[Boost-users] Re: Re: boost::program options question. Implicit() doesn't seem to work

From: Vladimir Prus (ghost_at_[hidden])
Date: 2005-03-16 09:49:48

The Grumpiest Man You Know wrote:

> On Wed, 09 Mar 2005 10:41:39 +0300, Vladimir Prus <ghost_at_[hidden]> wrote:
>> I think it's the library. But in any case, I plan to remove the
>> 'implicit' flag in 1.33. Why do you want it? What about:
>>
> 
> Really?  I thought that was quite useful for things like.
> 
> $ foo --help
> usage: foo [-sexy-options]
> $ foo --help topic
> The "topic" option crazumps the doobryferk.
> 
> Is there a better way than implicit for that?  

You can treat 'topic' as positional option and print help for all positional
options when --help is specified. Say:

  $ foo surprise 
  <monitor blows up, you buy a new one>
  $ foo surprise --help
  The 'surprise' command blows your monitor up.

Note that in this case you can use "--help" before and after a topic, which
is an additional convenience.

> Is implicit causing 
> some ugliness that warrants it's excise?

Yes, because in the above case it's not clear if "topic" is a positional
option or value of the "--help" option.

I bring this issue in

   http://article.gmane.org/gmane.comp.lib.boost.devel/118670

- Volodya