constexpr explicit adjacent_view(V base);
constexpr auto size() requires sized_range<V>;
constexpr auto size() const requires sized_range<const V>;
constexpr iterator(iterator_t<Base> first, sentinel_t<Base> last);
constexpr iterator(as-sentinel, iterator_t<Base> first, iterator_t<Base> last);
constexpr iterator(iterator<!Const> i)
requires Const && convertible_to<iterator_t<V>, iterator_t<Base>>;
constexpr auto operator*() const;
constexpr iterator& operator++();
constexpr iterator operator++(int);
constexpr iterator& operator--() requires bidirectional_range<Base>;
constexpr iterator operator--(int) requires bidirectional_range<Base>;
constexpr iterator& operator+=(difference_type x)
requires random_access_range<Base>;
constexpr iterator& operator-=(difference_type x)
requires random_access_range<Base>;
constexpr auto operator[](difference_type n) const
requires random_access_range<Base>;
friend constexpr bool operator==(const iterator& x, const iterator& y);
friend constexpr bool operator<(const iterator& x, const iterator& y)
requires random_access_range<Base>;
friend constexpr bool operator>(const iterator& x, const iterator& y)
requires random_access_range<Base>;
friend constexpr bool operator<=(const iterator& x, const iterator& y)
requires random_access_range<Base>;
friend constexpr bool operator>=(const iterator& x, const iterator& y)
requires random_access_range<Base>;
friend constexpr auto operator<=>(const iterator& x, const iterator& y)
requires random_access_range<Base> &&
three_way_comparable<iterator_t<Base>>;
friend constexpr iterator operator+(const iterator& i, difference_type n)
requires random_access_range<Base>;
friend constexpr iterator operator+(difference_type n, const iterator& i)
requires random_access_range<Base>;
friend constexpr iterator operator-(const iterator& i, difference_type n)
requires random_access_range<Base>;
friend constexpr difference_type operator-(const iterator& x, const iterator& y)
requires sized_sentinel_for<iterator_t<Base>, iterator_t<Base>>;
friend constexpr auto iter_move(const iterator& i) noexcept(see below);
friend constexpr void iter_swap(const iterator& l, const iterator& r) noexcept(see below)
requires indirectly_swappable<iterator_t<Base>>;
constexpr explicit sentinel(sentinel_t<Base> end);
constexpr sentinel(sentinel<!Const> i)
requires Const && convertible_to<sentinel_t<V>, sentinel_t<Base>>;
template<bool OtherConst>
requires sentinel_for<sentinel_t<Base>, iterator_t<maybe-const<OtherConst, V>>>
friend constexpr bool operator==(const iterator<OtherConst>& x, const sentinel& y);
template<bool OtherConst>
requires sized_sentinel_for<sentinel_t<Base>, iterator_t<maybe-const<OtherConst, V>>>
friend constexpr range_difference_t<maybe-const<OtherConst, V>>
operator-(const iterator<OtherConst>& x, const sentinel& y);
template<bool OtherConst>
requires sized_sentinel_for<sentinel_t<Base>, iterator_t<maybe-const<OtherConst, V>>>
friend constexpr range_difference_t<maybe-const<OtherConst, V>>
operator-(const sentinel& y, const iterator<OtherConst>& x);