Method name

native/thirdpart/json/json.hpp:1881–1884

    exception(int id_, const char* what_arg) : id(id_), m(what_arg) {}

    static std::string name(const std::string& ename, int id_)
    {
        return "[json.exception." + ename + "." + std::to_string(id_) + "] ";
    }

  private:
    /// an exception object as storage for error messages