Extend the optional delegate to accept a list of hardcoded acceptable values #78
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I propose to add the following overloads to the ArgParser@option function, so that we can specify a list of valid values, and if the user specifies anything else, it'll throw. Example usage would be
or with the latter overload
This would allow usage to be as follows:
$ ./app --mode=play // ok $ ./app -m play // ok $ ./app -m hello // error, "hello" was not a valid value $ ./app // ok, the option has a default value and isnt a required fieldIt's technically already possible through the already existing overloads, but I can definitely see this to be a very common use, so
I find it valuable enough to be included in the library.