vendor/clap/examples/derive_ref/augment_args.rs

   1 use clap::{arg, Args as _, Command, FromArgMatches as _, Parser};
   2
   3 #[derive(Parser, Debug)]
   4 struct DerivedArgs {
   5     #[clap(short, long, action)]
   6     derived: bool,
   7 }
   8
   9 fn main() {
  10     let cli = Command::new("CLI").arg(arg!(-b - -built).action(clap::ArgAction::SetTrue));
  11     // Augment built args with derived args
  12     let cli = DerivedArgs::augment_args(cli);
  13
  14     let matches = cli.get_matches();
  15     println!(
  16         "Value of built: {:?}",
  17         *matches.get_one::<bool>("built").unwrap()
  18     );
  19     println!(
  20         "Value of derived via ArgMatches: {:?}",
  21         *matches.get_one::<bool>("derived").unwrap()
  22     );
  23
  24     // Since DerivedArgs implements FromArgMatches, we can extract it from the unstructured ArgMatches.
  25     // This is the main benefit of using derived arguments.
  26     let derived_matches = DerivedArgs::from_arg_matches(&matches)
  27         .map_err(|err| err.exit())
  28         .unwrap();
  29     println!("Value of derived: {:#?}", derived_matches);
  30 }