Warning, /include/c++/v1/__split_buffer is written in an unsupported language. File is not indexed.
0001 // -*- C++ -*-
0002 //===----------------------------------------------------------------------===//
0003 //
0004 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
0005 // See https://llvm.org/LICENSE.txt for license information.
0006 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
0007 //
0008 //===----------------------------------------------------------------------===//
0009
0010 #ifndef _LIBCPP___SPLIT_BUFFER
0011 #define _LIBCPP___SPLIT_BUFFER
0012
0013 #include <__algorithm/max.h>
0014 #include <__algorithm/move.h>
0015 #include <__algorithm/move_backward.h>
0016 #include <__config>
0017 #include <__iterator/distance.h>
0018 #include <__iterator/iterator_traits.h>
0019 #include <__iterator/move_iterator.h>
0020 #include <__memory/allocate_at_least.h>
0021 #include <__memory/allocator.h>
0022 #include <__memory/allocator_traits.h>
0023 #include <__memory/compressed_pair.h>
0024 #include <__memory/pointer_traits.h>
0025 #include <__memory/swap_allocator.h>
0026 #include <__type_traits/conditional.h>
0027 #include <__type_traits/enable_if.h>
0028 #include <__type_traits/integral_constant.h>
0029 #include <__type_traits/is_nothrow_assignable.h>
0030 #include <__type_traits/is_nothrow_constructible.h>
0031 #include <__type_traits/is_swappable.h>
0032 #include <__type_traits/is_trivially_destructible.h>
0033 #include <__type_traits/is_trivially_relocatable.h>
0034 #include <__type_traits/remove_reference.h>
0035 #include <__utility/forward.h>
0036 #include <__utility/move.h>
0037
0038 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
0039 # pragma GCC system_header
0040 #endif
0041
0042 _LIBCPP_PUSH_MACROS
0043 #include <__undef_macros>
0044
0045 _LIBCPP_BEGIN_NAMESPACE_STD
0046
0047 // __split_buffer allocates a contiguous chunk of memory and stores objects in the range [__begin_, __end_).
0048 // It has uninitialized memory in the ranges [__first_, __begin_) and [__end_, __cap_). That allows
0049 // it to grow both in the front and back without having to move the data.
0050
0051 template <class _Tp, class _Allocator = allocator<_Tp> >
0052 struct __split_buffer {
0053 public:
0054 using value_type = _Tp;
0055 using allocator_type = _Allocator;
0056 using __alloc_rr _LIBCPP_NODEBUG = __libcpp_remove_reference_t<allocator_type>;
0057 using __alloc_traits _LIBCPP_NODEBUG = allocator_traits<__alloc_rr>;
0058 using reference = value_type&;
0059 using const_reference = const value_type&;
0060 using size_type = typename __alloc_traits::size_type;
0061 using difference_type = typename __alloc_traits::difference_type;
0062 using pointer = typename __alloc_traits::pointer;
0063 using const_pointer = typename __alloc_traits::const_pointer;
0064 using iterator = pointer;
0065 using const_iterator = const_pointer;
0066
0067 // A __split_buffer contains the following members which may be trivially relocatable:
0068 // - pointer: may be trivially relocatable, so it's checked
0069 // - allocator_type: may be trivially relocatable, so it's checked
0070 // __split_buffer doesn't have any self-references, so it's trivially relocatable if its members are.
