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/conditional.h> 28#include <__type_traits/enable_if.h> 29#include <__type_traits/integral_constant.h> 30#include <__type_traits/is_nothrow_assignable.h> 31#include <__type_traits/is_nothrow_constructible.h> 32#include <__type_traits/is_swappable.h> 33#include <__type_traits/is_trivially_destructible.h> 34#include <__type_traits/is_trivially_relocatable.h> 35#include <__type_traits/remove_reference.h> 36#include <__utility/forward.h> 37#include <__utility/move.h> 38#include <cstddef> 39 40#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 41# pragma GCC system_header 42#endif 43 44_LIBCPP_PUSH_MACROS 45#include <__undef_macros> 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 { 55public: 56 using value_type = _Tp; 57 using allocator_type = _Allocator; 58 using __alloc_rr = __libcpp_remove_reference_t<allocator_type>; 59 using __alloc_traits = allocator_traits<__alloc_rr>; 60 using reference = value_type&; 61 using const_reference = const value_type&; 62 using size_type = typename __alloc_traits::size_type; 63 using difference_type = typename __alloc_traits::difference_type; 64 using pointer = typename __alloc_traits::pointer; 65 using const_pointer = typename __alloc_traits::const_pointer; 66 using iterator = pointer; 67 using const_iterator = const_pointer; 68 69 // A __split_buffer contains the following members which may be trivially relocatable: 70 // - pointer: may be trivially relocatable, so it's checked 71 // - allocator_type: may be trivially relocatable, so it's checked 72 // __split_buffer doesn't have any self-references, so it's trivially relocatable if its members are. 73 using __trivially_relocatable = __conditional_t< 74 __libcpp_is_trivially_relocatable<pointer>::value && __libcpp_is_trivially_relocatable<allocator_type>::value, 75 __split_buffer, 76 void>; 77 78 pointer __first_; 79 pointer __begin_; 80 pointer __end_; 81 __compressed_pair<pointer, allocator_type> __end_cap_; 82 83 using __alloc_ref = __add_lvalue_reference_t<allocator_type>; 84 using __alloc_const_ref = __add_lvalue_reference_t<allocator_type>; 85 86 __split_buffer(const __split_buffer&) = delete; 87 __split_buffer& operator=(const __split_buffer&) = delete; 88 89 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI __split_buffer() 90 _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value) 91 : __first_(nullptr), __begin_(nullptr), __end_(nullptr), __end_cap_(nullptr, __default_init_tag()) {} 92 93 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI explicit __split_buffer(__alloc_rr& __a) 94 : __first_(nullptr), __begin_(nullptr), __end_(nullptr), __end_cap_(nullptr, __a) {} 95 96 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI explicit __split_buffer(const __alloc_rr& __a) 97 : __first_(nullptr), __begin_(nullptr), __end_(nullptr), __end_cap_(nullptr, __a) {} 98 99 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI 100 __split_buffer(size_type __cap, size_type __start, __alloc_rr& __a); 101 102 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI __split_buffer(__split_buffer&& __c) 103 _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value); 104 105 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI __split_buffer(__split_buffer&& __c, const __alloc_rr& __a); 106 107 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI __split_buffer& operator=(__split_buffer&& __c) 108 _NOEXCEPT_((__alloc_traits::propagate_on_container_move_assignment::value && 109 is_nothrow_move_assignable<allocator_type>::value) || 110 !