[range.chunk.fwd.iter] (original) (raw)

25 Ranges library [ranges]

25.7 Range adaptors [range.adaptors]

25.7.29 Chunk view [range.chunk]

25.7.29.7 Class template chunk_view​::​iterator for forward ranges [range.chunk.fwd.iter]

namespace std::ranges { template<view V> requires forward_range<V> template<bool Const> class chunk_view<V>::iterator { using Parent = maybe-const<Const, chunk_view>; using Base = maybe-const<Const, V>; iterator_t<_Base_> current_ = iterator_t<_Base_>(); sentinel_t<_Base_> end_ = sentinel_t<_Base_>(); range_difference_t<_Base_> n_ = 0; range_difference_t<_Base_> missing_ = 0; constexpr iterator(Parent* parent, iterator_t<_Base_> current, range_difference_t<_Base_> missing = 0);public: using iterator_category = input_iterator_tag;using iterator_concept = see below;using value_type = decltype(views::take(subrange(current_, end_), 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_>> && convertible_to<sentinel_t<V>, sentinel_t<_Base_>>;constexpr iterator_t<_Base_> base() const;constexpr value_type 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 value_type 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, default_sentinel_t);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 difference_type operator-(default_sentinel_t y, const iterator& x) requires sized_sentinel_for<sentinel_t<_Base_>, iterator_t<_Base_>>;friend constexpr difference_type operator-(const iterator& x, default_sentinel_t y) requires sized_sentinel_for<sentinel_t<_Base_>, iterator_t<_Base_>>;};}

_iterator_​::​iterator_concept is defined as follows:

constexpr _iterator_(_Parent_* parent, iterator_t<_Base_> current, range_difference_t<_Base_> missing = 0);

Effects: Initializes current_ with current,end_ with ranges​::​end(parent->base_),n_ with parent->n_, and_missing__ with missing.

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_>> && [convertible_to](concept.convertible#concept:convertible%5Fto "18.4.4 Concept convertible_­to [concept.convertible]")<sentinel_t<V>, sentinel_t<_Base_>>;

Effects: Initializes current_ with std​::​move(i.current_),end_ with std​::​move(i.end_),n_ with i.n_, and_missing__ with i.missing_.

constexpr iterator_t<_Base_> base() const;

constexpr value_type operator*() const;

Preconditions: current_ != end_ is true.

Returns: views​::​take(subrange(current_, end_), n_).

constexpr _iterator_& operator++();

Preconditions: current_ != end_ is true.

Effects: Equivalent to:missing_ = ranges::advance(current_, n_, end_);return *this;

constexpr _iterator_ operator++(int);

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

Effects: Equivalent to:ranges::advance(current_, missing_ - n_);missing_ = 0;return *this;

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

Preconditions: If x is positive,ranges​::​distance(current_, end_) > n_ * (x - 1)is true.

[Note 1:

If x is negative, the Effects paragraph implies a precondition.

— _end note_]

Effects: Equivalent to:if (x > 0) { ranges::advance(current_, n_ * (x - 1));missing_ = ranges::advance(current_, n_, end_);} else if (x < 0) { ranges::advance(current_, n_ * x + missing_);missing_ = 0;} return *this;

Effects: Equivalent to: return *this += -x;

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

Returns: x.current_ == y.current_.

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

Returns: x.current_ == x.end_.

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_ < y.current_.

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_ <=> y.current_.

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_>>;

Returns: (x.current_ - y.current_ + x.missing_ - y.missing_) / x.n_.

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

Returns: div-ceil(x.end_ - x.current_, x.n_).

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

Effects: Equivalent to: return -(y - x);