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// -*- 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
#define _LIBCPP_ITERATOR
/*
iterator synopsis
#include <concepts>
namespace std
{
template<class> struct incrementable_traits; // since C++20
template<class T>
using iter_difference_t = see below; // since C++20
template<class> struct indirectly_readable_traits; // since C++20
template<class T>
using iter_value_t = see below; // since C++20
template<class Iterator>
struct iterator_traits;
template<class T>
requires is_object_v<T> // since C++20
struct iterator_traits<T*>;
template<dereferenceable T>
using iter_reference_t = decltype(*declval<T&>());
namespace ranges::inline unspecified {
inline constexpr unspecified iter_move = unspecified; // since C++20, nodiscard as an extension
}}
template<dereferenceable T>
requires ...
using iter_rvalue_reference_t = decltype(ranges::iter_move(declval<T&>())); // since C++20
// [iterator.concepts], iterator concepts
// [iterator.concept.readable], concept indirectly_readable
template<class In>
concept indirectly_readable = see below; // since C++20
template<indirectly_readable T>
using iter_common_reference_t =
common_reference_t<iter_reference_t<T>, iter_value_t<T>&>; // since C++20
// [iterator.concept.writable], concept indirectly_writable
template<class Out, class T>
concept indirectly_writable = see below; // since C++20
// [iterator.concept.winc], concept weakly_incrementable
template<class I>
concept weakly_incrementable = see below; // since C++20
// [iterator.concept.inc], concept incrementable
template<class I>
concept incrementable = see below; // since C++20
// [iterator.concept.iterator], concept input_or_output_iterator
template<class I>
concept input_or_output_iterator = see below; // since C++20
// [iterator.concept.sentinel], concept sentinel_for
template<class S, class I>
concept sentinel_for = see below; // since C++20
// [iterator.concept.sizedsentinel], concept sized_sentinel_for
template<class S, class I>
inline constexpr bool disable_sized_sentinel_for = false;
template<class S, class I>
concept sized_sentinel_for = see below;
// [iterator.concept.input], concept input_iterator
template<class I>
concept input_iterator = see below; // since C++20
// [iterator.concept.output], concept output_iterator
template<class I, class T>
concept output_iterator = see below; // since C++20
// [iterator.concept.forward], concept forward_iterator
template<class I>
concept forward_iterator = see below; // since C++20
// [iterator.concept.bidir], concept bidirectional_iterator
template<class I>
concept bidirectional_iterator = see below; // since C++20
// [iterator.concept.random.access], concept random_access_iterator
template<class I>
concept random_access_iterator = see below; // since C++20
// [indirectcallable]
// [indirectcallable.indirectinvocable]
template<class F, class I>
concept indirectly_unary_invocable = see below; // since C++20
template<class F, class I>
concept indirectly_regular_unary_invocable = see below; // since C++20
template<class F, class I>
concept indirect_unary_predicate = see below; // since C++20
template<class F, class I1, class I2>
concept indirect_binary_predicate = see below; // since C++20
template<class F, class I1, class I2 = I1>
concept indirect_equivalence_relation = see below; // since C++20
template<class F, class I1, class I2 = I1>
concept indirect_strict_weak_order = see below; // since C++20
template<class F, class... Is>
using indirect_result_t = see below; // since C++20
// [projected], projected
template<indirectly_readable I, indirectly_regular_unary_invocable<I> Proj>
struct projected; // since C++20
template<weakly_incrementable I, indirectly_regular_unary_invocable<I> Proj>
struct incrementable_traits<projected<I, Proj>>; // since C++20
// [alg.req.ind.move], concept indirectly_movable
template<class In, class Out>
concept indirectly_movable = see below; // since C++20
template<class In, class Out>
