::as_reversed

#include <iterator>

namespace details {

    template<typename Container>
    struct reversed_container {

        Container& container;

        constexpr decltype(auto) begin() const {
            using std::end;
            return std::make_reverse_iterator(end(container));
        }

        constexpr decltype(auto) end() const {
            using std::begin;
            return std::make_reverse_iterator(begin(container));
        }

    };

}

template<typename Container>
constexpr details::reversed_container<Container> as_reversed(Container& container) {
    return {container};
}