__alloc_traits::propagate_on_container_move_assignment::value); 111 112 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI ~__split_buffer(); 113 114 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI __alloc_rr& __alloc() _NOEXCEPT { return __end_cap_.second(); } 115 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI const __alloc_rr& __alloc() const _NOEXCEPT { 116 return __end_cap_.second(); 117 } 118 119 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI pointer& __end_cap() _NOEXCEPT { return __end_cap_.first(); } 120 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI const pointer& __end_cap() const _NOEXCEPT { 121 return __end_cap_.first(); 122 } 123 124 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI iterator begin() _NOEXCEPT { return __begin_; } 125 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI const_iterator begin() const _NOEXCEPT { return __begin_; } 126 127 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI iterator end() _NOEXCEPT { return __end_; } 128 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI const_iterator end() const _NOEXCEPT { return __end_; } 129 130 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void clear() _NOEXCEPT { __destruct_at_end(__begin_); } 131 132 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI size_type size() const { 133 return static_cast<size_type>(__end_ - __begin_); 134 } 135 136 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI bool empty() const { return __end_ == __begin_; } 137 138 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI size_type capacity() const { 139 return static_cast<size_type>(__end_cap() - __first_); 140 } 141 142 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI size_type __front_spare() const { 143 return static_cast<size_type>(__begin_ - __first_); 144 } 145 146 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI size_type __back_spare() const { 147 return static_cast<size_type>(__end_cap() - __end_); 148 } 149 150 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI reference front() { return *__begin_; } 151 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI const_reference front() const { return *__begin_; } 152 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI reference back() { return *(__end_ - 1); } 153 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI const_reference back() const { return *(__end_ - 1); } 154 155 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void reserve(size_type __n); 156 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void shrink_to_fit() _NOEXCEPT; 157 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void push_front(const_reference __x); 158 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void push_back(const_reference __x); 159 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void push_front(value_type&& __x); 160 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void push_back(value_type&& __x); 161 162 template <class... _Args> 163 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void emplace_back(_Args&&... __args); 164 165 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void pop_front() { __destruct_at_begin(__begin_ + 1); } 166 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void pop_back() { __destruct_at_end(__end_ - 1); } 167 168 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __construct_at_end(size_type __n); 169 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __construct_at_end(size_type __n, const_reference __x); 170 171 template <class _InputIter, __enable_if_t<__has_exactly_input_iterator_category<_InputIter>::value, int> = 0> 172 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __construct_at_end(_InputIter __first, _InputIter __last); 173 174 template <class _ForwardIterator, __enable_if_t<__has_forward_iterator_category<_ForwardIterator>::value, int> = 0> 175 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void 176 __construct_at_end(_ForwardIterator __first, _ForwardIterator __last); 177 178 template <class _Iterator, class _Sentinel> 179 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void 180 __construct_at_end_with_sentinel(_Iterator __first, _Sentinel __last); 181 182 template <class _Iterator> 183 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void 184 __construct_at_end_with_size(_Iterator __first, size_type __n); 185 186 