x86_64/usr/include/c++/v1/__iterator/reverse_iterator.h - manifest_repos/toolchain - Git at Google

 // -*- 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___ITERATOR_REVERSE_ITERATOR_H
 #define _LIBCPP___ITERATOR_REVERSE_ITERATOR_H

 #include <__algorithm/unwrap_iter.h>
 #include <__compare/compare_three_way_result.h>
 #include <__compare/three_way_comparable.h>
 #include <__concepts/convertible_to.h>
 #include <__config>
 #include <__iterator/concepts.h>
 #include <__iterator/incrementable_traits.h>
 #include <__iterator/iter_move.h>
 #include <__iterator/iter_swap.h>
 #include <__iterator/iterator.h>
 #include <__iterator/iterator_traits.h>
 #include <__iterator/prev.h>
 #include <__iterator/readable_traits.h>
 #include <__memory/addressof.h>
 #include <__utility/move.h>
 #include <type_traits>

 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
 #endif

 _LIBCPP_BEGIN_NAMESPACE_STD

 _LIBCPP_SUPPRESS_DEPRECATED_PUSH
 template <class _Iter>
 class _LIBCPP_TEMPLATE_VIS reverse_iterator
 #if _LIBCPP_STD_VER <= 14 || !defined(_LIBCPP_ABI_NO_ITERATOR_BASES)
     : public iterator<typename iterator_traits<_Iter>::iterator_category,
                       typename iterator_traits<_Iter>::value_type,
                       typename iterator_traits<_Iter>::difference_type,
                       typename iterator_traits<_Iter>::pointer,
                       typename iterator_traits<_Iter>::reference>
 #endif
 {
 _LIBCPP_SUPPRESS_DEPRECATED_POP
 private:
 #ifndef _LIBCPP_ABI_NO_ITERATOR_BASES
     _Iter __t; // no longer used as of LWG #2360, not removed due to ABI break
 #endif

 #if _LIBCPP_STD_VER > 17
     static_assert(__is_cpp17_bidirectional_iterator<_Iter>::value || bidirectional_iterator<_Iter>,
         "reverse_iterator<It> requires It to be a bidirectional iterator.");
 #endif // _LIBCPP_STD_VER > 17

 protected:
     _Iter current;
 public:
     using iterator_type = _Iter;

     using iterator_category = _If<__is_cpp17_random_access_iterator<_Iter>::value,
                                   random_access_iterator_tag,
                                   typename iterator_traits<_Iter>::iterator_category>;
     using pointer = typename iterator_traits<_Iter>::pointer;
 #if _LIBCPP_STD_VER > 17
     using iterator_concept = _If<__is_cpp17_random_access_iterator<_Iter>::value,
                                   random_access_iterator_tag,
                                   bidirectional_iterator_tag>;
     using value_type = iter_value_t<_Iter>;
     using difference_type = iter_difference_t<_Iter>;
     using reference = iter_reference_t<_Iter>;
 #else
     using value_type = typename iterator_traits<_Iter>::value_type;
     using difference_type = typename iterator_traits<_Iter>::difference_type;
     using reference = typename iterator_traits<_Iter>::reference;
 #endif

 #ifndef _LIBCPP_ABI_NO_ITERATOR_BASES
     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
     reverse_iterator() : __t(), current() {}

     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
     explicit reverse_iterator(_Iter __x) : __t(__x), current(__x) {}

     template <class _Up, class = __enable_if_t<
         !is_same<_Up, _Iter>::value && is_convertible<_Up const&, _Iter>::value
     > >
     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
     reverse_iterator(const reverse_iterator<_Up>& __u)
         : __t(__u.base()), current(__u.base())
     { }

     template <class _Up, class = __enable_if_t<
         !is_same<_Up, _Iter>::value &&
         is_convertible<_Up const&, _Iter>::value &&
         is_assignable<_Iter&, _Up const&>::value
     > >
     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
     reverse_iterator& operator=(const reverse_iterator<_Up>& __u) {
         __t = current = __u.base();
         return *this;
     }
 #else
     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
     reverse_iterator() : current() {}

