04_02_parse_derive/
04_02_parse.rsuse clap::Parser;
#[derive(Parser)]
#[command(version, about, long_about = None)]
struct Cli {
#[arg(value_parser = clap::value_parser!(u16).range(1..))]
port: u16,
}
fn main() {
let cli = Cli::parse();
println!("PORT = {}", cli.port);
}