xref: /freebsd-14.2/contrib/llvm-project/libcxx/include/vector (revision a58f00ea)

// -*- C++ -*-
//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#ifndef _LIBCPP_VECTOR
#define _LIBCPP_VECTOR

// clang-format off

/*
    vector synopsis

namespace std
{

template <class T, class Allocator = allocator<T> >
class vector
{
public:
    typedef T                                        value_type;
    typedef Allocator                                allocator_type;
    typedef typename allocator_type::reference       reference;
    typedef typename allocator_type::const_reference const_reference;
    typedef implementation-defined                   iterator;
    typedef implementation-defined                   const_iterator;
    typedef typename allocator_type::size_type       size_type;
    typedef typename allocator_type::difference_type difference_type;
    typedef typename allocator_type::pointer         pointer;
    typedef typename allocator_type::const_pointer   const_pointer;
    typedef std::reverse_iterator<iterator>          reverse_iterator;
    typedef std::reverse_iterator<const_iterator>    const_reverse_iterator;

    vector()
        noexcept(is_nothrow_default_constructible<allocator_type>::value);
    explicit vector(const allocator_type&);
    explicit vector(size_type n);
    explicit vector(size_type n, const allocator_type&); // C++14
    vector(size_type n, const value_type& value, const allocator_type& = allocator_type());
    template <class InputIterator>
        vector(InputIterator first, InputIterator last, const allocator_type& = allocator_type());
    template<container-compatible-range<T> R>
      constexpr vector(from_range_t, R&& rg, const Allocator& = Allocator()); // C++23
    vector(const vector& x);
    vector(vector&& x)
        noexcept(is_nothrow_move_constructible<allocator_type>::value);
    vector(initializer_list<value_type> il);
    vector(initializer_list<value_type> il, const allocator_type& a);
    ~vector();
    vector& operator=(const vector& x);
    vector& operator=(vector&& x)
        noexcept(
             allocator_type::propagate_on_container_move_assignment::value ||
             allocator_type::is_always_equal::value); // C++17
    vector& operator=(initializer_list<value_type> il);
    template <class InputIterator>
        void assign(InputIterator first, InputIterator last);
    template<container-compatible-range<T> R>
      constexpr void assign_range(R&& rg); // C++23
    void assign(size_type n, const value_type& u);
    void assign(initializer_list<value_type> il);

    allocator_type get_allocator() const noexcept;

    iterator               begin() noexcept;
    const_iterator         begin()   const noexcept;
    iterator               end() noexcept;
    const_iterator         end()     const noexcept;

    reverse_iterator       rbegin() noexcept;
    const_reverse_iterator rbegin()  const noexcept;
    reverse_iterator       rend() noexcept;
    const_reverse_iterator rend()    const noexcept;

    const_iterator         cbegin()  const noexcept;
    const_iterator         cend()    const noexcept;
    const_reverse_iterator crbegin() const noexcept;
    const_reverse_iterator crend()   const noexcept;

    size_type size() const noexcept;
    size_type max_size() const noexcept;
    size_type capacity() const noexcept;
    bool empty() const noexcept;
    void reserve(size_type n);
    void shrink_to_fit() noexcept;

    reference       operator[](size_type n);
    const_reference operator[](size_type n) const;
    reference       at(size_type n);
    const_reference at(size_type n) const;

    reference       front();
    const_reference front() const;
    reference       back();
    const_reference back() const;

    value_type*       data() noexcept;
    const value_type* data() const noexcept;

    void push_back(const value_type& x);
    void push_back(value_type&& x);
    template <class... Args>
        reference emplace_back(Args&&... args); // reference in C++17
    template<container-compatible-range<T> R>
      constexpr void append_range(R&& rg); // C++23
    void pop_back();

    template <class... Args> iterator emplace(const_iterator position, Args&&... args);
    iterator insert(const_iterator position, const value_type& x);
    iterator insert(const_iterator position, value_type&& x);
    iterator insert(const_iterator position, size_type n, const value_type& x);
    template <class InputIterator>
        iterator insert(const_iterator position, InputIterator first, InputIterator last);
    template<container-compatible-range<T> R>
      constexpr iterator insert_range(const_iterator position, R&& rg); // C++23
    iterator insert(const_iterator position, initializer_list<value_type> il);

    iterator erase(const_iterator position);
    iterator erase(const_iterator first, const_iterator last);

    void clear() noexcept;

    void resize(size_type sz);
    void resize(size_type sz, const value_type& c);

    void swap(vector&)
        noexcept(allocator_traits<allocator_type>::propagate_on_container_swap::value ||
                 allocator_traits<allocator_type>::is_always_equal::value);  // C++17

    bool __invariants() const;
};

template <class Allocator = allocator<T> >
class vector<bool, Allocator>
{
public:
    typedef bool                                     value_type;
    typedef Allocator                                allocator_type;
    typedef implementation-defined                   iterator;
    typedef implementation-defined                   const_iterator;
    typedef typename allocator_type::size_type       size_type;
    typedef typename allocator_type::difference_type difference_type;
    typedef iterator                                 pointer;
    typedef const_iterator                           const_pointer;
    typedef std::reverse_iterator<iterator>          reverse_iterator;
    typedef std::reverse_iterator<const_iterator>    const_reverse_iterator;

    class reference
    {
    public:
        reference(const reference&) noexcept;
        operator bool() const noexcept;
        reference& operator=(bool x) noexcept;
        reference& operator=(const reference& x) noexcept;
        iterator operator&() const noexcept;
        void flip() noexcept;
    };

    class const_reference
    {
    public:
        const_reference(const reference&) noexcept;
        operator bool() const noexcept;
        const_iterator operator&() const noexcept;
    };

    vector()
        noexcept(is_nothrow_default_constructible<allocator_type>::value);
    explicit vector(const allocator_type&);
    explicit vector(size_type n, const allocator_type& a = allocator_type()); // C++14
    vector(size_type n, const value_type& value, const allocator_type& = allocator_type());
    template <class InputIterator>
        vector(InputIterator first, InputIterator last, const allocator_type& = allocator_type());
    template<container-compatible-range<bool> R>
      constexpr vector(from_range_t, R&& rg, const Allocator& = Allocator());
    vector(const vector& x);
    vector(vector&& x)
        noexcept(is_nothrow_move_constructible<allocator_type>::value);
    vector(initializer_list<value_type> il);
    vector(initializer_list<value_type> il, const allocator_type& a);
    ~vector();
    vector& operator=(const vector& x);
    vector& operator=(vector&& x)
        noexcept(
             allocator_type::propagate_on_container_move_assignment::value ||
             allocator_type::is_always_equal::value); // C++17
    vector& operator=(initializer_list<value_type> il);
    template <class InputIterator>
        void assign(InputIterator first, InputIterator last);
    template<container-compatible-range<T> R>
      constexpr void assign_range(R&& rg); // C++23
    void assign(size_type n, const value_type& u);
    void assign(initializer_list<value_type> il);

    allocator_type get_allocator() const noexcept;

    iterator               begin() noexcept;
    const_iterator         begin()   const noexcept;
    iterator               end() noexcept;
    const_iterator         end()     const noexcept;

    reverse_iterator       rbegin() noexcept;
    const_reverse_iterator rbegin()  const noexcept;
    reverse_iterator       rend() noexcept;
    const_reverse_iterator rend()    const noexcept;

    const_iterator         cbegin()  const noexcept;
    const_iterator         cend()    const noexcept;
    const_reverse_iterator crbegin() const noexcept;
    const_reverse_iterator crend()   const noexcept;

    size_type size() const noexcept;
    size_type max_size() const noexcept;
    size_type capacity() const noexcept;
    bool empty() const noexcept;
    void reserve(size_type n);
    void shrink_to_fit() noexcept;

    reference       operator[](size_type n);
    const_reference operator[](size_type n) const;
    reference       at(size_type n);
    const_reference at(size_type n) const;

    reference       front();
    const_reference front() const;
    reference       back();
    const_reference back() const;

    void push_back(const value_type& x);
    template <class... Args> reference emplace_back(Args&&... args);  // C++14; reference in C++17
    template<container-compatible-range<T> R>
      constexpr void append_range(R&& rg); // C++23
    void pop_back();

    template <class... Args> iterator emplace(const_iterator position, Args&&... args);  // C++14
    iterator insert(const_iterator position, const value_type& x);
    iterator insert(const_iterator position, size_type n, const value_type& x);
    template <class InputIterator>
        iterator insert(const_iterator position, InputIterator first, InputIterator last);
    template<container-compatible-range<T> R>
      constexpr iterator insert_range(const_iterator position, R&& rg); // C++23
    iterator insert(const_iterator position, initializer_list<value_type> il);

    iterator erase(const_iterator position);
    iterator erase(const_iterator first, const_iterator last);

    void clear() noexcept;

    void resize(size_type sz);
    void resize(size_type sz, value_type x);

    void swap(vector&)
        noexcept(allocator_traits<allocator_type>::propagate_on_container_swap::value ||
                 allocator_traits<allocator_type>::is_always_equal::value);  // C++17
    void flip() noexcept;

    bool __invariants() const;
};

template <class InputIterator, class Allocator = allocator<typename iterator_traits<InputIterator>::value_type>>
   vector(InputIterator, InputIterator, Allocator = Allocator())
   -> vector<typename iterator_traits<InputIterator>::value_type, Allocator>; // C++17

template<ranges::input_range R, class Allocator = allocator<ranges::range_value_t<R>>>
  vector(from_range_t, R&&, Allocator = Allocator())
    -> vector<ranges::range_value_t<R>, Allocator>; // C++23

template <class Allocator> struct hash<std::vector<bool, Allocator>>;

template <class T, class Allocator> bool operator==(const vector<T,Allocator>& x, const vector<T,Allocator>& y);   // constexpr since C++20
template <class T, class Allocator> bool operator!=(const vector<T,Allocator>& x, const vector<T,Allocator>& y);   // removed in C++20
template <class T, class Allocator> bool operator< (const vector<T,Allocator>& x, const vector<T,Allocator>& y);   // removed in C++20
template <class T, class Allocator> bool operator> (const vector<T,Allocator>& x, const vector<T,Allocator>& y);   // removed in C++20
template <class T, class Allocator> bool operator>=(const vector<T,Allocator>& x, const vector<T,Allocator>& y);   // removed in C++20
template <class T, class Allocator> bool operator<=(const vector<T,Allocator>& x, const vector<T,Allocator>& y);   // removed in C++20
template <class T, class Allocator> constexpr
  constexpr synth-three-way-result<T> operator<=>(const vector<T, Allocator>& x,
                                                  const vector<T, Allocator>& y);                                  // since C++20

template <class T, class Allocator>
void swap(vector<T,Allocator>& x, vector<T,Allocator>& y)
    noexcept(noexcept(x.swap(y)));

template <class T, class Allocator, class U>
typename vector<T, Allocator>::size_type
erase(vector<T, Allocator>& c, const U& value);       // since C++20
template <class T, class Allocator, class Predicate>
typename vector<T, Allocator>::size_type
erase_if(vector<T, Allocator>& c, Predicate pred);    // since C++20


template<class T>
 inline constexpr bool is-vector-bool-reference = see below;        // exposition only, since C++23

template<class T, class charT> requires is-vector-bool-reference<T> // Since C++23
 struct formatter<T, charT>;

}  // std

*/

// clang-format on

#include <__algorithm/copy.h>
#include <__algorithm/equal.h>
#include <__algorithm/fill_n.h>
#include <__algorithm/iterator_operations.h>
#include <__algorithm/lexicographical_compare.h>
#include <__algorithm/lexicographical_compare_three_way.h>
#include <__algorithm/remove.h>
#include <__algorithm/remove_if.h>
#include <__algorithm/rotate.h>
#include <__algorithm/unwrap_iter.h>
#include <__assert> // all public C++ headers provide the assertion handler
#include <__availability>
#include <__bit_reference>
#include <__concepts/same_as.h>
#include <__config>
#include <__format/enable_insertable.h>
#include <__format/formatter.h>
#include <__format/formatter_bool.h>
#include <__functional/hash.h>
#include <__functional/unary_function.h>
#include <__iterator/advance.h>
#include <__iterator/distance.h>
#include <__iterator/iterator_traits.h>
#include <__iterator/reverse_iterator.h>
#include <__iterator/wrap_iter.h>
#include <__memory/addressof.h>
#include <__memory/allocate_at_least.h>
#include <__memory/allocator_traits.h>
#include <__memory/pointer_traits.h>
#include <__memory/swap_allocator.h>
#include <__memory/temp_value.h>
#include <__memory/uninitialized_algorithms.h>
#include <__memory_resource/polymorphic_allocator.h>
#include <__ranges/access.h>
#include <__ranges/concepts.h>
#include <__ranges/container_compatible_range.h>
#include <__ranges/from_range.h>
#include <__ranges/size.h>
#include <__split_buffer>
#include <__type_traits/is_allocator.h>
#include <__type_traits/is_constructible.h>
#include <__type_traits/is_nothrow_move_assignable.h>
#include <__type_traits/noexcept_move_assign_container.h>
#include <__type_traits/type_identity.h>
#include <__utility/exception_guard.h>
#include <__utility/forward.h>
#include <__utility/move.h>
#include <__utility/pair.h>
#include <__utility/swap.h>
#include <climits>
#include <cstring>
#include <iosfwd> // for forward declaration of vector
#include <limits>
#include <stdexcept>
#include <version>

// standard-mandated includes

// [iterator.range]
#include <__iterator/access.h>
#include <__iterator/data.h>
#include <__iterator/empty.h>
#include <__iterator/reverse_access.h>
#include <__iterator/size.h>

// [vector.syn]
#include <compare>
#include <initializer_list>

#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> */>
class _LIBCPP_TEMPLATE_VIS vector {
private:
  typedef allocator<_Tp> __default_allocator_type;

public:
  typedef vector __self;
  typedef _Tp value_type;
  typedef _Allocator allocator_type;
  typedef allocator_traits<allocator_type> __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;
  // TODO: Implement iterator bounds checking without requiring the global database.
  typedef __wrap_iter<pointer> iterator;
  typedef __wrap_iter<const_pointer> const_iterator;
  typedef std::reverse_iterator<iterator> reverse_iterator;
  typedef std::reverse_iterator<const_iterator> const_reverse_iterator;

  static_assert((is_same<typename allocator_type::value_type, value_type>::value),
                "Allocator::value_type must be same type as value_type");

  static_assert(is_same<allocator_type, __rebind_alloc<__alloc_traits, value_type> >::value,
                "[allocator.requirements] states that rebinding an allocator to the same type should result in the "
                "original allocator");