0071 using __trivially_relocatable _LIBCPP_NODEBUG = __conditional_t<
0072 __libcpp_is_trivially_relocatable<pointer>::value && __libcpp_is_trivially_relocatable<allocator_type>::value,
0073 __split_buffer,
0074 void>;
0075
0076 pointer __first_;
0077 pointer __begin_;
0078 pointer __end_;
0079 _LIBCPP_COMPRESSED_PAIR(pointer, __cap_, allocator_type, __alloc_);
0080
0081 __split_buffer(const __split_buffer&) = delete;
0082 __split_buffer& operator=(const __split_buffer&) = delete;
0083
0084 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI __split_buffer()
0085 _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value)
0086 : __first_(nullptr), __begin_(nullptr), __end_(nullptr), __cap_(nullptr) {}
0087
0088 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI explicit __split_buffer(__alloc_rr& __a)
0089 : __first_(nullptr), __begin_(nullptr), __end_(nullptr), __cap_(nullptr), __alloc_(__a) {}
0090
0091 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI explicit __split_buffer(const __alloc_rr& __a)
0092 : __first_(nullptr), __begin_(nullptr), __end_(nullptr), __cap_(nullptr), __alloc_(__a) {}
0093
0094 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI
0095 __split_buffer(size_type __cap, size_type __start, __alloc_rr& __a);
0096
0097 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI __split_buffer(__split_buffer&& __c)
0098 _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value);
0099
0100 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI __split_buffer(__split_buffer&& __c, const __alloc_rr& __a);
0101
0102 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI __split_buffer& operator=(__split_buffer&& __c)
0103 _NOEXCEPT_((__alloc_traits::propagate_on_container_move_assignment::value &&
0104 is_nothrow_move_assignable<allocator_type>::value) ||
0105 !__alloc_traits::propagate_on_container_move_assignment::value);
0106
0107 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI ~__split_buffer();
0108
0109 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI iterator begin() _NOEXCEPT { return __begin_; }
0110 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI const_iterator begin() const _NOEXCEPT { return __begin_; }
0111
0112 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI iterator end() _NOEXCEPT { return __end_; }
0113 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI const_iterator end() const _NOEXCEPT { return __end_; }
0114
0115 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void clear() _NOEXCEPT { __destruct_at_end(__begin_); }
0116
0117 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI size_type size() const {
0118 return static_cast<size_type>(__end_ - __begin_);
0119 }
0120
0121 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI bool empty() const { return __end_ == __begin_; }
0122
0123 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI size_type capacity() const {
0124 return static_cast<size_type>(__cap_ - __first_);
0125 }
0126
0127 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI size_type __front_spare() const {
0128 return static_cast<size_type>(__begin_ - __first_);
0129 }
0130
0131 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI size_type __back_spare() const {
0132 return static_cast<size_type>(__cap_ - __end_);
0133 }
0134
0135 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI reference front() { return *__begin_; }
0136 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI const_reference front() const { return *__begin_; }
0137 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI reference back() { return *(__end_ - 1); }