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __destruct_at_begin(pointer __new_begin) { 187 __destruct_at_begin(__new_begin, is_trivially_destructible<value_type>()); 188 } 189 190 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __destruct_at_begin(pointer __new_begin, false_type); 191 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __destruct_at_begin(pointer __new_begin, true_type); 192 193 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __destruct_at_end(pointer __new_last) _NOEXCEPT { 194 __destruct_at_end(__new_last, false_type()); 195 } 196 197 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __destruct_at_end(pointer __new_last, false_type) _NOEXCEPT; 198 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __destruct_at_end(pointer __new_last, true_type) _NOEXCEPT; 199 200 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void swap(__split_buffer& __x) 201 _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value || __is_nothrow_swappable_v<__alloc_rr>); 202 203 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI bool __invariants() const; 204 205private: 206 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __move_assign_alloc(__split_buffer& __c, true_type) 207 _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value) { 208 __alloc() = std::move(__c.__alloc()); 209 } 210 211 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __move_assign_alloc(__split_buffer&, false_type) _NOEXCEPT {} 212 213 struct _ConstructTransaction { 214 _LIBCPP_CONSTEXPR_SINCE_CXX20 215 _LIBCPP_HIDE_FROM_ABI explicit _ConstructTransaction(pointer* __p, size_type __n) _NOEXCEPT 216 : __pos_(*__p), 217 __end_(*__p + __n), 218 __dest_(__p) {} 219 220 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI ~_ConstructTransaction() { *__dest_ = __pos_; } 221 222 pointer __pos_; 223 const pointer __end_; 224 225 private: 226 pointer* __dest_; 227 }; 228}; 229 230template <class _Tp, class _Allocator> 231_LIBCPP_CONSTEXPR_SINCE_CXX20 bool __split_buffer<_Tp, _Allocator>::__invariants() const { 232 if (__first_ == nullptr) { 233 if (__begin_ != nullptr) 234 return false; 235 if (__end_ != nullptr) 236 return false; 237 if (__end_cap() != nullptr) 238 return false; 239 } else { 240 if (__begin_ < __first_) 241 return false; 242 if (__end_ < __begin_) 243 return false; 244 if (__end_cap() < __end_) 245 return false; 246 } 247 return true; 248} 249 250// Default constructs __n objects starting at __end_ 251// throws if construction throws 252// Precondition: __n > 0 253// Precondition: size() + __n <= capacity() 254// Postcondition: size() == size() + __n 255template <class _Tp, class _Allocator> 256_LIBCPP_CONSTEXPR_SINCE_CXX20 void __split_buffer<_Tp, _Allocator>::__construct_at_end(size_type __n) { 257 _ConstructTransaction __tx(&this->__end_, __n); 258 for (; __tx.__pos_ != __tx.__end_; ++__tx.__pos_) { 259 __alloc_traits::construct(this->__alloc(), std::__to_address(__tx.__pos_)); 260 } 261} 262 263// Copy constructs __n objects starting at __end_ from __x 264// throws if construction throws 265// Precondition: __n > 0 266// Precondition: size() + __n <= capacity() 267// Postcondition: size() == old size() + __n 268// Postcondition: [i] == __x for all i in [size() - __n, __n) 269template <class _Tp, class _Allocator> 270_LIBCPP_CONSTEXPR_SINCE_CXX20 void 271__split_buffer<_Tp, _Allocator>::__construct_at_end(size_type __n, const_reference __x) { 272 _ConstructTransaction __tx(&this->__end_, __n); 273 for (; __tx.__pos_ != __tx.__end_; ++__tx.__pos_) { 274 __alloc_traits::construct(this->__alloc(), std::__to_address(__tx.