[range.adjacent.iterator] (original) (raw)

25 Ranges library [ranges]

25.7 Range adaptors [range.adaptors]

25.7.27 Adjacent view [range.adjacent]

25.7.27.3 Class template adjacent_view​::​iterator [range.adjacent.iterator]

namespace std::ranges { template<forward_range V, size_t N> requires view<V> && (N > 0) template<bool Const> class adjacent_view<V, N>::iterator { using Base = maybe-const<Const, V>; array<iterator_t<_Base_>, N> current_ = array<iterator_t<_Base_>, N>(); constexpr iterator(iterator_t<_Base_> first, sentinel_t<_Base_> last); constexpr iterator(as-sentinel, iterator_t<_Base_> first, iterator_t<_Base_> last);public: using iterator_category = input_iterator_tag;using iterator_concept = see below;using value_type = tuple<_REPEAT_(range_value_t<_Base_>, N)...>;using difference_type = range_difference_t<_Base_>;iterator() = default;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_>>;};}

_iterator_​::​iterator_concept is defined as follows:

If the invocation of any non-const member function of _iterator_exits via an exception, the iterator acquires a singular value.

constexpr _iterator_(iterator_t<_Base_> first, sentinel_t<_Base_> last);

Postconditions: _current__[0] == first is true, and for every integer ,_current__[i] == ranges​::​next(_current__[i-1], 1, last)is true.

constexpr _iterator_(_as-sentinel_, iterator_t<_Base_> first, iterator_t<_Base_> last);

Postconditions: If Base does not model bidirectional_range, each element of current_ is equal to last.

Otherwise, _current__[N-1] == last is true, and for every integer ,_current__[i] == ranges​::​prev(_current__[i+1], 1, first)is true.

constexpr _iterator_(_iterator_<!Const> i) requires Const && [convertible_to](concept.convertible#concept:convertible%5Fto "18.4.4 Concept convertible_­to [concept.convertible]")<iterator_t<V>, iterator_t<_Base_>>;

Effects: Initializes each element of _current__with the corresponding element of i.current_ as an xvalue.

constexpr auto operator*() const;

Effects: Equivalent to:return tuple-transform([](auto& i) -> decltype(auto) { return *i; }, current_);

constexpr _iterator_& operator++();

Preconditions: current_.back() is incrementable.

Postconditions: Each element of current_ is equal to ranges​::​next(i), where i is the value of that element before the call.

constexpr _iterator_ operator++(int);

Effects: Equivalent to:auto tmp = *this;++*this;return tmp;

Preconditions: current_.front() is decrementable.

Postconditions: Each element of current_ is equal to ranges​::​prev(i), where i is the value of that element before the call.

Effects: Equivalent to:auto tmp = *this;--*this;return tmp;

Preconditions: current_.back() + x has well-defined behavior.

Postconditions: Each element of current_ is equal to i + x, where i is the value of that element before the call.

Preconditions: current_.front() - x has well-defined behavior.

Postconditions: Each element of current_ is equal to i - x, where i is the value of that element before the call.

Effects: Equivalent to:return tuple-transform([&](auto& i) -> decltype(auto) { return i[n]; }, current_);

friend constexpr bool operator==(const _iterator_& x, const _iterator_& y);

Returns: x.current_.back() == y.current_.back().

friend constexpr bool operator<(const _iterator_& x, const _iterator_& y) requires [random_access_range](range.refinements#concept:random%5Faccess%5Frange "25.4.5 Other range refinements [range.refinements]")<_Base_>;

Returns: x.current_.back() < y.current_.back().

friend constexpr bool operator>(const _iterator_& x, const _iterator_& y) requires [random_access_range](range.refinements#concept:random%5Faccess%5Frange "25.4.5 Other range refinements [range.refinements]")<_Base_>;

Effects: Equivalent to: return y < x;

friend constexpr bool operator<=(const _iterator_& x, const _iterator_& y) requires [random_access_range](range.refinements#concept:random%5Faccess%5Frange "25.4.5 Other range refinements [range.refinements]")<_Base_>;

Effects: Equivalent to: return !(y < x);

friend constexpr bool operator>=(const _iterator_& x, const _iterator_& y) requires [random_access_range](range.refinements#concept:random%5Faccess%5Frange "25.4.5 Other range refinements [range.refinements]")<_Base_>;

Effects: Equivalent to: return !(x < y);

Returns: x.current_.back() <=> y.current_.back().

friend constexpr _iterator_ operator+(const _iterator_& i, difference_type n) requires [random_access_range](range.refinements#concept:random%5Faccess%5Frange "25.4.5 Other range refinements [range.refinements]")<_Base_>;friend constexpr _iterator_ operator+(difference_type n, const _iterator_& i) requires [random_access_range](range.refinements#concept:random%5Faccess%5Frange "25.4.5 Other range refinements [range.refinements]")<_Base_>;

Effects: Equivalent to:auto r = i; r += n;return r;

friend constexpr _iterator_ operator-(const _iterator_& i, difference_type n) requires [random_access_range](range.refinements#concept:random%5Faccess%5Frange "25.4.5 Other range refinements [range.refinements]")<_Base_>;

Effects: Equivalent to:auto r = i; r -= n;return r;

friend constexpr difference_type operator-(const _iterator_& x, const _iterator_& y) requires [sized_sentinel_for](iterator.concept.sizedsentinel#concept:sized%5Fsentinel%5Ffor "24.3.4.8 Concept sized_­sentinel_­for [iterator.concept.sizedsentinel]")<iterator_t<_Base_>, iterator_t<_Base_>>;

Effects: Equivalent to:return x.current_.back() - y.current_.back();

friend constexpr auto iter_move(const _iterator_& i) noexcept(_see below_);

Effects: Equivalent to:return tuple-transform(ranges​::​iter_move, i.current_);

Remarks: The exception specification is equivalent to:noexcept(ranges::iter_move(declval<const iterator_t<_Base_>&>())) &&is_nothrow_move_constructible_v<range_rvalue_reference_t<_Base_>>

friend constexpr void iter_swap(const _iterator_& l, const _iterator_& r) noexcept(_see below_) requires [indirectly_swappable](alg.req.ind.swap#concept:indirectly%5Fswappable "24.3.7.4 Concept indirectly_­swappable [alg.req.ind.swap]")<iterator_t<_Base_>>;

Preconditions: None of the iterators in l.current_ is equal to an iterator in r.current_.

Effects: For every integer , performsranges​::​iter_swap(l._current__[i], r._current__[i]).

Remarks: The exception specification is equivalent to:noexcept(ranges::iter_swap(declval<iterator_t<_Base_>>(), declval<iterator_t<_Base_>>()))