name for a mutually inclusive relationship

[Ethan Furman]

On 2/24/21 1:54 PM, 2QdxY4RzWzUUiLuE at potatochowder.com wrote:
> Ethan Furman wrote:

>> I didn't say it was a good example.  ;-)  Hopefully it gets the idea across.
> 
> Ditto.  ;-)
> 
> IMO, the whole idea of "my program has two options, and the user has to
> specify both or neither," isn't a question of whether or not the
> argument parsing library supports it, but a question of whether or not
> it's a good API.

Like I said, at this moment I don't have a good example, only an awareness that such a thing could exist and I don't know the name for it (if it has one).

So far I have seen that there are even fewer good use-cases than I might have guessed, and that no one seems to have a name for the general idea.

--
~Ethan~