[Boost-users] Questions about Program_options

Subject: [Boost-users] Questions about Program_options
From: Yang Zhang (yanghatespam_at_[hidden])
Date: 2008-12-03 16:33:06

Hi, I'm currently enjoying using Program_options, and I have a few 
questions/comments about it.

Is it necessary to create and use a variable_map for parsing program 
options?  Is there a way to forgo this if I've already used value<T>(T*) 
to bind the options to other storage locations?

What is notify() for, exactly?  This is not really described in the 
documentation.

It may be worth mentioning bool_switch somewhere in the documentation. 
(I dug this up from the header files.)

Can I access positional arguments without going through the 
positional_options_description?  My program is "variadic" and takes 
either 1 or 2 arguments (where the first has a completely different 
meaning depending on the number of args).  I realize I can assign 
meaningless names in the positional_options_description, like "arg0," 
"arg1," etc., but I'm just wondering if there's already a way to access 
the raw positional arguments without going through the 
positional_options_description boilerplate.

Is there a way to specify a *hierarchy* of command-line parameters, such 
as those found in svn (a two-layer hierarchy), git, etc.?  If not, 
consider this a feature request!  In svn, for instance, there are global 
options, there's the exact command, and then there are sub-options 
associated with the command.  See the Python argparse module for an 
example of such a library design: http://argparse.python-hosting.com/

Thanks in advance for any answers.
-- 
Yang Zhang
http://www.mit.edu/~y_z/