Re: [Boost-users] program_options: documentation dead end

From: Vladimir Prus (ghost_at_[hidden])
Date: 2007-07-18 14:21:23

Bryan Green wrote:

> Ian McCulloch writes:
>> Bryan Green wrote:
>> [snip]
>> >
>> > While I'm on the subject, you sometimes see something like the
>> > following:
>> > 
>> > ./prog -vvv
>> >   or
>> > ./prog -v -v -v
>> > 
>> > This would *increment* the verbosity level three times.  I can't see
>> > how to replicate this in program_options.
>> 
>> This is something I have asked about before on this list, but at the time
>> there was no response.  I would be very interested in knowing how to do
>> this using boost::program_options!
> 
> Hmm, I'm starting to see a pattern here.  Does there happen to be any
> development going on in program_options, or is it in need of developers?

If you're volunteering, you're most welcome.

Speaking about -v -v -v, there's no stock way to achieve that. However, the
provided interfaces seem to make it possible:

        1. Derive from value_semantics.

        2. Define the 'parse' method to add one to already stored value.

Compare this to handing of vector<string> -- each new token is *appened*
to existing value. In the case of -v -v -v, you need each new token to
increment existing value, which is essentially the same.

- Volodya