feat: Support of "exclusive or" argument sets

[milbrandt]

Description

If the list of arguments contain multiple sets of "exclusive or" options how can this be handled?

Repro steps

test [--option1 | --option2] [--option3 | --option4] [--option5 | --option6] 

Expected behavior

Possibility to group arguments from which exactely one is allowed.

Actual behavior

As far as I understood the tutorial no formal grouping of options is supported today.

Known workarounds

• Up to two sets of exclusive-or Arguments: A first set can be marked with [<FirstAttribute>], a second set as [<LastAttribute>].
• Use combinatorics to define "group" Options like option1_option4_option5. Will get cumbersome.
• use subcommands

[eiriktsarpalis]

That's typically handled using subcommands.

[milbrandt]

Yes, this is one of the Workarounds mentioned.
But as far as I understand this requires that from each option group one Argument is selected. At the moment I can't see how to map the case that either a group is omitted or exacteley one is allowed . Continuing the exampe from Repor steps, I want to allow all of the following

test --option1 --option3 --option5
test --option1 --option3
test --option1 --option5
test --option3 --option5
test --option1
test --option3
test --option5
test

whereas e.g. test --option3 --option4 would not be allowed.