Restoring authorship annotation for Andrey Khalyavin <halyavin@gmail.com>. Commit 2 of 2.

1 files changed, 628 insertions, 628 deletions

diff --git a/contrib/libs/cxxsupp/libcxx/include/__split_buffer b/contrib/libs/cxxsupp/libcxx/include/__split_buffer
index 8985bc90f5..0bff575323 100644
--- a/contrib/libs/cxxsupp/libcxx/include/__split_buffer
+++ b/contrib/libs/cxxsupp/libcxx/include/__split_buffer
@@ -1,628 +1,628 @@
-// -*- C++ -*- 
-#ifndef _LIBCPP_SPLIT_BUFFER 
-#define _LIBCPP_SPLIT_BUFFER 
- 
-#include <__config> 
-#include <__utility/forward.h> 
-#include <algorithm> 
-#include <type_traits> 
- 
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 
-#pragma GCC system_header 
-#endif 
- 
-_LIBCPP_PUSH_MACROS 
-#include <__undef_macros> 
- 
- 
-_LIBCPP_BEGIN_NAMESPACE_STD 
- 
-template <class _Tp, class _Allocator = allocator<_Tp> > 
-struct __split_buffer 
-{ 
-private: 
-    __split_buffer(const __split_buffer&); 
-    __split_buffer& operator=(const __split_buffer&); 
-public: 
-    typedef _Tp                                             value_type; 
-    typedef _Allocator                                      allocator_type; 
-    typedef typename remove_reference<allocator_type>::type __alloc_rr; 
-    typedef allocator_traits<__alloc_rr>                    __alloc_traits; 
-    typedef value_type&                                     reference; 
-    typedef const value_type&                               const_reference; 
-    typedef typename __alloc_traits::size_type              size_type; 
-    typedef typename __alloc_traits::difference_type        difference_type; 
-    typedef typename __alloc_traits::pointer                pointer; 
-    typedef typename __alloc_traits::const_pointer          const_pointer; 
-    typedef pointer                                         iterator; 
-    typedef const_pointer                                   const_iterator; 
- 
-    pointer                                         __first_; 
-    pointer                                         __begin_; 
-    pointer                                         __end_; 
-    __compressed_pair<pointer, allocator_type> __end_cap_; 
- 
-    typedef typename add_lvalue_reference<allocator_type>::type __alloc_ref; 
-    typedef typename add_lvalue_reference<allocator_type>::type __alloc_const_ref; 
- 
-    _LIBCPP_INLINE_VISIBILITY __alloc_rr&           __alloc() _NOEXCEPT         {return __end_cap_.second();} 
-    _LIBCPP_INLINE_VISIBILITY const __alloc_rr&     __alloc() const _NOEXCEPT   {return __end_cap_.second();} 
-    _LIBCPP_INLINE_VISIBILITY pointer&              __end_cap() _NOEXCEPT       {return __end_cap_.first();} 
-    _LIBCPP_INLINE_VISIBILITY const pointer&        __end_cap() const _NOEXCEPT {return __end_cap_.first();} 
- 
-    _LIBCPP_INLINE_VISIBILITY 
-    __split_buffer() 
-        _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value); 
-    _LIBCPP_INLINE_VISIBILITY 
-    explicit __split_buffer(__alloc_rr& __a); 
-    _LIBCPP_INLINE_VISIBILITY 
-    explicit __split_buffer(const __alloc_rr& __a); 
-    __split_buffer(size_type __cap, size_type __start, __alloc_rr& __a); 
-    ~__split_buffer(); 
- 
-    __split_buffer(__split_buffer&& __c) 
-        _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value); 
-    __split_buffer(__split_buffer&& __c, const __alloc_rr& __a); 
-    __split_buffer& operator=(__split_buffer&& __c) 
-        _NOEXCEPT_((__alloc_traits::propagate_on_container_move_assignment::value && 
-                is_nothrow_move_assignable<allocator_type>::value) || 
-               !__alloc_traits::propagate_on_container_move_assignment::value); 
- 
-    _LIBCPP_INLINE_VISIBILITY       iterator begin() _NOEXCEPT       {return __begin_;} 
-    _LIBCPP_INLINE_VISIBILITY const_iterator begin() const _NOEXCEPT {return __begin_;} 
-    _LIBCPP_INLINE_VISIBILITY       iterator end() _NOEXCEPT         {return __end_;} 
-    _LIBCPP_INLINE_VISIBILITY const_iterator end() const _NOEXCEPT   {return __end_;} 
- 
-    _LIBCPP_INLINE_VISIBILITY 
-    void clear() _NOEXCEPT 
-        {__destruct_at_end(__begin_);} 
-    _LIBCPP_INLINE_VISIBILITY size_type size() const {return static_cast<size_type>(__end_ - __begin_);} 
-    _LIBCPP_INLINE_VISIBILITY bool empty()     const {return __end_ == __begin_;} 
-    _LIBCPP_INLINE_VISIBILITY size_type capacity() const {return static_cast<size_type>(__end_cap() - __first_);} 
-    _LIBCPP_INLINE_VISIBILITY size_type __front_spare() const {return static_cast<size_type>(__begin_ - __first_);} 
-    _LIBCPP_INLINE_VISIBILITY size_type __back_spare() const {return static_cast<size_type>(__end_cap() - __end_);} 
- 
-    _LIBCPP_INLINE_VISIBILITY       reference front()       {return *__begin_;} 
-    _LIBCPP_INLINE_VISIBILITY const_reference front() const {return *__begin_;} 
-    _LIBCPP_INLINE_VISIBILITY       reference back()        {return *(__end_ - 1);} 
-    _LIBCPP_INLINE_VISIBILITY const_reference back() const  {return *(__end_ - 1);} 
- 
-    void reserve(size_type __n); 
-    void shrink_to_fit() _NOEXCEPT; 
-    void push_front(const_reference __x); 
-    _LIBCPP_INLINE_VISIBILITY void push_back(const_reference __x); 
-    void push_front(value_type&& __x); 
-    void push_back(value_type&& __x); 
-    template <class... _Args> 
-        void emplace_back(_Args&&... __args); 
- 
-    _LIBCPP_INLINE_VISIBILITY void pop_front() {__destruct_at_begin(__begin_+1);} 
-    _LIBCPP_INLINE_VISIBILITY void pop_back() {__destruct_at_end(__end_-1);} 
- 
-    void __uninitialized_at_end(size_type __n); 
-    void __construct_at_end(size_type __n); 
-    void __construct_at_end(size_type __n, const_reference __x); 
-    template <class _InputIter> 
-        typename enable_if 
-        < 
-            __is_cpp17_input_iterator<_InputIter>::value && 
-           !__is_cpp17_forward_iterator<_InputIter>::value, 
-            void 
-        >::type 