     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
     explicit reverse_iterator(_Iter __x) : current(__x) {}

     template <class _Up, class = __enable_if_t<
         !is_same<_Up, _Iter>::value && is_convertible<_Up const&, _Iter>::value
     > >
     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
     reverse_iterator(const reverse_iterator<_Up>& __u)
         : current(__u.base())
     { }

     template <class _Up, class = __enable_if_t<
         !is_same<_Up, _Iter>::value &&
         is_convertible<_Up const&, _Iter>::value &&
         is_assignable<_Iter&, _Up const&>::value
     > >
     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
     reverse_iterator& operator=(const reverse_iterator<_Up>& __u) {
         current = __u.base();
         return *this;
     }
 #endif
     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
     _Iter base() const {return current;}
     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
     reference operator*() const {_Iter __tmp = current; return *--__tmp;}

 #if _LIBCPP_STD_VER > 17
     _LIBCPP_INLINE_VISIBILITY
     constexpr pointer operator->() const
       requires is_pointer_v<_Iter> || requires(const _Iter i) { i.operator->(); }
     {
       if constexpr (is_pointer_v<_Iter>) {
         return std::prev(current);
       } else {
         return std::prev(current).operator->();
       }
     }
 #else
     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
     pointer operator->() const {
       return std::addressof(operator*());
     }
 #endif // _LIBCPP_STD_VER > 17

     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
     reverse_iterator& operator++() {--current; return *this;}
     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
     reverse_iterator operator++(int) {reverse_iterator __tmp(*this); --current; return __tmp;}
     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
     reverse_iterator& operator--() {++current; return *this;}
     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
     reverse_iterator operator--(int) {reverse_iterator __tmp(*this); ++current; return __tmp;}
     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
     reverse_iterator operator+(difference_type __n) const {return reverse_iterator(current - __n);}
     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
     reverse_iterator& operator+=(difference_type __n) {current -= __n; return *this;}
     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
     reverse_iterator operator-(difference_type __n) const {return reverse_iterator(current + __n);}
     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
     reverse_iterator& operator-=(difference_type __n) {current += __n; return *this;}
     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
     reference operator[](difference_type __n) const {return *(*this + __n);}

 #if _LIBCPP_STD_VER > 17
     _LIBCPP_HIDE_FROM_ABI friend constexpr
     iter_rvalue_reference_t<_Iter> iter_move(const reverse_iterator& __i)
       noexcept(is_nothrow_copy_constructible_v<_Iter> &&
           noexcept(ranges::iter_move(--declval<_Iter&>()))) {
       auto __tmp = __i.base();
       return ranges::iter_move(--__tmp);
     }

     template <indirectly_swappable<_Iter> _Iter2>
     _LIBCPP_HIDE_FROM_ABI friend constexpr
     void iter_swap(const reverse_iterator& __x, const reverse_iterator<_Iter2>& __y)
       noexcept(is_nothrow_copy_constructible_v<_Iter> &&
           is_nothrow_copy_constructible_v<_Iter2> &&
           noexcept(ranges::iter_swap(--declval<_Iter&>(), --declval<_Iter2&>()))) {
       auto __xtmp = __x.base();
       auto __ytmp = __y.base();
       ranges::iter_swap(--__xtmp, --__ytmp);
     }
 #endif // _LIBCPP_STD_VER > 17
 };

 template <class _Iter1, class _Iter2>
 inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
 bool
 operator==(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
 #if _LIBCPP_STD_VER > 17
     requires requires {
       { __x.base() == __y.base() } -> convertible_to<bool>;
     }
 #endif // _LIBCPP_STD_VER > 17
 {
     return __x.base() == __y.base();
 }