0138 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI const_reference back() const { return *(__end_ - 1); }
0139
0140 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void shrink_to_fit() _NOEXCEPT;
0141
0142 template <class... _Args>
0143 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void emplace_front(_Args&&... __args);
0144 template <class... _Args>
0145 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void emplace_back(_Args&&... __args);
0146
0147 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void pop_front() { __destruct_at_begin(__begin_ + 1); }
0148 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void pop_back() { __destruct_at_end(__end_ - 1); }
0149
0150 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __construct_at_end(size_type __n);
0151 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __construct_at_end(size_type __n, const_reference __x);
0152
0153 template <class _ForwardIterator, __enable_if_t<__has_forward_iterator_category<_ForwardIterator>::value, int> = 0>
0154 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void
0155 __construct_at_end(_ForwardIterator __first, _ForwardIterator __last);
0156
0157 template <class _Iterator, class _Sentinel>
0158 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void
0159 __construct_at_end_with_sentinel(_Iterator __first, _Sentinel __last);
0160
0161 template <class _Iterator>
0162 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void
0163 __construct_at_end_with_size(_Iterator __first, size_type __n);
0164
0165 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __destruct_at_begin(pointer __new_begin) {
0166 __destruct_at_begin(__new_begin, is_trivially_destructible<value_type>());
0167 }
0168
0169 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __destruct_at_begin(pointer __new_begin, false_type);
0170 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __destruct_at_begin(pointer __new_begin, true_type);
0171
0172 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __destruct_at_end(pointer __new_last) _NOEXCEPT {
0173 __destruct_at_end(__new_last, false_type());
0174 }
0175
0176 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __destruct_at_end(pointer __new_last, false_type) _NOEXCEPT;
0177 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __destruct_at_end(pointer __new_last, true_type) _NOEXCEPT;
0178
0179 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void swap(__split_buffer& __x)
0180 _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value || __is_nothrow_swappable_v<__alloc_rr>);
0181
0182 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI bool __invariants() const;
0183
0184 private:
0185 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __move_assign_alloc(__split_buffer& __c, true_type)
0186 _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value) {
0187 __alloc_ = std::move(__c.__alloc_);
0188 }
0189
0190 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __move_assign_alloc(__split_buffer&, false_type) _NOEXCEPT {}
0191
0192 struct _ConstructTransaction {
0193 _LIBCPP_CONSTEXPR_SINCE_CXX20
0194 _LIBCPP_HIDE_FROM_ABI explicit _ConstructTransaction(pointer* __p, size_type __n) _NOEXCEPT
0195 : __pos_(*__p),
0196 __end_(*__p + __n),
0197 __dest_(__p) {}
0198
0199 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI ~_ConstructTransaction() { *__dest_ = __pos_; }
0200
0201 pointer __pos_;
0202 const pointer __end_;
0203
0204 private:
0205 pointer* __dest_;
0206 };
0207 };
0208
0209 template <class _Tp, class _Allocator>
0210 _LIBCPP_CONSTEXPR_SINCE_CXX20 bool __split_buffer<_Tp, _Allocator>::__invariants() const {
