26 Ranges library [ranges]

26.7 Range adaptors [range.adaptors]

26.7.27 Adjacent transform view [range.adjacent.transform]

26.7.27.3 Class template adjacent_transform_view​::​iterator [range.adjacent.transform.iterator]

namespace std::ranges { template<forward_range V, move_constructible F, size_t N> requires view<V> && (N > 0) && is_object_v<F> && regular_invocable<F&, REPEAT(range_reference_t<V>, N)...> && can-reference<invoke_result_t<F&, REPEAT(range_reference_t<V>, N)...>> template<bool Const> class adjacent_transform_view<V, F, N>::iterator { using Parent = maybe-const<Const, adjacent_transform_view>; // exposition only using Base = maybe-const<Const, V>; // exposition only Parent* parent_ = nullptr; // exposition only inner-iterator<Const> inner_; // exposition only constexpr iterator(Parent& parent, inner-iterator<Const> inner); // exposition only public: using iterator_category = see below; using iterator_concept = typename inner-iterator<Const>::iterator_concept; using value_type = remove_cvref_t<invoke_result_t<maybe-const<Const, F>&, REPEAT(range_reference_t<Base>, N)...>>; using difference_type = range_difference_t<Base>; iterator() = default; constexpr iterator(iterator<!Const> i) requires Const && convertible_to<inner-iterator<false>, inner-iterator<Const>>; constexpr decltype(auto) operator*() const noexcept(see below); 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 decltype(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<inner-iterator<Const>>; 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<inner-iterator<Const>, inner-iterator<Const>>; }; }
The member typedef-name iterator​::​iterator_category is defined as follows:
  • If invoke_result_t<maybe-const<Const, F>&, REPEAT(range_reference_t<Base>, N)...> is
    not a reference, iterator_category denotes input_iterator_tag.
  • Otherwise, let C denote the type iterator_traits<iterator_t<Base>>​::​iterator_category.
    • If derived_from<C, random_access_iterator_tag> is true, iterator_category denotes random_access_iterator_tag.
    • Otherwise, if derived_from<C, bidirectional_iterator_tag> is true, iterator_category denotes bidirectional_iterator_tag.
    • Otherwise, if derived_from<C, forward_iterator_tag> is true, iterator_category denotes forward_iterator_tag.
    • Otherwise, iterator_category denotes input_iterator_tag.
constexpr iterator(Parent& parent, inner-iterator<Const> inner);
Effects: Initializes parent_ with addressof(parent) and inner_ with std​::​move(inner).
constexpr iterator(iterator<!Const> i) requires Const && convertible_to<inner-iterator<false>, inner-iterator<Const>>;
Effects: Initializes parent_ with i.parent_ and inner_ with std​::​move(i.inner_).
constexpr decltype(auto) operator*() const noexcept(see below);
Effects: Equivalent to: return apply([&](const auto&... iters) -> decltype(auto) { return invoke(*parent_->fun_, *iters...); }, inner_.current_);
Remarks: Let Is be the pack 0, 1, …, (N-1).
The exception specification is equivalent to: noexcept(invoke(*parent_->fun_, *std::get<Is>(inner_.current_)...))
constexpr iterator& operator++();
Effects: Equivalent to: ++inner_; return *this;
constexpr iterator operator++(int);
Effects: Equivalent to: auto tmp = *this; ++*this; return tmp;
constexpr iterator& operator--() requires bidirectional_range<Base>;
Effects: Equivalent to: --inner_; return *this;
constexpr iterator operator--(int) requires bidirectional_range<Base>;
Effects: Equivalent to: auto tmp = *this; --*this; return tmp;
constexpr iterator& operator+=(difference_type x) requires random_access_range<Base>;
Effects: Equivalent to: inner_ += x; return *this;
constexpr iterator& operator-=(difference_type x) requires random_access_range<Base>;
Effects: Equivalent to: inner_ -= x; return *this;
constexpr decltype(auto) operator[](difference_type n) const requires random_access_range<Base>;
Effects: Equivalent to: return apply([&](const auto&... iters) -> decltype(auto) { return invoke(*parent_->fun_, iters[n]...); }, inner_.current_);
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<inner-iterator<Const>>;
Let op be the operator.
Effects: Equivalent to: return x.inner_ op y.inner_;
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>;
Effects: Equivalent to: return iterator(*i.parent_, i.inner_ + n);
friend constexpr iterator operator-(const iterator& i, difference_type n) requires random_access_range<Base>;
Effects: Equivalent to: return iterator(*i.parent_, i.inner_ - n);
friend constexpr difference_type operator-(const iterator& x, const iterator& y) requires sized_sentinel_for<inner-iterator<Const>, inner-iterator<Const>>;
Effects: Equivalent to: return x.inner_ - y.inner_;