 template <class _Iter1, class _Iter2>
 inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
 bool
 operator<(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
 #if _LIBCPP_STD_VER > 17
     requires requires {
         { __x.base() > __y.base() } -> convertible_to<bool>;
       }
 #endif // _LIBCPP_STD_VER > 17
 {
     return __x.base() > __y.base();
 }

 template <class _Iter1, class _Iter2>
 inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
 bool
 operator!=(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
 #if _LIBCPP_STD_VER > 17
     requires requires {
       { __x.base() != __y.base() } -> convertible_to<bool>;
     }
 #endif // _LIBCPP_STD_VER > 17
 {
     return __x.base() != __y.base();
 }

 template <class _Iter1, class _Iter2>
 inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
 bool
 operator>(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
 #if _LIBCPP_STD_VER > 17
     requires requires {
         { __x.base() < __y.base() } -> convertible_to<bool>;
       }
 #endif // _LIBCPP_STD_VER > 17
 {
     return __x.base() < __y.base();
 }

 template <class _Iter1, class _Iter2>
 inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
 bool
 operator>=(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
 #if _LIBCPP_STD_VER > 17
     requires requires {
         { __x.base() <= __y.base() } -> convertible_to<bool>;
       }
 #endif // _LIBCPP_STD_VER > 17
 {
     return __x.base() <= __y.base();
 }

 template <class _Iter1, class _Iter2>
 inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
 bool
 operator<=(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
 #if _LIBCPP_STD_VER > 17
     requires requires {
         { __x.base() >= __y.base() } -> convertible_to<bool>;
       }
 #endif // _LIBCPP_STD_VER > 17
 {
     return __x.base() >= __y.base();
 }

 #if _LIBCPP_STD_VER > 17
 template <class _Iter1, three_way_comparable_with<_Iter1> _Iter2>
 _LIBCPP_HIDE_FROM_ABI constexpr
 compare_three_way_result_t<_Iter1, _Iter2>
 operator<=>(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
 {
     return __y.base() <=> __x.base();
 }
 #endif // _LIBCPP_STD_VER > 17

 #ifndef _LIBCPP_CXX03_LANG
 template <class _Iter1, class _Iter2>
 inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
 auto
 operator-(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
 -> decltype(__y.base() - __x.base())
 {
     return __y.base() - __x.base();
 }
 #else
 template <class _Iter1, class _Iter2>
 inline _LIBCPP_INLINE_VISIBILITY
 typename reverse_iterator<_Iter1>::difference_type
 operator-(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
 {
     return __y.base() - __x.base();
 }
 #endif

 template <class _Iter>
 inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
 reverse_iterator<_Iter>
 operator+(typename reverse_iterator<_Iter>::difference_type __n, const reverse_iterator<_Iter>& __x)
 {
     return reverse_iterator<_Iter>(__x.base() - __n);
 }

 #if _LIBCPP_STD_VER > 17
 template <class _Iter1, class _Iter2>
   requires (!sized_sentinel_for<_Iter1, _Iter2>)
 inline constexpr bool disable_sized_sentinel_for<reverse_iterator<_Iter1>, reverse_iterator<_Iter2>> = true;
 #endif // _LIBCPP_STD_VER > 17

 #if _LIBCPP_STD_VER > 11
 template <class _Iter>
 inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
 reverse_iterator<_Iter> make_reverse_iterator(_Iter __i)
 {
     return reverse_iterator<_Iter>(__i);
 }
 #endif

 template <class _Iter>
 using _ReverseWrapper = reverse_iterator<reverse_iterator<_Iter> >;

 template <class _Iter, bool __b>
 struct __unwrap_iter_impl<_ReverseWrapper<_Iter>, __b> {
   static _LIBCPP_CONSTEXPR decltype(std::__unwrap_iter(std::declval<_Iter>()))
   __apply(_ReverseWrapper<_Iter> __i) _NOEXCEPT {
     return std::__unwrap_iter(__i.base().base());
   }
 };