concept indirectly_movable_storable = see below; // since C++20
// [alg.req.ind.copy], concept indirectly_copyable
template<class In, class Out>
concept indirectly_copyable = see below; // since C++20
template<class In, class Out>
concept indirectly_copyable_storable = see below; // since C++20
// [alg.req.ind.swap], concept indirectly_swappable
template<class I1, class I2 = I1>
concept indirectly_swappable = see below; // since C++20
template<class I1, class I2, class R, class P1 = identity,
class P2 = identity>
concept indirectly_comparable =
indirect_binary_predicate<R, projected<I1, P1>, projected<I2, P2>>; // since C++20
// [alg.req.permutable], concept permutable
template<class I>
concept permutable = see below; // since C++20
// [alg.req.mergeable], concept mergeable
template<class I1, class I2, class Out,
class R = ranges::less, class P1 = identity, class P2 = identity>
concept mergeable = see below; // since C++20
// [alg.req.sortable], concept sortable
template<class I, class R = ranges::less, class P = identity>
concept sortable = see below; // since C++20
template<input_or_output_iterator I, sentinel_for<I> S>
requires (!same_as<I, S> && copyable<I>)
class common_iterator; // since C++20
template<class Category, class T, class Distance = ptrdiff_t,
class Pointer = T*, class Reference = T&>
struct iterator // deprecated in C++17
{
typedef T value_type;
typedef Distance difference_type;
typedef Pointer pointer;
typedef Reference reference;
typedef Category iterator_category;
};
struct input_iterator_tag {};
struct output_iterator_tag {};
struct forward_iterator_tag : public input_iterator_tag {};
struct bidirectional_iterator_tag : public forward_iterator_tag {};
struct random_access_iterator_tag : public bidirectional_iterator_tag {};
struct contiguous_iterator_tag : public random_access_iterator_tag {};
// 27.4.3, iterator operations
template <class InputIterator, class Distance> // constexpr in C++17
constexpr void advance(InputIterator& i, Distance n);
template <class InputIterator> // constexpr in C++17
constexpr typename iterator_traits<InputIterator>::difference_type
distance(InputIterator first, InputIterator last);
template <class InputIterator> // constexpr in C++17
constexpr InputIterator next(InputIterator x,
typename iterator_traits<InputIterator>::difference_type n = 1);
template <class BidirectionalIterator> // constexpr in C++17
constexpr BidirectionalIterator prev(BidirectionalIterator x,
typename iterator_traits<BidirectionalIterator>::difference_type n = 1);
// [range.iter.ops], range iterator operations
namespace ranges {
// [range.iter.op.advance], ranges::advance
template<input_or_output_iterator I>
constexpr void advance(I& i, iter_difference_t<I> n); // since C++20
template<input_or_output_iterator I, sentinel_for<I> S>
constexpr void advance(I& i, S bound); // since C++20
template<input_or_output_iterator I, sentinel_for<I> S>
constexpr iter_difference_t<I> advance(I& i, iter_difference_t<I> n, S bound); // since C++20
}
template <class Iterator>
class reverse_iterator
: public iterator<typename iterator_traits<Iterator>::iterator_category, // until C++17
typename iterator_traits<Iterator>::value_type,
typename iterator_traits<Iterator>::difference_type,
typename iterator_traits<Iterator>::pointer,
typename iterator_traits<Iterator>::reference>
{
protected:
Iterator current;
public:
using iterator_type = Iterator;
using iterator_concept = see below; // since C++20
using iterator_category = typename iterator_traits<Iterator>::iterator_category; // since C++17, until C++20
using iterator_category = see below; // since C++20
using value_type = typename iterator_traits<Iterator>::value_type; // since C++17, until C++20
using value_type = iter_value_t<Iterator>; // since C++20
using difference_type = typename iterator_traits<Iterator>::difference_type; // until C++20
using difference_type = iter_difference_t<Iterator>; // since C++20
using pointer = typename iterator_traits<Iterator>::pointer;