__pos_), __x); 275 } 276} 277 278template <class _Tp, class _Allocator> 279template <class _InputIter, __enable_if_t<__has_exactly_input_iterator_category<_InputIter>::value, int> > 280_LIBCPP_CONSTEXPR_SINCE_CXX20 void 281__split_buffer<_Tp, _Allocator>::__construct_at_end(_InputIter __first, _InputIter __last) { 282 __construct_at_end_with_sentinel(__first, __last); 283} 284 285template <class _Tp, class _Allocator> 286template <class _Iterator, class _Sentinel> 287_LIBCPP_CONSTEXPR_SINCE_CXX20 void 288__split_buffer<_Tp, _Allocator>::__construct_at_end_with_sentinel(_Iterator __first, _Sentinel __last) { 289 __alloc_rr& __a = this->__alloc(); 290 for (; __first != __last; ++__first) { 291 if (__end_ == __end_cap()) { 292 size_type __old_cap = __end_cap() - __first_; 293 size_type __new_cap = std::max<size_type>(2 * __old_cap, 8); 294 __split_buffer __buf(__new_cap, 0, __a); 295 for (pointer __p = __begin_; __p != __end_; ++__p, (void)++__buf.__end_) 296 __alloc_traits::construct(__buf.__alloc(), std::__to_address(__buf.__end_), std::move(*__p)); 297 swap(__buf); 298 } 299 __alloc_traits::construct(__a, std::__to_address(this->__end_), *__first); 300 ++this->__end_; 301 } 302} 303template <class _Tp, class _Allocator> 304template <class _ForwardIterator, __enable_if_t<__has_forward_iterator_category<_ForwardIterator>::value, int> > 305_LIBCPP_CONSTEXPR_SINCE_CXX20 void 306__split_buffer<_Tp, _Allocator>::__construct_at_end(_ForwardIterator __first, _ForwardIterator __last) { 307 __construct_at_end_with_size(__first, std::distance(__first, __last)); 308} 309 310template <class _Tp, class _Allocator> 311template <class _ForwardIterator> 312_LIBCPP_CONSTEXPR_SINCE_CXX20 void 313__split_buffer<_Tp, _Allocator>::__construct_at_end_with_size(_ForwardIterator __first, size_type __n) { 314 _ConstructTransaction __tx(&this->__end_, __n); 315 for (; __tx.__pos_ != __tx.__end_; ++__tx.__pos_, (void)++__first) { 316 __alloc_traits::construct(this->__alloc(), std::__to_address(__tx.__pos_), *__first); 317 } 318} 319 320template <class _Tp, class _Allocator> 321_LIBCPP_CONSTEXPR_SINCE_CXX20 inline void 322__split_buffer<_Tp, _Allocator>::__destruct_at_begin(pointer __new_begin, false_type) { 323 while (__begin_ != __new_begin) 324 __alloc_traits::destroy(__alloc(), std::__to_address(__begin_++)); 325} 326 327template <class _Tp, class _Allocator> 328_LIBCPP_CONSTEXPR_SINCE_CXX20 inline void 329__split_buffer<_Tp, _Allocator>::__destruct_at_begin(pointer __new_begin, true_type) { 330 __begin_ = __new_begin; 331} 332 333template <class _Tp, class _Allocator> 334_LIBCPP_CONSTEXPR_SINCE_CXX20 inline _LIBCPP_HIDE_FROM_ABI void 335__split_buffer<_Tp, _Allocator>::__destruct_at_end(pointer __new_last, false_type) _NOEXCEPT { 336 while (__new_last != __end_) 337 __alloc_traits::destroy(__alloc(), std::__to_address(--__end_)); 338} 339 340template <class _Tp, class _Allocator> 341_LIBCPP_CONSTEXPR_SINCE_CXX20 inline _LIBCPP_HIDE_FROM_ABI void 342__split_buffer<_Tp, _Allocator>::__destruct_at_end(pointer __new_last, true_type) _NOEXCEPT { 343 __end_ = __new_last; 344} 345 346template <class _Tp, class _Allocator> 347_LIBCPP_CONSTEXPR_SINCE_CXX20 348__split_buffer<_Tp, _Allocator>::__split_buffer(size_type __cap, size_type __start, __alloc_rr& __a) 349 : __end_cap_(nullptr, __a) { 350 if (__cap == 0) { 351 __first_ = nullptr; 352 } else { 353 auto __allocation = std::__allocate_at_least(__alloc(), __cap); 354 __first_ = __allocation.ptr; 355 __cap = __allocation.count; 356 } 357 __begin_ = __end_ = __first_ + __start; 358 __end_cap() = __first_ + __cap; 359} 360 361template <class _Tp, class _Allocator> 362_LIBCPP_CONSTEXPR_SINCE_CXX20 __split_buffer<_Tp, _Allocator>::~__split_buffer() { 363 clear(); 364 if (__first_) 365 __alloc_traits::deallocate(__alloc(), __first_, capacity()); 366} 367 368template <class _Tp, class _Allocator> 369_LIBCPP_CONSTEXPR_SINCE_CXX20 __split_buffer<_Tp, _Allocator>::__split_buffer(__split_buffer&& __c) 370 _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value) 371 : __first_(std::move(__c.__first_)), 372 __begin_(std::move(__c.__begin_)), 373 __end_(std::move(__c.__end_)), 374 __end_cap_(std::move(__c.__end_cap_)) { 375 __c.__first_ = nullptr; 376 __c.__begin_ = nullptr; 377 __c.__end_ = nullptr; 378 __c.