clap/examples/tutorial_builder/04_01_possible.rs
Ed Page befee6667b docs: Re-work examples
This creates distinct tutorial examples from complex feature examples
(more how-tos).  Both sets are getting builder / derive versions (at
least the critical ones).
2021-11-30 21:33:52 -06:00

25 lines
619 B
Rust

use clap::{app_from_crate, arg};
fn main() {
let matches = app_from_crate!()
.arg(
arg!(<MODE>)
.help("What mode to run the program in")
.possible_values(["fast", "slow"]),
)
.get_matches();
// Note, it's safe to call unwrap() because the arg is required
match matches
.value_of("MODE")
.expect("'MODE' is required and parsing will fail if its missing")
{
"fast" => {
println!("Hare");
}
"slow" => {
println!("Tortoise");
}
_ => unreachable!(),
}
}