24 Ranges library [ranges]

24.7 Range adaptors [range.adaptors]

24.7.12 Split view [range.split]

24.7.12.2 Class template split_­view [range.split.view]

namespace std::ranges { template<auto> struct require-constant; // exposition only template<class R> concept tiny-range = // exposition only sized_­range<R> && requires { typename require-constant<remove_reference_t<R>::size()>; } && (remove_reference_t<R>::size() <= 1); template<input_­range V, forward_­range Pattern> requires view<V> && view<Pattern> && indirectly_­comparable<iterator_t<V>, iterator_t<Pattern>, ranges::equal_to> && (forward_­range<V> || tiny-range<Pattern>) class split_view : public view_interface<split_view<V, Pattern>> { private: V base_ = V(); // exposition only Pattern pattern_ = Pattern(); // exposition only iterator_t<V> current_ = iterator_t<V>(); // exposition only, present only if !forward_­range<V> // [range.split.outer], class template split_­view​::​outer-iterator template<bool> struct outer-iterator; // exposition only // [range.split.inner], class template split_­view​::​inner-iterator template<bool> struct inner-iterator; // exposition only public: split_view() = default; constexpr split_view(V base, Pattern pattern); template<input_­range R> requires constructible_­from<V, views::all_t<R>> && constructible_­from<Pattern, single_view<range_value_t<R>>> constexpr split_view(R&& r, range_value_t<R> e); constexpr V base() const& requires copy_­constructible<V> { return base_; } constexpr V base() && { return std::move(base_); } constexpr auto begin() { if constexpr (forward_­range<V>) return outer-iterator<simple-view<V>>{*this, ranges::begin(base_)}; else { current_ = ranges::begin(base_); return outer-iterator<false>{*this}; } } constexpr auto begin() const requires forward_­range<V> && forward_­range<const V> { return outer-iterator<true>{*this, ranges::begin(base_)}; } constexpr auto end() requires forward_­range<V> && common_­range<V> { return outer-iterator<simple-view<V>>{*this, ranges::end(base_)}; } constexpr auto end() const { if constexpr (forward_­range<V> && forward_­range<const V> && common_­range<const V>) return outer-iterator<true>{*this, ranges::end(base_)}; else return default_sentinel; } }; template<class R, class P> split_view(R&&, P&&) -> split_view<views::all_t<R>, views::all_t<P>>; template<input_­range R> split_view(R&&, range_value_t<R>) -> split_view<views::all_t<R>, single_view<range_value_t<R>>>; }
constexpr split_view(V base, Pattern pattern);
Effects: Initializes base_­ with std​::​move(base), and pattern_­ with std​::​move(pattern).
template<input_­range R> requires constructible_­from<V, views::all_t<R>> && constructible_­from<Pattern, single_view<range_value_t<R>>> constexpr split_view(R&& r, range_value_t<R> e);
Effects: Initializes base_­ with views​::​all(std​::​forward<R>(r)), and pattern_­ with single_­view{​std​::​move(e)}.