// Note: this requires the `cargo` feature use clap::{command, Arg, ArgAction}; fn main() { let matches = command!() .arg( Arg::new("verbose") .short('v') .long("verbose") .action(ArgAction::SetTrue), ) .get_matches(); println!( "verbose: {:?}", *matches .get_one::("verbose") .expect("defaulted by clap") ); }