Function make_string

extlibs/sol3/include/sol/sol.hpp:20879–20882

		template <typename Arg>
		inline std::string make_string(Arg&& arg) {
			string_view s = make_string_view(arg);
			return std::string(s.data(), s.size());
		}

		inline int is_indexer(string_view s) {
			if (s == to_string(meta_function::index)) {