-        __construct_at_end(_InputIter __first, _InputIter __last); 
-    template <class _ForwardIterator> 
-        typename enable_if 
-        < 
-            __is_cpp17_forward_iterator<_ForwardIterator>::value, 
-            void 
-        >::type 
-        __construct_at_end(_ForwardIterator __first, _ForwardIterator __last); 
- 
-    _LIBCPP_INLINE_VISIBILITY void __destruct_at_begin(pointer __new_begin) 
-        {__destruct_at_begin(__new_begin, is_trivially_destructible<value_type>());} 
-        _LIBCPP_INLINE_VISIBILITY 
-        void __destruct_at_begin(pointer __new_begin, false_type); 
-        _LIBCPP_INLINE_VISIBILITY 
-        void __destruct_at_begin(pointer __new_begin, true_type); 
- 
-    _LIBCPP_INLINE_VISIBILITY 
-    void __destruct_at_end(pointer __new_last) _NOEXCEPT 
-        {__destruct_at_end(__new_last, false_type());} 
-    _LIBCPP_INLINE_VISIBILITY 
-        void __destruct_at_end(pointer __new_last, false_type) _NOEXCEPT; 
-    _LIBCPP_INLINE_VISIBILITY 
-        void __destruct_at_end(pointer __new_last, true_type) _NOEXCEPT; 
- 
-    void swap(__split_buffer& __x) 
-        _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value|| 
-                   __is_nothrow_swappable<__alloc_rr>::value); 
- 
-    bool __invariants() const; 
- 
-private: 
-    _LIBCPP_INLINE_VISIBILITY 
-    void __move_assign_alloc(__split_buffer& __c, true_type) 
-        _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value) 
-        { 
-            __alloc() = _VSTD::move(__c.__alloc()); 
-        } 
- 
-    _LIBCPP_INLINE_VISIBILITY 
-    void __move_assign_alloc(__split_buffer&, false_type) _NOEXCEPT 
-        {} 
- 
-    struct _ConstructTransaction { 
-      explicit _ConstructTransaction(pointer* __p, size_type __n) _NOEXCEPT 
-      : __pos_(*__p), __end_(*__p + __n), __dest_(__p) { 
-      } 
-      ~_ConstructTransaction() { 
-        *__dest_ = __pos_; 
-      } 
-      pointer __pos_; 
-     const pointer __end_; 
-    private: 
-     pointer *__dest_; 
-    }; 
-}; 
- 
-template <class _Tp, class _Allocator> 
-bool 
-__split_buffer<_Tp, _Allocator>::__invariants() const 
-{ 
-    if (__first_ == nullptr) 
-    { 
-        if (__begin_ != nullptr) 
-            return false; 
-        if (__end_ != nullptr) 
-            return false; 
-        if (__end_cap() != nullptr) 
-            return false; 
-    } 
-    else 
-    { 
-        if (__begin_ < __first_) 
-            return false; 
-        if (__end_ < __begin_) 
-            return false; 
-        if (__end_cap() < __end_) 
-            return false; 
-    } 
-    return true; 
-} 
- 
-template <class _Tp, class _Allocator> 
-void 
-__split_buffer<_Tp, _Allocator>::__uninitialized_at_end(size_type __n) 
-{ 
-    this->__end_ += __n; 
-} 
- 
-//  Default constructs __n objects starting at __end_ 
-//  throws if construction throws 
-//  Precondition:  __n > 0 
-//  Precondition:  size() + __n <= capacity() 
-//  Postcondition:  size() == size() + __n 
-template <class _Tp, class _Allocator> 
-void 
-__split_buffer<_Tp, _Allocator>::__construct_at_end(size_type __n) 
-{ 
-    _ConstructTransaction __tx(&this->__end_, __n); 
-    for (; __tx.__pos_ != __tx.__end_; ++__tx.__pos_) { 
-        __alloc_traits::construct(this->__alloc(), _VSTD::__to_address(__tx.__pos_)); 
-    } 
-} 
- 
-//  Copy constructs __n objects starting at __end_ from __x 
-//  throws if construction throws 
-//  Precondition:  __n > 0 
-//  Precondition:  size() + __n <= capacity() 
-//  Postcondition:  size() == old size() + __n 
-//  Postcondition:  [i] == __x for all i in [size() - __n, __n) 
-template <class _Tp, class _Allocator> 
-void 
-__split_buffer<_Tp, _Allocator>::__construct_at_end(size_type __n, const_reference __x) 
-{ 
-    _ConstructTransaction __tx(&this->__end_, __n); 
-    for (; __tx.__pos_ != __tx.__end_; ++__tx.__pos_) { 
-        __alloc_traits::construct(this->__alloc(), 
-            _VSTD::__to_address(__tx.__pos_), __x); 
-    } 
-} 
- 
-template <class _Tp, class _Allocator> 
-template <class _InputIter> 
-typename enable_if 
-< 
-     __is_cpp17_input_iterator<_InputIter>::value && 
-    !__is_cpp17_forward_iterator<_InputIter>::value, 
-    void 
->::type 
-__split_buffer<_Tp, _Allocator>::__construct_at_end(_InputIter __first, _InputIter __last) 
-{ 
-    __alloc_rr& __a = this->__alloc(); 
-    for (; __first != __last; ++__first) 
-    { 
-        if (__end_ == __end_cap()) 
-        { 
-            size_type __old_cap = __end_cap() - __first_; 
-            size_type __new_cap = _VSTD::max<size_type>(2 * __old_cap, 8); 
-            __split_buffer __buf(__new_cap, 0, __a); 
-            for (pointer __p = __begin_; __p != __end_; ++__p, (void) ++__buf.__end_) 
-                __alloc_traits::construct(__buf.__alloc(), 
-                        _VSTD::__to_address(__buf.__end_), _VSTD::move(*__p)); 
-            swap(__buf); 
-        } 
-        __alloc_traits::construct(__a, _VSTD::__to_address(this->__end_), *__first); 
-        ++this->__end_; 
-    } 
-} 
- 
-template <class _Tp, class _Allocator> 
-template <class _ForwardIterator> 
-typename enable_if 
-< 
-    __is_cpp17_forward_iterator<_ForwardIterator>::value, 
-    void 
->::type 
-__split_buffer<_Tp, _Allocator>::__construct_at_end(_ForwardIterator __first, _ForwardIterator __last) 
-{ 
-    _ConstructTransaction __tx(&this->__end_, _VSTD::distance(__first, __last)); 
-    for (; __tx.__pos_ != __tx.__end_; ++__tx.__pos_, (void) ++__first) { 
-        __alloc_traits::construct(this->__alloc(), 
-            _VSTD::__to_address(__tx.__pos_), *__first); 
-    } 
-} 
- 
-template <class _Tp, class _Allocator> 
-inline 
-void 
-__split_buffer<_Tp, _Allocator>::__destruct_at_begin(pointer __new_begin, false_type) 
-{ 
-    while (__begin_ != __new_begin) 
-        __alloc_traits::destroy(__alloc(), _VSTD::__to_address(__begin_++)); 
-} 
- 
-template <class _Tp, class _Allocator> 