  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI vector()
      _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value) {}
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI explicit vector(const allocator_type& __a)
#if _LIBCPP_STD_VER <= 14
      _NOEXCEPT_(is_nothrow_copy_constructible<allocator_type>::value)
#else
      _NOEXCEPT
#endif
      : __end_cap_(nullptr, __a) {
  }
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI explicit vector(size_type __n);
#if _LIBCPP_STD_VER >= 14
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI explicit vector(size_type __n, const allocator_type& __a);
#endif
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI vector(size_type __n, const value_type& __x);

  template <class = __enable_if_t<__is_allocator<_Allocator>::value> >
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI
  vector(size_type __n, const value_type& __x, const allocator_type& __a)
      : __end_cap_(nullptr, __a) {
    if (__n > 0) {
      __vallocate(__n);
      __construct_at_end(__n, __x);
    }
  }

  template <class _InputIterator,
            __enable_if_t<__has_exactly_input_iterator_category<_InputIterator>::value &&
                              is_constructible<value_type, typename iterator_traits<_InputIterator>::reference>::value,
                          int> = 0>
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI vector(_InputIterator __first, _InputIterator __last);
  template <class _InputIterator,
            __enable_if_t<__has_exactly_input_iterator_category<_InputIterator>::value &&
                              is_constructible<value_type, typename iterator_traits<_InputIterator>::reference>::value,
                          int> = 0>
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI
  vector(_InputIterator __first, _InputIterator __last, const allocator_type& __a);

  template <
      class _ForwardIterator,
      __enable_if_t<__has_forward_iterator_category<_ForwardIterator>::value &&
                        is_constructible<value_type, typename iterator_traits<_ForwardIterator>::reference>::value,
                    int> = 0>
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI vector(_ForwardIterator __first, _ForwardIterator __last);

  template <
      class _ForwardIterator,
      __enable_if_t<__has_forward_iterator_category<_ForwardIterator>::value &&
                        is_constructible<value_type, typename iterator_traits<_ForwardIterator>::reference>::value,
                    int> = 0>
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI
  vector(_ForwardIterator __first, _ForwardIterator __last, const allocator_type& __a);

#if _LIBCPP_STD_VER >= 23
  template <_ContainerCompatibleRange<_Tp> _Range>
  _LIBCPP_HIDE_FROM_ABI constexpr vector(
      from_range_t, _Range&& __range, const allocator_type& __alloc = allocator_type())
      : __end_cap_(nullptr, __alloc) {
    if constexpr (ranges::forward_range<_Range> || ranges::sized_range<_Range>) {
      auto __n = static_cast<size_type>(ranges::distance(__range));
      __init_with_size(ranges::begin(__range), ranges::end(__range), __n);

    } else {
      __init_with_sentinel(ranges::begin(__range), ranges::end(__range));
    }
  }
#endif

private:
  class __destroy_vector {
  public:
    _LIBCPP_CONSTEXPR _LIBCPP_HIDE_FROM_ABI __destroy_vector(vector& __vec) : __vec_(__vec) {}

    _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void operator()() {
      if (__vec_.__begin_ != nullptr) {
        __vec_.__clear();
        __vec_.__annotate_delete();
        __alloc_traits::deallocate(__vec_.__alloc(), __vec_.__begin_, __vec_.capacity());
      }
    }

  private:
    vector& __vec_;
  };

public:
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI ~vector() { __destroy_vector (*this)(); }

  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI vector(const vector& __x);
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI
  vector(const vector& __x, const __type_identity_t<allocator_type>& __a);
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI vector& operator=(const vector& __x);

#ifndef _LIBCPP_CXX03_LANG
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI vector(initializer_list<value_type> __il);

  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI
  vector(initializer_list<value_type> __il, const allocator_type& __a);

  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI vector& operator=(initializer_list<value_type> __il) {
    assign(__il.begin(), __il.end());
    return *this;
  }
#endif // !_LIBCPP_CXX03_LANG

  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI vector(vector&& __x)
#if _LIBCPP_STD_VER >= 17
      noexcept;
#else
      _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value);
#endif

  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI
  vector(vector&& __x, const __type_identity_t<allocator_type>& __a);
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI vector& operator=(vector&& __x)
      _NOEXCEPT_((__noexcept_move_assign_container<_Allocator, __alloc_traits>::value));

  template <class _InputIterator,
            __enable_if_t<__has_exactly_input_iterator_category<_InputIterator>::value &&
                              is_constructible<value_type, typename iterator_traits<_InputIterator>::reference>::value,
                          int> = 0>
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void assign(_InputIterator __first, _InputIterator __last);
  template <
      class _ForwardIterator,
      __enable_if_t<__has_forward_iterator_category<_ForwardIterator>::value &&
                        is_constructible<value_type, typename iterator_traits<_ForwardIterator>::reference>::value,
                    int> = 0>
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void assign(_ForwardIterator __first, _ForwardIterator __last);

#if _LIBCPP_STD_VER >= 23
  template <_ContainerCompatibleRange<_Tp> _Range>
  _LIBCPP_HIDE_FROM_ABI constexpr void assign_range(_Range&& __range) {
    if constexpr (ranges::forward_range<_Range> || ranges::sized_range<_Range>) {
      auto __n = static_cast<size_type>(ranges::distance(__range));
      __assign_with_size(ranges::begin(__range), ranges::end(__range), __n);

    } else {
      __assign_with_sentinel(ranges::begin(__range), ranges::end(__range));
    }
  }
#endif

  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void assign(size_type __n, const_reference __u);

#ifndef _LIBCPP_CXX03_LANG
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void assign(initializer_list<value_type> __il) {
    assign(__il.begin(), __il.end());
  }
#endif

  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI allocator_type get_allocator() const _NOEXCEPT {
    return this->__alloc();
  }

  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI iterator begin() _NOEXCEPT;
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI const_iterator begin() const _NOEXCEPT;
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI iterator end() _NOEXCEPT;
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI const_iterator end() const _NOEXCEPT;

  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI reverse_iterator rbegin() _NOEXCEPT {
    return reverse_iterator(end());
  }
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI const_reverse_iterator rbegin() const _NOEXCEPT {
    return const_reverse_iterator(end());
  }
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI reverse_iterator rend() _NOEXCEPT {
    return reverse_iterator(begin());
  }
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI const_reverse_iterator rend() const _NOEXCEPT {
    return const_reverse_iterator(begin());
  }

  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI const_iterator cbegin() const _NOEXCEPT { return begin(); }
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI const_iterator cend() const _NOEXCEPT { return end(); }
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI const_reverse_iterator crbegin() const _NOEXCEPT {
    return rbegin();
  }
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI const_reverse_iterator crend() const _NOEXCEPT { return rend(); }

  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI size_type size() const _NOEXCEPT {
    return static_cast<size_type>(this->__end_ - this->__begin_);
  }
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI size_type capacity() const _NOEXCEPT {
    return static_cast<size_type>(__end_cap() - this->__begin_);
  }
  _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI bool empty() const _NOEXCEPT {
    return this->__begin_ == this->__end_;
  }
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI size_type max_size() const _NOEXCEPT;
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void reserve(size_type __n);
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void shrink_to_fit() _NOEXCEPT;

  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI reference operator[](size_type __n) _NOEXCEPT;
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI const_reference operator[](size_type __n) const _NOEXCEPT;
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI reference at(size_type __n);
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI const_reference at(size_type __n) const;

  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI reference front() _NOEXCEPT {
    _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(!empty(), "front() called on an empty vector");
    return *this->__begin_;
  }
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI const_reference front() const _NOEXCEPT {
    _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(!empty(), "front() called on an empty vector");
    return *this->__begin_;
  }
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI reference back() _NOEXCEPT {
    _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(!empty(), "back() called on an empty vector");
    return *(this->__end_ - 1);
  }
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI const_reference back() const _NOEXCEPT {
    _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(!empty(), "back() called on an empty vector");
    return *(this->__end_ - 1);
  }

  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI value_type* data() _NOEXCEPT {
    return std::__to_address(this->__begin_);
  }

  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI const value_type* data() const _NOEXCEPT {
    return std::__to_address(this->__begin_);
  }

  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void push_back(const_reference __x);

  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void push_back(value_type&& __x);

  template <class... _Args>
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI
#if _LIBCPP_STD_VER >= 17
      reference
      emplace_back(_Args&&... __args);
#else
      void
      emplace_back(_Args&&... __args);
#endif

#if _LIBCPP_STD_VER >= 23
  template <_ContainerCompatibleRange<_Tp> _Range>
  _LIBCPP_HIDE_FROM_ABI constexpr void append_range(_Range&& __range) {
    insert_range(end(), std::forward<_Range>(__range));
  }
#endif

  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void pop_back();

  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI iterator insert(const_iterator __position, const_reference __x);

  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI iterator insert(const_iterator __position, value_type&& __x);
  template <class... _Args>
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI iterator emplace(const_iterator __position, _Args&&... __args);

  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI iterator
  insert(const_iterator __position, size_type __n, const_reference __x);

  template <class _InputIterator,
            __enable_if_t<__has_exactly_input_iterator_category<_InputIterator>::value &&
                              is_constructible< value_type, typename iterator_traits<_InputIterator>::reference>::value,
                          int> = 0>
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI iterator
  insert(const_iterator __position, _InputIterator __first, _InputIterator __last);

#if _LIBCPP_STD_VER >= 23
  template <_ContainerCompatibleRange<_Tp> _Range>
  _LIBCPP_HIDE_FROM_ABI constexpr iterator insert_range(const_iterator __position, _Range&& __range) {
    if constexpr (ranges::forward_range<_Range> || ranges::sized_range<_Range>) {
      auto __n = static_cast<size_type>(ranges::distance(__range));
      return __insert_with_size(__position, ranges::begin(__range), ranges::end(__range), __n);

    } else {
      return __insert_with_sentinel(__position, ranges::begin(__range), ranges::end(__range));
    }
  }
#endif

  template <
      class _ForwardIterator,
      __enable_if_t<__has_forward_iterator_category<_ForwardIterator>::value &&
                        is_constructible< value_type, typename iterator_traits<_ForwardIterator>::reference>::value,
                    int> = 0>
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI iterator
  insert(const_iterator __position, _ForwardIterator __first, _ForwardIterator __last);

#ifndef _LIBCPP_CXX03_LANG
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI iterator
  insert(const_iterator __position, initializer_list<value_type> __il) {
    return insert(__position, __il.begin(), __il.end());
  }
#endif

  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI iterator erase(const_iterator __position);
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI iterator erase(const_iterator __first, const_iterator __last);

  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void clear() _NOEXCEPT {
    size_type __old_size = size();
    __clear();
    __annotate_shrink(__old_size);
  }

  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void resize(size_type __sz);
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void resize(size_type __sz, const_reference __x);

  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void swap(vector&)
#if _LIBCPP_STD_VER >= 14
      _NOEXCEPT;
#else
      _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value || __is_nothrow_swappable<allocator_type>::value);
#endif

  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI bool __invariants() const;

private:
  pointer __begin_ = nullptr;
  pointer __end_   = nullptr;
  __compressed_pair<pointer, allocator_type> __end_cap_ =
      __compressed_pair<pointer, allocator_type>(nullptr, __default_init_tag());

  //  Allocate space for __n objects
  //  throws length_error if __n > max_size()
  //  throws (probably bad_alloc) if memory run out
  //  Precondition:  __begin_ == __end_ == __end_cap() == 0
  //  Precondition:  __n > 0
  //  Postcondition:  capacity() >= __n
  //  Postcondition:  size() == 0
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __vallocate(size_type __n) {
    if (__n > max_size())
      __throw_length_error();
    auto __allocation = std::__allocate_at_least(__alloc(), __n);
    __begin_          = __allocation.ptr;
    __end_            = __allocation.ptr;
    __end_cap()       = __begin_ + __allocation.count;
    __annotate_new(0);
  }

  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __vdeallocate() _NOEXCEPT;
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI size_type __recommend(size_type __new_size) const;
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __construct_at_end(size_type __n);
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __construct_at_end(size_type __n, const_reference __x);

  template <class _InputIterator, class _Sentinel>
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void
  __init_with_size(_InputIterator __first, _Sentinel __last, size_type __n) {
    auto __guard = std::__make_exception_guard(__destroy_vector(*this));

    if (__n > 0) {
      __vallocate(__n);
      __construct_at_end(__first, __last, __n);
    }

    __guard.__complete();
  }

  template <class _InputIterator, class _Sentinel>
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void
  __init_with_sentinel(_InputIterator __first, _Sentinel __last) {
    auto __guard = std::__make_exception_guard(__destroy_vector(*this));

    for (; __first != __last; ++__first)
      emplace_back(*__first);

    __guard.__complete();
  }

  template <class _Iterator, class _Sentinel>
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __assign_with_sentinel(_Iterator __first, _Sentinel __last);

  template <class _ForwardIterator, class _Sentinel>
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void
  __assign_with_size(_ForwardIterator __first, _Sentinel __last, difference_type __n);

  template <class _InputIterator, class _Sentinel>
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI iterator
  __insert_with_sentinel(const_iterator __position, _InputIterator __first, _Sentinel __last);

  template <class _Iterator, class _Sentinel>
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI iterator
  __insert_with_size(const_iterator __position, _Iterator __first, _Sentinel __last, difference_type __n);

  template <class _InputIterator, class _Sentinel>
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void
  __construct_at_end(_InputIterator __first, _Sentinel __last, size_type __n);

  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __append(size_type __n);
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __append(size_type __n, const_reference __x);
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI iterator __make_iter(pointer __p) _NOEXCEPT {
    return iterator(__p);
  }
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI const_iterator __make_iter(const_pointer __p) const _NOEXCEPT {
    return const_iterator(__p);
  }
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void
  __swap_out_circular_buffer(__split_buffer<value_type, allocator_type&>& __v);
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI pointer
  __swap_out_circular_buffer(__split_buffer<value_type, allocator_type&>& __v, pointer __p);
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void
  __move_range(pointer __from_s, pointer __from_e, pointer __to);
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __move_assign(vector& __c, true_type)
      _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value);
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __move_assign(vector& __c, false_type)
      _NOEXCEPT_(__alloc_traits::is_always_equal::value);
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __destruct_at_end(pointer __new_last) _NOEXCEPT {
    size_type __old_size = size();
    __base_destruct_at_end(__new_last);
    __annotate_shrink(__old_size);
  }

  template <class _Up>
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI inline pointer __push_back_slow_path(_Up&& __x);

  template <class... _Args>
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI inline pointer __emplace_back_slow_path(_Args&&... __args);

  // The following functions are no-ops outside of AddressSanitizer mode.
  // We call annotations for every allocator, unless explicitly disabled.
  //
  // To disable annotations for a particular allocator, change value of
  // __asan_annotate_container_with_allocator to false.
  // For more details, see the "Using libc++" documentation page or
  // the documentation for __sanitizer_annotate_contiguous_container.

