clap/examples/tutorial_builder/03_03_positional.rs

// Note: this requires the `cargo` feature

use clap::{arg, command};

fn main() {
    let matches = command!().arg(arg!([NAME])).get_matches();

    println!(
        "NAME: {:?}",
        matches
            .get_one::<String>("NAME")
            .expect("matches definition")
    );
}