0211 if (__first_ == nullptr) {
0212 if (__begin_ != nullptr)
0213 return false;
0214 if (__end_ != nullptr)
0215 return false;
0216 if (__cap_ != nullptr)
0217 return false;
0218 } else {
0219 if (__begin_ < __first_)
0220 return false;
0221 if (__end_ < __begin_)
0222 return false;
0223 if (__cap_ < __end_)
0224 return false;
0225 }
0226 return true;
0227 }
0228
0229 // Default constructs __n objects starting at __end_
0230 // throws if construction throws
0231 // Precondition: __n > 0
0232 // Precondition: size() + __n <= capacity()
0233 // Postcondition: size() == size() + __n
0234 template <class _Tp, class _Allocator>
0235 _LIBCPP_CONSTEXPR_SINCE_CXX20 void __split_buffer<_Tp, _Allocator>::__construct_at_end(size_type __n) {
0236 _ConstructTransaction __tx(&this->__end_, __n);
0237 for (; __tx.__pos_ != __tx.__end_; ++__tx.__pos_) {
0238 __alloc_traits::construct(__alloc_, std::__to_address(__tx.__pos_));
0239 }
0240 }
0241
0242 // Copy constructs __n objects starting at __end_ from __x
0243 // throws if construction throws
0244 // Precondition: __n > 0
0245 // Precondition: size() + __n <= capacity()
0246 // Postcondition: size() == old size() + __n
0247 // Postcondition: [i] == __x for all i in [size() - __n, __n)
0248 template <class _Tp, class _Allocator>
0249 _LIBCPP_CONSTEXPR_SINCE_CXX20 void
0250 __split_buffer<_Tp, _Allocator>::__construct_at_end(size_type __n, const_reference __x) {
0251 _ConstructTransaction __tx(&this->__end_, __n);
0252 for (; __tx.__pos_ != __tx.__end_; ++__tx.__pos_) {
0253 __alloc_traits::construct(__alloc_, std::__to_address(__tx.__pos_), __x);
0254 }
0255 }
0256
0257 template <class _Tp, class _Allocator>
0258 template <class _Iterator, class _Sentinel>
0259 _LIBCPP_CONSTEXPR_SINCE_CXX20 void
0260 __split_buffer<_Tp, _Allocator>::__construct_at_end_with_sentinel(_Iterator __first, _Sentinel __last) {
0261 __alloc_rr& __a = __alloc_;
0262 for (; __first != __last; ++__first) {
0263 if (__end_ == __cap_) {
0264 size_type __old_cap = __cap_ - __first_;
0265 size_type __new_cap = std::max<size_type>(2 * __old_cap, 8);
0266 __split_buffer __buf(__new_cap, 0, __a);
0267 for (pointer __p = __begin_; __p != __end_; ++__p, (void)++__buf.__end_)
0268 __alloc_traits::construct(__buf.__alloc_, std::__to_address(__buf.__end_), std::move(*__p));
0269 swap(__buf);
0270 }
0271 __alloc_traits::construct(__a, std::__to_address(this->__end_), *__first);
0272 ++this->__end_;
0273 }
0274 }
0275 template <class _Tp, class _Allocator>
0276 template <class _ForwardIterator, __enable_if_t<__has_forward_iterator_category<_ForwardIterator>::value, int> >
0277 _LIBCPP_CONSTEXPR_SINCE_CXX20 void
0278 __split_buffer<_Tp, _Allocator>::__construct_at_end(_ForwardIterator __first, _ForwardIterator __last) {
0279 __construct_at_end_with_size(__first, std::distance(__first, __last));
0280 }
0281
0282 template <class _Tp, class _Allocator>
0283 template <class _ForwardIterator>
0284 _LIBCPP_CONSTEXPR_SINCE_CXX20 void
0285 __split_buffer<_Tp, _Allocator>::__construct_at_end_with_size(_ForwardIterator __first, size_type __n) {
0286 _ConstructTransaction __tx(&this->__end_, __n);
0287 for (; __tx.__pos_ != __tx.__end_; ++__tx.__pos_, (void)++__first) {
0288 __alloc_traits::construct(__alloc_, std::__to_address(__tx.__pos_), *__first);
0289 }
0290 }
0291
0292 template <class _Tp, class _Allocator>
0293 _LIBCPP_CONSTEXPR_SINCE_CXX20 inline void
0294 __split_buffer<_Tp, _Allocator>::__destruct_at_begin(pointer __new_begin, false_type) {
0295 while (__begin_ != __new_begin)
0296 __alloc_traits::destroy(__alloc_, std::__to_address(__begin_++));
0297 }
0298
