Re: [Boost-users] [Options Description] positional_options_description throw exception

Subject: Re: [Boost-users] [Options Description] positional_options_description throw exception
From: Vladimir Prus (vladimir_at_[hidden])
Date: 2010-03-24 12:41:33

Sakharuk, Vladimir wrote:

> Trying to access positional arguments with sample program bellow:
> 
> If I run: "a.out one"
> Error: unknown option positional
> Same error I got on "a.out -h one" and "a.out one -h"
> 
> 
> If I run: "a.out one two"
> Error: too many positional options
> 
> But "a.out -h works"
> Thanks \/.
> 
> 
> 
>     namespace po=boost::program_options;
>     po::options_description cmds("Options");
>     cmds.add_options()
>       ("help,h", "output help message");
> 
>     po::positional_options_description positional;
>     positional.add("positional", 1);
> 
>     po::variables_map vm;
>     po::parsed_options parsed = po::command_line_parser(argc,
> argv).options(cmds).positional(positional).run();

Per documentation, this code only makes the first positional option be
treated as option named 'positional'. You still need to define such
an option inside an options_description object, since otherwise
the library will have no idea what type it has and what to do with it.

Does this help?

- Volodya