extern crate clap;
use clap::{App, Arg, ArgGroup};

fn main() {
    let app = App::new("clap_weirdness")
        .arg(Arg::with_name("selection_a").short("a"))
        .arg(Arg::with_name("selection_b").short("b"))
        .arg(
            Arg::with_name("selection_c")
                .short("c")
                .conflicts_with("not_with_c"),  // this also precludes -ae and -be
        )
        .group(
            ArgGroup::with_name("selection")
                .args(&["selection_a", "selection_b", "selection_c"])
                .required(true),
        )
        .arg(
            Arg::with_name("not_with_c")
                .short("e")
                //.conflicts_with("selection_c"),  // this works as expected, only precluding -ce
        );

    app.get_matches();
}