-inline 
-void 
-__split_buffer<_Tp, _Allocator>::__destruct_at_begin(pointer __new_begin, true_type) 
-{ 
-    __begin_ = __new_begin; 
-} 
- 
-template <class _Tp, class _Allocator> 
-inline _LIBCPP_INLINE_VISIBILITY 
-void 
-__split_buffer<_Tp, _Allocator>::__destruct_at_end(pointer __new_last, false_type) _NOEXCEPT 
-{ 
-    while (__new_last != __end_) 
-        __alloc_traits::destroy(__alloc(), _VSTD::__to_address(--__end_)); 
-} 
- 
-template <class _Tp, class _Allocator> 
-inline _LIBCPP_INLINE_VISIBILITY 
-void 
-__split_buffer<_Tp, _Allocator>::__destruct_at_end(pointer __new_last, true_type) _NOEXCEPT 
-{ 
-    __end_ = __new_last; 
-} 
- 
-template <class _Tp, class _Allocator> 
-__split_buffer<_Tp, _Allocator>::__split_buffer(size_type __cap, size_type __start, __alloc_rr& __a) 
-    : __end_cap_(nullptr, __a) 
-{ 
-    __first_ = __cap != 0 ? __alloc_traits::allocate(__alloc(), __cap) : nullptr; 
-    __begin_ = __end_ = __first_ + __start; 
-    __end_cap() = __first_ + __cap; 
-} 
- 
-template <class _Tp, class _Allocator> 
-inline 
-__split_buffer<_Tp, _Allocator>::__split_buffer() 
-    _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value) 
-    : __first_(nullptr), __begin_(nullptr), __end_(nullptr), __end_cap_(nullptr, __default_init_tag()) 
-{ 
-} 
- 
-template <class _Tp, class _Allocator> 
-inline 
-__split_buffer<_Tp, _Allocator>::__split_buffer(__alloc_rr& __a) 
-    : __first_(nullptr), __begin_(nullptr), __end_(nullptr), __end_cap_(nullptr, __a) 
-{ 
-} 
- 
-template <class _Tp, class _Allocator> 
-inline 
-__split_buffer<_Tp, _Allocator>::__split_buffer(const __alloc_rr& __a) 
-    : __first_(nullptr), __begin_(nullptr), __end_(nullptr), __end_cap_(nullptr, __a) 
-{ 
-} 
- 
-template <class _Tp, class _Allocator> 
-__split_buffer<_Tp, _Allocator>::~__split_buffer() 
-{ 
-    clear(); 
-    if (__first_) 
-        __alloc_traits::deallocate(__alloc(), __first_, capacity()); 
-} 
- 
-template <class _Tp, class _Allocator> 
-__split_buffer<_Tp, _Allocator>::__split_buffer(__split_buffer&& __c) 
-    _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value) 
-    : __first_(_VSTD::move(__c.__first_)), 
-      __begin_(_VSTD::move(__c.__begin_)), 
-      __end_(_VSTD::move(__c.__end_)), 
-      __end_cap_(_VSTD::move(__c.__end_cap_)) 
-{ 
-    __c.__first_ = nullptr; 
-    __c.__begin_ = nullptr; 
-    __c.__end_ = nullptr; 
-    __c.__end_cap() = nullptr; 
-} 
- 
-template <class _Tp, class _Allocator> 
-__split_buffer<_Tp, _Allocator>::__split_buffer(__split_buffer&& __c, const __alloc_rr& __a) 
-    : __end_cap_(nullptr, __a) 
-{ 
-    if (__a == __c.__alloc()) 
-    { 
-        __first_ = __c.__first_; 
-        __begin_ = __c.__begin_; 
-        __end_ = __c.__end_; 
-        __end_cap() = __c.__end_cap(); 
-        __c.__first_ = nullptr; 
-        __c.__begin_ = nullptr; 
-        __c.__end_ = nullptr; 
-        __c.__end_cap() = nullptr; 
-    } 
-    else 
-    { 
-        size_type __cap = __c.size(); 
-        __first_ = __alloc_traits::allocate(__alloc(), __cap); 
-        __begin_ = __end_ = __first_; 
-        __end_cap() = __first_ + __cap; 
-        typedef move_iterator<iterator> _Ip; 
-        __construct_at_end(_Ip(__c.begin()), _Ip(__c.end())); 
-    } 
-} 
- 
-template <class _Tp, class _Allocator> 
-__split_buffer<_Tp, _Allocator>& 
-__split_buffer<_Tp, _Allocator>::operator=(__split_buffer&& __c) 
-    _NOEXCEPT_((__alloc_traits::propagate_on_container_move_assignment::value && 
-                is_nothrow_move_assignable<allocator_type>::value) || 
-               !__alloc_traits::propagate_on_container_move_assignment::value) 
-{ 
-    clear(); 
-    shrink_to_fit(); 
-    __first_ = __c.__first_; 
-    __begin_ = __c.__begin_; 
-    __end_ = __c.__end_; 
-    __end_cap() = __c.__end_cap(); 
-    __move_assign_alloc(__c, 
-        integral_constant<bool, 
-                          __alloc_traits::propagate_on_container_move_assignment::value>()); 
-    __c.__first_ = __c.__begin_ = __c.__end_ = __c.__end_cap() = nullptr; 
-    return *this; 
-} 
- 
-template <class _Tp, class _Allocator> 
-void 
-__split_buffer<_Tp, _Allocator>::swap(__split_buffer& __x) 
-        _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value|| 
-                   __is_nothrow_swappable<__alloc_rr>::value) 
-{ 
-    _VSTD::swap(__first_, __x.__first_); 
-    _VSTD::swap(__begin_, __x.__begin_); 
-    _VSTD::swap(__end_, __x.__end_); 
-    _VSTD::swap(__end_cap(), __x.__end_cap()); 
-    _VSTD::__swap_allocator(__alloc(), __x.__alloc()); 
-} 
- 
-template <class _Tp, class _Allocator> 
-void 
-__split_buffer<_Tp, _Allocator>::reserve(size_type __n) 
-{ 
-    if (__n < capacity()) 
-    { 
-        __split_buffer<value_type, __alloc_rr&> __t(__n, 0, __alloc()); 
-        __t.__construct_at_end(move_iterator<pointer>(__begin_), 
-                               move_iterator<pointer>(__end_)); 
-        _VSTD::swap(__first_, __t.__first_); 
-        _VSTD::swap(__begin_, __t.__begin_); 
-        _VSTD::swap(__end_, __t.__end_); 
-        _VSTD::swap(__end_cap(), __t.__end_cap()); 
-    } 
-} 
- 
-template <class _Tp, class _Allocator> 
-void 
-__split_buffer<_Tp, _Allocator>::shrink_to_fit() _NOEXCEPT 
-{ 
-    if (capacity() > size()) 
-    { 
-#ifndef _LIBCPP_NO_EXCEPTIONS 
-        try 
-        { 
-#endif // _LIBCPP_NO_EXCEPTIONS 
-            __split_buffer<value_type, __alloc_rr&> __t(size(), 0, __alloc()); 
-            __t.__construct_at_end(move_iterator<pointer>(__begin_), 
-                                   move_iterator<pointer>(__end_)); 
-            __t.__end_ = __t.__begin_ + (__end_ - __begin_); 
-            _VSTD::swap(__first_, __t.__first_); 
-            _VSTD::swap(__begin_, __t.__begin_); 
-            _VSTD::swap(__end_, __t.__end_); 
-            _VSTD::swap(__end_cap(), __t.__end_cap()); 
-#ifndef _LIBCPP_NO_EXCEPTIONS 
-        } 
-        catch (...) 