  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __annotate_contiguous_container(
      const void* __old_mid, const void* __new_mid) const {
    (void)__old_mid;
    (void)__new_mid;
#ifndef _LIBCPP_HAS_NO_ASAN
    const void* __beg = data();
    const void* __end = data() + capacity();
    if (!__libcpp_is_constant_evaluated() && __beg != nullptr &&
        __asan_annotate_container_with_allocator<_Allocator>::value)
      __sanitizer_annotate_contiguous_container(__beg, __end, __old_mid, __new_mid);
#endif
  }

  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __annotate_new(size_type __current_size) const _NOEXCEPT {
    (void)__current_size;
#ifndef _LIBCPP_HAS_NO_ASAN
    __annotate_contiguous_container(data() + capacity(), data() + __current_size);
#endif
  }

  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __annotate_delete() const _NOEXCEPT {
#ifndef _LIBCPP_HAS_NO_ASAN
    __annotate_contiguous_container(data() + size(), data() + capacity());
#endif
  }

  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __annotate_increase(size_type __n) const _NOEXCEPT {
    (void)__n;
#ifndef _LIBCPP_HAS_NO_ASAN
    __annotate_contiguous_container(data() + size(), data() + size() + __n);
#endif
  }

  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __annotate_shrink(size_type __old_size) const _NOEXCEPT {
    (void)__old_size;
#ifndef _LIBCPP_HAS_NO_ASAN
    __annotate_contiguous_container(data() + __old_size, data() + size());
#endif
  }

  struct _ConstructTransaction {
    _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI explicit _ConstructTransaction(vector& __v, size_type __n)
        : __v_(__v), __pos_(__v.__end_), __new_end_(__v.__end_ + __n) {
#ifndef _LIBCPP_HAS_NO_ASAN
      __v_.__annotate_increase(__n);
#endif
    }
    _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI ~_ConstructTransaction() {
      __v_.__end_ = __pos_;
#ifndef _LIBCPP_HAS_NO_ASAN
      if (__pos_ != __new_end_) {
        __v_.__annotate_shrink(__new_end_ - __v_.__begin_);
      }
#endif
    }

    vector& __v_;
    pointer __pos_;
    const_pointer const __new_end_;

  private:
    _ConstructTransaction(_ConstructTransaction const&)            = delete;
    _ConstructTransaction& operator=(_ConstructTransaction const&) = delete;
  };

  template <class... _Args>
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __construct_one_at_end(_Args&&... __args) {
    _ConstructTransaction __tx(*this, 1);
    __alloc_traits::construct(this->__alloc(), std::__to_address(__tx.__pos_), std::forward<_Args>(__args)...);
    ++__tx.__pos_;
  }

  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI allocator_type& __alloc() _NOEXCEPT {
    return this->__end_cap_.second();
  }
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI const allocator_type& __alloc() const _NOEXCEPT {
    return this->__end_cap_.second();
  }
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI pointer& __end_cap() _NOEXCEPT {
    return this->__end_cap_.first();
  }
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI const pointer& __end_cap() const _NOEXCEPT {
    return this->__end_cap_.first();
  }

  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __clear() _NOEXCEPT {
    __base_destruct_at_end(this->__begin_);
  }

  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __base_destruct_at_end(pointer __new_last) _NOEXCEPT {
    pointer __soon_to_be_end = this->__end_;
    while (__new_last != __soon_to_be_end)
      __alloc_traits::destroy(__alloc(), std::__to_address(--__soon_to_be_end));
    this->__end_ = __new_last;
  }

  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __copy_assign_alloc(const vector& __c) {
    __copy_assign_alloc(__c, integral_constant<bool, __alloc_traits::propagate_on_container_copy_assignment::value>());
  }

  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __move_assign_alloc(vector& __c)
      _NOEXCEPT_(!__alloc_traits::propagate_on_container_move_assignment::value ||
                 is_nothrow_move_assignable<allocator_type>::value) {
    __move_assign_alloc(__c, integral_constant<bool, __alloc_traits::propagate_on_container_move_assignment::value>());
  }

  _LIBCPP_NORETURN _LIBCPP_HIDE_FROM_ABI void __throw_length_error() const { std::__throw_length_error("vector"); }

  _LIBCPP_NORETURN _LIBCPP_HIDE_FROM_ABI void __throw_out_of_range() const { std::__throw_out_of_range("vector"); }

  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __copy_assign_alloc(const vector& __c, true_type) {
    if (__alloc() != __c.__alloc()) {
      __clear();
      __annotate_delete();
      __alloc_traits::deallocate(__alloc(), this->__begin_, capacity());
      this->__begin_ = this->__end_ = __end_cap() = nullptr;
    }
    __alloc() = __c.__alloc();
  }

  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __copy_assign_alloc(const vector&, false_type) {}

  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __move_assign_alloc(vector& __c, true_type)
      _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value) {
    __alloc() = std::move(__c.__alloc());
  }

  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __move_assign_alloc(vector&, false_type) _NOEXCEPT {}
};

#if _LIBCPP_STD_VER >= 17
template <class _InputIterator,
          class _Alloc = allocator<__iter_value_type<_InputIterator>>,
          class        = enable_if_t<__has_input_iterator_category<_InputIterator>::value>,
          class        = enable_if_t<__is_allocator<_Alloc>::value> >
vector(_InputIterator, _InputIterator) -> vector<__iter_value_type<_InputIterator>, _Alloc>;

template <class _InputIterator,
          class _Alloc,
          class = enable_if_t<__has_input_iterator_category<_InputIterator>::value>,
          class = enable_if_t<__is_allocator<_Alloc>::value> >
vector(_InputIterator, _InputIterator, _Alloc) -> vector<__iter_value_type<_InputIterator>, _Alloc>;
#endif

#if _LIBCPP_STD_VER >= 23
template <ranges::input_range _Range,
          class _Alloc = allocator<ranges::range_value_t<_Range>>,
          class        = enable_if_t<__is_allocator<_Alloc>::value> >
vector(from_range_t, _Range&&, _Alloc = _Alloc()) -> vector<ranges::range_value_t<_Range>, _Alloc>;
#endif

template <class _Tp, class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 void
vector<_Tp, _Allocator>::__swap_out_circular_buffer(__split_buffer<value_type, allocator_type&>& __v) {
  __annotate_delete();
  using _RevIter = std::reverse_iterator<pointer>;
  __v.__begin_   = std::__uninitialized_allocator_move_if_noexcept(
                     __alloc(), _RevIter(__end_), _RevIter(__begin_), _RevIter(__v.__begin_))
                     .base();
  std::swap(this->__begin_, __v.__begin_);
  std::swap(this->__end_, __v.__end_);
  std::swap(this->__end_cap(), __v.__end_cap());
  __v.__first_ = __v.__begin_;
  __annotate_new(size());
}

template <class _Tp, class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 typename vector<_Tp, _Allocator>::pointer
vector<_Tp, _Allocator>::__swap_out_circular_buffer(__split_buffer<value_type, allocator_type&>& __v, pointer __p) {
  __annotate_delete();
  pointer __r    = __v.__begin_;
  using _RevIter = std::reverse_iterator<pointer>;
  __v.__begin_   = std::__uninitialized_allocator_move_if_noexcept(
                     __alloc(), _RevIter(__p), _RevIter(__begin_), _RevIter(__v.__begin_))
                     .base();
  __v.__end_ = std::__uninitialized_allocator_move_if_noexcept(__alloc(), __p, __end_, __v.__end_);
  std::swap(this->__begin_, __v.__begin_);
  std::swap(this->__end_, __v.__end_);
  std::swap(this->__end_cap(), __v.__end_cap());
  __v.__first_ = __v.__begin_;
  __annotate_new(size());
  return __r;
}

template <class _Tp, class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 void vector<_Tp, _Allocator>::__vdeallocate() _NOEXCEPT {
  if (this->__begin_ != nullptr) {
    clear();
    __annotate_delete();
    __alloc_traits::deallocate(this->__alloc(), this->__begin_, capacity());
    this->__begin_ = this->__end_ = this->__end_cap() = nullptr;
  }
}

template <class _Tp, class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 typename vector<_Tp, _Allocator>::size_type
vector<_Tp, _Allocator>::max_size() const _NOEXCEPT {
  return std::min<size_type>(__alloc_traits::max_size(this->__alloc()), numeric_limits<difference_type>::max());
}

//  Precondition:  __new_size > capacity()
template <class _Tp, class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 inline _LIBCPP_HIDE_FROM_ABI typename vector<_Tp, _Allocator>::size_type
vector<_Tp, _Allocator>::__recommend(size_type __new_size) const {
  const size_type __ms = max_size();
  if (__new_size > __ms)
    this->__throw_length_error();
  const size_type __cap = capacity();
  if (__cap >= __ms / 2)
    return __ms;
  return std::max<size_type>(2 * __cap, __new_size);
}

//  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>
_LIBCPP_CONSTEXPR_SINCE_CXX20 void vector<_Tp, _Allocator>::__construct_at_end(size_type __n) {
  _ConstructTransaction __tx(*this, __n);
  const_pointer __new_end = __tx.__new_end_;
  for (pointer __pos = __tx.__pos_; __pos != __new_end; __tx.__pos_ = ++__pos) {
    __alloc_traits::construct(this->__alloc(), std::__to_address(__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>
_LIBCPP_CONSTEXPR_SINCE_CXX20 inline void
vector<_Tp, _Allocator>::__construct_at_end(size_type __n, const_reference __x) {
  _ConstructTransaction __tx(*this, __n);
  const_pointer __new_end = __tx.__new_end_;
  for (pointer __pos = __tx.__pos_; __pos != __new_end; __tx.__pos_ = ++__pos) {
    __alloc_traits::construct(this->__alloc(), std::__to_address(__pos), __x);
  }
}

template <class _Tp, class _Allocator>
template <class _InputIterator, class _Sentinel>
_LIBCPP_CONSTEXPR_SINCE_CXX20 void
vector<_Tp, _Allocator>::__construct_at_end(_InputIterator __first, _Sentinel __last, size_type __n) {
  _ConstructTransaction __tx(*this, __n);
  __tx.__pos_ = std::__uninitialized_allocator_copy(__alloc(), __first, __last, __tx.__pos_);
}

//  Default constructs __n objects starting at __end_
//  throws if construction throws
//  Postcondition:  size() == size() + __n
//  Exception safety: strong.
template <class _Tp, class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 void vector<_Tp, _Allocator>::__append(size_type __n) {
  if (static_cast<size_type>(this->__end_cap() - this->__end_) >= __n)
    this->__construct_at_end(__n);
  else {
    allocator_type& __a = this->__alloc();
    __split_buffer<value_type, allocator_type&> __v(__recommend(size() + __n), size(), __a);
    __v.__construct_at_end(__n);
    __swap_out_circular_buffer(__v);
  }
}

//  Default constructs __n objects starting at __end_
//  throws if construction throws
//  Postcondition:  size() == size() + __n
//  Exception safety: strong.
template <class _Tp, class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 void vector<_Tp, _Allocator>::__append(size_type __n, const_reference __x) {
  if (static_cast<size_type>(this->__end_cap() - this->__end_) >= __n)
    this->__construct_at_end(__n, __x);
  else {
    allocator_type& __a = this->__alloc();
    __split_buffer<value_type, allocator_type&> __v(__recommend(size() + __n), size(), __a);
    __v.__construct_at_end(__n, __x);
    __swap_out_circular_buffer(__v);
  }
}

template <class _Tp, class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 vector<_Tp, _Allocator>::vector(size_type __n) {
  auto __guard = std::__make_exception_guard(__destroy_vector(*this));
  if (__n > 0) {
    __vallocate(__n);
    __construct_at_end(__n);
  }
  __guard.__complete();
}

