"Funny" code. I'm quite sure nobody would do something like that "in production"… The problem starts with the signature of this function: There is—of course—n

"Funny" code. I'm quite sure nobody would do something like that "in production"… The problem starts with the signature of this function: There is—of course—no function which could take an arbitrary String and return a SubscriberName. You need to return at least an Option, or better a Result. But at this point the fun starts. You need to thread this wrapped value throughout your whole program. Crashing your program (by a panic in the above function, or by a unwrap somewhere later) because someone sent you an invalid String is not an option in real life.