-        { 
-        } 
-#endif // _LIBCPP_NO_EXCEPTIONS 
-    } 
-} 
- 
-template <class _Tp, class _Allocator> 
-void 
-__split_buffer<_Tp, _Allocator>::push_front(const_reference __x) 
-{ 
-    if (__begin_ == __first_) 
-    { 
-        if (__end_ < __end_cap()) 
-        { 
-            difference_type __d = __end_cap() - __end_; 
-            __d = (__d + 1) / 2; 
-            __begin_ = _VSTD::move_backward(__begin_, __end_, __end_ + __d); 
-            __end_ += __d; 
-        } 
-        else 
-        { 
-            size_type __c = max<size_type>(2 * static_cast<size_t>(__end_cap() - __first_), 1); 
-            __split_buffer<value_type, __alloc_rr&> __t(__c, (__c + 3) / 4, __alloc()); 
-            __t.__construct_at_end(move_iterator<pointer>(__begin_), 
-                                   move_iterator<pointer>(__end_)); 
-            _VSTD::swap(__first_, __t.__first_); 
-            _VSTD::swap(__begin_, __t.__begin_); 
-            _VSTD::swap(__end_, __t.__end_); 
-            _VSTD::swap(__end_cap(), __t.__end_cap()); 
-        } 
-    } 
-    __alloc_traits::construct(__alloc(), _VSTD::__to_address(__begin_-1), __x); 
-    --__begin_; 
-} 
- 
-template <class _Tp, class _Allocator> 
-void 
-__split_buffer<_Tp, _Allocator>::push_front(value_type&& __x) 
-{ 
-    if (__begin_ == __first_) 
-    { 
-        if (__end_ < __end_cap()) 
-        { 
-            difference_type __d = __end_cap() - __end_; 
-            __d = (__d + 1) / 2; 
-            __begin_ = _VSTD::move_backward(__begin_, __end_, __end_ + __d); 
-            __end_ += __d; 
-        } 
-        else 
-        { 
-            size_type __c = max<size_type>(2 * static_cast<size_t>(__end_cap() - __first_), 1); 
-            __split_buffer<value_type, __alloc_rr&> __t(__c, (__c + 3) / 4, __alloc()); 
-            __t.__construct_at_end(move_iterator<pointer>(__begin_), 
-                                   move_iterator<pointer>(__end_)); 
-            _VSTD::swap(__first_, __t.__first_); 
-            _VSTD::swap(__begin_, __t.__begin_); 
-            _VSTD::swap(__end_, __t.__end_); 
-            _VSTD::swap(__end_cap(), __t.__end_cap()); 
-        } 
-    } 
-    __alloc_traits::construct(__alloc(), _VSTD::__to_address(__begin_-1), 
-            _VSTD::move(__x)); 
-    --__begin_; 
-} 
- 
-template <class _Tp, class _Allocator> 
-inline _LIBCPP_INLINE_VISIBILITY 
-void 
-__split_buffer<_Tp, _Allocator>::push_back(const_reference __x) 
-{ 
-    if (__end_ == __end_cap()) 
-    { 
-        if (__begin_ > __first_) 
-        { 
-            difference_type __d = __begin_ - __first_; 
-            __d = (__d + 1) / 2; 
-            __end_ = _VSTD::move(__begin_, __end_, __begin_ - __d); 
-            __begin_ -= __d; 
-        } 
-        else 
-        { 
-            size_type __c = max<size_type>(2 * static_cast<size_t>(__end_cap() - __first_), 1); 
-            __split_buffer<value_type, __alloc_rr&> __t(__c, __c / 4, __alloc()); 
-            __t.__construct_at_end(move_iterator<pointer>(__begin_), 
-                                   move_iterator<pointer>(__end_)); 
-            _VSTD::swap(__first_, __t.__first_); 
-            _VSTD::swap(__begin_, __t.__begin_); 
-            _VSTD::swap(__end_, __t.__end_); 
-            _VSTD::swap(__end_cap(), __t.__end_cap()); 
-        } 
-    } 
-    __alloc_traits::construct(__alloc(), _VSTD::__to_address(__end_), __x); 
-    ++__end_; 
-} 
- 
-template <class _Tp, class _Allocator> 
-void 
-__split_buffer<_Tp, _Allocator>::push_back(value_type&& __x) 
-{ 
-    if (__end_ == __end_cap()) 
-    { 
-        if (__begin_ > __first_) 
-        { 
-            difference_type __d = __begin_ - __first_; 
-            __d = (__d + 1) / 2; 
-            __end_ = _VSTD::move(__begin_, __end_, __begin_ - __d); 
-            __begin_ -= __d; 
-        } 
-        else 
-        { 
-            size_type __c = max<size_type>(2 * static_cast<size_t>(__end_cap() - __first_), 1); 
-            __split_buffer<value_type, __alloc_rr&> __t(__c, __c / 4, __alloc()); 
-            __t.__construct_at_end(move_iterator<pointer>(__begin_), 
-                                   move_iterator<pointer>(__end_)); 
-            _VSTD::swap(__first_, __t.__first_); 
-            _VSTD::swap(__begin_, __t.__begin_); 
-            _VSTD::swap(__end_, __t.__end_); 
-            _VSTD::swap(__end_cap(), __t.__end_cap()); 
-        } 
-    } 
-    __alloc_traits::construct(__alloc(), _VSTD::__to_address(__end_), 
-            _VSTD::move(__x)); 
-    ++__end_; 
-} 
- 
-template <class _Tp, class _Allocator> 
-template <class... _Args> 
-void 
-__split_buffer<_Tp, _Allocator>::emplace_back(_Args&&... __args) 
-{ 
-    if (__end_ == __end_cap()) 
-    { 
-        if (__begin_ > __first_) 
-        { 
-            difference_type __d = __begin_ - __first_; 
-            __d = (__d + 1) / 2; 
-            __end_ = _VSTD::move(__begin_, __end_, __begin_ - __d); 
-            __begin_ -= __d; 
-        } 
-        else 
-        { 
-            size_type __c = max<size_type>(2 * static_cast<size_t>(__end_cap() - __first_), 1); 
-            __split_buffer<value_type, __alloc_rr&> __t(__c, __c / 4, __alloc()); 
-            __t.__construct_at_end(move_iterator<pointer>(__begin_), 
-                                   move_iterator<pointer>(__end_)); 
-            _VSTD::swap(__first_, __t.__first_); 
-            _VSTD::swap(__begin_, __t.__begin_); 
-            _VSTD::swap(__end_, __t.__end_); 
-            _VSTD::swap(__end_cap(), __t.__end_cap()); 
-        } 
-    } 
-    __alloc_traits::construct(__alloc(), _VSTD::__to_address(__end_), 
-                              _VSTD::forward<_Args>(__args)...); 
-    ++__end_; 
-} 
- 