#if _LIBCPP_STD_VER >= 14
template <class _Tp, class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 vector<_Tp, _Allocator>::vector(size_type __n, const allocator_type& __a)
    : __end_cap_(nullptr, __a) {
  auto __guard = std::__make_exception_guard(__destroy_vector(*this));
  if (__n > 0) {
    __vallocate(__n);
    __construct_at_end(__n);
  }
  __guard.__complete();
}
#endif

template <class _Tp, class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 vector<_Tp, _Allocator>::vector(size_type __n, const value_type& __x) {
  auto __guard = std::__make_exception_guard(__destroy_vector(*this));
  if (__n > 0) {
    __vallocate(__n);
    __construct_at_end(__n, __x);
  }
  __guard.__complete();
}

template <class _Tp, class _Allocator>
template <class _InputIterator,
          __enable_if_t<__has_exactly_input_iterator_category<_InputIterator>::value &&
                            is_constructible<_Tp, typename iterator_traits<_InputIterator>::reference>::value,
                        int> >
_LIBCPP_CONSTEXPR_SINCE_CXX20 vector<_Tp, _Allocator>::vector(_InputIterator __first, _InputIterator __last) {
  __init_with_sentinel(__first, __last);
}

template <class _Tp, class _Allocator>
template <class _InputIterator,
          __enable_if_t<__has_exactly_input_iterator_category<_InputIterator>::value &&
                            is_constructible<_Tp, typename iterator_traits<_InputIterator>::reference>::value,
                        int> >
_LIBCPP_CONSTEXPR_SINCE_CXX20
vector<_Tp, _Allocator>::vector(_InputIterator __first, _InputIterator __last, const allocator_type& __a)
    : __end_cap_(nullptr, __a) {
  __init_with_sentinel(__first, __last);
}

template <class _Tp, class _Allocator>
template <class _ForwardIterator,
          __enable_if_t<__has_forward_iterator_category<_ForwardIterator>::value &&
                            is_constructible<_Tp, typename iterator_traits<_ForwardIterator>::reference>::value,
                        int> >
_LIBCPP_CONSTEXPR_SINCE_CXX20 vector<_Tp, _Allocator>::vector(_ForwardIterator __first, _ForwardIterator __last) {
  size_type __n = static_cast<size_type>(std::distance(__first, __last));
  __init_with_size(__first, __last, __n);
}

template <class _Tp, class _Allocator>
template <class _ForwardIterator,
          __enable_if_t<__has_forward_iterator_category<_ForwardIterator>::value &&
                            is_constructible<_Tp, typename iterator_traits<_ForwardIterator>::reference>::value,
                        int> >
_LIBCPP_CONSTEXPR_SINCE_CXX20
vector<_Tp, _Allocator>::vector(_ForwardIterator __first, _ForwardIterator __last, const allocator_type& __a)
    : __end_cap_(nullptr, __a) {
  size_type __n = static_cast<size_type>(std::distance(__first, __last));
  __init_with_size(__first, __last, __n);
}

template <class _Tp, class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 vector<_Tp, _Allocator>::vector(const vector& __x)
    : __end_cap_(nullptr, __alloc_traits::select_on_container_copy_construction(__x.__alloc())) {
  __init_with_size(__x.__begin_, __x.__end_, __x.size());
}

template <class _Tp, class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20
vector<_Tp, _Allocator>::vector(const vector& __x, const __type_identity_t<allocator_type>& __a)
    : __end_cap_(nullptr, __a) {
  __init_with_size(__x.__begin_, __x.__end_, __x.size());
}

template <class _Tp, class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 inline _LIBCPP_HIDE_FROM_ABI vector<_Tp, _Allocator>::vector(vector&& __x)
#if _LIBCPP_STD_VER >= 17
    noexcept
#else
    _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value)
#endif
    : __end_cap_(nullptr, std::move(__x.__alloc())) {
  this->__begin_    = __x.__begin_;
  this->__end_      = __x.__end_;
  this->__end_cap() = __x.__end_cap();
  __x.__begin_ = __x.__end_ = __x.__end_cap() = nullptr;
}

template <class _Tp, class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 inline _LIBCPP_HIDE_FROM_ABI
vector<_Tp, _Allocator>::vector(vector&& __x, const __type_identity_t<allocator_type>& __a)
    : __end_cap_(nullptr, __a) {
  if (__a == __x.__alloc()) {
    this->__begin_    = __x.__begin_;
    this->__end_      = __x.__end_;
    this->__end_cap() = __x.__end_cap();
    __x.__begin_ = __x.__end_ = __x.__end_cap() = nullptr;
  } else {
    typedef move_iterator<iterator> _Ip;
    auto __guard = std::__make_exception_guard(__destroy_vector(*this));
    assign(_Ip(__x.begin()), _Ip(__x.end()));
    __guard.__complete();
  }
}

#ifndef _LIBCPP_CXX03_LANG

template <class _Tp, class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 inline _LIBCPP_HIDE_FROM_ABI
vector<_Tp, _Allocator>::vector(initializer_list<value_type> __il) {
  auto __guard = std::__make_exception_guard(__destroy_vector(*this));
  if (__il.size() > 0) {
    __vallocate(__il.size());
    __construct_at_end(__il.begin(), __il.end(), __il.size());
  }
  __guard.__complete();
}

template <class _Tp, class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 inline _LIBCPP_HIDE_FROM_ABI
vector<_Tp, _Allocator>::vector(initializer_list<value_type> __il, const allocator_type& __a)
    : __end_cap_(nullptr, __a) {
  auto __guard = std::__make_exception_guard(__destroy_vector(*this));
  if (__il.size() > 0) {
    __vallocate(__il.size());
    __construct_at_end(__il.begin(), __il.end(), __il.size());
  }
  __guard.__complete();
}

#endif // _LIBCPP_CXX03_LANG

template <class _Tp, class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 inline _LIBCPP_HIDE_FROM_ABI vector<_Tp, _Allocator>&
vector<_Tp, _Allocator>::operator=(vector&& __x)
    _NOEXCEPT_((__noexcept_move_assign_container<_Allocator, __alloc_traits>::value)) {
  __move_assign(__x, integral_constant<bool, __alloc_traits::propagate_on_container_move_assignment::value>());
  return *this;
}

template <class _Tp, class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 void vector<_Tp, _Allocator>::__move_assign(vector& __c, false_type)
    _NOEXCEPT_(__alloc_traits::is_always_equal::value) {
  if (__alloc() != __c.__alloc()) {
    typedef move_iterator<iterator> _Ip;
    assign(_Ip(__c.begin()), _Ip(__c.end()));
  } else
    __move_assign(__c, true_type());
}

template <class _Tp, class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 void vector<_Tp, _Allocator>::__move_assign(vector& __c, true_type)
    _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value) {
  __vdeallocate();
  __move_assign_alloc(__c); // this can throw
  this->__begin_    = __c.__begin_;
  this->__end_      = __c.__end_;
  this->__end_cap() = __c.__end_cap();
  __c.__begin_ = __c.__end_ = __c.__end_cap() = nullptr;
}

template <class _Tp, class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 inline _LIBCPP_HIDE_FROM_ABI vector<_Tp, _Allocator>&
vector<_Tp, _Allocator>::operator=(const vector& __x) {
  if (this != std::addressof(__x)) {
    __copy_assign_alloc(__x);
    assign(__x.__begin_, __x.__end_);
  }
  return *this;
}

template <class _Tp, class _Allocator>
template <class _InputIterator,
          __enable_if_t<__has_exactly_input_iterator_category<_InputIterator>::value &&
                            is_constructible<_Tp, typename iterator_traits<_InputIterator>::reference>::value,
                        int> >
_LIBCPP_CONSTEXPR_SINCE_CXX20 void vector<_Tp, _Allocator>::assign(_InputIterator __first, _InputIterator __last) {
  __assign_with_sentinel(__first, __last);
}

template <class _Tp, class _Allocator>
template <class _Iterator, class _Sentinel>
_LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void
vector<_Tp, _Allocator>::__assign_with_sentinel(_Iterator __first, _Sentinel __last) {
  clear();
  for (; __first != __last; ++__first)
    emplace_back(*__first);
}

template <class _Tp, class _Allocator>
template <class _ForwardIterator,
          __enable_if_t<__has_forward_iterator_category<_ForwardIterator>::value &&
                            is_constructible<_Tp, typename iterator_traits<_ForwardIterator>::reference>::value,
                        int> >
_LIBCPP_CONSTEXPR_SINCE_CXX20 void vector<_Tp, _Allocator>::assign(_ForwardIterator __first, _ForwardIterator __last) {
  __assign_with_size(__first, __last, std::distance(__first, __last));
}

template <class _Tp, class _Allocator>
template <class _ForwardIterator, class _Sentinel>
_LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void
vector<_Tp, _Allocator>::__assign_with_size(_ForwardIterator __first, _Sentinel __last, difference_type __n) {
  size_type __new_size = static_cast<size_type>(__n);
  if (__new_size <= capacity()) {
    if (__new_size > size()) {
      _ForwardIterator __mid = std::next(__first, size());
      std::copy(__first, __mid, this->__begin_);
      __construct_at_end(__mid, __last, __new_size - size());
    } else {
      pointer __m = std::__copy<_ClassicAlgPolicy>(__first, __last, this->__begin_).second;
      this->__destruct_at_end(__m);
    }
  } else {
    __vdeallocate();
    __vallocate(__recommend(__new_size));
    __construct_at_end(__first, __last, __new_size);
  }
}

template <class _Tp, class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 void vector<_Tp, _Allocator>::assign(size_type __n, const_reference __u) {
  if (__n <= capacity()) {
    size_type __s = size();
    std::fill_n(this->__begin_, std::min(__n, __s), __u);
    if (__n > __s)
      __construct_at_end(__n - __s, __u);
    else
      this->__destruct_at_end(this->__begin_ + __n);
  } else {
    __vdeallocate();
    __vallocate(__recommend(static_cast<size_type>(__n)));
    __construct_at_end(__n, __u);
  }
}

template <class _Tp, class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 inline _LIBCPP_HIDE_FROM_ABI typename vector<_Tp, _Allocator>::iterator
vector<_Tp, _Allocator>::begin() _NOEXCEPT {
  return __make_iter(this->__begin_);
}

template <class _Tp, class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 inline _LIBCPP_HIDE_FROM_ABI typename vector<_Tp, _Allocator>::const_iterator
vector<_Tp, _Allocator>::begin() const _NOEXCEPT {
  return __make_iter(this->__begin_);
}

template <class _Tp, class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 inline _LIBCPP_HIDE_FROM_ABI typename vector<_Tp, _Allocator>::iterator
vector<_Tp, _Allocator>::end() _NOEXCEPT {
  return __make_iter(this->__end_);
}

template <class _Tp, class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 inline _LIBCPP_HIDE_FROM_ABI typename vector<_Tp, _Allocator>::const_iterator
vector<_Tp, _Allocator>::end() const _NOEXCEPT {
  return __make_iter(this->__end_);
}

template <class _Tp, class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 inline _LIBCPP_HIDE_FROM_ABI typename vector<_Tp, _Allocator>::reference
vector<_Tp, _Allocator>::operator[](size_type __n) _NOEXCEPT {
  _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(__n < size(), "vector[] index out of bounds");
  return this->__begin_[__n];
}

template <class _Tp, class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 inline _LIBCPP_HIDE_FROM_ABI typename vector<_Tp, _Allocator>::const_reference
vector<_Tp, _Allocator>::operator[](size_type __n) const _NOEXCEPT {
  _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(__n < size(), "vector[] index out of bounds");
  return this->__begin_[__n];
}

template <class _Tp, class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 typename vector<_Tp, _Allocator>::reference vector<_Tp, _Allocator>::at(size_type __n) {
  if (__n >= size())
    this->__throw_out_of_range();
  return this->__begin_[__n];
}

template <class _Tp, class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 typename vector<_Tp, _Allocator>::const_reference
vector<_Tp, _Allocator>::at(size_type __n) const {
  if (__n >= size())
    this->__throw_out_of_range();
  return this->__begin_[__n];
}

template <class _Tp, class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 void vector<_Tp, _Allocator>::reserve(size_type __n) {
  if (__n > capacity()) {
    if (__n > max_size())
      this->__throw_length_error();
    allocator_type& __a = this->__alloc();
    __split_buffer<value_type, allocator_type&> __v(__n, size(), __a);
    __swap_out_circular_buffer(__v);
  }
}

template <class _Tp, class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 void vector<_Tp, _Allocator>::shrink_to_fit() _NOEXCEPT {
  if (capacity() > size()) {
#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
    try {
#endif // _LIBCPP_HAS_NO_EXCEPTIONS
      allocator_type& __a = this->__alloc();
      __split_buffer<value_type, allocator_type&> __v(size(), size(), __a);
      __swap_out_circular_buffer(__v);
#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
    } catch (...) {
    }
#endif // _LIBCPP_HAS_NO_EXCEPTIONS
  }
}

template <class _Tp, class _Allocator>
template <class _Up>
_LIBCPP_CONSTEXPR_SINCE_CXX20 typename vector<_Tp, _Allocator>::pointer
vector<_Tp, _Allocator>::__push_back_slow_path(_Up&& __x) {
  allocator_type& __a = this->__alloc();
  __split_buffer<value_type, allocator_type&> __v(__recommend(size() + 1), size(), __a);
  // __v.push_back(std::forward<_Up>(__x));
  __alloc_traits::construct(__a, std::__to_address(__v.__end_), std::forward<_Up>(__x));
  __v.__end_++;
  __swap_out_circular_buffer(__v);
  return this->__end_;
}

template <class _Tp, class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 inline _LIBCPP_HIDE_FROM_ABI void
vector<_Tp, _Allocator>::push_back(const_reference __x) {
  pointer __end = this->__end_;
  if (__end < this->__end_cap()) {
    __construct_one_at_end(__x);
    ++__end;
  } else {
    __end = __push_back_slow_path(__x);
  }
  this->__end_ = __end;
}

template <class _Tp, class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 inline _LIBCPP_HIDE_FROM_ABI void vector<_Tp, _Allocator>::push_back(value_type&& __x) {
  pointer __end = this->__end_;
  if (__end < this->__end_cap()) {
    __construct_one_at_end(std::move(__x));
    ++__end;
  } else {
    __end = __push_back_slow_path(std::move(__x));
  }
  this->__end_ = __end;
}

template <class _Tp, class _Allocator>
template <class... _Args>
_LIBCPP_CONSTEXPR_SINCE_CXX20 typename vector<_Tp, _Allocator>::pointer
vector<_Tp, _Allocator>::__emplace_back_slow_path(_Args&&... __args) {
  allocator_type& __a = this->__alloc();
  __split_buffer<value_type, allocator_type&> __v(__recommend(size() + 1), size(), __a);
  //    __v.emplace_back(std::forward<_Args>(__args)...);
  __alloc_traits::construct(__a, std::__to_address(__v.__end_), std::forward<_Args>(__args)...);
  __v.__end_++;
  __swap_out_circular_buffer(__v);
  return this->__end_;
}

template <class _Tp, class _Allocator>
template <class... _Args>
_LIBCPP_CONSTEXPR_SINCE_CXX20 inline
#if _LIBCPP_STD_VER >= 17
    typename vector<_Tp, _Allocator>::reference
#else
    void
#endif
    vector<_Tp, _Allocator>::emplace_back(_Args&&... __args) {
  pointer __end = this->__end_;
  if (__end < this->__end_cap()) {
    __construct_one_at_end(std::forward<_Args>(__args)...);
    ++__end;
  } else {
    __end = __emplace_back_slow_path(std::forward<_Args>(__args)...);
  }
  this->__end_ = __end;
#if _LIBCPP_STD_VER >= 17
  return *(__end - 1);
#endif
}

