Function make_view_end

include/boost/parser/parser.hpp:2787–2794

        template<typename R>
        constexpr auto make_view_end(R & r) noexcept
        {
            if constexpr (std::is_pointer_v<std::decay_t<R>>) {
                return text::null_sentinel;
            } else {
                return detail::text::detail::end(r);
            }
        }

        template<
            typename Iter1,