 template <class _OrigIter, class _UnwrappedIter>
 struct __rewrap_iter_impl<_ReverseWrapper<_OrigIter>, _UnwrappedIter> {
   template <class _Iter>
   struct _ReverseWrapperCount {
     static _LIBCPP_CONSTEXPR const size_t value = 1;
   };

   template <class _Iter>
   struct _ReverseWrapperCount<_ReverseWrapper<_Iter> > {
     static _LIBCPP_CONSTEXPR const size_t value = 1 + _ReverseWrapperCount<_Iter>::value;
   };

   template <size_t _RewrapCount, class _OIter, class _UIter, __enable_if_t<_RewrapCount != 0, int> = 0>
   _LIBCPP_HIDE_FROM_ABI static _LIBCPP_CONSTEXPR _ReverseWrapper<_OIter> __rewrap(_ReverseWrapper<_OIter> __iter1,
                                                                                   _UIter __iter2) {
     return _ReverseWrapper<_OIter>(
         reverse_iterator<_OIter>(__rewrap<_RewrapCount - 1>(__iter1.base().base(), __iter2)));
   }

   template <size_t _RewrapCount, class _OIter, class _UIter, __enable_if_t<_RewrapCount == 0, int> = 0>
   _LIBCPP_HIDE_FROM_ABI static _LIBCPP_CONSTEXPR decltype(std::__rewrap_iter(std::declval<_OIter>(),
                                                                              std::declval<_UIter>()))
   __rewrap(_OIter __iter1, _UIter __iter2) {
     return std::__rewrap_iter(__iter1, __iter2);
   }

   _LIBCPP_HIDE_FROM_ABI static _LIBCPP_CONSTEXPR _ReverseWrapper<_OrigIter> __apply(_ReverseWrapper<_OrigIter> __iter1,
                                                                                     _UnwrappedIter __iter2) {
     return __rewrap<_ReverseWrapperCount<_OrigIter>::value>(__iter1, __iter2);
   }
 };

 _LIBCPP_END_NAMESPACE_STD

 #endif // _LIBCPP___ITERATOR_REVERSE_ITERATOR_H
	// -- 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___ITERATOR_REVERSE_ITERATOR_H
	#define _LIBCPP___ITERATOR_REVERSE_ITERATOR_H

	#include <__algorithm/unwrap_iter.h>
	#include <__compare/compare_three_way_result.h>
	#include <__compare/three_way_comparable.h>
	#include <__concepts/convertible_to.h>
	#include <__config>
	#include <__iterator/concepts.h>
	#include <__iterator/incrementable_traits.h>
	#include <__iterator/iter_move.h>
	#include <__iterator/iter_swap.h>
	#include <__iterator/iterator.h>
	#include <__iterator/iterator_traits.h>
	#include <__iterator/prev.h>
	#include <__iterator/readable_traits.h>
	#include <__memory/addressof.h>
	#include <__utility/move.h>
	#include <type_traits>

	#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
	# pragma GCC system_header
	#endif

	_LIBCPP_BEGIN_NAMESPACE_STD

	_LIBCPP_SUPPRESS_DEPRECATED_PUSH
	template <class _Iter>
	class _LIBCPP_TEMPLATE_VIS reverse_iterator
	#if _LIBCPP_STD_VER <= 14 \|\| !defined(_LIBCPP_ABI_NO_ITERATOR_BASES)
	: public iterator<typename iterator_traits<_Iter>::iterator_category,
	typename iterator_traits<_Iter>::value_type,
	typename iterator_traits<_Iter>::difference_type,
	typename iterator_traits<_Iter>::pointer,
	typename iterator_traits<_Iter>::reference>
	#endif
	{
	_LIBCPP_SUPPRESS_DEPRECATED_POP
	private:
	#ifndef _LIBCPP_ABI_NO_ITERATOR_BASES
	_Iter __t; // no longer used as of LWG #2360, not removed due to ABI break
	#endif

