Re: [Boost-users] Comments on the usability of program_options

From: Paul Giaccone (paulg_at_[hidden])
Date: 2006-01-26 13:27:23

Antonio Piccolboni wrote:

>If I can add my 2c, before switching to program_options I was using
>TCLAP (tclap.sourceforge.net/). The main reason for swtiching was to
>avoid relying on one-man-show libraries, so it's not a technical one
>and I am not in a position to do thorough comparison. One thing I
>noticed though, is that with program_options I have to specify the
>type of an argument twice, first with po::value<type>, then with
>vm["optname"].as<type>().
>Not only it is verbose, but it is checked only runtime.
>

Really?  I've never done this.  I always used po::value<type> alone, and 
everything works fine for me.  What is .as used for?

For myself, what I would like to see is straightforward support for 
multiple-argument options, of the form:

-x a b c -y d e

The documentation suggests that this is possible, but does not seem to 
explain how.  The documentation suggests that this is somehow unusual 
behaviour (and that each flag should have at most one argument) but I 
have seen numerous people asking about it on this mailing list.  I don't 
remember seeing any explanation of how to do it on the mailing list, though.

Paul