Version flag/option

[infinity0n3]

So far to get a simple flag that triggers it's callback first time it's detected I had to do this workaround.

auto ver = app.add_option("-v,--version", (CLI::callback_t)show_version, "Show version");
ver->set_custom_option("", 0); 

It would be much more user friendly to have it similar to add_flag syntax but just with a callback.
No sure if it qualifies to be a separate function as add_config.

Option *add_version(std::string name, callback_t callback, std::string description = "") {
    Option *opt = add_option(name, callback, description, false);
    opt->set_custom_option("", 0);
    return opt;
}

[henryiii]

Added a function basically like your add_version, but a bit more generally named. It's just an overload on .add_flag for C++14 that takes a callback (signature void(size_t)), but in C++11 you have to use the explicit name, .add_flag_function. Does this make sense, and work for you? Suggestions welcome. I'm assuming there's not a reason to have it return a bool, for example, but maybe that would be useful for requiring 1 flag, for example?

[infinity0n3]

I can confirm that it works now. Would have been nicer to have the add_flag syntax but I have to use c++11.
Good thing is that it's a one liner now.

Thank you!

[henryiii]

I do too in several of my projects 😢