1 use clap::{Parser, ValueEnum};
2
3 #[derive(Parser)]
4 #[command(author, version, about, long_about = None)]
5 struct Cli {
6 /// What mode to run the program in
7 #[arg(value_enum)]
8 mode: Mode,
9 }
10
11 #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, ValueEnum)]
12 enum Mode {
13 /// Run swiftly
14 Fast,
15 /// Crawl slowly but steadily
16 ///
17 /// This paragraph is ignored because there is no long help text for possible values.
18 Slow,
19 }
20
main()21 fn main() {
22 let cli = Cli::parse();
23
24 match cli.mode {
25 Mode::Fast => {
26 println!("Hare");
27 }
28 Mode::Slow => {
29 println!("Tortoise");
30 }
31 }
32 }
33