12 typedef std::variant<double, bool, std::string>
argument_t;
18 typedef std::pair<std::string, type>
named_t;
std::pair< std::string, type > named_t
std::function< std::tuple< double, bool >(arguments_t)> type
std::vector< argument_t > arguments_t
std::variant< double, bool, std::string > argument_t