[Boost-users] Unknown number of multitoken lists?

I want to do something like this: --NumLists 2 --List0 a.txt b.txt --List1 c.txt d.txt vector<vector<string> > Lists(2); po::options_description desc("Allowed options"); desc.add_options() ("help", "produce help message") ("List0", po::value<vector<string> >(&Lists[0])->multitoken(), "List0.") ("List1", po::value<vector<string> >(&Lists[1])->multitoken(), "List1.") ; But if I wanted to handle --NumLists 10, I would have to manually add List0, List1, ... List10 as parameters. That seems a bit silly, but maybe this is a very odd usage? Please let me know if you can think of a better way to handle this. Thanks, David