using reference = typename iterator_traits<Iterator>::reference; // until C++20
using reference = iter_reference_t<Iterator>; // since C++20
constexpr reverse_iterator();
constexpr explicit reverse_iterator(Iterator x);
template <class U> constexpr reverse_iterator(const reverse_iterator<U>& u);
template <class U> constexpr reverse_iterator& operator=(const reverse_iterator<U>& u);
constexpr Iterator base() const;
constexpr reference operator*() const;
constexpr pointer operator->() const; // until C++20
constexpr pointer operator->() const requires see below; // since C++20
constexpr reverse_iterator& operator++();
constexpr reverse_iterator operator++(int);
constexpr reverse_iterator& operator--();
constexpr reverse_iterator operator--(int);
constexpr reverse_iterator operator+ (difference_type n) const;
constexpr reverse_iterator& operator+=(difference_type n);
constexpr reverse_iterator operator- (difference_type n) const;
constexpr reverse_iterator& operator-=(difference_type n);
constexpr unspecified operator[](difference_type n) const;
friend constexpr iter_rvalue_reference_t<Iterator>
iter_move(const reverse_iterator& i) noexcept(see below);
template<indirectly_swappable<Iterator> Iterator2>
friend constexpr void
iter_swap(const reverse_iterator& x,
const reverse_iterator<Iterator2>& y) noexcept(see below);
};
template <class Iterator1, class Iterator2>
constexpr bool // constexpr in C++17
operator==(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y);
template <class Iterator1, class Iterator2>
constexpr bool // constexpr in C++17
operator!=(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y);
template <class Iterator1, class Iterator2>
constexpr bool // constexpr in C++17
operator<(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y);
template <class Iterator1, class Iterator2>
constexpr bool // constexpr in C++17
operator>(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y);
template <class Iterator1, class Iterator2>
constexpr bool // constexpr in C++17
operator<=(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y);
template <class Iterator1, class Iterator2>
constexpr bool // constexpr in C++17
operator>=(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y);
template<class Iterator1, three_way_comparable_with<Iterator1> Iterator2>
constexpr compare_three_way_result_t<Iterator1, Iterator2>
operator<=>(const reverse_iterator<Iterator1>& x,
const reverse_iterator<Iterator2>& y);
template <class Iterator1, class Iterator2>
constexpr auto
operator-(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y)
-> decltype(__y.base() - __x.base()); // constexpr in C++17
template <class Iterator>
constexpr reverse_iterator<Iterator>
operator+(typename reverse_iterator<Iterator>::difference_type n,
const reverse_iterator<Iterator>& x); // constexpr in C++17
template <class Iterator>
constexpr reverse_iterator<Iterator> make_reverse_iterator(Iterator i); // C++14, constexpr in C++17
template<class Iterator1, class Iterator2>
requires (!sized_sentinel_for<Iterator1, Iterator2>)
inline constexpr bool disable_sized_sentinel_for<reverse_iterator<Iterator1>,
reverse_iterator<Iterator2>> = true;
template <class Container>
class back_insert_iterator
: public iterator<output_iterator_tag, void, void, void, void> // until C++17
{
protected:
Container* container;
public:
typedef Container container_type;
typedef void value_type;
typedef void difference_type; // until C++20
typedef ptrdiff_t difference_type; // since C++20
typedef void reference;
typedef void pointer;
explicit back_insert_iterator(Container& x); // constexpr in C++20
back_insert_iterator& operator=(const typename Container::value_type& value); // constexpr in C++20
back_insert_iterator& operator*(); // constexpr in C++20
back_insert_iterator& operator++(); // constexpr in C++20
back_insert_iterator operator++(int); // constexpr in C++20
};
template <class Container> back_insert_iterator<Container> back_inserter(Container& x); // constexpr in C++20
template <class Container>
