Re: [Boost-users] [boost::program_options] Different usage

Subject: Re: [Boost-users] [boost::program_options] Different usage
From: Vladimir Prus (vladimir_at_[hidden])
Date: 2009-03-05 10:50:04

Everton Patitucci wrote:

> Hello, I'm wondering if I should use boost::program_options and I got some
> questions about it.
> 
> All examples that I found are using std::string and std::ostream everytime
> they're dealing with values being some kind of text...
> 
> so to display the "usage" of their program they would do something like...
> 
> cout << desc;
> 
> 'desc' being a boost::program_options::options_description.
> 
> or...
> 
> when adding options to their command line...
> 
> desc.add_options()
>                           ...
>                           ("opt",
> boost::program_options::value<std::string>, "desc")
>                           ...
> 
> 
> What I want to know is, if I didn't want to use std::string nor std::ostream
> nor std anything in my specific code (I know boost uses it).
> 
> Is there a not-so-time-expensive way to do it? If there's could someone show
> me (there's no need for the real code, pseudo is more than OK) if it's
> supported?

Values of the option can be of any type, it is not necessary to use std::anything.
You might need to 'validate' function for the custom types.

> something like this for example...
> 
> desc.add_options() ("opt", bpo::value<char*>, "blabla")
> 
> and in usage()-like:
> 
> I don't know if this works, I looked in doc...
> std::vector< shared_ptr<po::option_description> > opts = desc.options();
> std::vector< shared_ptr<po::option_description> >::iterator it =
> opts.begin();
> for (; it != opts.end(); ++it)
> {
>      shared_ptr<po::option_description> opt = *it;
>      printf("%s\n", opt->format_parameter().c_str());
> }

There's nothing preventing code like this from working.

- Volodya