24 Ranges library [ranges]

24.2 Header <ranges> synopsis [ranges.syn]

#include <compare> // see [compare.syn] #include <initializer_list> // see [initializer.list.syn] #include <iterator> // see [iterator.synopsis] namespace std::ranges { inline namespace unspecified { // [range.access], range access inline constexpr unspecified begin = unspecified; inline constexpr unspecified end = unspecified; inline constexpr unspecified cbegin = unspecified; inline constexpr unspecified cend = unspecified; inline constexpr unspecified rbegin = unspecified; inline constexpr unspecified rend = unspecified; inline constexpr unspecified crbegin = unspecified; inline constexpr unspecified crend = unspecified; inline constexpr unspecified size = unspecified; inline constexpr unspecified ssize = unspecified; inline constexpr unspecified empty = unspecified; inline constexpr unspecified data = unspecified; inline constexpr unspecified cdata = unspecified; } // [range.range], ranges template<class T> concept range = see below; template<class T> inline constexpr bool enable_borrowed_range = false; template<class T> concept borrowed_range = see below; template<class T> using iterator_t = decltype(ranges::begin(declval<T&>())); template<range R> using sentinel_t = decltype(ranges::end(declval<R&>())); template<range R> using range_difference_t = iter_difference_t<iterator_t<R>>; template<sized_­range R> using range_size_t = decltype(ranges::size(declval<R&>())); template<range R> using range_value_t = iter_value_t<iterator_t<R>>; template<range R> using range_reference_t = iter_reference_t<iterator_t<R>>; template<range R> using range_rvalue_reference_t = iter_rvalue_reference_t<iterator_t<R>>; // [range.sized], sized ranges template<class> inline constexpr bool disable_sized_range = false; template<class T> concept sized_range = see below; // [range.view], views template<class T> inline constexpr bool enable_view = see below; struct view_base { }; template<class T> concept view = see below; // [range.refinements], other range refinements template<class R, class T> concept output_range = see below; template<class T> concept input_range = see below; template<class T> concept forward_range = see below; template<class T> concept bidirectional_range = see below; template<class T> concept random_access_range = see below; template<class T> concept contiguous_range = see below; template<class T> concept common_range = see below; template<class T> concept viewable_range = see below; // [view.interface], class template view_­interface template<class D> requires is_class_v<D> && same_­as<D, remove_cv_t<D>> class view_interface; // [range.subrange], sub-ranges enum class subrange_kind : bool { unsized, sized }; template<input_­or_­output_­iterator I, sentinel_­for<I> S = I, subrange_kind K = see below> requires (K == subrange_kind::sized || !sized_­sentinel_­for<S, I>) class subrange; template<class I, class S, subrange_kind K> inline constexpr bool enable_borrowed_range<subrange<I, S, K>> = true; // [range.dangling], dangling iterator handling struct dangling; template<range R> using borrowed_iterator_t = see below; template<range R> using borrowed_subrange_t = see below; // [range.empty], empty view template<class T> requires is_object_v<T> class empty_view; template<class T> inline constexpr bool enable_borrowed_range<empty_view<T>> = true; namespace views { template<class T> inline constexpr empty_view<T> empty{}; } // [range.single], single view template<copy_­constructible T> requires is_object_v<T> class single_view; namespace views { inline constexpr unspecified single = unspecified; } template<bool Const, class T> using maybe-const = conditional_t<Const, const T, T>; // exposition only // [range.iota], iota view template<weakly_­incrementable W, semiregular Bound = unreachable_sentinel_t> requires weakly-equality-comparable-with<W, Bound> && copyable<W> class iota_view; template<class W, class Bound> inline constexpr bool enable_borrowed_range<iota_view<W, Bound>> = true; namespace views { inline constexpr unspecified iota = unspecified; } // [range.istream], istream view template<movable Val, class CharT, class Traits = char_traits<CharT>> requires see below class basic_istream_view; template<class Val, class CharT, class Traits> basic_istream_view<Val, CharT, Traits> istream_view(basic_istream<CharT, Traits>& s); // [range.all], all view namespace views { inline constexpr unspecified all = unspecified; template<viewable_­range R> using all_t = decltype(all(declval<R>())); } template<range R> requires is_object_v<R> class ref_view; template<class T> inline constexpr bool enable_borrowed_range<ref_view<T>> = true; // [range.filter], filter view template<input_­range V, indirect_­unary_­predicate<iterator_t<V>> Pred> requires