0299 template <class _Tp, class _Allocator>
0300 _LIBCPP_CONSTEXPR_SINCE_CXX20 inline void
0301 __split_buffer<_Tp, _Allocator>::__destruct_at_begin(pointer __new_begin, true_type) {
0302 __begin_ = __new_begin;
0303 }
0304
0305 template <class _Tp, class _Allocator>
0306 _LIBCPP_CONSTEXPR_SINCE_CXX20 inline _LIBCPP_HIDE_FROM_ABI void
0307 __split_buffer<_Tp, _Allocator>::__destruct_at_end(pointer __new_last, false_type) _NOEXCEPT {
0308 while (__new_last != __end_)
0309 __alloc_traits::destroy(__alloc_, std::__to_address(--__end_));
0310 }
0311
0312 template <class _Tp, class _Allocator>
0313 _LIBCPP_CONSTEXPR_SINCE_CXX20 inline _LIBCPP_HIDE_FROM_ABI void
0314 __split_buffer<_Tp, _Allocator>::__destruct_at_end(pointer __new_last, true_type) _NOEXCEPT {
0315 __end_ = __new_last;
0316 }
0317
0318 template <class _Tp, class _Allocator>
0319 _LIBCPP_CONSTEXPR_SINCE_CXX20
0320 __split_buffer<_Tp, _Allocator>::__split_buffer(size_type __cap, size_type __start, __alloc_rr& __a)
0321 : __cap_(nullptr), __alloc_(__a) {
0322 if (__cap == 0) {
0323 __first_ = nullptr;
0324 } else {
0325 auto __allocation = std::__allocate_at_least(__alloc_, __cap);
0326 __first_ = __allocation.ptr;
0327 __cap = __allocation.count;
0328 }
0329 __begin_ = __end_ = __first_ + __start;
0330 __cap_ = __first_ + __cap;
0331 }
0332
0333 template <class _Tp, class _Allocator>
0334 _LIBCPP_CONSTEXPR_SINCE_CXX20 __split_buffer<_Tp, _Allocator>::~__split_buffer() {
0335 clear();
0336 if (__first_)
0337 __alloc_traits::deallocate(__alloc_, __first_, capacity());
0338 }
0339
0340 template <class _Tp, class _Allocator>
0341 _LIBCPP_CONSTEXPR_SINCE_CXX20 __split_buffer<_Tp, _Allocator>::__split_buffer(__split_buffer&& __c)
0342 _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value)
0343 : __first_(std::move(__c.__first_)),
0344 __begin_(std::move(__c.__begin_)),
0345 __end_(std::move(__c.__end_)),
0346 __cap_(std::move(__c.__cap_)),
0347 __alloc_(std::move(__c.__alloc_)) {
0348 __c.__first_ = nullptr;
0349 __c.__begin_ = nullptr;
0350 __c.__end_ = nullptr;
0351 __c.__cap_ = nullptr;
0352 }
0353
0354 template <class _Tp, class _Allocator>
0355 _LIBCPP_CONSTEXPR_SINCE_CXX20
0356 __split_buffer<_Tp, _Allocator>::__split_buffer(__split_buffer&& __c, const __alloc_rr& __a)
0357 : __cap_(nullptr), __alloc_(__a) {
0358 if (__a == __c.__alloc_) {
0359 __first_ = __c.__first_;
0360 __begin_ = __c.__begin_;
0361 __end_ = __c.__end_;
0362 __cap_ = __c.__cap_;
0363 __c.__first_ = nullptr;
0364 __c.__begin_ = nullptr;
0365 __c.__end_ = nullptr;
0366 __c.__cap_ = nullptr;
0367 } else {
0368 auto __allocation = std::__allocate_at_least(__alloc_, __c.size());
0369 __first_ = __allocation.ptr;
0370 __begin_ = __end_ = __first_;
0371 __cap_ = __first_ + __allocation.count;
0372 typedef move_iterator<iterator> _Ip;
0373 __construct_at_end(_Ip(__c.begin()), _Ip(__c.end()));
0374 }
0375 }
0376
0377 template <class _Tp, class _Allocator>
0378 _LIBCPP_CONSTEXPR_SINCE_CXX20 __split_buffer<_Tp, _Allocator>&
0379 __split_buffer<_Tp, _Allocator>::operator=(__split_buffer&& __c)
0380 _NOEXCEPT_((__alloc_traits::propagate_on_container_move_assignment::value &&
0381 is_nothrow_move_assignable<allocator_type>::value) ||
0382 !__alloc_traits::propagate_on_container_move_assignment::value) {
0383 clear();
0384 shrink_to_fit();
0385 __first_ = __c.__first_;
0386 __begin_ = __c.__begin_;
0387 __end_ = __c.__end_;
0388 __cap_ = __c.__cap_;
0389 __move_assign_alloc(__c, integral_constant<bool, __alloc_traits::propagate_on_container_move_assignment::value>());
0390 __c.__first_ = __c.__begin_ = __c.__end_ = __c.__cap_ = nullptr;
0391 return *this;