-template <class _Tp, class _Allocator> 
-inline _LIBCPP_INLINE_VISIBILITY 
-void 
-swap(__split_buffer<_Tp, _Allocator>& __x, __split_buffer<_Tp, _Allocator>& __y) 
-        _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y))) 
-{ 
-    __x.swap(__y); 
-} 
- 
-_LIBCPP_END_NAMESPACE_STD 
- 
-_LIBCPP_POP_MACROS 
- 
-#endif // _LIBCPP_SPLIT_BUFFER 
+// -*- C++ -*-
+#ifndef _LIBCPP_SPLIT_BUFFER
+#define _LIBCPP_SPLIT_BUFFER
+
+#include <__config>
+#include <__utility/forward.h>
+#include <algorithm>
+#include <type_traits>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_PUSH_MACROS
+#include <__undef_macros>
+
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _Tp, class _Allocator = allocator<_Tp> >
+struct __split_buffer
+{
+private:
+    __split_buffer(const __split_buffer&);
+    __split_buffer& operator=(const __split_buffer&);
+public:
+    typedef _Tp                                             value_type;
+    typedef _Allocator                                      allocator_type;
+    typedef typename remove_reference<allocator_type>::type __alloc_rr;
+    typedef allocator_traits<__alloc_rr>                    __alloc_traits;
+    typedef value_type&                                     reference;
+    typedef const value_type&                               const_reference;
+    typedef typename __alloc_traits::size_type              size_type;
+    typedef typename __alloc_traits::difference_type        difference_type;
+    typedef typename __alloc_traits::pointer                pointer;
+    typedef typename __alloc_traits::const_pointer          const_pointer;
+    typedef pointer                                         iterator;
+    typedef const_pointer                                   const_iterator;
+
+    pointer                                         __first_;
+    pointer                                         __begin_;
+    pointer                                         __end_;
+    __compressed_pair<pointer, allocator_type> __end_cap_;
+
+    typedef typename add_lvalue_reference<allocator_type>::type __alloc_ref;
+    typedef typename add_lvalue_reference<allocator_type>::type __alloc_const_ref;
+
+    _LIBCPP_INLINE_VISIBILITY __alloc_rr&           __alloc() _NOEXCEPT         {return __end_cap_.second();}
+    _LIBCPP_INLINE_VISIBILITY const __alloc_rr&     __alloc() const _NOEXCEPT   {return __end_cap_.second();}
+    _LIBCPP_INLINE_VISIBILITY pointer&              __end_cap() _NOEXCEPT       {return __end_cap_.first();}
+    _LIBCPP_INLINE_VISIBILITY const pointer&        __end_cap() const _NOEXCEPT {return __end_cap_.first();}
+
+    _LIBCPP_INLINE_VISIBILITY
+    __split_buffer()
+        _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value);
+    _LIBCPP_INLINE_VISIBILITY
+    explicit __split_buffer(__alloc_rr& __a);
+    _LIBCPP_INLINE_VISIBILITY
+    explicit __split_buffer(const __alloc_rr& __a);
+    __split_buffer(size_type __cap, size_type __start, __alloc_rr& __a);
+    ~__split_buffer();
+
+    __split_buffer(__split_buffer&& __c)
+        _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value);
+    __split_buffer(__split_buffer&& __c, const __alloc_rr& __a);
+    __split_buffer& operator=(__split_buffer&& __c)
+        _NOEXCEPT_((__alloc_traits::propagate_on_container_move_assignment::value &&
+                is_nothrow_move_assignable<allocator_type>::value) ||
+               !__alloc_traits::propagate_on_container_move_assignment::value);
+
+    _LIBCPP_INLINE_VISIBILITY       iterator begin() _NOEXCEPT       {return __begin_;}
+    _LIBCPP_INLINE_VISIBILITY const_iterator begin() const _NOEXCEPT {return __begin_;}
+    _LIBCPP_INLINE_VISIBILITY       iterator end() _NOEXCEPT         {return __end_;}
+    _LIBCPP_INLINE_VISIBILITY const_iterator end() const _NOEXCEPT   {return __end_;}
+
+    _LIBCPP_INLINE_VISIBILITY
+    void clear() _NOEXCEPT
+        {__destruct_at_end(__begin_);}
+    _LIBCPP_INLINE_VISIBILITY size_type size() const {return static_cast<size_type>(__end_ - __begin_);}
+    _LIBCPP_INLINE_VISIBILITY bool empty()     const {return __end_ == __begin_;}
+    _LIBCPP_INLINE_VISIBILITY size_type capacity() const {return static_cast<size_type>(__end_cap() - __first_);}
+    _LIBCPP_INLINE_VISIBILITY size_type __front_spare() const {return static_cast<size_type>(__begin_ - __first_);}
+    _LIBCPP_INLINE_VISIBILITY size_type __back_spare() const {return static_cast<size_type>(__end_cap() - __end_);}
+
+    _LIBCPP_INLINE_VISIBILITY       reference front()       {return *__begin_;}
+    _LIBCPP_INLINE_VISIBILITY const_reference front() const {return *__begin_;}
+    _LIBCPP_INLINE_VISIBILITY       reference back()        {return *(__end_ - 1);}
+    _LIBCPP_INLINE_VISIBILITY const_reference back() const  {return *(__end_ - 1);}
+
+    void reserve(size_type __n);
+    void shrink_to_fit() _NOEXCEPT;
+    void push_front(const_reference __x);
+    _LIBCPP_INLINE_VISIBILITY void push_back(const_reference __x);
+    void push_front(value_type&& __x);
+    void push_back(value_type&& __x);
+    template <class... _Args>
+        void emplace_back(_Args&&... __args);
+
+    _LIBCPP_INLINE_VISIBILITY void pop_front() {__destruct_at_begin(__begin_+1);}
+    _LIBCPP_INLINE_VISIBILITY void pop_back() {__destruct_at_end(__end_-1);}
+
+    void __uninitialized_at_end(size_type __n);
+    void __construct_at_end(size_type __n);
+    void __construct_at_end(size_type __n, const_reference __x);
+    template <class _InputIter>
+        typename enable_if
+        <
+            __is_cpp17_input_iterator<_InputIter>::value &&
+           !__is_cpp17_forward_iterator<_InputIter>::value,
+            void
+        >::type
+        __construct_at_end(_InputIter __first, _InputIter __last);
