Jonathan Graehl wrote:
I grepped through the program_options source and couldn't find anything about declaratively specifying required options (or even more specifically, min/max # of occurrences), except for positional options.
Does "min/max" number of occurrences makes much sense? In variables_map, an option is either present, or not, it cannot be present twice.
I know it's possible to do variables_map::count("option-name") or if I have an impossible default value bound to an option, I could check for that (default would = option absence), but it might be nice to have "requiredness" be a declared option trait, that could show up in the option description.
value<int>(&myoption)->required()
That's something that was requested some time ago, but not yet there. I'll note your request (really can't implement all this right before release). I think that for now you'd have to use .count. - Volodya