__end_cap() = nullptr; 379} 380 381template <class _Tp, class _Allocator> 382_LIBCPP_CONSTEXPR_SINCE_CXX20 383__split_buffer<_Tp, _Allocator>::__split_buffer(__split_buffer&& __c, const __alloc_rr& __a) 384 : __end_cap_(nullptr, __a) { 385 if (__a == __c.__alloc()) { 386 __first_ = __c.__first_; 387 __begin_ = __c.__begin_; 388 __end_ = __c.__end_; 389 __end_cap() = __c.__end_cap(); 390 __c.__first_ = nullptr; 391 __c.__begin_ = nullptr; 392 __c.__end_ = nullptr; 393 __c.__end_cap() = nullptr; 394 } else { 395 auto __allocation = std::__allocate_at_least(__alloc(), __c.size()); 396 __first_ = __allocation.ptr; 397 __begin_ = __end_ = __first_; 398 __end_cap() = __first_ + __allocation.count; 399 typedef move_iterator<iterator> _Ip; 400 __construct_at_end(_Ip(__c.begin()), _Ip(__c.end())); 401 } 402} 403 404template <class _Tp, class _Allocator> 405_LIBCPP_CONSTEXPR_SINCE_CXX20 __split_buffer<_Tp, _Allocator>& 406__split_buffer<_Tp, _Allocator>::operator=(__split_buffer&& __c) 407 _NOEXCEPT_((__alloc_traits::propagate_on_container_move_assignment::value && 408 is_nothrow_move_assignable<allocator_type>::value) || 409 !__alloc_traits::propagate_on_container_move_assignment::value) { 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, integral_constant<bool, __alloc_traits::propagate_on_container_move_assignment::value>()); 417 __c.__first_ = __c.__begin_ = __c.__end_ = __c.__end_cap() = nullptr; 418 return *this; 419} 420 421template <class _Tp, class _Allocator> 422_LIBCPP_CONSTEXPR_SINCE_CXX20 void __split_buffer<_Tp, _Allocator>::swap(__split_buffer& __x) 423 _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value || __is_nothrow_swappable_v<__alloc_rr>) { 424 std::swap(__first_, __x.__first_); 425 std::swap(__begin_, __x.__begin_); 426 std::swap(__end_, __x.__end_); 427 std::swap(__end_cap(), __x.__end_cap()); 428 std::__swap_allocator(__alloc(), __x.__alloc()); 429} 430 431template <class _Tp, class _Allocator> 432_LIBCPP_CONSTEXPR_SINCE_CXX20 void __split_buffer<_Tp, _Allocator>::reserve(size_type __n) { 433 if (__n < capacity()) { 434 __split_buffer<value_type, __alloc_rr&> __t(__n, 0, __alloc()); 435 __t.__construct_at_end(move_iterator<pointer>(__begin_), move_iterator<pointer>(__end_)); 436 std::swap(__first_, __t.__first_); 437 std::swap(__begin_, __t.__begin_); 438 std::swap(__end_, __t.__end_); 439 std::swap(__end_cap(), __t.__end_cap()); 440 } 441} 442 443template <class _Tp, class _Allocator> 444_LIBCPP_CONSTEXPR_SINCE_CXX20 void __split_buffer<_Tp, _Allocator>::shrink_to_fit() _NOEXCEPT { 445 if (capacity() > size()) { 446#ifndef _LIBCPP_HAS_NO_EXCEPTIONS 447 try { 448#endif // _LIBCPP_HAS_NO_EXCEPTIONS 449 __split_buffer<value_type, __alloc_rr&> __t(size(), 0, __alloc()); 450 __t.__construct_at_end(move_iterator<pointer>(__begin_), move_iterator<pointer>(__end_)); 451 __t.__end_ = __t.__begin_ + (__end_ - __begin_); 452 std::swap(__first_, __t.__first_); 453 std::swap(__begin_, __t.__begin_); 454 std::swap(__end_, __t.__end_); 455 std::swap(__end_cap(), __t.__end_cap()); 456#ifndef _LIBCPP_HAS_NO_EXCEPTIONS 457 } catch (...) { 458 } 459#endif // _LIBCPP_HAS_NO_EXCEPTIONS 460 } 461} 462 463template <class _Tp, class _Allocator> 464_LIBCPP_CONSTEXPR_SINCE_CXX20 void __split_buffer<_Tp, _Allocator>::push_front(const_reference __x) { 465 if (__begin_ == __first_) { 466 if (__end_ < __end_cap()) { 467 difference_type __d = __end_cap() - __end_; 468 __d = (__d + 1) / 2; 469 __begin_ = std::move_backward(__begin_, __end_, __end_ + __d); 470 __end_ += __d; 471 } else { 472 size_type __c = std::max<size_type>(2 * static_cast<size_t>(__end_cap() - __first_), 1); 473 __split_buffer<value_type, __alloc_rr&> __t(__c, (__c + 3) / 4, __alloc()); 474 __t.__construct_at_end(move_iterator<pointer>(__begin_), move_iterator<pointer>(__end_)); 475 std::swap(__first_, __t.__first_); 476 std::swap(__begin_, __t.__begin_); 477 std::swap(__end_, __t.__end_); 478 std::swap(__end_cap(), __t.