+    template <class _ForwardIterator>
+        typename enable_if
+        <
+            __is_cpp17_forward_iterator<_ForwardIterator>::value,
+            void
+        >::type
+        __construct_at_end(_ForwardIterator __first, _ForwardIterator __last);
+
+    _LIBCPP_INLINE_VISIBILITY void __destruct_at_begin(pointer __new_begin)
+        {__destruct_at_begin(__new_begin, is_trivially_destructible<value_type>());}
+        _LIBCPP_INLINE_VISIBILITY
+        void __destruct_at_begin(pointer __new_begin, false_type);
+        _LIBCPP_INLINE_VISIBILITY
+        void __destruct_at_begin(pointer __new_begin, true_type);
+
+    _LIBCPP_INLINE_VISIBILITY
+    void __destruct_at_end(pointer __new_last) _NOEXCEPT
+        {__destruct_at_end(__new_last, false_type());}
+    _LIBCPP_INLINE_VISIBILITY
+        void __destruct_at_end(pointer __new_last, false_type) _NOEXCEPT;
+    _LIBCPP_INLINE_VISIBILITY
+        void __destruct_at_end(pointer __new_last, true_type) _NOEXCEPT;
+
+    void swap(__split_buffer& __x)
+        _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value||
+                   __is_nothrow_swappable<__alloc_rr>::value);
+
+    bool __invariants() const;
+
+private:
+    _LIBCPP_INLINE_VISIBILITY
+    void __move_assign_alloc(__split_buffer& __c, true_type)
+        _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value)
+        {
+            __alloc() = _VSTD::move(__c.__alloc());
+        }
+
+    _LIBCPP_INLINE_VISIBILITY
+    void __move_assign_alloc(__split_buffer&, false_type) _NOEXCEPT
+        {}
+
+    struct _ConstructTransaction {
+      explicit _ConstructTransaction(pointer* __p, size_type __n) _NOEXCEPT
+      : __pos_(*__p), __end_(*__p + __n), __dest_(__p) {
+      }
+      ~_ConstructTransaction() {
+        *__dest_ = __pos_;
+      }
+      pointer __pos_;
+     const pointer __end_;
+    private:
+     pointer *__dest_;
+    };
+};
+
+template <class _Tp, class _Allocator>
+bool
+__split_buffer<_Tp, _Allocator>::__invariants() const
+{
+    if (__first_ == nullptr)
+    {
+        if (__begin_ != nullptr)
+            return false;
+        if (__end_ != nullptr)
+            return false;
+        if (__end_cap() != nullptr)
+            return false;
+    }
+    else
+    {
+        if (__begin_ < __first_)
+            return false;
+        if (__end_ < __begin_)
+            return false;
+        if (__end_cap() < __end_)
+            return false;
+    }
+    return true;
+}
+
+template <class _Tp, class _Allocator>
+void
+__split_buffer<_Tp, _Allocator>::__uninitialized_at_end(size_type __n)
+{
+    this->__end_ += __n;
+}
+
+//  Default constructs __n objects starting at __end_
+//  throws if construction throws
+//  Precondition:  __n > 0
+//  Precondition:  size() + __n <= capacity()
+//  Postcondition:  size() == size() + __n
+template <class _Tp, class _Allocator>
+void
+__split_buffer<_Tp, _Allocator>::__construct_at_end(size_type __n)
+{
+    _ConstructTransaction __tx(&this->__end_, __n);
+    for (; __tx.__pos_ != __tx.__end_; ++__tx.__pos_) {
+        __alloc_traits::construct(this->__alloc(), _VSTD::__to_address(__tx.__pos_));
+    }
+}
+
+//  Copy constructs __n objects starting at __end_ from __x
+//  throws if construction throws
+//  Precondition:  __n > 0
+//  Precondition:  size() + __n <= capacity()
+//  Postcondition:  size() == old size() + __n
+//  Postcondition:  [i] == __x for all i in [size() - __n, __n)
+template <class _Tp, class _Allocator>
+void
+__split_buffer<_Tp, _Allocator>::__construct_at_end(size_type __n, const_reference __x)
+{
+    _ConstructTransaction __tx(&this->__end_, __n);
+    for (; __tx.__pos_ != __tx.__end_; ++__tx.__pos_) {
+        __alloc_traits::construct(this->__alloc(),
+            _VSTD::__to_address(__tx.__pos_), __x);
+    }
+}
+
+template <class _Tp, class _Allocator>
+template <class _InputIter>
+typename enable_if
+<
+     __is_cpp17_input_iterator<_InputIter>::value &&
+    !__is_cpp17_forward_iterator<_InputIter>::value,
+    void
+>::type
+__split_buffer<_Tp, _Allocator>::__construct_at_end(_InputIter __first, _InputIter __last)
+{
+    __alloc_rr& __a = this->__alloc();
+    for (; __first != __last; ++__first)
+    {
+        if (__end_ == __end_cap())
+        {
+            size_type __old_cap = __end_cap() - __first_;
+            size_type __new_cap = _VSTD::max<size_type>(2 * __old_cap, 8);
+            __split_buffer __buf(__new_cap, 0, __a);
+            for (pointer __p = __begin_; __p != __end_; ++__p, (void) ++__buf.__end_)
+                __alloc_traits::construct(__buf.__alloc(),
+                        _VSTD::__to_address(__buf.__end_), _VSTD::move(*__p));
+            swap(__buf);
+        }
+        __alloc_traits::construct(__a, _VSTD::__to_address(this->__end_), *__first);
+        ++this->__end_;
+    }
+}
+
+template <class _Tp, class _Allocator>
+template <class _ForwardIterator>
+typename enable_if
+<
+    __is_cpp17_forward_iterator<_ForwardIterator>::value,
+    void
+>::type
+__split_buffer<_Tp, _Allocator>::__construct_at_end(_ForwardIterator __first, _ForwardIterator __last)
+{
+    _ConstructTransaction __tx(&this->__end_, _VSTD::distance(__first, __last));
+    for (; __tx.__pos_ != __tx.__end_; ++__tx.__pos_, (void) ++__first) {
+        __alloc_traits::construct(this->__alloc(),
+            _VSTD::__to_address(__tx.__pos_), *__first);
+    }
+}
+
+template <class _Tp, class _Allocator>
+inline
+void
+__split_buffer<_Tp, _Allocator>::__destruct_at_begin(pointer __new_begin, false_type)
+{
+    while (__begin_ != __new_begin)
+        __alloc_traits::destroy(__alloc(), _VSTD::__to_address(__begin_++));
+}
+
+template <class _Tp, class _Allocator>
+inline
