new_begin, false_type) { 313 while (__begin_ != __new_begin) 314 __alloc_traits::destroy(__alloc(), std::__to_address(__begin_++)); 315} 316 317template <class _Tp, class _Allocator> 318_LIBCPP_CONSTEXPR_SINCE_CXX20 inline void 319__split_buffer<_Tp, _Allocator>::__destruct_at_begin(pointer __new_begin, true_type) { 320 __begin_ = __new_begin; 321} 322 323template <class _Tp, class _Allocator> 324_LIBCPP_CONSTEXPR_SINCE_CXX20 inline _LIBCPP_HIDE_FROM_ABI void 325__split_buffer<_Tp, _Allocator>::__destruct_at_end(pointer __new_last, false_type) _NOEXCEPT { 326 while (__new_last != __end_) 327 __alloc_traits::destroy(__alloc(), std::__to_address(--__end_)); 328} 329 330template <class _Tp, class _Allocator> 331_LIBCPP_CONSTEXPR_SINCE_CXX20 inline _LIBCPP_HIDE_FROM_ABI void 332__split_buffer<_Tp, _Allocator>::__destruct_at_end(pointer __new_last, true_type) _NOEXCEPT { 333 __end_ = __new_last; 334} 335 336template <class _Tp, class _Allocator> 337_LIBCPP_CONSTEXPR_SINCE_CXX20 338__split_buffer<_Tp, _Allocator>::__split_buffer(size_type __cap, size_type __start, __alloc_rr& __a) 339 : __end_cap_(nullptr, __a) { 340 if (__cap == 0) { 341 __first_ = nullptr; 342 } else { 343 auto __allocation = std::__allocate_at_least(__alloc(), __cap); 344 __first_ = __allocation.ptr; 345 __cap = __allocation.count; 346 } 347 __begin_ = __end_ = __first_ + __start; 348 __end_cap() = __first_ + __cap; 349} 350 351template <class _Tp, class _Allocator> 352_LIBCPP_CONSTEXPR_SINCE_CXX20 __split_buffer<_Tp, _Allocator>::~__split_buffer() { 353 clear(); 354 if (__first_) 355 __alloc_traits::deallocate(__alloc(), __first_, capacity()); 356} 357 358template <class _Tp, class _Allocator> 359_LIBCPP_CONSTEXPR_SINCE_CXX20 __split_buffer<_Tp, _Allocator>::__split_buffer(__split_buffer&& __c) 360 _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value) 361 : __first_(std::move(__c.__first_)), 362 __begin_(std::move(__c.__begin_)), 363 __end_(std::move(__c.__end_)), 364 __end_cap_(std::move(__c.__end_cap_)) { 365 __c.__first_ = nullptr; 366 __c.__begin_ = nullptr; 367 __c.__end_ = nullptr; 368 __c.__end_cap() = nullptr; 369} 370 371template <class _Tp, class _Allocator> 372_LIBCPP_CONSTEXPR_SINCE_CXX20 373__split_buffer<_Tp, _Allocator>::__split_buffer(__split_buffer&& __c, const __alloc_rr& __a) 374 : __end_cap_(nullptr, __a) { 375 if (__a == __c.__alloc()) { 376 __first_ = __c.__first_; 377 __begin_ = __c.__begin_; 378 __end_ = __c.__end_; 379 __end_cap() = __c.__end_cap(); 380 __c.__first_ = nullptr; 381 __c.__begin_ = nullptr; 382 __c.__end_ = nullptr; 383 __c.__end_cap() = nullptr; 384 } else { 385 auto __allocation = std::__allocate_at_least(__alloc(), __c.size()); 386 __first_ = __allocation.ptr; 387 __begin_ = __end_ = __first_; 388 __end_cap() = __first_ + __allocation.count; 389 typedef move_iterator<iterator> _Ip; 390 __construct_at_end(_Ip(__c.begin()), _Ip(__c.end())); 391 } 392} 393 394template <class _Tp, class _Allocator> 395_LIBCPP_CONSTEXPR_SINCE_CXX20 __split_buffer<_Tp, _Allocator>& 396__split_buffer<_Tp, _Allocator>::operator=(__split_buffer&& __c) 397 _NOEXCEPT_((__alloc_traits::propagate_on_container_move_assignment::value && 398 is_nothrow_move_assignable<allocator_type>::value) || 399 !__alloc_traits::propagate_on_container_move_assignment::value) { 400 clear(); 401 shrink_to_fit(); 402 __first_ = __c.__first_; 403 __begin_ = __c.__begin_; 404 __end_ = __c.__end_; 405 __end_cap() = __c.