[boost] program_options: Why it throw ambiguous_option?

From: Peng Yu (pengyu.ut_at_[hidden])
Date: 2007-01-23 23:33:42

Hi,

I got the following error for the program list below. Where
program_options considers "help" and "help_abc" as ambiguous?

$ ./main --help
terminate called after throwing an instance of
'boost::program_options::ambiguous_option'
 what():  ambiguous option help
Aborted

Thanks,
Peng

#include <boost/program_options.hpp>
namespace po = boost::program_options;

int main(int ac, char* av[])
{
 po::options_description desc("Allowed options");
 desc.add_options()
   ("help", "produce help message")
   ("help_abc", po::value<int>(), "set compression level")
   ;

 po::variables_map vm;
 po::store(po::parse_command_line(ac, av, desc), vm);
 po::notify(vm);

 return 0;
}