+void
+__split_buffer<_Tp, _Allocator>::__destruct_at_begin(pointer __new_begin, true_type)
+{
+    __begin_ = __new_begin;
+}
+
+template <class _Tp, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+__split_buffer<_Tp, _Allocator>::__destruct_at_end(pointer __new_last, false_type) _NOEXCEPT
+{
+    while (__new_last != __end_)
+        __alloc_traits::destroy(__alloc(), _VSTD::__to_address(--__end_));
+}
+
+template <class _Tp, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+__split_buffer<_Tp, _Allocator>::__destruct_at_end(pointer __new_last, true_type) _NOEXCEPT
+{
+    __end_ = __new_last;
+}
+
+template <class _Tp, class _Allocator>
+__split_buffer<_Tp, _Allocator>::__split_buffer(size_type __cap, size_type __start, __alloc_rr& __a)
+    : __end_cap_(nullptr, __a)
+{
+    __first_ = __cap != 0 ? __alloc_traits::allocate(__alloc(), __cap) : nullptr;
+    __begin_ = __end_ = __first_ + __start;
+    __end_cap() = __first_ + __cap;
+}
+
+template <class _Tp, class _Allocator>
+inline
+__split_buffer<_Tp, _Allocator>::__split_buffer()
+    _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value)
+    : __first_(nullptr), __begin_(nullptr), __end_(nullptr), __end_cap_(nullptr, __default_init_tag())
+{
+}
+
+template <class _Tp, class _Allocator>
+inline
+__split_buffer<_Tp, _Allocator>::__split_buffer(__alloc_rr& __a)
+    : __first_(nullptr), __begin_(nullptr), __end_(nullptr), __end_cap_(nullptr, __a)
+{
+}
+
+template <class _Tp, class _Allocator>
+inline
+__split_buffer<_Tp, _Allocator>::__split_buffer(const __alloc_rr& __a)
+    : __first_(nullptr), __begin_(nullptr), __end_(nullptr), __end_cap_(nullptr, __a)
+{
+}
+
+template <class _Tp, class _Allocator>
+__split_buffer<_Tp, _Allocator>::~__split_buffer()
+{
+    clear();
+    if (__first_)
+        __alloc_traits::deallocate(__alloc(), __first_, capacity());
+}
+
+template <class _Tp, class _Allocator>
+__split_buffer<_Tp, _Allocator>::__split_buffer(__split_buffer&& __c)
+    _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value)
+    : __first_(_VSTD::move(__c.__first_)),
+      __begin_(_VSTD::move(__c.__begin_)),
+      __end_(_VSTD::move(__c.__end_)),
+      __end_cap_(_VSTD::move(__c.__end_cap_))
+{
+    __c.__first_ = nullptr;
+    __c.__begin_ = nullptr;
+    __c.__end_ = nullptr;
+    __c.__end_cap() = nullptr;
+}
+
+template <class _Tp, class _Allocator>
+__split_buffer<_Tp, _Allocator>::__split_buffer(__split_buffer&& __c, const __alloc_rr& __a)
+    : __end_cap_(nullptr, __a)
+{
+    if (__a == __c.__alloc())
+    {
+        __first_ = __c.__first_;
+        __begin_ = __c.__begin_;
+        __end_ = __c.__end_;
+        __end_cap() = __c.__end_cap();
+        __c.__first_ = nullptr;
+        __c.__begin_ = nullptr;
+        __c.__end_ = nullptr;
+        __c.__end_cap() = nullptr;
+    }
+    else
+    {
+        size_type __cap = __c.size();
+        __first_ = __alloc_traits::allocate(__alloc(), __cap);
+        __begin_ = __end_ = __first_;
+        __end_cap() = __first_ + __cap;
+        typedef move_iterator<iterator> _Ip;
+        __construct_at_end(_Ip(__c.begin()), _Ip(__c.end()));
+    }
+}
+
+template <class _Tp, class _Allocator>
+__split_buffer<_Tp, _Allocator>&
+__split_buffer<_Tp, _Allocator>::operator=(__split_buffer&& __c)
+    _NOEXCEPT_((__alloc_traits::propagate_on_container_move_assignment::value &&
+                is_nothrow_move_assignable<allocator_type>::value) ||
+               !__alloc_traits::propagate_on_container_move_assignment::value)
+{
+    clear();
+    shrink_to_fit();
+    __first_ = __c.__first_;
+    __begin_ = __c.__begin_;
+    __end_ = __c.__end_;
+    __end_cap() = __c.__end_cap();
+    __move_assign_alloc(__c,
+        integral_constant<bool,
+                          __alloc_traits::propagate_on_container_move_assignment::value>());
+    __c.__first_ = __c.__begin_ = __c.__end_ = __c.__end_cap() = nullptr;
+    return *this;
+}
+
+template <class _Tp, class _Allocator>
+void
+__split_buffer<_Tp, _Allocator>::swap(__split_buffer& __x)
+        _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value||
+                   __is_nothrow_swappable<__alloc_rr>::value)
+{
+    _VSTD::swap(__first_, __x.__first_);
+    _VSTD::swap(__begin_, __x.__begin_);
+    _VSTD::swap(__end_, __x.__end_);
+    _VSTD::swap(__end_cap(), __x.__end_cap());
+    _VSTD::__swap_allocator(__alloc(), __x.__alloc());
+}
+
+template <class _Tp, class _Allocator>
+void
+__split_buffer<_Tp, _Allocator>::reserve(size_type __n)
+{
+    if (__n < capacity())
+    {
+        __split_buffer<value_type, __alloc_rr&> __t(__n, 0, __alloc());
+        __t.__construct_at_end(move_iterator<pointer>(__begin_),
+                               move_iterator<pointer>(__end_));
+        _VSTD::swap(__first_, __t.__first_);
+        _VSTD::swap(__begin_, __t.__begin_);
+        _VSTD::swap(__end_, __t.__end_);
+        _VSTD::swap(__end_cap(), __t.__end_cap());
+    }
+}
+
+template <class _Tp, class _Allocator>
+void
+__split_buffer<_Tp, _Allocator>::shrink_to_fit() _NOEXCEPT
+{
+    if (capacity() > size())
+    {
+#ifndef _LIBCPP_NO_EXCEPTIONS
+        try
+        {
+#endif // _LIBCPP_NO_EXCEPTIONS
+            __split_buffer<value_type, __alloc_rr&> __t(size(), 0, __alloc());
+            __t.__construct_at_end(move_iterator<pointer>(__begin_),
+                                   move_iterator<pointer>(__end_));
+            __t.__end_ = __t.__begin_ + (__end_ - __begin_);
+            _VSTD::swap(__first_, __t.__first_);
+            _VSTD::swap(__begin_, __t.__begin_);
+            _VSTD::swap(__end_, __t.__end_);
+            _VSTD::swap(__end_cap(), __t.__end_cap());
+#ifndef _LIBCPP_NO_EXCEPTIONS
+        }
+        catch (...)
