03_01_flag_count_derive/
03_01_flag_count.rsuse clap::Parser;
#[derive(Parser)]
#[command(version, about, long_about = None)]
struct Cli {
#[arg(short, long, action = clap::ArgAction::Count)]
verbose: u8,
}
fn main() {
let cli = Cli::parse();
println!("verbose: {:?}", cli.verbose);
}