__end_cap()); 479 } 480 } 481 __alloc_traits::construct(__alloc(), std::__to_address(__begin_ - 1), __x); 482 --__begin_; 483} 484 485template <class _Tp, class _Allocator> 486_LIBCPP_CONSTEXPR_SINCE_CXX20 void __split_buffer<_Tp, _Allocator>::push_front(value_type&& __x) { 487 if (__begin_ == __first_) { 488 if (__end_ < __end_cap()) { 489 difference_type __d = __end_cap() - __end_; 490 __d = (__d + 1) / 2; 491 __begin_ = std::move_backward(__begin_, __end_, __end_ + __d); 492 __end_ += __d; 493 } else { 494 size_type __c = std::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_), move_iterator<pointer>(__end_)); 497 std::swap(__first_, __t.__first_); 498 std::swap(__begin_, __t.__begin_); 499 std::swap(__end_, __t.__end_); 500 std::swap(__end_cap(), __t.__end_cap()); 501 } 502 } 503 __alloc_traits::construct(__alloc(), std::__to_address(__begin_ - 1), std::move(__x)); 504 --__begin_; 505} 506 507template <class _Tp, class _Allocator> 508_LIBCPP_CONSTEXPR_SINCE_CXX20 inline _LIBCPP_HIDE_FROM_ABI void 509__split_buffer<_Tp, _Allocator>::push_back(const_reference __x) { 510 if (__end_ == __end_cap()) { 511 if (__begin_ > __first_) { 512 difference_type __d = __begin_ - __first_; 513 __d = (__d + 1) / 2; 514 __end_ = std::move(__begin_, __end_, __begin_ - __d); 515 __begin_ -= __d; 516 } else { 517 size_type __c = std::max<size_type>(2 * static_cast<size_t>(__end_cap() - __first_), 1); 518 __split_buffer<value_type, __alloc_rr&> __t(__c, __c / 4, __alloc()); 519 __t.__construct_at_end(move_iterator<pointer>(__begin_), move_iterator<pointer>(__end_)); 520 std::swap(__first_, __t.__first_); 521 std::swap(__begin_, __t.__begin_); 522 std::swap(__end_, __t.__end_); 523 std::swap(__end_cap(), __t.__end_cap()); 524 } 525 } 526 __alloc_traits::construct(__alloc(), std::__to_address(__end_), __x); 527 ++__end_; 528} 529 530template <class _Tp, class _Allocator> 531_LIBCPP_CONSTEXPR_SINCE_CXX20 void __split_buffer<_Tp, _Allocator>::push_back(value_type&& __x) { 532 if (__end_ == __end_cap()) { 533 if (__begin_ > __first_) { 534 difference_type __d = __begin_ - __first_; 535 __d = (__d + 1) / 2; 536 __end_ = std::move(__begin_, __end_, __begin_ - __d); 537 __begin_ -= __d; 538 } else { 539 size_type __c = std::max<size_type>(2 * static_cast<size_t>(__end_cap() - __first_), 1); 540 __split_buffer<value_type, __alloc_rr&> __t(__c, __c / 4, __alloc()); 541 __t.__construct_at_end(move_iterator<pointer>(__begin_), move_iterator<pointer>(__end_)); 542 std::swap(__first_, __t.__first_); 543 std::swap(__begin_, __t.__begin_); 544 std::swap(__end_, __t.__end_); 545 std::swap(__end_cap(), __t.__end_cap()); 546 } 547 } 548 __alloc_traits::construct(__alloc(), std::__to_address(__end_), std::move(__x)); 549 ++__end_; 550} 551 552template <class _Tp, class _Allocator> 553template <class... _Args> 554_LIBCPP_CONSTEXPR_SINCE_CXX20 void __split_buffer<_Tp, _Allocator>::emplace_back(_Args&&... __args) { 555 if (__end_ == __end_cap()) { 556 if (__begin_ > __first_) { 557 difference_type __d = __begin_ - __first_; 558 __d = (__d + 1) / 2; 559 __end_ = std::move(__begin_, __end_, __begin_ - __d); 560 __begin_ -= __d; 561 } else { 562 size_type __c = std::max<size_type>(2 * static_cast<size_t>(__end_cap() - __first_), 1); 563 __split_buffer<value_type, __alloc_rr&> __t(__c, __c / 4, __alloc()); 564 __t.__construct_at_end(move_iterator<pointer>(__begin_), move_iterator<pointer>(__end_)); 565 std::swap(__first_, __t.__first_); 566 std::swap(__begin_, __t.__begin_); 567 std::swap(__end_, __t.__end_); 568 std::swap(__end_cap(), __t.__end_cap()); 569 } 570 } 571 __alloc_traits::construct(__alloc(), std::__to_address(__end_), std::forward<_Args>(__args)...); 572 ++__end_; 573} 574 575template <class _Tp, class _Allocator> 576_LIBCPP_CONSTEXPR_SINCE_CXX20 inline _LIBCPP_HIDE_FROM_ABI void 577swap(__split_buffer<_Tp, _Allocator>& __x, __split_buffer<_Tp, _Allocator>& __y) _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y))) { 578 __x.swap(__y); 579} 580 581_LIBCPP_END_NAMESPACE_STD 582 583_LIBCPP_POP_MACROS 584 585#endif // _LIBCPP___SPLIT_BUFFER 586