class front_insert_iterator
: public iterator<output_iterator_tag, void, void, void, void> // until C++17
{
protected:
Container* container;
public:
typedef Container container_type;
typedef void value_type;
typedef void difference_type; // until C++20
typedef ptrdiff_t difference_type; // since C++20
typedef void reference;
typedef void pointer;
explicit front_insert_iterator(Container& x); // constexpr in C++20
front_insert_iterator& operator=(const typename Container::value_type& value); // constexpr in C++20
front_insert_iterator& operator*(); // constexpr in C++20
front_insert_iterator& operator++(); // constexpr in C++20
front_insert_iterator operator++(int); // constexpr in C++20
};
template <class Container> front_insert_iterator<Container> front_inserter(Container& x); // constexpr in C++20
template <class Container>
class insert_iterator
: public iterator<output_iterator_tag, void, void, void, void> // until C++17
{
protected:
Container* container;
typename Container::iterator iter;
public:
typedef Container container_type;
typedef void value_type;
typedef void difference_type; // until C++20
typedef ptrdiff_t difference_type; // since C++20
typedef void reference;
typedef void pointer;
insert_iterator(Container& x, typename Container::iterator i); // constexpr in C++20
insert_iterator& operator=(const typename Container::value_type& value); // constexpr in C++20
insert_iterator& operator*(); // constexpr in C++20
insert_iterator& operator++(); // constexpr in C++20
insert_iterator& operator++(int); // constexpr in C++20
};
template <class Container>
insert_iterator<Container> inserter(Container& x, typename Container::iterator i); // until C++20
template <class Container>
constexpr insert_iterator<Container> inserter(Container& x, ranges::iterator_t<Container> i); // since C++20
template <class Iterator>
class move_iterator {
public:
using iterator_type = Iterator;
using iterator_concept = see below; // From C++20
using iterator_category = see below; // not always present starting from C++20
using value_type = iter_value_t<Iterator>; // Until C++20, iterator_traits<Iterator>::value_type
using difference_type = iter_difference_t<Iterator>; // Until C++20, iterator_traits<Iterator>::difference_type;
using pointer = Iterator;
using reference = iter_rvalue_reference_t<Iterator>; // Until C++20, value_type&&
constexpr move_iterator(); // all the constexprs are in C++17
constexpr explicit move_iterator(Iterator i);
template <class U>
constexpr move_iterator(const move_iterator<U>& u);
template <class U>
constexpr move_iterator& operator=(const move_iterator<U>& u);
constexpr iterator_type base() const; // Until C++20
constexpr const Iterator& base() const & noexcept; // From C++20
constexpr Iterator base() &&; // From C++20
constexpr reference operator*() const;
constexpr pointer operator->() const; // Deprecated in C++20
constexpr move_iterator& operator++();
constexpr auto operator++(int); // Return type was move_iterator until C++20
constexpr move_iterator& operator--();
constexpr move_iterator operator--(int);
constexpr move_iterator operator+(difference_type n) const;
constexpr move_iterator& operator+=(difference_type n);
constexpr move_iterator operator-(difference_type n) const;
constexpr move_iterator& operator-=(difference_type n);
constexpr reference operator[](difference_type n) const; // Return type unspecified until C++20
template<sentinel_for<Iterator> S>
friend constexpr bool
operator==(const move_iterator& x, const move_sentinel<S>& y); // Since C++20
template<sized_sentinel_for<Iterator> S>
friend constexpr iter_difference_t<Iterator>
operator-(const move_sentinel<S>& x, const move_iterator& y); // Since C++20
template<sized_sentinel_for<Iterator> S>
friend constexpr iter_difference_t<Iterator>
operator-(const move_iterator& x, const move_sentinel<S>& y); // Since C++20
friend constexpr iter_rvalue_reference_t<Iterator>
iter_move(const move_iterator& i)
noexcept(noexcept(ranges::iter_move(i.current))); // Since C++20