	#if _LIBCPP_STD_VER > 17
	static_assert(__is_cpp17_bidirectional_iterator<_Iter>::value \|\| bidirectional_iterator<_Iter>,
	"reverse_iterator<It> requires It to be a bidirectional iterator.");
	#endif // _LIBCPP_STD_VER > 17

	protected:
	_Iter current;
	public:
	using iterator_type = _Iter;

	using iterator_category = _If<__is_cpp17_random_access_iterator<_Iter>::value,
	random_access_iterator_tag,
	typename iterator_traits<_Iter>::iterator_category>;
	using pointer = typename iterator_traits<_Iter>::pointer;
	#if _LIBCPP_STD_VER > 17
	using iterator_concept = _If<__is_cpp17_random_access_iterator<_Iter>::value,
	random_access_iterator_tag,
	bidirectional_iterator_tag>;
	using value_type = iter_value_t<_Iter>;
	using difference_type = iter_difference_t<_Iter>;
	using reference = iter_reference_t<_Iter>;
	#else
	using value_type = typename iterator_traits<_Iter>::value_type;
	using difference_type = typename iterator_traits<_Iter>::difference_type;
	using reference = typename iterator_traits<_Iter>::reference;
	#endif

	#ifndef _LIBCPP_ABI_NO_ITERATOR_BASES
	_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
	reverse_iterator() : __t(), current() {}

	_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
	explicit reverse_iterator(_Iter __x) : __t(__x), current(__x) {}

	template <class _Up, class = __enable_if_t<
	!is_same<_Up, _Iter>::value && is_convertible<_Up const&, _Iter>::value
	> >
	_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
	reverse_iterator(const reverse_iterator<_Up>& __u)
	: __t(__u.base()), current(__u.base())
	{ }

	template <class _Up, class = __enable_if_t<
	!is_same<_Up, _Iter>::value &&
	is_convertible<_Up const&, _Iter>::value &&
	is_assignable<_Iter&, _Up const&>::value
	> >
	_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
	reverse_iterator& operator=(const reverse_iterator<_Up>& __u) {
	__t = current = __u.base();
	return *this;
	}
	#else
	_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
	reverse_iterator() : current() {}

	_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
	explicit reverse_iterator(_Iter __x) : current(__x) {}

	template <class _Up, class = __enable_if_t<
	!is_same<_Up, _Iter>::value && is_convertible<_Up const&, _Iter>::value
	> >
	_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
	reverse_iterator(const reverse_iterator<_Up>& __u)
	: current(__u.base())
	{ }

	template <class _Up, class = __enable_if_t<
	!is_same<_Up, _Iter>::value &&
	is_convertible<_Up const&, _Iter>::value &&
	is_assignable<_Iter&, _Up const&>::value
	> >
	_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
	reverse_iterator& operator=(const reverse_iterator<_Up>& __u) {
	current = __u.base();
	return *this;
	}
	#endif
	_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
	_Iter base() const {return current;}
	_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
	reference operator() const {_Iter __tmp = current; return --__tmp;}

	#if _LIBCPP_STD_VER > 17
	_LIBCPP_INLINE_VISIBILITY
	constexpr pointer operator->() const
	requires is_pointer_v<_Iter> \|\| requires(const _Iter i) { i.operator->(); }
	{
	if constexpr (is_pointer_v<_Iter>) {
	return std::prev(current);
	} else {
	return std::prev(current).operator->();
	}
	}
	#else
	_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
	pointer operator->() const {
	return std::addressof(operator*());
	}
	#endif // _LIBCPP_STD_VER > 17

	_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
	reverse_iterator& operator++() {--current; return *this;}
	_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
	reverse_iterator operator++(int) {reverse_iterator __tmp(*this); --current; return __tmp;}
	_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
	reverse_iterator& operator--() {++current; return *this;}
	_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
	reverse_iterator operator--(int) {reverse_iterator __tmp(*this); ++current; return __tmp;}
	_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
	reverse_iterator operator+(difference_type __n) const {return reverse_iterator(current - __n);}
	_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
	reverse_iterator& operator+=(difference_type __n) {current -= __n; return *this;}
	_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
	reverse_iterator operator-(difference_type __n) const {return reverse_iterator(current + __n);}
	_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
	reverse_iterator& operator-=(difference_type __n) {current += __n; return *this;}
	_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
	reference operator[](difference_type __n) const {return (this + __n);}

