[Boost-users] [program_options] Problem using value<string>()->zero_tokens() with config file

Subject: [Boost-users] [program_options] Problem using value<string>()->zero_tokens() with config file
From: Marcio Paim de Aquino (marcio.paim_at_[hidden])
Date: 2008-09-18 08:30:22

Hi,

I have the following code section:

    po::options_description config;
    config.add_options()
        ( "HOST", po::value<string>(&host) )
        ( "USER", po::value<string>(&user) )
        ( "PASSWD", po::value<string>(&passwd) )
        ( "DATABASE", po::value<string>(&database) )
        ( "PORT", po::value<int>(&port) )
        ( "VERTEX.WEIGHT", po::value<string>()->zero_tokens() );

    po::variables_map vm;
    ifstream ifs( "myfile.conf" );
    store( parse_config_file( ifs, config ), vm );
    notify( vm );

If in myfile.conf I leave WEIGHT  blank like this

    [VERTEX]

        WEIGHT   =

I get the following error message:

terminate called after throwing an instance of
'boost::exception_detail::clone_impl<boost::exception_detail::error_info_injector<boost::program_options::invalid_syntax>
>'
  what():  no value given in 'WEIGHT   ='
Aborted

Someone can tell whats is wrong?

Thanks

Marcio