template <class _Tp, class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 inline void vector<_Tp, _Allocator>::pop_back() {
  _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(!empty(), "vector::pop_back called on an empty vector");
  this->__destruct_at_end(this->__end_ - 1);
}

template <class _Tp, class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 inline _LIBCPP_HIDE_FROM_ABI typename vector<_Tp, _Allocator>::iterator
vector<_Tp, _Allocator>::erase(const_iterator __position) {
  _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
      __position != end(), "vector::erase(iterator) called with a non-dereferenceable iterator");
  difference_type __ps = __position - cbegin();
  pointer __p          = this->__begin_ + __ps;
  this->__destruct_at_end(std::move(__p + 1, this->__end_, __p));
  return __make_iter(__p);
}

template <class _Tp, class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 typename vector<_Tp, _Allocator>::iterator
vector<_Tp, _Allocator>::erase(const_iterator __first, const_iterator __last) {
  _LIBCPP_ASSERT_VALID_INPUT_RANGE(__first <= __last, "vector::erase(first, last) called with invalid range");
  pointer __p = this->__begin_ + (__first - begin());
  if (__first != __last) {
    this->__destruct_at_end(std::move(__p + (__last - __first), this->__end_, __p));
  }
  return __make_iter(__p);
}

template <class _Tp, class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 void
vector<_Tp, _Allocator>::__move_range(pointer __from_s, pointer __from_e, pointer __to) {
  pointer __old_last  = this->__end_;
  difference_type __n = __old_last - __to;
  {
    pointer __i = __from_s + __n;
    _ConstructTransaction __tx(*this, __from_e - __i);
    for (pointer __pos = __tx.__pos_; __i < __from_e; ++__i, (void)++__pos, __tx.__pos_ = __pos) {
      __alloc_traits::construct(this->__alloc(), std::__to_address(__pos), std::move(*__i));
    }
  }
  std::move_backward(__from_s, __from_s + __n, __old_last);
}

template <class _Tp, class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 typename vector<_Tp, _Allocator>::iterator
vector<_Tp, _Allocator>::insert(const_iterator __position, const_reference __x) {
  pointer __p = this->__begin_ + (__position - begin());
  // We can't compare unrelated pointers inside constant expressions
  if (!__libcpp_is_constant_evaluated() && this->__end_ < this->__end_cap()) {
    if (__p == this->__end_) {
      __construct_one_at_end(__x);
    } else {
      __move_range(__p, this->__end_, __p + 1);
      const_pointer __xr = pointer_traits<const_pointer>::pointer_to(__x);
      if (__p <= __xr && __xr < this->__end_)
        ++__xr;
      *__p = *__xr;
    }
  } else {
    allocator_type& __a = this->__alloc();
    __split_buffer<value_type, allocator_type&> __v(__recommend(size() + 1), __p - this->__begin_, __a);
    __v.push_back(__x);
    __p = __swap_out_circular_buffer(__v, __p);
  }
  return __make_iter(__p);
}

template <class _Tp, class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 typename vector<_Tp, _Allocator>::iterator
vector<_Tp, _Allocator>::insert(const_iterator __position, value_type&& __x) {
  pointer __p = this->__begin_ + (__position - begin());
  if (this->__end_ < this->__end_cap()) {
    if (__p == this->__end_) {
      __construct_one_at_end(std::move(__x));
    } else {
      __move_range(__p, this->__end_, __p + 1);
      *__p = std::move(__x);
    }
  } else {
    allocator_type& __a = this->__alloc();
    __split_buffer<value_type, allocator_type&> __v(__recommend(size() + 1), __p - this->__begin_, __a);
    __v.push_back(std::move(__x));
    __p = __swap_out_circular_buffer(__v, __p);
  }
  return __make_iter(__p);
}

template <class _Tp, class _Allocator>
template <class... _Args>
_LIBCPP_CONSTEXPR_SINCE_CXX20 typename vector<_Tp, _Allocator>::iterator
vector<_Tp, _Allocator>::emplace(const_iterator __position, _Args&&... __args) {
  pointer __p = this->__begin_ + (__position - begin());
  if (this->__end_ < this->__end_cap()) {
    if (__p == this->__end_) {
      __construct_one_at_end(std::forward<_Args>(__args)...);
    } else {
      __temp_value<value_type, _Allocator> __tmp(this->__alloc(), std::forward<_Args>(__args)...);
      __move_range(__p, this->__end_, __p + 1);
      *__p = std::move(__tmp.get());
    }
  } else {
    allocator_type& __a = this->__alloc();
    __split_buffer<value_type, allocator_type&> __v(__recommend(size() + 1), __p - this->__begin_, __a);
    __v.emplace_back(std::forward<_Args>(__args)...);
    __p = __swap_out_circular_buffer(__v, __p);
  }
  return __make_iter(__p);
}

template <class _Tp, class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 typename vector<_Tp, _Allocator>::iterator
vector<_Tp, _Allocator>::insert(const_iterator __position, size_type __n, const_reference __x) {
  pointer __p = this->__begin_ + (__position - begin());
  if (__n > 0) {
    // We can't compare unrelated pointers inside constant expressions
    if (!__libcpp_is_constant_evaluated() && __n <= static_cast<size_type>(this->__end_cap() - this->__end_)) {
      size_type __old_n  = __n;
      pointer __old_last = this->__end_;
      if (__n > static_cast<size_type>(this->__end_ - __p)) {
        size_type __cx = __n - (this->__end_ - __p);
        __construct_at_end(__cx, __x);
        __n -= __cx;
      }
      if (__n > 0) {
        __move_range(__p, __old_last, __p + __old_n);
        const_pointer __xr = pointer_traits<const_pointer>::pointer_to(__x);
        if (__p <= __xr && __xr < this->__end_)
          __xr += __old_n;
        std::fill_n(__p, __n, *__xr);
      }
    } else {
      allocator_type& __a = this->__alloc();
      __split_buffer<value_type, allocator_type&> __v(__recommend(size() + __n), __p - this->__begin_, __a);
      __v.__construct_at_end(__n, __x);
      __p = __swap_out_circular_buffer(__v, __p);
    }
  }
  return __make_iter(__p);
}
template <class _Tp, class _Allocator>
template <class _InputIterator,
          __enable_if_t<__has_exactly_input_iterator_category<_InputIterator>::value &&
                            is_constructible<_Tp, typename iterator_traits<_InputIterator>::reference>::value,
                        int> >
_LIBCPP_CONSTEXPR_SINCE_CXX20 typename vector<_Tp, _Allocator>::iterator
vector<_Tp, _Allocator>::insert(const_iterator __position, _InputIterator __first, _InputIterator __last) {
  return __insert_with_sentinel(__position, __first, __last);
}

template <class _Tp, class _Allocator>
template <class _InputIterator, class _Sentinel>
_LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI typename vector<_Tp, _Allocator>::iterator
vector<_Tp, _Allocator>::__insert_with_sentinel(const_iterator __position, _InputIterator __first, _Sentinel __last) {
  difference_type __off = __position - begin();
  pointer __p           = this->__begin_ + __off;
  allocator_type& __a   = this->__alloc();
  pointer __old_last    = this->__end_;
  for (; this->__end_ != this->__end_cap() && __first != __last; ++__first) {
    __construct_one_at_end(*__first);
  }
  __split_buffer<value_type, allocator_type&> __v(__a);
  if (__first != __last) {
#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
    try {
#endif // _LIBCPP_HAS_NO_EXCEPTIONS
      __v.__construct_at_end_with_sentinel(std::move(__first), std::move(__last));
      difference_type __old_size = __old_last - this->__begin_;
      difference_type __old_p    = __p - this->__begin_;
      reserve(__recommend(size() + __v.size()));
      __p        = this->__begin_ + __old_p;
      __old_last = this->__begin_ + __old_size;
#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
    } catch (...) {
      erase(__make_iter(__old_last), end());
      throw;
    }
#endif // _LIBCPP_HAS_NO_EXCEPTIONS
  }
  __p = std::rotate(__p, __old_last, this->__end_);
  insert(__make_iter(__p), std::make_move_iterator(__v.begin()), std::make_move_iterator(__v.end()));
  return begin() + __off;
}

template <class _Tp, class _Allocator>
template <class _ForwardIterator,
          __enable_if_t<__has_forward_iterator_category<_ForwardIterator>::value &&
                            is_constructible<_Tp, typename iterator_traits<_ForwardIterator>::reference>::value,
                        int> >
_LIBCPP_CONSTEXPR_SINCE_CXX20 typename vector<_Tp, _Allocator>::iterator
vector<_Tp, _Allocator>::insert(const_iterator __position, _ForwardIterator __first, _ForwardIterator __last) {
  return __insert_with_size(__position, __first, __last, std::distance(__first, __last));
}

template <class _Tp, class _Allocator>
template <class _Iterator, class _Sentinel>
_LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI typename vector<_Tp, _Allocator>::iterator
vector<_Tp, _Allocator>::__insert_with_size(
    const_iterator __position, _Iterator __first, _Sentinel __last, difference_type __n) {
  auto __insertion_size = __n;
  pointer __p           = this->__begin_ + (__position - begin());
  if (__n > 0) {
    if (__n <= this->__end_cap() - this->__end_) {
      size_type __old_n    = __n;
      pointer __old_last   = this->__end_;
      _Iterator __m        = std::next(__first, __n);
      difference_type __dx = this->__end_ - __p;
      if (__n > __dx) {
        __m                    = __first;
        difference_type __diff = this->__end_ - __p;
        std::advance(__m, __diff);
        __construct_at_end(__m, __last, __n - __diff);
        __n = __dx;
      }
      if (__n > 0) {
        __move_range(__p, __old_last, __p + __old_n);
        std::copy(__first, __m, __p);
      }
    } else {
      allocator_type& __a = this->__alloc();
      __split_buffer<value_type, allocator_type&> __v(__recommend(size() + __n), __p - this->__begin_, __a);
      __v.__construct_at_end_with_size(__first, __insertion_size);
      __p = __swap_out_circular_buffer(__v, __p);
    }
  }
  return __make_iter(__p);
}

template <class _Tp, class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 void vector<_Tp, _Allocator>::resize(size_type __sz) {
  size_type __cs = size();
  if (__cs < __sz)
    this->__append(__sz - __cs);
  else if (__cs > __sz)
    this->__destruct_at_end(this->__begin_ + __sz);
}

template <class _Tp, class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 void vector<_Tp, _Allocator>::resize(size_type __sz, const_reference __x) {
  size_type __cs = size();
  if (__cs < __sz)
    this->__append(__sz - __cs, __x);
  else if (__cs > __sz)
    this->__destruct_at_end(this->__begin_ + __sz);
}

template <class _Tp, class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 void vector<_Tp, _Allocator>::swap(vector& __x)
#if _LIBCPP_STD_VER >= 14
    _NOEXCEPT
#else
    _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value || __is_nothrow_swappable<allocator_type>::value)
#endif
{
  _LIBCPP_ASSERT_COMPATIBLE_ALLOCATOR(
      __alloc_traits::propagate_on_container_swap::value || this->__alloc() == __x.__alloc(),
      "vector::swap: Either propagate_on_container_swap must be true"
      " or the allocators must compare equal");
  std::swap(this->__begin_, __x.__begin_);
  std::swap(this->__end_, __x.__end_);
  std::swap(this->__end_cap(), __x.__end_cap());
  std::__swap_allocator(
      this->__alloc(), __x.__alloc(), integral_constant<bool, __alloc_traits::propagate_on_container_swap::value>());
}

template <class _Tp, class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 bool vector<_Tp, _Allocator>::__invariants() const {
  if (this->__begin_ == nullptr) {
    if (this->__end_ != nullptr || this->__end_cap() != nullptr)
      return false;
  } else {
    if (this->__begin_ > this->__end_)
      return false;
    if (this->__begin_ == this->__end_cap())
      return false;
    if (this->__end_ > this->__end_cap())
      return false;
  }
  return true;
}

// vector<bool>

template <class _Allocator>
class vector<bool, _Allocator>;

template <class _Allocator>
struct hash<vector<bool, _Allocator> >;

template <class _Allocator>
struct __has_storage_type<vector<bool, _Allocator> > {
  static const bool value = true;
};

template <class _Allocator>
class _LIBCPP_TEMPLATE_VIS vector<bool, _Allocator> {
public:
  typedef vector __self;
  typedef bool value_type;
  typedef _Allocator allocator_type;
  typedef allocator_traits<allocator_type> __alloc_traits;
  typedef typename __alloc_traits::size_type size_type;
  typedef typename __alloc_traits::difference_type difference_type;
  typedef size_type __storage_type;
  typedef __bit_iterator<vector, false> pointer;
  typedef __bit_iterator<vector, true> const_pointer;
  typedef pointer iterator;
  typedef const_pointer const_iterator;
  typedef std::reverse_iterator<iterator> reverse_iterator;
  typedef std::reverse_iterator<const_iterator> const_reverse_iterator;

private:
  typedef __rebind_alloc<__alloc_traits, __storage_type> __storage_allocator;
  typedef allocator_traits<__storage_allocator> __storage_traits;
  typedef typename __storage_traits::pointer __storage_pointer;
  typedef typename __storage_traits::const_pointer __const_storage_pointer;

  __storage_pointer __begin_;
  size_type __size_;
  __compressed_pair<size_type, __storage_allocator> __cap_alloc_;

public:
  typedef __bit_reference<vector> reference;
#ifdef _LIBCPP_ABI_BITSET_VECTOR_BOOL_CONST_SUBSCRIPT_RETURN_BOOL
  using const_reference = bool;
#else
  typedef __bit_const_reference<vector> const_reference;
#endif

private:
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type& __cap() _NOEXCEPT { return __cap_alloc_.first(); }
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const size_type& __cap() const _NOEXCEPT {
    return __cap_alloc_.first();
  }
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __storage_allocator& __alloc() _NOEXCEPT {
    return __cap_alloc_.second();
  }
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const __storage_allocator& __alloc() const _NOEXCEPT {
    return __cap_alloc_.second();
  }

  static const unsigned __bits_per_word = static_cast<unsigned>(sizeof(__storage_type) * CHAR_BIT);

  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 static size_type
  __internal_cap_to_external(size_type __n) _NOEXCEPT {
    return __n * __bits_per_word;
  }
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 static size_type
  __external_cap_to_internal(size_type __n) _NOEXCEPT {
    return (__n - 1) / __bits_per_word + 1;
  }

public:
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 vector()
      _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value);