	#if _LIBCPP_STD_VER > 17
	_LIBCPP_HIDE_FROM_ABI friend constexpr
	iter_rvalue_reference_t<_Iter> iter_move(const reverse_iterator& __i)
	noexcept(is_nothrow_copy_constructible_v<_Iter> &&
	noexcept(ranges::iter_move(--declval<_Iter&>()))) {
	auto __tmp = __i.base();
	return ranges::iter_move(--__tmp);
	}

	template <indirectly_swappable<_Iter> _Iter2>
	_LIBCPP_HIDE_FROM_ABI friend constexpr
	void iter_swap(const reverse_iterator& __x, const reverse_iterator<_Iter2>& __y)
	noexcept(is_nothrow_copy_constructible_v<_Iter> &&
	is_nothrow_copy_constructible_v<_Iter2> &&
	noexcept(ranges::iter_swap(--declval<_Iter&>(), --declval<_Iter2&>()))) {
	auto __xtmp = __x.base();
	auto __ytmp = __y.base();
	ranges::iter_swap(--__xtmp, --__ytmp);
	}
	#endif // _LIBCPP_STD_VER > 17
	};

	template <class _Iter1, class _Iter2>
	inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
	bool
	operator==(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
	#if _LIBCPP_STD_VER > 17
	requires requires {
	{ __x.base() == __y.base() } -> convertible_to<bool>;
	}
	#endif // _LIBCPP_STD_VER > 17
	{
	return __x.base() == __y.base();
	}

	template <class _Iter1, class _Iter2>
	inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
	bool
	operator<(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
	#if _LIBCPP_STD_VER > 17
	requires requires {
	{ __x.base() > __y.base() } -> convertible_to<bool>;
	}
	#endif // _LIBCPP_STD_VER > 17
	{
	return __x.base() > __y.base();
	}

	template <class _Iter1, class _Iter2>
	inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
	bool
	operator!=(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
	#if _LIBCPP_STD_VER > 17
	requires requires {
	{ __x.base() != __y.base() } -> convertible_to<bool>;
	}
	#endif // _LIBCPP_STD_VER > 17
	{
	return __x.base() != __y.base();
	}

	template <class _Iter1, class _Iter2>
	inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
	bool
	operator>(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
	#if _LIBCPP_STD_VER > 17
	requires requires {
	{ __x.base() < __y.base() } -> convertible_to<bool>;
	}
	#endif // _LIBCPP_STD_VER > 17
	{
	return __x.base() < __y.base();
	}

	template <class _Iter1, class _Iter2>
	inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
	bool
	operator>=(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
	#if _LIBCPP_STD_VER > 17
	requires requires {
	{ __x.base() <= __y.base() } -> convertible_to<bool>;
	}
	#endif // _LIBCPP_STD_VER > 17
	{
	return __x.base() <= __y.base();
	}

	template <class _Iter1, class _Iter2>
	inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
	bool
	operator<=(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
	#if _LIBCPP_STD_VER > 17
	requires requires {
	{ __x.base() >= __y.base() } -> convertible_to<bool>;
	}
	#endif // _LIBCPP_STD_VER > 17
	{
	return __x.base() >= __y.base();
	}

	#if _LIBCPP_STD_VER > 17
	template <class _Iter1, three_way_comparable_with<_Iter1> _Iter2>
	_LIBCPP_HIDE_FROM_ABI constexpr
	compare_three_way_result_t<_Iter1, _Iter2>
	operator<=>(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
	{
	return __y.base() <=> __x.base();
	}
	#endif // _LIBCPP_STD_VER > 17