+        {
+        }
+#endif // _LIBCPP_NO_EXCEPTIONS
+    }
+}
+
+template <class _Tp, class _Allocator>
+void
+__split_buffer<_Tp, _Allocator>::push_front(const_reference __x)
+{
+    if (__begin_ == __first_)
+    {
+        if (__end_ < __end_cap())
+        {
+            difference_type __d = __end_cap() - __end_;
+            __d = (__d + 1) / 2;
+            __begin_ = _VSTD::move_backward(__begin_, __end_, __end_ + __d);
+            __end_ += __d;
+        }
+        else
+        {
+            size_type __c = max<size_type>(2 * static_cast<size_t>(__end_cap() - __first_), 1);
+            __split_buffer<value_type, __alloc_rr&> __t(__c, (__c + 3) / 4, __alloc());
+            __t.__construct_at_end(move_iterator<pointer>(__begin_),
+                                   move_iterator<pointer>(__end_));
+            _VSTD::swap(__first_, __t.__first_);
+            _VSTD::swap(__begin_, __t.__begin_);
+            _VSTD::swap(__end_, __t.__end_);
+            _VSTD::swap(__end_cap(), __t.__end_cap());
+        }
+    }
+    __alloc_traits::construct(__alloc(), _VSTD::__to_address(__begin_-1), __x);
+    --__begin_;
+}
+
+template <class _Tp, class _Allocator>
+void
+__split_buffer<_Tp, _Allocator>::push_front(value_type&& __x)
+{
+    if (__begin_ == __first_)
+    {
+        if (__end_ < __end_cap())
+        {
+            difference_type __d = __end_cap() - __end_;
+            __d = (__d + 1) / 2;
+            __begin_ = _VSTD::move_backward(__begin_, __end_, __end_ + __d);
+            __end_ += __d;
+        }
+        else
+        {
+            size_type __c = max<size_type>(2 * static_cast<size_t>(__end_cap() - __first_), 1);
+            __split_buffer<value_type, __alloc_rr&> __t(__c, (__c + 3) / 4, __alloc());
+            __t.__construct_at_end(move_iterator<pointer>(__begin_),
+                                   move_iterator<pointer>(__end_));
+            _VSTD::swap(__first_, __t.__first_);
+            _VSTD::swap(__begin_, __t.__begin_);
+            _VSTD::swap(__end_, __t.__end_);
+            _VSTD::swap(__end_cap(), __t.__end_cap());
+        }
+    }
+    __alloc_traits::construct(__alloc(), _VSTD::__to_address(__begin_-1),
+            _VSTD::move(__x));
+    --__begin_;
+}
+
+template <class _Tp, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+__split_buffer<_Tp, _Allocator>::push_back(const_reference __x)
+{
+    if (__end_ == __end_cap())
+    {
+        if (__begin_ > __first_)
+        {
+            difference_type __d = __begin_ - __first_;
+            __d = (__d + 1) / 2;
+            __end_ = _VSTD::move(__begin_, __end_, __begin_ - __d);
+            __begin_ -= __d;
+        }
+        else
+        {
+            size_type __c = max<size_type>(2 * static_cast<size_t>(__end_cap() - __first_), 1);
+            __split_buffer<value_type, __alloc_rr&> __t(__c, __c / 4, __alloc());
+            __t.__construct_at_end(move_iterator<pointer>(__begin_),
+                                   move_iterator<pointer>(__end_));
+            _VSTD::swap(__first_, __t.__first_);
+            _VSTD::swap(__begin_, __t.__begin_);
+            _VSTD::swap(__end_, __t.__end_);
+            _VSTD::swap(__end_cap(), __t.__end_cap());
+        }
+    }
+    __alloc_traits::construct(__alloc(), _VSTD::__to_address(__end_), __x);
+    ++__end_;
+}
+
+template <class _Tp, class _Allocator>
+void
+__split_buffer<_Tp, _Allocator>::push_back(value_type&& __x)
+{
+    if (__end_ == __end_cap())
+    {
+        if (__begin_ > __first_)
+        {
+            difference_type __d = __begin_ - __first_;
+            __d = (__d + 1) / 2;
+            __end_ = _VSTD::move(__begin_, __end_, __begin_ - __d);
+            __begin_ -= __d;
+        }
+        else
+        {
+            size_type __c = max<size_type>(2 * static_cast<size_t>(__end_cap() - __first_), 1);
+            __split_buffer<value_type, __alloc_rr&> __t(__c, __c / 4, __alloc());
+            __t.__construct_at_end(move_iterator<pointer>(__begin_),
+                                   move_iterator<pointer>(__end_));
+            _VSTD::swap(__first_, __t.__first_);
+            _VSTD::swap(__begin_, __t.__begin_);
+            _VSTD::swap(__end_, __t.__end_);
+            _VSTD::swap(__end_cap(), __t.__end_cap());
+        }
+    }
+    __alloc_traits::construct(__alloc(), _VSTD::__to_address(__end_),
+            _VSTD::move(__x));
+    ++__end_;
+}
+
+template <class _Tp, class _Allocator>
+template <class... _Args>
+void
+__split_buffer<_Tp, _Allocator>::emplace_back(_Args&&... __args)
+{
+    if (__end_ == __end_cap())
+    {
+        if (__begin_ > __first_)
+        {
+            difference_type __d = __begin_ - __first_;
+            __d = (__d + 1) / 2;
+            __end_ = _VSTD::move(__begin_, __end_, __begin_ - __d);
+            __begin_ -= __d;
+        }
+        else
+        {
+            size_type __c = max<size_type>(2 * static_cast<size_t>(__end_cap() - __first_), 1);
+            __split_buffer<value_type, __alloc_rr&> __t(__c, __c / 4, __alloc());
+            __t.__construct_at_end(move_iterator<pointer>(__begin_),
+                                   move_iterator<pointer>(__end_));
+            _VSTD::swap(__first_, __t.__first_);
+            _VSTD::swap(__begin_, __t.__begin_);
+            _VSTD::swap(__end_, __t.__end_);
+            _VSTD::swap(__end_cap(), __t.__end_cap());
+        }
+    }
+    __alloc_traits::construct(__alloc(), _VSTD::__to_address(__end_),
+                              _VSTD::forward<_Args>(__args)...);
+    ++__end_;
+}
+
+template <class _Tp, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+swap(__split_buffer<_Tp, _Allocator>& __x, __split_buffer<_Tp, _Allocator>& __y)
+        _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y)))
+{
+    __x.swap(__y);
+}
+
+_LIBCPP_END_NAMESPACE_STD
+
+_LIBCPP_POP_MACROS
+
+#endif // _LIBCPP_SPLIT_BUFFER