__end_cap(); 406 __move_assign_alloc(__c, integral_constant<bool, __alloc_traits::propagate_on_container_move_assignment::value>()); 407 __c.__first_ = __c.__begin_ = __c.__end_ = __c.__end_cap() = nullptr; 408 return *this; 409} 410 411template <class _Tp, class _Allocator> 412_LIBCPP_CONSTEXPR_SINCE_CXX20 void __split_buffer<_Tp, _Allocator>::swap(__split_buffer& __x) 413 _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value || __is_nothrow_swappable<__alloc_rr>::value) { 414 std::swap(__first_, __x.__first_); 415 std::swap(__begin_, __x.__begin_); 416 std::swap(__end_, __x.__end_); 417 std::swap(__end_cap(), __x.__end_cap()); 418 std::__swap_allocator(__alloc(), __x.__alloc()); 419} 420 421template <class _Tp, class _Allocator> 422_LIBCPP_CONSTEXPR_SINCE_CXX20 void __split_buffer<_Tp, _Allocator>::reserve(size_type __n) { 423 if (__n < capacity()) { 424 __split_buffer<value_type, __alloc_rr&> __t(__n, 0, __alloc()); 425 __t.__construct_at_end(move_iterator<pointer>(__begin_), move_iterator<pointer>(__end_)); 426 std::swap(__first_, __t.__first_); 427 std::swap(__begin_, __t.__begin_); 428 std::swap(__end_, __t.__end_); 429 std::swap(__end_cap(), __t.__end_cap()); 430 } 431} 432 433template <class _Tp, class _Allocator> 434_LIBCPP_CONSTEXPR_SINCE_CXX20 void __split_buffer<_Tp, _Allocator>::shrink_to_fit() _NOEXCEPT { 435 if (capacity() > size()) { 436#ifndef _LIBCPP_HAS_NO_EXCEPTIONS 437 try { 438#endif // _LIBCPP_HAS_NO_EXCEPTIONS 439 __split_buffer<value_type, __alloc_rr&> __t(size(), 0, __alloc()); 440 __t.__construct_at_end(move_iterator<pointer>(__begin_), move_iterator<pointer>(__end_)); 441 __t.__end_ = __t.__begin_ + (__end_ - __begin_); 442 std::swap(__first_, __t.__first_); 443 std::swap(__begin_, __t.__begin_); 444 std::swap(__end_, __t.__end_); 445 std::swap(__end_cap(), __t.__end_cap()); 446#ifndef _LIBCPP_HAS_NO_EXCEPTIONS 447 } catch (...) { 448 } 449#endif // _LIBCPP_HAS_NO_EXCEPTIONS 450 } 451} 452 453template <class _Tp, class _Allocator> 454_LIBCPP_CONSTEXPR_SINCE_CXX20 void __split_buffer<_Tp, _Allocator>::push_front(const_reference __x) { 455 if (__begin_ == __first_) { 456 if (__end_ < __end_cap()) { 457 difference_type __d = __end_cap() - __end_; 458 __d = (__d + 1) / 2; 459 __begin_ = std::move_backward(__begin_, __end_, __end_ + __d); 460 __end_ += __d; 461 } else { 462 size_type __c = std::max<size_type>(2 * static_cast<size_t>(__end_cap() - __first_), 1); 463 __split_buffer<value_type, __alloc_rr&> __t(__c, (__c + 3) / 4, __alloc()); 464 __t.__construct_at_end(move_iterator<pointer>(__begin_), move_iterator<pointer>(__end_)); 465 std::swap(__first_, __t.__first_); 466 std::swap(__begin_, __t.__begin_); 467 std::swap(__end_, __t.__end_); 468 std::swap(__end_cap(), __t.__end_cap()); 469 } 470 } 471 __alloc_traits::construct(__alloc(), std::__to_address(__begin_ - 1), __x); 472 --__begin_; 473} 474 475template <class _Tp, class _Allocator> 476_LIBCPP_CONSTEXPR_SINCE_CXX20 void __split_buffer<_Tp, _Allocator>::push_front(value_type&& __x) { 477 if (__begin_ == __first_) { 478 if (__end_ < __end_cap()) { 479 difference_type __d = __end_cap() - __end_; 480 __d = (__d + 1) / 2; 481 __begin_ = std::move_backward(__begin_, __end_, __end_ + __d); 482 __end_ += __d; 483 } else { 484 size_type __c = std::max<size_type>(2 * static_cast<size_t>(__end_cap() - __first_), 1); 485 __split_buffer<value_type, __alloc_rr&> __t(__c, (__c + 3) / 4, __alloc()); 486 __t.__construct_at_end(move_iterator<pointer>(__begin_), move_iterator<pointer>(__end_)); 487 std::swap(__first_, __t.