view<V> && is_object_v<Pred> class filter_view; namespace views { inline constexpr unspecified filter = unspecified; } // [range.transform], transform view template<input_­range V, copy_­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; namespace views { inline constexpr unspecified transform = unspecified; } // [range.take], take view template<view> class take_view; template<class T> inline constexpr bool enable_borrowed_range<take_view<T>> = enable_borrowed_range<T>; namespace views { inline constexpr unspecified take = unspecified; } // [range.take.while], take while view template<view V, class Pred> requires input_­range<V> && is_object_v<Pred> && indirect_­unary_­predicate<const Pred, iterator_t<V>> class take_while_view; namespace views { inline constexpr unspecified take_while = unspecified; } // [range.drop], drop view template<view V> class drop_view; template<class T> inline constexpr bool enable_borrowed_range<drop_view<T>> = enable_borrowed_range<T>; namespace views { inline constexpr unspecified drop = unspecified; } // [range.drop.while], drop while view template<view V, class Pred> requires input_­range<V> && is_object_v<Pred> && indirect_­unary_­predicate<const Pred, iterator_t<V>> class drop_while_view; template<class T, class Pred> inline constexpr bool enable_borrowed_range<drop_while_view<T, Pred>> = enable_borrowed_range<T>; namespace views { inline constexpr unspecified drop_while = unspecified; } // [range.join], join view template<input_­range V> requires view<V> && input_­range<range_reference_t<V>> class join_view; namespace views { inline constexpr unspecified join = unspecified; } // [range.lazy.split], lazy split view template<class R> concept tiny-range = see below; // exposition only 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 lazy_split_view; // [range.split], split view template<forward_­range V, forward_­range Pattern> requires view<V> && view<Pattern> && indirectly_­comparable<iterator_t<V>, iterator_t<Pattern>, ranges::equal_to> class split_view; namespace views { inline constexpr unspecified lazy_split = unspecified; inline constexpr unspecified split = unspecified; } // [range.counted], counted view namespace views { inline constexpr unspecified counted = unspecified; } // [range.common], common view template<view V> requires (!common_­range<V> && copyable<iterator_t<V>>) class common_view; template<class T> inline constexpr bool enable_borrowed_range<common_view<T>> = enable_borrowed_range<T>; namespace views { inline constexpr unspecified common = unspecified; } // [range.reverse], reverse view template<view V> requires bidirectional_­range<V> class reverse_view; template<class T> inline constexpr bool enable_borrowed_range<reverse_view<T>> = enable_borrowed_range<T>; namespace views { inline constexpr unspecified reverse = unspecified; } // [range.elements], elements view template<input_­range V, size_t N> requires see below class elements_view; template<class T, size_t N> inline constexpr bool enable_borrowed_range<elements_view<T, N>> = enable_borrowed_range<T>; template<class R> using keys_view = elements_view<views::all_t<R>, 0>; template<class R> using values_view = elements_view<views::all_t<R>, 1>; namespace views { template<size_t N> inline constexpr unspecified elements = unspecified ; inline constexpr auto keys = elements<0>; inline constexpr auto values = elements<1>; } } namespace std { namespace views = ranges::views; template<class T> struct tuple_size; template<size_t I, class T> struct tuple_element; template<class I, class S, ranges::subrange_kind K> struct tuple_size<ranges::subrange<I, S, K>> : integral_constant<size_t, 2> {}; template<class I, class S, ranges::subrange_kind K> struct tuple_element<0, ranges::subrange<I, S, K>> { using type = I; }; template<class I, class S, ranges::subrange_kind K> struct tuple_element<1, ranges::subrange<I, S, K>> { using type = S; }; template<class I, class S, ranges::subrange_kind K> struct tuple_element<0, const ranges::subrange<I, S, K>> { using type = I; }; template<class I, class S, ranges::subrange_kind K> struct tuple_element<1, const ranges::subrange<I, S, K>> { using type = S; }; }
Within this Clause, for an integer-like type X ([iterator.concept.winc]), make-unsigned-like-t<X> denotes make_­unsigned_­t<X> if X is an integer type; otherwise, it denotes a corresponding unspecified unsigned-integer-like type of the same width as X.
For an expression x of type X, to-unsigned-like(x) is x explicitly converted to make-unsigned-like-t<X>.
Also within this Clause, make-signed-like-t<X> for an integer-like type X denotes make_­signed_­t<X> if X is an integer type; otherwise, it denotes a corresponding unspecified signed-integer-like type of the same width as X.