* @throws std::runtime_error in case of any invalid argument */

Call parse_known_args_internal - which does all the work * Then, validate the parsed arguments * This variant is used mainly for testing * @t

* Like parse_args_internal but collects unused args into a vector<string> */

* Pre-process this argument list. Anything starting with "--", that * contains an =, where the prefix before the = has an entry in the * options

Printing the one and only help message I've stuck with a simple message format, nothing fancy.