  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 explicit vector(const allocator_type& __a)
#if _LIBCPP_STD_VER <= 14
      _NOEXCEPT_(is_nothrow_copy_constructible<allocator_type>::value);
#else
      _NOEXCEPT;
#endif

private:
  class __destroy_vector {
  public:
    _LIBCPP_CONSTEXPR _LIBCPP_HIDE_FROM_ABI __destroy_vector(vector& __vec) : __vec_(__vec) {}

    _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void operator()() {
      if (__vec_.__begin_ != nullptr)
        __storage_traits::deallocate(__vec_.__alloc(), __vec_.__begin_, __vec_.__cap());
    }

  private:
    vector& __vec_;
  };

public:
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 ~vector() { __destroy_vector (*this)(); }

  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 explicit vector(size_type __n);
#if _LIBCPP_STD_VER >= 14
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 explicit vector(size_type __n, const allocator_type& __a);
#endif
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 vector(size_type __n, const value_type& __v);
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
  vector(size_type __n, const value_type& __v, const allocator_type& __a);
  template <class _InputIterator, __enable_if_t<__has_exactly_input_iterator_category<_InputIterator>::value, int> = 0>
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 vector(_InputIterator __first, _InputIterator __last);
  template <class _InputIterator, __enable_if_t<__has_exactly_input_iterator_category<_InputIterator>::value, int> = 0>
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
  vector(_InputIterator __first, _InputIterator __last, const allocator_type& __a);
  template <class _ForwardIterator, __enable_if_t<__has_forward_iterator_category<_ForwardIterator>::value, int> = 0>
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 vector(_ForwardIterator __first, _ForwardIterator __last);
  template <class _ForwardIterator, __enable_if_t<__has_forward_iterator_category<_ForwardIterator>::value, int> = 0>
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
  vector(_ForwardIterator __first, _ForwardIterator __last, const allocator_type& __a);

#if _LIBCPP_STD_VER >= 23
  template <_ContainerCompatibleRange<bool> _Range>
  _LIBCPP_HIDE_FROM_ABI constexpr vector(from_range_t, _Range&& __range, const allocator_type& __a = allocator_type())
      : __begin_(nullptr), __size_(0), __cap_alloc_(0, static_cast<__storage_allocator>(__a)) {
    if constexpr (ranges::forward_range<_Range> || ranges::sized_range<_Range>) {
      auto __n = static_cast<size_type>(ranges::distance(__range));
      __init_with_size(ranges::begin(__range), ranges::end(__range), __n);

    } else {
      __init_with_sentinel(ranges::begin(__range), ranges::end(__range));
    }
  }
#endif

  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 vector(const vector& __v);
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 vector(const vector& __v, const allocator_type& __a);
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 vector& operator=(const vector& __v);

#ifndef _LIBCPP_CXX03_LANG
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 vector(initializer_list<value_type> __il);
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
  vector(initializer_list<value_type> __il, const allocator_type& __a);

  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 vector& operator=(initializer_list<value_type> __il) {
    assign(__il.begin(), __il.end());
    return *this;
  }

#endif // !_LIBCPP_CXX03_LANG

  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 vector(vector&& __v)
#if _LIBCPP_STD_VER >= 17
      noexcept;
#else
      _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value);
#endif
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
  vector(vector&& __v, const __type_identity_t<allocator_type>& __a);
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 vector& operator=(vector&& __v)
      _NOEXCEPT_((__noexcept_move_assign_container<_Allocator, __alloc_traits>::value));

  template <class _InputIterator, __enable_if_t<__has_exactly_input_iterator_category<_InputIterator>::value, int> = 0>
  void _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 assign(_InputIterator __first, _InputIterator __last);
  template <class _ForwardIterator, __enable_if_t<__has_forward_iterator_category<_ForwardIterator>::value, int> = 0>
  void _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 assign(_ForwardIterator __first, _ForwardIterator __last);

#if _LIBCPP_STD_VER >= 23
  template <_ContainerCompatibleRange<bool> _Range>
  _LIBCPP_HIDE_FROM_ABI constexpr void assign_range(_Range&& __range) {
    if constexpr (ranges::forward_range<_Range> || ranges::sized_range<_Range>) {
      auto __n = static_cast<size_type>(ranges::distance(__range));
      __assign_with_size(ranges::begin(__range), ranges::end(__range), __n);

    } else {
      __assign_with_sentinel(ranges::begin(__range), ranges::end(__range));
    }
  }
#endif

  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void assign(size_type __n, const value_type& __x);

#ifndef _LIBCPP_CXX03_LANG
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void assign(initializer_list<value_type> __il) {
    assign(__il.begin(), __il.end());
  }
#endif

  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 allocator_type get_allocator() const _NOEXCEPT {
    return allocator_type(this->__alloc());
  }

  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type max_size() const _NOEXCEPT;
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type capacity() const _NOEXCEPT {
    return __internal_cap_to_external(__cap());
  }
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type size() const _NOEXCEPT { return __size_; }
  _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool empty() const _NOEXCEPT {
    return __size_ == 0;
  }
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void reserve(size_type __n);
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void shrink_to_fit() _NOEXCEPT;

  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 iterator begin() _NOEXCEPT { return __make_iter(0); }
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const_iterator begin() const _NOEXCEPT { return __make_iter(0); }
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 iterator end() _NOEXCEPT { return __make_iter(__size_); }
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const_iterator end() const _NOEXCEPT {
    return __make_iter(__size_);
  }

  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 reverse_iterator rbegin() _NOEXCEPT {
    return reverse_iterator(end());
  }
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const_reverse_iterator rbegin() const _NOEXCEPT {
    return const_reverse_iterator(end());
  }
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 reverse_iterator rend() _NOEXCEPT {
    return reverse_iterator(begin());
  }
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const_reverse_iterator rend() const _NOEXCEPT {
    return const_reverse_iterator(begin());
  }

  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const_iterator cbegin() const _NOEXCEPT { return __make_iter(0); }
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const_iterator cend() const _NOEXCEPT {
    return __make_iter(__size_);
  }
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const_reverse_iterator crbegin() const _NOEXCEPT {
    return rbegin();
  }
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const_reverse_iterator crend() const _NOEXCEPT { return rend(); }

  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 reference operator[](size_type __n) { return __make_ref(__n); }
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const_reference operator[](size_type __n) const {
    return __make_ref(__n);
  }
  _LIBCPP_HIDE_FROM_ABI reference at(size_type __n);
  _LIBCPP_HIDE_FROM_ABI const_reference at(size_type __n) const;

  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 reference front() { return __make_ref(0); }
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const_reference front() const { return __make_ref(0); }
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 reference back() { return __make_ref(__size_ - 1); }
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const_reference back() const { return __make_ref(__size_ - 1); }

  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void push_back(const value_type& __x);
#if _LIBCPP_STD_VER >= 14
  template <class... _Args>
#  if _LIBCPP_STD_VER >= 17
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 reference emplace_back(_Args&&... __args)
#  else
  _LIBCPP_HIDE_FROM_ABI void emplace_back(_Args&&... __args)
#  endif
  {
    push_back(value_type(std::forward<_Args>(__args)...));
#  if _LIBCPP_STD_VER >= 17
    return this->back();
#  endif
  }
#endif

#if _LIBCPP_STD_VER >= 23
  template <_ContainerCompatibleRange<bool> _Range>
  _LIBCPP_HIDE_FROM_ABI constexpr void append_range(_Range&& __range) {
    insert_range(end(), std::forward<_Range>(__range));
  }
#endif

  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void pop_back() { --__size_; }

#if _LIBCPP_STD_VER >= 14
  template <class... _Args>
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 iterator emplace(const_iterator __position, _Args&&... __args) {
    return insert(__position, value_type(std::forward<_Args>(__args)...));
  }
#endif

  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 iterator insert(const_iterator __position, const value_type& __x);
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 iterator
  insert(const_iterator __position, size_type __n, const value_type& __x);
  template <class _InputIterator, __enable_if_t<__has_exactly_input_iterator_category<_InputIterator>::value, int> = 0>
  iterator _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
  insert(const_iterator __position, _InputIterator __first, _InputIterator __last);
  template <class _ForwardIterator, __enable_if_t<__has_forward_iterator_category<_ForwardIterator>::value, int> = 0>
  iterator _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
  insert(const_iterator __position, _ForwardIterator __first, _ForwardIterator __last);

#if _LIBCPP_STD_VER >= 23
  template <_ContainerCompatibleRange<bool> _Range>
  _LIBCPP_HIDE_FROM_ABI constexpr iterator insert_range(const_iterator __position, _Range&& __range) {
    if constexpr (ranges::forward_range<_Range> || ranges::sized_range<_Range>) {
      auto __n = static_cast<size_type>(ranges::distance(__range));
      return __insert_with_size(__position, ranges::begin(__range), ranges::end(__range), __n);

    } else {
      return __insert_with_sentinel(__position, ranges::begin(__range), ranges::end(__range));
    }
  }
#endif

#ifndef _LIBCPP_CXX03_LANG
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 iterator
  insert(const_iterator __position, initializer_list<value_type> __il) {
    return insert(__position, __il.begin(), __il.end());
  }
#endif

  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 iterator erase(const_iterator __position);
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 iterator erase(const_iterator __first, const_iterator __last);

  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void clear() _NOEXCEPT { __size_ = 0; }

  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void swap(vector&)
#if _LIBCPP_STD_VER >= 14
      _NOEXCEPT;
#else
      _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value || __is_nothrow_swappable<allocator_type>::value);
#endif
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 static void swap(reference __x, reference __y) _NOEXCEPT {
    std::swap(__x, __y);
  }

  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void resize(size_type __sz, value_type __x = false);
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void flip() _NOEXCEPT;

  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool __invariants() const;

private:
  _LIBCPP_NORETURN _LIBCPP_HIDE_FROM_ABI void __throw_length_error() const { std::__throw_length_error("vector"); }

  _LIBCPP_NORETURN _LIBCPP_HIDE_FROM_ABI void __throw_out_of_range() const { std::__throw_out_of_range("vector"); }

  template <class _InputIterator, class _Sentinel>
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void
  __init_with_size(_InputIterator __first, _Sentinel __last, size_type __n) {
    auto __guard = std::__make_exception_guard(__destroy_vector(*this));

    if (__n > 0) {
      __vallocate(__n);
      __construct_at_end(std::move(__first), std::move(__last), __n);
    }

    __guard.__complete();
  }

  template <class _InputIterator, class _Sentinel>
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void
  __init_with_sentinel(_InputIterator __first, _Sentinel __last) {
#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
    try {
#endif // _LIBCPP_HAS_NO_EXCEPTIONS
      for (; __first != __last; ++__first)
        push_back(*__first);
#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
    } catch (...) {
      if (__begin_ != nullptr)
        __storage_traits::deallocate(__alloc(), __begin_, __cap());
      throw;
    }
#endif // _LIBCPP_HAS_NO_EXCEPTIONS
  }

  template <class _Iterator, class _Sentinel>
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __assign_with_sentinel(_Iterator __first, _Sentinel __last);

  template <class _ForwardIterator, class _Sentinel>
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void
  __assign_with_size(_ForwardIterator __first, _Sentinel __last, difference_type __ns);

  template <class _InputIterator, class _Sentinel>
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI iterator
  __insert_with_sentinel(const_iterator __position, _InputIterator __first, _Sentinel __last);

  template <class _Iterator, class _Sentinel>
  _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI iterator
  __insert_with_size(const_iterator __position, _Iterator __first, _Sentinel __last, difference_type __n);

  //  Allocate space for __n objects
  //  throws length_error if __n > max_size()
  //  throws (probably bad_alloc) if memory run out
  //  Precondition:  __begin_ == __end_ == __cap() == 0
  //  Precondition:  __n > 0
  //  Postcondition:  capacity() >= __n
  //  Postcondition:  size() == 0
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void __vallocate(size_type __n) {
    if (__n > max_size())
      __throw_length_error();
    auto __allocation = std::__allocate_at_least(__alloc(), __external_cap_to_internal(__n));
    __begin_          = __allocation.ptr;
    __size_           = 0;
    __cap()           = __allocation.count;
    if (__libcpp_is_constant_evaluated()) {
      for (size_type __i = 0; __i != __cap(); ++__i)
        std::__construct_at(std::__to_address(__begin_) + __i);
    }
  }

  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void __vdeallocate() _NOEXCEPT;
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 static size_type __align_it(size_type __new_size) _NOEXCEPT {
    return (__new_size + (__bits_per_word - 1)) & ~((size_type)__bits_per_word - 1);
  }
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type __recommend(size_type __new_size) const;
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void __construct_at_end(size_type __n, bool __x);
  template <class _InputIterator, class _Sentinel>
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void
  __construct_at_end(_InputIterator __first, _Sentinel __last, size_type __n);
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void __append(size_type __n, const_reference __x);
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 reference __make_ref(size_type __pos) _NOEXCEPT {
    return reference(__begin_ + __pos / __bits_per_word, __storage_type(1) << __pos % __bits_per_word);
  }
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const_reference __make_ref(size_type __pos) const _NOEXCEPT {
    return __bit_const_reference<vector>(
        __begin_ + __pos / __bits_per_word, __storage_type(1) << __pos % __bits_per_word);
  }
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 iterator __make_iter(size_type __pos) _NOEXCEPT {
    return iterator(__begin_ + __pos / __bits_per_word, static_cast<unsigned>(__pos % __bits_per_word));
  }
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const_iterator __make_iter(size_type __pos) const _NOEXCEPT {
    return const_iterator(__begin_ + __pos / __bits_per_word, static_cast<unsigned>(__pos % __bits_per_word));
  }
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 iterator __const_iterator_cast(const_iterator __p) _NOEXCEPT {
    return begin() + (__p - cbegin());
  }

  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void __copy_assign_alloc(const vector& __v) {
    __copy_assign_alloc(
        __v, integral_constant<bool, __storage_traits::propagate_on_container_copy_assignment::value>());
  }
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void __copy_assign_alloc(const vector& __c, true_type) {
    if (__alloc() != __c.__alloc())
      __vdeallocate();
    __alloc() = __c.__alloc();
  }

  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void __copy_assign_alloc(const vector&, false_type) {}

