Dealing with Flags that are Mutually Exclusive

[Zalanshah64]

Certain flags should not be able to be written at the same time. For example:

• --difficulty should only be allowed to be called when --generate or --play are called
• --generate shouldn't be callable when --play is called, and vice versa
• --help and --version shouldn't allow any other flags to work together
• Maybe allowing --generate and --play alongside --solve would be okay? I'm not totally sure about this idea though.

I think the best way of dealing with flags is creating a priority list, and letting one thing take priority over another (i.e. help > version > play > generate, etc), while of course ensuring there's no mutually exclusive calls.