__first_); 488 std::swap(__begin_, __t.__begin_); 489 std::swap(__end_, __t.__end_); 490 std::swap(__end_cap(), __t.__end_cap()); 491 } 492 } 493 __alloc_traits::construct(__alloc(), std::__to_address(__begin_ - 1), std::move(__x)); 494 --__begin_; 495} 496 497template <class _Tp, class _Allocator> 498_LIBCPP_CONSTEXPR_SINCE_CXX20 inline _LIBCPP_HIDE_FROM_ABI void 499__split_buffer<_Tp, _Allocator>::push_back(const_reference __x) { 500 if (__end_ == __end_cap()) { 501 if (__begin_ > __first_) { 502 difference_type __d = __begin_ - __first_; 503 __d = (__d + 1) / 2; 504 __end_ = std::move(__begin_, __end_, __begin_ - __d); 505 __begin_ -= __d; 506 } else { 507 size_type __c = std::max<size_type>(2 * static_cast<size_t>(__end_cap() - __first_), 1); 508 __split_buffer<value_type, __alloc_rr&> __t(__c, __c / 4, __alloc()); 509 __t.__construct_at_end(move_iterator<pointer>(__begin_), move_iterator<pointer>(__end_)); 510 std::swap(__first_, __t.__first_); 511 std::swap(__begin_, __t.__begin_); 512 std::swap(__end_, __t.__end_); 513 std::swap(__end_cap(), __t.__end_cap()); 514 } 515 } 516 __alloc_traits::construct(__alloc(), std::__to_address(__end_), __x); 517 ++__end_; 518} 519 520template <class _Tp, class _Allocator> 521_LIBCPP_CONSTEXPR_SINCE_CXX20 void __split_buffer<_Tp, _Allocator>::push_back(value_type&& __x) { 522 if (__end_ == __end_cap()) { 523 if (__begin_ > __first_) { 524 difference_type __d = __begin_ - __first_; 525 __d = (__d + 1) / 2; 526 __end_ = std::move(__begin_, __end_, __begin_ - __d); 527 __begin_ -= __d; 528 } else { 529 size_type __c = std::max<size_type>(2 * static_cast<size_t>(__end_cap() - __first_), 1); 530 __split_buffer<value_type, __alloc_rr&> __t(__c, __c / 4, __alloc()); 531 __t.__construct_at_end(move_iterator<pointer>(__begin_), move_iterator<pointer>(__end_)); 532 std::swap(__first_, __t.__first_); 533 std::swap(__begin_, __t.__begin_); 534 std::swap(__end_, __t.__end_); 535 std::swap(__end_cap(), __t.__end_cap()); 536 } 537 } 538 __alloc_traits::construct(__alloc(), std::__to_address(__end_), std::move(__x)); 539 ++__end_; 540} 541 542template <class _Tp, class _Allocator> 543template <class... _Args> 544_LIBCPP_CONSTEXPR_SINCE_CXX20 void __split_buffer<_Tp, _Allocator>::emplace_back(_Args&&... __args) { 545 if (__end_ == __end_cap()) { 546 if (__begin_ > __first_) { 547 difference_type __d = __begin_ - __first_; 548 __d = (__d + 1) / 2; 549 __end_ = std::move(__begin_, __end_, __begin_ - __d); 550 __begin_ -= __d; 551 } else { 552 size_type __c = std::max<size_type>(2 * static_cast<size_t>(__end_cap() - __first_), 1); 553 __split_buffer<value_type, __alloc_rr&> __t(__c, __c / 4, __alloc()); 554 __t.__construct_at_end(move_iterator<pointer>(__begin_), move_iterator<pointer>(__end_)); 555 std::swap(__first_, __t.__first_); 556 std::swap(__begin_, __t.__begin_); 557 std::swap(__end_, __t.__end_); 558 std::swap(__end_cap(), __t.__end_cap()); 559 } 560 } 561 __alloc_traits::construct(__alloc(), std::__to_address(__end_), std::forward<_Args>(__args)...); 562 ++__end_; 563} 564 565template <class _Tp, class _Allocator> 566_LIBCPP_CONSTEXPR_SINCE_CXX20 inline _LIBCPP_HIDE_FROM_ABI void 567swap(__split_buffer<_Tp, _Allocator>& __x, __split_buffer<_Tp, _Allocator>& __y) _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y))) { 568 __x.swap(__y); 569} 570 571_LIBCPP_END_NAMESPACE_STD 572 573_LIBCPP_POP_MACROS 574 575#endif // _LIBCPP___SPLIT_BUFFER 576