  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void __move_assign(vector& __c, false_type);
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void __move_assign(vector& __c, true_type)
      _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value);
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void __move_assign_alloc(vector& __c)
      _NOEXCEPT_(!__storage_traits::propagate_on_container_move_assignment::value ||
                 is_nothrow_move_assignable<allocator_type>::value) {
    __move_assign_alloc(
        __c, integral_constant<bool, __storage_traits::propagate_on_container_move_assignment::value>());
  }
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void __move_assign_alloc(vector& __c, true_type)
      _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value) {
    __alloc() = std::move(__c.__alloc());
  }

  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void __move_assign_alloc(vector&, false_type) _NOEXCEPT {}

  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_t __hash_code() const _NOEXCEPT;

  friend class __bit_reference<vector>;
  friend class __bit_const_reference<vector>;
  friend class __bit_iterator<vector, false>;
  friend class __bit_iterator<vector, true>;
  friend struct __bit_array<vector>;
  friend struct _LIBCPP_TEMPLATE_VIS hash<vector>;
};

template <class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 void vector<bool, _Allocator>::__vdeallocate() _NOEXCEPT {
  if (this->__begin_ != nullptr) {
    __storage_traits::deallocate(this->__alloc(), this->__begin_, __cap());
    this->__begin_ = nullptr;
    this->__size_ = this->__cap() = 0;
  }
}

template <class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 typename vector<bool, _Allocator>::size_type
vector<bool, _Allocator>::max_size() const _NOEXCEPT {
  size_type __amax = __storage_traits::max_size(__alloc());
  size_type __nmax = numeric_limits<size_type>::max() / 2; // end() >= begin(), always
  if (__nmax / __bits_per_word <= __amax)
    return __nmax;
  return __internal_cap_to_external(__amax);
}

//  Precondition:  __new_size > capacity()
template <class _Allocator>
inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 typename vector<bool, _Allocator>::size_type
vector<bool, _Allocator>::__recommend(size_type __new_size) const {
  const size_type __ms = max_size();
  if (__new_size > __ms)
    this->__throw_length_error();
  const size_type __cap = capacity();
  if (__cap >= __ms / 2)
    return __ms;
  return std::max(2 * __cap, __align_it(__new_size));
}

//  Default constructs __n objects starting at __end_
//  Precondition:  __n > 0
//  Precondition:  size() + __n <= capacity()
//  Postcondition:  size() == size() + __n
template <class _Allocator>
inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void
vector<bool, _Allocator>::__construct_at_end(size_type __n, bool __x) {
  size_type __old_size = this->__size_;
  this->__size_ += __n;
  if (__old_size == 0 || ((__old_size - 1) / __bits_per_word) != ((this->__size_ - 1) / __bits_per_word)) {
    if (this->__size_ <= __bits_per_word)
      this->__begin_[0] = __storage_type(0);
    else
      this->__begin_[(this->__size_ - 1) / __bits_per_word] = __storage_type(0);
  }
  std::fill_n(__make_iter(__old_size), __n, __x);
}

template <class _Allocator>
template <class _InputIterator, class _Sentinel>
_LIBCPP_CONSTEXPR_SINCE_CXX20 void
vector<bool, _Allocator>::__construct_at_end(_InputIterator __first, _Sentinel __last, size_type __n) {
  size_type __old_size = this->__size_;
  this->__size_ += __n;
  if (__old_size == 0 || ((__old_size - 1) / __bits_per_word) != ((this->__size_ - 1) / __bits_per_word)) {
    if (this->__size_ <= __bits_per_word)
      this->__begin_[0] = __storage_type(0);
    else
      this->__begin_[(this->__size_ - 1) / __bits_per_word] = __storage_type(0);
  }
  std::__copy<_ClassicAlgPolicy>(__first, __last, __make_iter(__old_size));
}

template <class _Allocator>
inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 vector<bool, _Allocator>::vector()
    _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value)
    : __begin_(nullptr), __size_(0), __cap_alloc_(0, __default_init_tag()) {}

template <class _Allocator>
inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 vector<bool, _Allocator>::vector(const allocator_type& __a)
#if _LIBCPP_STD_VER <= 14
    _NOEXCEPT_(is_nothrow_copy_constructible<allocator_type>::value)
#else
        _NOEXCEPT
#endif
    : __begin_(nullptr), __size_(0), __cap_alloc_(0, static_cast<__storage_allocator>(__a)) {
}

template <class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 vector<bool, _Allocator>::vector(size_type __n)
    : __begin_(nullptr), __size_(0), __cap_alloc_(0, __default_init_tag()) {
  if (__n > 0) {
    __vallocate(__n);
    __construct_at_end(__n, false);
  }
}

#if _LIBCPP_STD_VER >= 14
template <class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 vector<bool, _Allocator>::vector(size_type __n, const allocator_type& __a)
    : __begin_(nullptr), __size_(0), __cap_alloc_(0, static_cast<__storage_allocator>(__a)) {
  if (__n > 0) {
    __vallocate(__n);
    __construct_at_end(__n, false);
  }
}
#endif

template <class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 vector<bool, _Allocator>::vector(size_type __n, const value_type& __x)
    : __begin_(nullptr), __size_(0), __cap_alloc_(0, __default_init_tag()) {
  if (__n > 0) {
    __vallocate(__n);
    __construct_at_end(__n, __x);
  }
}

template <class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20
vector<bool, _Allocator>::vector(size_type __n, const value_type& __x, const allocator_type& __a)
    : __begin_(nullptr), __size_(0), __cap_alloc_(0, static_cast<__storage_allocator>(__a)) {
  if (__n > 0) {
    __vallocate(__n);
    __construct_at_end(__n, __x);
  }
}

template <class _Allocator>
template <class _InputIterator, __enable_if_t<__has_exactly_input_iterator_category<_InputIterator>::value, int> >
_LIBCPP_CONSTEXPR_SINCE_CXX20 vector<bool, _Allocator>::vector(_InputIterator __first, _InputIterator __last)
    : __begin_(nullptr), __size_(0), __cap_alloc_(0, __default_init_tag()) {
  __init_with_sentinel(__first, __last);
}

template <class _Allocator>
template <class _InputIterator, __enable_if_t<__has_exactly_input_iterator_category<_InputIterator>::value, int> >
_LIBCPP_CONSTEXPR_SINCE_CXX20
vector<bool, _Allocator>::vector(_InputIterator __first, _InputIterator __last, const allocator_type& __a)
    : __begin_(nullptr), __size_(0), __cap_alloc_(0, static_cast<__storage_allocator>(__a)) {
  __init_with_sentinel(__first, __last);
}

template <class _Allocator>
template <class _ForwardIterator, __enable_if_t<__has_forward_iterator_category<_ForwardIterator>::value, int> >
_LIBCPP_CONSTEXPR_SINCE_CXX20 vector<bool, _Allocator>::vector(_ForwardIterator __first, _ForwardIterator __last)
    : __begin_(nullptr), __size_(0), __cap_alloc_(0, __default_init_tag()) {
  auto __n = static_cast<size_type>(std::distance(__first, __last));
  __init_with_size(__first, __last, __n);
}

template <class _Allocator>
template <class _ForwardIterator, __enable_if_t<__has_forward_iterator_category<_ForwardIterator>::value, int> >
_LIBCPP_CONSTEXPR_SINCE_CXX20
vector<bool, _Allocator>::vector(_ForwardIterator __first, _ForwardIterator __last, const allocator_type& __a)
    : __begin_(nullptr), __size_(0), __cap_alloc_(0, static_cast<__storage_allocator>(__a)) {
  auto __n = static_cast<size_type>(std::distance(__first, __last));
  __init_with_size(__first, __last, __n);
}

#ifndef _LIBCPP_CXX03_LANG

template <class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 vector<bool, _Allocator>::vector(initializer_list<value_type> __il)
    : __begin_(nullptr), __size_(0), __cap_alloc_(0, __default_init_tag()) {
  size_type __n = static_cast<size_type>(__il.size());
  if (__n > 0) {
    __vallocate(__n);
    __construct_at_end(__il.begin(), __il.end(), __n);
  }
}

template <class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20
vector<bool, _Allocator>::vector(initializer_list<value_type> __il, const allocator_type& __a)
    : __begin_(nullptr), __size_(0), __cap_alloc_(0, static_cast<__storage_allocator>(__a)) {
  size_type __n = static_cast<size_type>(__il.size());
  if (__n > 0) {
    __vallocate(__n);
    __construct_at_end(__il.begin(), __il.end(), __n);
  }
}

#endif // _LIBCPP_CXX03_LANG

template <class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 vector<bool, _Allocator>::vector(const vector& __v)
    : __begin_(nullptr),
      __size_(0),
      __cap_alloc_(0, __storage_traits::select_on_container_copy_construction(__v.__alloc())) {
  if (__v.size() > 0) {
    __vallocate(__v.size());
    __construct_at_end(__v.begin(), __v.end(), __v.size());
  }
}

template <class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 vector<bool, _Allocator>::vector(const vector& __v, const allocator_type& __a)
    : __begin_(nullptr), __size_(0), __cap_alloc_(0, __a) {
  if (__v.size() > 0) {
    __vallocate(__v.size());
    __construct_at_end(__v.begin(), __v.end(), __v.size());
  }
}

template <class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 vector<bool, _Allocator>& vector<bool, _Allocator>::operator=(const vector& __v) {
  if (this != std::addressof(__v)) {
    __copy_assign_alloc(__v);
    if (__v.__size_) {
      if (__v.__size_ > capacity()) {
        __vdeallocate();
        __vallocate(__v.__size_);
      }
      std::copy(__v.__begin_, __v.__begin_ + __external_cap_to_internal(__v.__size_), __begin_);
    }
    __size_ = __v.__size_;
  }
  return *this;
}

template <class _Allocator>
inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 vector<bool, _Allocator>::vector(vector&& __v)
#if _LIBCPP_STD_VER >= 17
    _NOEXCEPT
#else
    _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value)
#endif
    : __begin_(__v.__begin_),
      __size_(__v.__size_),
      __cap_alloc_(std::move(__v.__cap_alloc_)) {
  __v.__begin_ = nullptr;
  __v.__size_  = 0;
  __v.__cap()  = 0;
}

template <class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20
vector<bool, _Allocator>::vector(vector&& __v, const __type_identity_t<allocator_type>& __a)
    : __begin_(nullptr), __size_(0), __cap_alloc_(0, __a) {
  if (__a == allocator_type(__v.__alloc())) {
    this->__begin_ = __v.__begin_;
    this->__size_  = __v.__size_;
    this->__cap()  = __v.__cap();
    __v.__begin_   = nullptr;
    __v.__cap() = __v.__size_ = 0;
  } else if (__v.size() > 0) {
    __vallocate(__v.size());
    __construct_at_end(__v.begin(), __v.end(), __v.size());
  }
}

template <class _Allocator>
inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 vector<bool, _Allocator>&
vector<bool, _Allocator>::operator=(vector&& __v)
    _NOEXCEPT_((__noexcept_move_assign_container<_Allocator, __alloc_traits>::value)) {
  __move_assign(__v, integral_constant<bool, __storage_traits::propagate_on_container_move_assignment::value>());
  return *this;
}

template <class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 void vector<bool, _Allocator>::__move_assign(vector& __c, false_type) {
  if (__alloc() != __c.__alloc())
    assign(__c.begin(), __c.end());
  else
    __move_assign(__c, true_type());
}

template <class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 void vector<bool, _Allocator>::__move_assign(vector& __c, true_type)
    _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value) {
  __vdeallocate();
  __move_assign_alloc(__c);
  this->__begin_ = __c.__begin_;
  this->__size_  = __c.__size_;
  this->__cap()  = __c.__cap();
  __c.__begin_   = nullptr;
  __c.__cap() = __c.__size_ = 0;
}

template <class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 void vector<bool, _Allocator>::assign(size_type __n, const value_type& __x) {
  __size_ = 0;
  if (__n > 0) {
    size_type __c = capacity();
    if (__n <= __c)
      __size_ = __n;
    else {
      vector __v(get_allocator());
      __v.reserve(__recommend(__n));
      __v.__size_ = __n;
      swap(__v);
    }
    std::fill_n(begin(), __n, __x);
  }
}

template <class _Allocator>
template <class _InputIterator, __enable_if_t<__has_exactly_input_iterator_category<_InputIterator>::value, int> >
_LIBCPP_CONSTEXPR_SINCE_CXX20 void vector<bool, _Allocator>::assign(_InputIterator __first, _InputIterator __last) {
  __assign_with_sentinel(__first, __last);
}

template <class _Allocator>
template <class _Iterator, class _Sentinel>
_LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void
vector<bool, _Allocator>::__assign_with_sentinel(_Iterator __first, _Sentinel __last) {
  clear();
  for (; __first != __last; ++__first)
    push_back(*__first);
}

template <class _Allocator>
template <class _ForwardIterator, __enable_if_t<__has_forward_iterator_category<_ForwardIterator>::value, int> >
_LIBCPP_CONSTEXPR_SINCE_CXX20 void vector<bool, _Allocator>::assign(_ForwardIterator __first, _ForwardIterator __last) {
  __assign_with_size(__first, __last, std::distance(__first, __last));
}

template <class _Allocator>
template <class _ForwardIterator, class _Sentinel>
_LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void
vector<bool, _Allocator>::__assign_with_size(_ForwardIterator __first, _Sentinel __last, difference_type __ns) {
  _LIBCPP_ASSERT_VALID_INPUT_RANGE(__ns >= 0, "invalid range specified");

  clear();

  const size_t __n = static_cast<size_type>(__ns);
  if (__n) {
    if (__n > capacity()) {
      __vdeallocate();
      __vallocate(__n);
    }
    __construct_at_end(__first, __last, __n);
  }
}

template <class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 void vector<bool, _Allocator>::reserve(size_type __n) {
  if (__n > capacity()) {
    if (__n > max_size())
      this->__throw_length_error();
    vector __v(this->get_allocator());
    __v.__vallocate(__n);
    __v.__construct_at_end(this->begin(), this->end(), this->size());
    swap(__v);
  }
}

