Function delimiter

include/boost/parser/parser.hpp:6683–6687

        `delimiter_parser`. */
    template<typename DelimiterParser>
    constexpr delimiter_directive<DelimiterParser>
    delimiter(parser_interface<DelimiterParser> delimiter_parser) noexcept
    {
        return delimiter_directive<DelimiterParser>{delimiter_parser.parser_};
    }

    /** Represents a skip parser as a directive.  When used without a skip
        parser, e.g. `skip[parser_in_which_to_do_skipping]`, the skipper for