template<indirectly_swappable<Iterator> Iterator2>
friend constexpr void
iter_swap(const move_iterator& x, const move_iterator<Iterator2>& y)
noexcept(noexcept(ranges::iter_swap(x.current, y.current))); // Since C++20
private:
Iterator current; // exposition only
};
template <class Iterator1, class Iterator2>
constexpr bool // constexpr in C++17
operator==(const move_iterator<Iterator1>& x, const move_iterator<Iterator2>& y);
template <class Iterator1, class Iterator2>
constexpr bool // constexpr in C++17
operator!=(const move_iterator<Iterator1>& x, const move_iterator<Iterator2>& y);
template <class Iterator1, class Iterator2>
constexpr bool // constexpr in C++17
operator<(const move_iterator<Iterator1>& x, const move_iterator<Iterator2>& y);
template <class Iterator1, class Iterator2>
constexpr bool // constexpr in C++17
operator<=(const move_iterator<Iterator1>& x, const move_iterator<Iterator2>& y);
template <class Iterator1, class Iterator2>
constexpr bool // constexpr in C++17
operator>(const move_iterator<Iterator1>& x, const move_iterator<Iterator2>& y);
template <class Iterator1, class Iterator2>
constexpr bool // constexpr in C++17
operator>=(const move_iterator<Iterator1>& x, const move_iterator<Iterator2>& y);
template <class Iterator1, class Iterator2>
constexpr auto // constexpr in C++17
operator-(const move_iterator<Iterator1>& x,
const move_iterator<Iterator2>& y) -> decltype(x.base() - y.base());
template <class Iterator>
constexpr move_iterator<Iterator> operator+( // constexpr in C++17
typename move_iterator<Iterator>::difference_type n,
const move_iterator<Iterator>& x);
template <class Iterator> // constexpr in C++17
constexpr move_iterator<Iterator> make_move_iterator(const Iterator& i);
template<class Iterator1, class Iterator2>
requires (!sized_sentinel_for<Iterator1, Iterator2>)
inline constexpr bool disable_sized_sentinel_for<move_iterator<Iterator1>, // since C++20
move_iterator<Iterator2>> = true;
template<semiregular S>
class move_sentinel {
public:
constexpr move_sentinel();
constexpr explicit move_sentinel(S s);
template<class S2>
requires convertible_to<const S2&, S>
constexpr move_sentinel(const move_sentinel<S2>& s);
template<class S2>
requires assignable_from<S&, const S2&>
constexpr move_sentinel& operator=(const move_sentinel<S2>& s);
constexpr S base() const;
private:
S last; // exposition only
};
// [default.sentinel], default sentinel
struct default_sentinel_t;
inline constexpr default_sentinel_t default_sentinel{};
// [iterators.counted], counted iterators
template<input_or_output_iterator I> class counted_iterator;
template<input_iterator I>
requires see below
struct iterator_traits<counted_iterator<I>>;
// [unreachable.sentinel], unreachable sentinel
struct unreachable_sentinel_t;
inline constexpr unreachable_sentinel_t unreachable_sentinel{};
template <class T, class charT = char, class traits = char_traits<charT>, class Distance = ptrdiff_t>
class istream_iterator
: public iterator<input_iterator_tag, T, Distance, const T*, const T&> // until C++17
{
public:
typedef input_iterator_tag iterator_category;
typedef T value_type;
typedef Distance difference_type;
typedef const T* pointer;
typedef const T& reference;
typedef charT char_type;
typedef traits traits_type;
typedef basic_istream<charT, traits> istream_type;
istream_iterator(); // constexpr since C++11
constexpr istream_iterator(default_sentinel_t); // since C++20
istream_iterator(istream_type& s);
istream_iterator(const istream_iterator& x);
~istream_iterator();
const T& operator*() const;
const T* operator->() const;
istream_iterator& operator++();
istream_iterator operator++(int);
friend bool operator==(const istream_iterator& i, default_sentinel_t); // since C++20
};
template <class T, class charT, class traits, class Distance>
bool operator==(const istream_iterator<T,charT,traits,Distance>& x,
const istream_iterator<T,charT,traits,Distance>& y);
template <class T, class charT, class traits, class Distance>
