25 Ranges library [ranges]

Many of the types in [range.utility] are specified in terms of the following exposition-only concepts: template<class R> concept simple-view = // exposition only view<R> && range<const R> && same_as<iterator_t<R>, iterator_t<const R>> && same_as<sentinel_t<R>, sentinel_t<const R>>; template<class I> concept has-arrow = // exposition only input_iterator<I> && (is_pointer_v<I> || requires(const I i) { i.operator->(); }); template<class T, class U> concept different-from = // exposition only !same_as<remove_cvref_t<T>, remove_cvref_t<U>>; template<class R> concept range-with-movable-references = // exposition only input_range<R> && move_constructible<range_reference_t<R>> && move_constructible<range_rvalue_reference_t<R>>;