Re: [boost] [program_options] implicit value and non-adjacent tokens

Subject: Re: [boost] [program_options] implicit value and non-adjacent tokens
From: Roger Martin (roger_at_[hidden])
Date: 2017-01-04 15:43:07

Hi,
As of 1.63.0 this new behavior still breaks my command line and I have 
to revert back to using boost 1.57.0.  Is there a work around to revert 
this behavior in the 1.63.0 release?  Any hope for those of us who use 
positional for file paths?

On 12/21/2016 02:36 AM, Vladimir Prus wrote:
>
> Hi,
>
> some time ago, program_options was modified so that options
> with implicit value would only take value from the same token.
>
> Previously, one could have:
>
>     ./program -a foo -b # uses 'foo' as value for 'a'
>     ./program -a -b     # uses some default value for 'a'
>     ./program -b        # has no value for 'a'
>
> Now, the first syntax interprets 'foo' as positional option,
> and one has two write
>
>     ./program -a=foo
>
> Ever since, I hear concerns from users about this behavior. Maybe not 
> very loud, but quite consistent. Maybe, the new behavior is not
> very good, indeed, because it now mixes syntax matter (whether value
> is in the same token) with semantic matter (whether an option has
> implied value).
>
> I am considering reverting this change for next version of Boost.
> Does anybody have opinions either way?
>
> Thanks,
> Volodya
>
>
> _______________________________________________
> Unsubscribe & other changes: 
> http://lists.boost.org/mailman/listinfo.cgi/boost
>