bool operator!=(const istream_iterator<T,charT,traits,Distance>& x,
const istream_iterator<T,charT,traits,Distance>& y); // until C++20
template <class T, class charT = char, class traits = char_traits<charT> >
class ostream_iterator
: public iterator<output_iterator_tag, void, void, void, void> // until C++17
{
public:
typedef output_iterator_tag iterator_category;
typedef void value_type;
typedef void difference_type; // until C++20
typedef ptrdiff_t difference_type; // since C++20
typedef void pointer;
typedef void reference;
typedef charT char_type;
typedef traits traits_type;
typedef basic_ostream<charT,traits> ostream_type;
ostream_iterator(ostream_type& s);
ostream_iterator(ostream_type& s, const charT* delimiter);
ostream_iterator(const ostream_iterator& x);
~ostream_iterator();
ostream_iterator& operator=(const T& value);
ostream_iterator& operator*();
ostream_iterator& operator++();
ostream_iterator& operator++(int);
};
template<class charT, class traits = char_traits<charT> >
class istreambuf_iterator
: public iterator<input_iterator_tag, charT, traits::off_type, unspecified, charT> // until C++17
{
public:
typedef input_iterator_tag iterator_category;
typedef charT value_type;
typedef traits::off_type difference_type;
typedef unspecified pointer;
typedef charT reference;
typedef charT char_type;
typedef traits traits_type;
typedef traits::int_type int_type;
typedef basic_streambuf<charT, traits> streambuf_type;
typedef basic_istream<charT, traits> istream_type;
istreambuf_iterator() noexcept; // constexpr since C++11
constexpr istreambuf_iterator(default_sentinel_t) noexcept; // since C++20
istreambuf_iterator(istream_type& s) noexcept;
istreambuf_iterator(streambuf_type* s) noexcept;
istreambuf_iterator(a-private-type) noexcept;
charT operator*() const;
pointer operator->() const;
istreambuf_iterator& operator++();
a-private-type operator++(int);
bool equal(const istreambuf_iterator& b) const;
friend bool operator==(const istreambuf_iterator& i, default_sentinel_t s); // since C++20
};
template <class charT, class traits>
bool operator==(const istreambuf_iterator<charT,traits>& a,
const istreambuf_iterator<charT,traits>& b);
template <class charT, class traits>
bool operator!=(const istreambuf_iterator<charT,traits>& a,
const istreambuf_iterator<charT,traits>& b); // until C++20
template <class charT, class traits = char_traits<charT> >
class ostreambuf_iterator
: public iterator<output_iterator_tag, void, void, void, void> // until C++17
{
public:
typedef output_iterator_tag iterator_category;
typedef void value_type;
typedef void difference_type; // until C++20
typedef ptrdiff_t difference_type; // since C++20
typedef void pointer;
typedef void reference;
typedef charT char_type;
typedef traits traits_type;
typedef basic_streambuf<charT, traits> streambuf_type;
typedef basic_ostream<charT, traits> ostream_type;
ostreambuf_iterator(ostream_type& s) noexcept;
ostreambuf_iterator(streambuf_type* s) noexcept;
ostreambuf_iterator& operator=(charT c);
ostreambuf_iterator& operator*();
ostreambuf_iterator& operator++();
ostreambuf_iterator& operator++(int);
bool failed() const noexcept;
};
template <class C> constexpr auto begin(C& c) -> decltype(c.begin()); // constexpr since C++17
template <class C> constexpr auto begin(const C& c) -> decltype(c.begin()); // constexpr since C++17
template <class C> constexpr auto end(C& c) -> decltype(c.end()); // constexpr since C++17
template <class C> constexpr auto end(const C& c) -> decltype(c.end()); // constexpr since C++17
template <class T, size_t N> constexpr T* begin(T (&array)[N]) noexcept;
template <class T, size_t N> constexpr T* end(T (&array)[N]) noexcept;
template <class C> constexpr auto cbegin(const C& c) noexcept(see-below) -> decltype(std::begin(c)); // C++14
template <class C> constexpr auto cend(const C& c) noexcept(see-below) -> decltype(std::end(c)); // C++14
template <class C> constexpr auto rbegin(C& c) -> decltype(c.rbegin()); // C++14, constexpr since C++17
