This thread discusses the issue: http://archives.free.net.ph/message/20070718.222859.2c087966.en.html (follow that post up and down the thread a couple of posts as necessary). Basically, that kind of syntax not directly supported by program_options, but can be coded up by writing some helper classes. Not worth the effort, much nicer to your users to write an application that takes more sensible arguments (-d 1 or -d 2 or -d 3). Note that getting -d or -d=2 or -d=3 to work requires a patch to program_options itself, described in another interesting thread: http://archives.free.net.ph/message/20070723.222625.66f39345.en.html Hope that helps, Steven F David Sacerdoti wrote:

As per Volodya's suggestion, posting this question here. He mentioned it had been discussed, but I was unable to find anything appropriate using search engines. I apologize in advance if this is a repeat question.

Hi,

I am trying to do a simple thing with your program_options boost library:

I have a program foo, and I want to invoke it like this: foo -d -d -d

I want foo to know "I have counted three -d".

I followed your tutorial and tried this: desc.add_options() ("debug,d",po::value< vector<int> >()->default_value(1), "Debug level") ;

po::variables_map vm; po::store(po::parse_command_line(argc, argv, desc), vm); po::notify(vm);

if (vm.count("debug")) {

cout << "Running, debug level: " << vm["debug"].as< vector<int> >().size() << "\n"; }

But it did not work, always prints "debug level: 0". For background, this is to make the program compatible with a Python implementation which uses optparse. I have an extensive testing framework that assumes this behavior and it would be nice to implement the same with program_options.

Thanks, Federico