25 Ranges library [ranges]

25.7 Range adaptors [range.adaptors]

25.7.9 Transform view [range.transform]

25.7.9.2 Class template transform_view [range.transform.view]

namespace std::ranges { template<input_range V, move_constructible F> requires view<V> && is_object_v<F> && regular_invocable<F&, range_reference_t<V>> && can-reference<invoke_result_t<F&, range_reference_t<V>>> class transform_view : public view_interface<transform_view<V, F>> { private: // [range.transform.iterator], class template transform_view::iterator template<bool> struct iterator; // exposition only // [range.transform.sentinel], class template transform_view::sentinel template<bool> struct sentinel; // exposition only V base_ = V(); // exposition only movable-box<F> fun_; // exposition only public: transform_view() requires default_initializable<V> && default_initializable<F> = default; constexpr explicit transform_view(V base, F fun); constexpr V base() const & requires copy_constructible<V> { return base_; } constexpr V base() && { return std::move(base_); } constexpr iterator<false> begin(); constexpr iterator<true> begin() const requires range<const V> && regular_invocable<const F&, range_reference_t<const V>>; constexpr sentinel<false> end(); constexpr iterator<false> end() requires common_range<V>; constexpr sentinel<true> end() const requires range<const V> && regular_invocable<const F&, range_reference_t<const V>>; constexpr iterator<true> end() const requires common_range<const V> && regular_invocable<const F&, range_reference_t<const V>>; constexpr auto size() requires sized_range<V> { return ranges::size(base_); } constexpr auto size() const requires sized_range<const V> { return ranges::size(base_); } }; template<class R, class F> transform_view(R&&, F) -> transform_view<views::all_t<R>, F>; }

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constexpr explicit transform_view(V base, F fun);

Effects: Initializes base_ with std::move(base) and fun_ with std::move(fun).

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constexpr iterator<false> begin();

Effects: Equivalent to: return iterator<false>{*this, ranges::begin(base_)};

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constexpr iterator<true> begin() const
  requires range<const V> &&
           regular_invocable<const F&, range_reference_t<const V>>;

Effects: Equivalent to: return iterator<true>{*this, ranges::begin(base_)};

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constexpr sentinel<false> end();

Effects: Equivalent to: return sentinel<false>{ranges::end(base_)};

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constexpr iterator<false> end() requires common_range<V>;

Effects: Equivalent to: return iterator<false>{*this, ranges::end(base_)};

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constexpr sentinel<true> end() const
  requires range<const V> &&
           regular_invocable<const F&, range_reference_t<const V>>;

Effects: Equivalent to: return sentinel<true>{ranges::end(base_)};

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constexpr iterator<true> end() const
  requires common_range<const V> &&
           regular_invocable<const F&, range_reference_t<const V>>;

Effects: Equivalent to: return iterator<true>{*this, ranges::end(base_)};