data_error(const std::string &, unsigned, const std::string &);
data_error(const std::string &, unsigned, const std::exception &);
data_error(const std::string &, unsigned, const data_error &);
data_error(const std::string &, unsigned, const std::string &);
data_error(const std::string &, unsigned, const std::exception &);
data_error(const std::string &, unsigned, const data_error &);