0392 }
0393
0394 template <class _Tp, class _Allocator>
0395 _LIBCPP_CONSTEXPR_SINCE_CXX20 void __split_buffer<_Tp, _Allocator>::swap(__split_buffer& __x)
0396 _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value || __is_nothrow_swappable_v<__alloc_rr>) {
0397 std::swap(__first_, __x.__first_);
0398 std::swap(__begin_, __x.__begin_);
0399 std::swap(__end_, __x.__end_);
0400 std::swap(__cap_, __x.__cap_);
0401 std::__swap_allocator(__alloc_, __x.__alloc_);
0402 }
0403
0404 template <class _Tp, class _Allocator>
0405 _LIBCPP_CONSTEXPR_SINCE_CXX20 void __split_buffer<_Tp, _Allocator>::shrink_to_fit() _NOEXCEPT {
0406 if (capacity() > size()) {
0407 #if _LIBCPP_HAS_EXCEPTIONS
0408 try {
0409 #endif // _LIBCPP_HAS_EXCEPTIONS
0410 __split_buffer<value_type, __alloc_rr&> __t(size(), 0, __alloc_);
0411 if (__t.capacity() < capacity()) {
0412 __t.__construct_at_end(move_iterator<pointer>(__begin_), move_iterator<pointer>(__end_));
0413 __t.__end_ = __t.__begin_ + (__end_ - __begin_);
0414 std::swap(__first_, __t.__first_);
0415 std::swap(__begin_, __t.__begin_);
0416 std::swap(__end_, __t.__end_);
0417 std::swap(__cap_, __t.__cap_);
0418 }
0419 #if _LIBCPP_HAS_EXCEPTIONS
0420 } catch (...) {
0421 }
0422 #endif // _LIBCPP_HAS_EXCEPTIONS
0423 }
0424 }
0425
0426 template <class _Tp, class _Allocator>
0427 template <class... _Args>
0428 _LIBCPP_CONSTEXPR_SINCE_CXX20 void __split_buffer<_Tp, _Allocator>::emplace_front(_Args&&... __args) {
0429 if (__begin_ == __first_) {
0430 if (__end_ < __cap_) {
0431 difference_type __d = __cap_ - __end_;
0432 __d = (__d + 1) / 2;
0433 __begin_ = std::move_backward(__begin_, __end_, __end_ + __d);
0434 __end_ += __d;
0435 } else {
0436 size_type __c = std::max<size_type>(2 * static_cast<size_type>(__cap_ - __first_), 1);
0437 __split_buffer<value_type, __alloc_rr&> __t(__c, (__c + 3) / 4, __alloc_);
0438 __t.__construct_at_end(move_iterator<pointer>(__begin_), move_iterator<pointer>(__end_));
0439 std::swap(__first_, __t.__first_);
0440 std::swap(__begin_, __t.__begin_);
0441 std::swap(__end_, __t.__end_);
0442 std::swap(__cap_, __t.__cap_);
0443 }
0444 }
0445 __alloc_traits::construct(__alloc_, std::__to_address(__begin_ - 1), std::forward<_Args>(__args)...);
0446 --__begin_;
0447 }
0448
0449 template <class _Tp, class _Allocator>
0450 template <class... _Args>
0451 _LIBCPP_CONSTEXPR_SINCE_CXX20 void __split_buffer<_Tp, _Allocator>::emplace_back(_Args&&... __args) {
0452 if (__end_ == __cap_) {
0453 if (__begin_ > __first_) {
0454 difference_type __d = __begin_ - __first_;
0455 __d = (__d + 1) / 2;
0456 __end_ = std::move(__begin_, __end_, __begin_ - __d);
0457 __begin_ -= __d;
0458 } else {
0459 size_type __c = std::max<size_type>(2 * static_cast<size_type>(__cap_ - __first_), 1);
0460 __split_buffer<value_type, __alloc_rr&> __t(__c, __c / 4, __alloc_);
0461 __t.__construct_at_end(move_iterator<pointer>(__begin_), move_iterator<pointer>(__end_));
0462 std::swap(__first_, __t.__first_);
0463 std::swap(__begin_, __t.__begin_);
0464 std::swap(__end_, __t.__end_);
0465 std::swap(__cap_, __t.__cap_);
0466 }
0467 }
0468 __alloc_traits::construct(__alloc_, std::__to_address(__end_), std::forward<_Args>(__args)...);
0469 ++__end_;
0470 }
0471
0472 template <class _Tp, class _Allocator>
0473 _LIBCPP_CONSTEXPR_SINCE_CXX20 inline _LIBCPP_HIDE_FROM_ABI void
0474 swap(__split_buffer<_Tp, _Allocator>& __x, __split_buffer<_Tp, _Allocator>& __y) _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y))) {
0475 __x.swap(__y);
0476 }
0477
0478 _LIBCPP_END_NAMESPACE_STD
0479
0480 _LIBCPP_POP_MACROS
0481
0482 #endif // _LIBCPP___SPLIT_BUFFER
