Is there a way to disable positional arguments altogether ?

[aphecetche]

By this I mean something like :

• make the dash (or dashes) mandatory when declaring an option
• and throw an exception if the parser encounters something that it cannot associate with any option

[phlptp]

->allow_extras(false) will generate an exception for unrecognized options including positional ones. (if you don't define any positionals).

[aphecetche]

Thanks. That would solve the second point above only, right ?
For the first one, could this be achieved with subclassing App somehow ?

[phlptp]

The first could be achieved by wrapping the add_option call and doing the check there or probably slightly less complicated would be using the get_options(filter) method with a filter that selects options with the get_positional() check. If that list is not empty throw an error. That could be done in a method that operates on an app and does the check.

Curious what the use case for not allowing positionals in that manner is?

[aphecetche]

Something like :

void myparse(CLI::App& app, int argc, char** argv)
{
  app.parse(argc, argv);
  // disallow positional arguments
  auto with_pos_arg = app.get_options([](const CLI::Option* opt)
                                      { return opt->get_positional(); });
  if (!with_pos_arg.empty()) {
    throw std::invalid_argument("no positional argument allowed");
  }
}

indeed works fine. Thanks.

As for the reason : I'm trying to see if the current parser we are using could be replaced with CLI11. And our current parser simply does not allow positional arguments.