template <class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 void vector<bool, _Allocator>::shrink_to_fit() _NOEXCEPT {
  if (__external_cap_to_internal(size()) > __cap()) {
#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
    try {
#endif // _LIBCPP_HAS_NO_EXCEPTIONS
      vector(*this, allocator_type(__alloc())).swap(*this);
#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
    } catch (...) {
    }
#endif // _LIBCPP_HAS_NO_EXCEPTIONS
  }
}

template <class _Allocator>
typename vector<bool, _Allocator>::reference vector<bool, _Allocator>::at(size_type __n) {
  if (__n >= size())
    this->__throw_out_of_range();
  return (*this)[__n];
}

template <class _Allocator>
typename vector<bool, _Allocator>::const_reference vector<bool, _Allocator>::at(size_type __n) const {
  if (__n >= size())
    this->__throw_out_of_range();
  return (*this)[__n];
}

template <class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 void vector<bool, _Allocator>::push_back(const value_type& __x) {
  if (this->__size_ == this->capacity())
    reserve(__recommend(this->__size_ + 1));
  ++this->__size_;
  back() = __x;
}

template <class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 typename vector<bool, _Allocator>::iterator
vector<bool, _Allocator>::insert(const_iterator __position, const value_type& __x) {
  iterator __r;
  if (size() < capacity()) {
    const_iterator __old_end = end();
    ++__size_;
    std::copy_backward(__position, __old_end, end());
    __r = __const_iterator_cast(__position);
  } else {
    vector __v(get_allocator());
    __v.reserve(__recommend(__size_ + 1));
    __v.__size_ = __size_ + 1;
    __r         = std::copy(cbegin(), __position, __v.begin());
    std::copy_backward(__position, cend(), __v.end());
    swap(__v);
  }
  *__r = __x;
  return __r;
}

template <class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 typename vector<bool, _Allocator>::iterator
vector<bool, _Allocator>::insert(const_iterator __position, size_type __n, const value_type& __x) {
  iterator __r;
  size_type __c = capacity();
  if (__n <= __c && size() <= __c - __n) {
    const_iterator __old_end = end();
    __size_ += __n;
    std::copy_backward(__position, __old_end, end());
    __r = __const_iterator_cast(__position);
  } else {
    vector __v(get_allocator());
    __v.reserve(__recommend(__size_ + __n));
    __v.__size_ = __size_ + __n;
    __r         = std::copy(cbegin(), __position, __v.begin());
    std::copy_backward(__position, cend(), __v.end());
    swap(__v);
  }
  std::fill_n(__r, __n, __x);
  return __r;
}

template <class _Allocator>
template <class _InputIterator, __enable_if_t<__has_exactly_input_iterator_category<_InputIterator>::value, int> >
_LIBCPP_CONSTEXPR_SINCE_CXX20 typename vector<bool, _Allocator>::iterator
vector<bool, _Allocator>::insert(const_iterator __position, _InputIterator __first, _InputIterator __last) {
  return __insert_with_sentinel(__position, __first, __last);
}

template <class _Allocator>
template <class _InputIterator, class _Sentinel>
_LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI typename vector<bool, _Allocator>::iterator
vector<bool, _Allocator>::__insert_with_sentinel(const_iterator __position, _InputIterator __first, _Sentinel __last) {
  difference_type __off = __position - begin();
  iterator __p          = __const_iterator_cast(__position);
  iterator __old_end    = end();
  for (; size() != capacity() && __first != __last; ++__first) {
    ++this->__size_;
    back() = *__first;
  }
  vector __v(get_allocator());
  if (__first != __last) {
#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
    try {
#endif // _LIBCPP_HAS_NO_EXCEPTIONS
      __v.__assign_with_sentinel(std::move(__first), std::move(__last));
      difference_type __old_size = static_cast<difference_type>(__old_end - begin());
      difference_type __old_p    = __p - begin();
      reserve(__recommend(size() + __v.size()));
      __p       = begin() + __old_p;
      __old_end = begin() + __old_size;
#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
    } catch (...) {
      erase(__old_end, end());
      throw;
    }
#endif // _LIBCPP_HAS_NO_EXCEPTIONS
  }
  __p = std::rotate(__p, __old_end, end());
  insert(__p, __v.begin(), __v.end());
  return begin() + __off;
}

template <class _Allocator>
template <class _ForwardIterator, __enable_if_t<__has_forward_iterator_category<_ForwardIterator>::value, int> >
_LIBCPP_CONSTEXPR_SINCE_CXX20 typename vector<bool, _Allocator>::iterator
vector<bool, _Allocator>::insert(const_iterator __position, _ForwardIterator __first, _ForwardIterator __last) {
  return __insert_with_size(__position, __first, __last, std::distance(__first, __last));
}

template <class _Allocator>
template <class _ForwardIterator, class _Sentinel>
_LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI typename vector<bool, _Allocator>::iterator
vector<bool, _Allocator>::__insert_with_size(
    const_iterator __position, _ForwardIterator __first, _Sentinel __last, difference_type __n_signed) {
  _LIBCPP_ASSERT_VALID_INPUT_RANGE(__n_signed >= 0, "invalid range specified");
  const size_type __n = static_cast<size_type>(__n_signed);
  iterator __r;
  size_type __c = capacity();
  if (__n <= __c && size() <= __c - __n) {
    const_iterator __old_end = end();
    __size_ += __n;
    std::copy_backward(__position, __old_end, end());
    __r = __const_iterator_cast(__position);
  } else {
    vector __v(get_allocator());
    __v.reserve(__recommend(__size_ + __n));
    __v.__size_ = __size_ + __n;
    __r         = std::copy(cbegin(), __position, __v.begin());
    std::copy_backward(__position, cend(), __v.end());
    swap(__v);
  }
  std::__copy<_ClassicAlgPolicy>(__first, __last, __r);
  return __r;
}

template <class _Allocator>
inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 typename vector<bool, _Allocator>::iterator
vector<bool, _Allocator>::erase(const_iterator __position) {
  iterator __r = __const_iterator_cast(__position);
  std::copy(__position + 1, this->cend(), __r);
  --__size_;
  return __r;
}

template <class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 typename vector<bool, _Allocator>::iterator
vector<bool, _Allocator>::erase(const_iterator __first, const_iterator __last) {
  iterator __r        = __const_iterator_cast(__first);
  difference_type __d = __last - __first;
  std::copy(__last, this->cend(), __r);
  __size_ -= __d;
  return __r;
}

template <class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 void vector<bool, _Allocator>::swap(vector& __x)
#if _LIBCPP_STD_VER >= 14
    _NOEXCEPT
#else
    _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value || __is_nothrow_swappable<allocator_type>::value)
#endif
{
  std::swap(this->__begin_, __x.__begin_);
  std::swap(this->__size_, __x.__size_);
  std::swap(this->__cap(), __x.__cap());
  std::__swap_allocator(
      this->__alloc(), __x.__alloc(), integral_constant<bool, __alloc_traits::propagate_on_container_swap::value>());
}

template <class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 void vector<bool, _Allocator>::resize(size_type __sz, value_type __x) {
  size_type __cs = size();
  if (__cs < __sz) {
    iterator __r;
    size_type __c = capacity();
    size_type __n = __sz - __cs;
    if (__n <= __c && __cs <= __c - __n) {
      __r = end();
      __size_ += __n;
    } else {
      vector __v(get_allocator());
      __v.reserve(__recommend(__size_ + __n));
      __v.__size_ = __size_ + __n;
      __r         = std::copy(cbegin(), cend(), __v.begin());
      swap(__v);
    }
    std::fill_n(__r, __n, __x);
  } else
    __size_ = __sz;
}

template <class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 void vector<bool, _Allocator>::flip() _NOEXCEPT {
  // do middle whole words
  size_type __n         = __size_;
  __storage_pointer __p = __begin_;
  for (; __n >= __bits_per_word; ++__p, __n -= __bits_per_word)
    *__p = ~*__p;
  // do last partial word
  if (__n > 0) {
    __storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n);
    __storage_type __b = *__p & __m;
    *__p &= ~__m;
    *__p |= ~__b & __m;
  }
}

template <class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 bool vector<bool, _Allocator>::__invariants() const {
  if (this->__begin_ == nullptr) {
    if (this->__size_ != 0 || this->__cap() != 0)
      return false;
  } else {
    if (this->__cap() == 0)
      return false;
    if (this->__size_ > this->capacity())
      return false;
  }
  return true;
}

template <class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 size_t vector<bool, _Allocator>::__hash_code() const _NOEXCEPT {
  size_t __h = 0;
  // do middle whole words
  size_type __n         = __size_;
  __storage_pointer __p = __begin_;
  for (; __n >= __bits_per_word; ++__p, __n -= __bits_per_word)
    __h ^= *__p;
  // do last partial word
  if (__n > 0) {
    const __storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n);
    __h ^= *__p & __m;
  }
  return __h;
}

template <class _Allocator>
struct _LIBCPP_TEMPLATE_VIS hash<vector<bool, _Allocator> >
    : public __unary_function<vector<bool, _Allocator>, size_t> {
  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_t
  operator()(const vector<bool, _Allocator>& __vec) const _NOEXCEPT {
    return __vec.__hash_code();
  }
};

template <class _Tp, class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 inline _LIBCPP_HIDE_FROM_ABI bool
operator==(const vector<_Tp, _Allocator>& __x, const vector<_Tp, _Allocator>& __y) {
  const typename vector<_Tp, _Allocator>::size_type __sz = __x.size();
  return __sz == __y.size() && std::equal(__x.begin(), __x.end(), __y.begin());
}

#if _LIBCPP_STD_VER <= 17

template <class _Tp, class _Allocator>
inline _LIBCPP_HIDE_FROM_ABI bool operator!=(const vector<_Tp, _Allocator>& __x, const vector<_Tp, _Allocator>& __y) {
  return !(__x == __y);
}

template <class _Tp, class _Allocator>
inline _LIBCPP_HIDE_FROM_ABI bool operator<(const vector<_Tp, _Allocator>& __x, const vector<_Tp, _Allocator>& __y) {
  return std::lexicographical_compare(__x.begin(), __x.end(), __y.begin(), __y.end());
}

template <class _Tp, class _Allocator>
inline _LIBCPP_HIDE_FROM_ABI bool operator>(const vector<_Tp, _Allocator>& __x, const vector<_Tp, _Allocator>& __y) {
  return __y < __x;
}

template <class _Tp, class _Allocator>
inline _LIBCPP_HIDE_FROM_ABI bool operator>=(const vector<_Tp, _Allocator>& __x, const vector<_Tp, _Allocator>& __y) {
  return !(__x < __y);
}

template <class _Tp, class _Allocator>
inline _LIBCPP_HIDE_FROM_ABI bool operator<=(const vector<_Tp, _Allocator>& __x, const vector<_Tp, _Allocator>& __y) {
  return !(__y < __x);
}

#else // _LIBCPP_STD_VER <= 17

template <class _Tp, class _Allocator>
_LIBCPP_HIDE_FROM_ABI constexpr __synth_three_way_result<_Tp>
operator<=>(const vector<_Tp, _Allocator>& __x, const vector<_Tp, _Allocator>& __y) {
  return std::lexicographical_compare_three_way(
      __x.begin(), __x.end(), __y.begin(), __y.end(), std::__synth_three_way<_Tp, _Tp>);
}

#endif // _LIBCPP_STD_VER <= 17

template <class _Tp, class _Allocator>
_LIBCPP_CONSTEXPR_SINCE_CXX20 inline _LIBCPP_HIDE_FROM_ABI void
swap(vector<_Tp, _Allocator>& __x, vector<_Tp, _Allocator>& __y) _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y))) {
  __x.swap(__y);
}

#if _LIBCPP_STD_VER >= 20
template <class _Tp, class _Allocator, class _Up>
_LIBCPP_CONSTEXPR_SINCE_CXX20 inline _LIBCPP_HIDE_FROM_ABI typename vector<_Tp, _Allocator>::size_type
erase(vector<_Tp, _Allocator>& __c, const _Up& __v) {
  auto __old_size = __c.size();
  __c.erase(std::remove(__c.begin(), __c.end(), __v), __c.end());
  return __old_size - __c.size();
}

template <class _Tp, class _Allocator, class _Predicate>
_LIBCPP_CONSTEXPR_SINCE_CXX20 inline _LIBCPP_HIDE_FROM_ABI typename vector<_Tp, _Allocator>::size_type
erase_if(vector<_Tp, _Allocator>& __c, _Predicate __pred) {
  auto __old_size = __c.size();
  __c.erase(std::remove_if(__c.begin(), __c.end(), __pred), __c.end());
  return __old_size - __c.size();
}

template <>
inline constexpr bool __format::__enable_insertable<vector<char>> = true;
#  ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
template <>
inline constexpr bool __format::__enable_insertable<vector<wchar_t>> = true;
#  endif

#endif // _LIBCPP_STD_VER >= 20

#if _LIBCPP_STD_VER >= 23
template <class _Tp, class _CharT>
// Since is-vector-bool-reference is only used once it's inlined here.
  requires same_as<typename _Tp::__container, vector<bool, typename _Tp::__container::allocator_type>>
struct _LIBCPP_TEMPLATE_VIS formatter<_Tp, _CharT> {
private:
  formatter<bool, _CharT> __underlying_;

public:
  template <class _ParseContext>
  _LIBCPP_HIDE_FROM_ABI constexpr typename _ParseContext::iterator parse(_ParseContext& __ctx) {
    return __underlying_.parse(__ctx);
  }

  template <class _FormatContext>
  _LIBCPP_HIDE_FROM_ABI typename _FormatContext::iterator format(const _Tp& __ref, _FormatContext& __ctx) const {
    return __underlying_.format(__ref, __ctx);
  }
};
#endif // _LIBCPP_STD_VER >= 23

_LIBCPP_END_NAMESPACE_STD

#if _LIBCPP_STD_VER >= 17
_LIBCPP_BEGIN_NAMESPACE_STD
namespace pmr {
template <class _ValueT>
using vector _LIBCPP_AVAILABILITY_PMR = std::vector<_ValueT, polymorphic_allocator<_ValueT>>;
} // namespace pmr
_LIBCPP_END_NAMESPACE_STD
#endif

_LIBCPP_POP_MACROS

#if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 20
#  include <algorithm>
#  include <atomic>
#  include <concepts>
#  include <cstdlib>
#  include <type_traits>
#  include <typeinfo>
#  include <utility>
#endif

#endif // _LIBCPP_VECTOR