template <class C> constexpr auto rbegin(const C& c) -> decltype(c.rbegin()); // C++14, constexpr since C++17
template <class C> constexpr auto rend(C& c) -> decltype(c.rend()); // C++14, constexpr since C++17
template <class C> constexpr auto rend(const C& c) -> decltype(c.rend()); // C++14, constexpr since C++17
template <class E> constexpr reverse_iterator<const E*> rbegin(initializer_list<E> il); // C++14, constexpr since C++17
template <class E> constexpr reverse_iterator<const E*> rend(initializer_list<E> il); // C++14, constexpr since C++17
template <class T, size_t N> constexpr reverse_iterator<T*> rbegin(T (&array)[N]); // C++14, constexpr since C++17
template <class T, size_t N> constexpr reverse_iterator<T*> rend(T (&array)[N]); // C++14, constexpr since C++17
template <class C> constexpr auto crbegin(const C& c) -> decltype(std::rbegin(c)); // C++14, constexpr since C++17
template <class C> constexpr auto crend(const C& c) -> decltype(std::rend(c)); // C++14, constexpr since C++17
// 24.8, container access:
template <class C> constexpr auto size(const C& c) -> decltype(c.size()); // C++17
template <class T, size_t N> constexpr size_t size(const T (&array)[N]) noexcept; // C++17
template <class C> constexpr auto ssize(const C& c)
-> common_type_t<ptrdiff_t, make_signed_t<decltype(c.size())>>; // C++20
template <class T, ptrdiff_t> constexpr ptrdiff_t ssize(const T (&array)[N]) noexcept; // C++20
template <class C> constexpr auto empty(const C& c) -> decltype(c.empty()); // C++17
template <class T, size_t N> constexpr bool empty(const T (&array)[N]) noexcept; // C++17
template <class E> constexpr bool empty(initializer_list<E> il) noexcept; // C++17
template <class C> constexpr auto data(C& c) -> decltype(c.data()); // C++17
template <class C> constexpr auto data(const C& c) -> decltype(c.data()); // C++17
template <class T, size_t N> constexpr T* data(T (&array)[N]) noexcept; // C++17
template <class E> constexpr const E* data(initializer_list<E> il) noexcept; // C++17
} // std
*/
#include <__config>
#include <__iterator/access.h>
#include <__iterator/advance.h>
#include <__iterator/back_insert_iterator.h>
#include <__iterator/distance.h>
#include <__iterator/front_insert_iterator.h>
#include <__iterator/insert_iterator.h>
#include <__iterator/istream_iterator.h>
#include <__iterator/istreambuf_iterator.h>
#include <__iterator/iterator.h>
#include <__iterator/iterator_traits.h>
#include <__iterator/move_iterator.h>
#include <__iterator/next.h>
#include <__iterator/ostream_iterator.h>
#include <__iterator/ostreambuf_iterator.h>
#include <__iterator/prev.h>
#include <__iterator/reverse_iterator.h>
#include <__iterator/wrap_iter.h>
#if _LIBCPP_STD_VER >= 14
# include <__iterator/reverse_access.h>
#endif
#if _LIBCPP_STD_VER >= 17
# include <__iterator/data.h>
# include <__iterator/empty.h>
# include <__iterator/size.h>
#endif
#if _LIBCPP_STD_VER >= 20
# include <__iterator/common_iterator.h>
# include <__iterator/concepts.h>
# include <__iterator/counted_iterator.h>
# include <__iterator/default_sentinel.h>
# include <__iterator/incrementable_traits.h>
# include <__iterator/indirectly_comparable.h>
# include <__iterator/iter_move.h>
# include <__iterator/iter_swap.h>
# include <__iterator/mergeable.h>
# include <__iterator/move_sentinel.h>
# include <__iterator/permutable.h>
# include <__iterator/projected.h>
# include <__iterator/readable_traits.h>
# include <__iterator/sortable.h>
# include <__iterator/unreachable_sentinel.h>
#endif
#include <version>
// standard-mandated includes
// [iterator.synopsis]
#include <compare>
#include <concepts>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
#endif
#if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 17
# include <variant>
#endif
#if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 20
# include <cstdlib>
# include <exception>
# include <new>
# include <type_traits>
# include <typeinfo>
# include <utility>
#endif
#endif // _LIBCPP_ITERATOR