	#ifndef _LIBCPP_CXX03_LANG
	template <class _Iter1, class _Iter2>
	inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
	auto
	operator-(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
	-> decltype(__y.base() - __x.base())
	{
	return __y.base() - __x.base();
	}
	#else
	template <class _Iter1, class _Iter2>
	inline _LIBCPP_INLINE_VISIBILITY
	typename reverse_iterator<_Iter1>::difference_type
	operator-(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
	{
	return __y.base() - __x.base();
	}
	#endif

	template <class _Iter>
	inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
	reverse_iterator<_Iter>
	operator+(typename reverse_iterator<_Iter>::difference_type __n, const reverse_iterator<_Iter>& __x)
	{
	return reverse_iterator<_Iter>(__x.base() - __n);
	}

	#if _LIBCPP_STD_VER > 17
	template <class _Iter1, class _Iter2>
	requires (!sized_sentinel_for<_Iter1, _Iter2>)
	inline constexpr bool disable_sized_sentinel_for<reverse_iterator<_Iter1>, reverse_iterator<_Iter2>> = true;
	#endif // _LIBCPP_STD_VER > 17

	#if _LIBCPP_STD_VER > 11
	template <class _Iter>
	inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
	reverse_iterator<_Iter> make_reverse_iterator(_Iter __i)
	{
	return reverse_iterator<_Iter>(__i);
	}
	#endif

	template <class _Iter>
	using _ReverseWrapper = reverse_iterator<reverse_iterator<_Iter> >;

	template <class _Iter, bool __b>
	struct __unwrap_iter_impl<_ReverseWrapper<_Iter>, __b> {
	static _LIBCPP_CONSTEXPR decltype(std::__unwrap_iter(std::declval<_Iter>()))
	__apply(_ReverseWrapper<_Iter> __i) _NOEXCEPT {
	return std::__unwrap_iter(__i.base().base());
	}
	};

	template <class _OrigIter, class _UnwrappedIter>
	struct __rewrap_iter_impl<_ReverseWrapper<_OrigIter>, _UnwrappedIter> {
	template <class _Iter>
	struct _ReverseWrapperCount {
	static _LIBCPP_CONSTEXPR const size_t value = 1;
	};

	template <class _Iter>
	struct _ReverseWrapperCount<_ReverseWrapper<_Iter> > {
	static _LIBCPP_CONSTEXPR const size_t value = 1 + _ReverseWrapperCount<_Iter>::value;
	};

	template <size_t _RewrapCount, class _OIter, class _UIter, __enable_if_t<_RewrapCount != 0, int> = 0>
	_LIBCPP_HIDE_FROM_ABI static _LIBCPP_CONSTEXPR _ReverseWrapper<_OIter> __rewrap(_ReverseWrapper<_OIter> __iter1,
	_UIter __iter2) {
	return _ReverseWrapper<_OIter>(
	reverse_iterator<_OIter>(__rewrap<_RewrapCount - 1>(__iter1.base().base(), __iter2)));
	}

	template <size_t _RewrapCount, class _OIter, class _UIter, __enable_if_t<_RewrapCount == 0, int> = 0>
	_LIBCPP_HIDE_FROM_ABI static _LIBCPP_CONSTEXPR decltype(std::__rewrap_iter(std::declval<_OIter>(),
	std::declval<_UIter>()))
	__rewrap(_OIter __iter1, _UIter __iter2) {
	return std::__rewrap_iter(__iter1, __iter2);
	}

	_LIBCPP_HIDE_FROM_ABI static _LIBCPP_CONSTEXPR _ReverseWrapper<_OrigIter> __apply(_ReverseWrapper<_OrigIter> __iter1,
	_UnwrappedIter __iter2) {
	return __rewrap<_ReverseWrapperCount<_OrigIter>::value>(__iter1, __iter2);
	}
	};

	_LIBCPP_END_NAMESPACE_STD

	#endif // _LIBCPP___ITERATOR_REVERSE_ITERATOR_H