clap/examples/tutorial_builder/05_01_assert.rs

24 lines
557 B
Rust

use clap::{app_from_crate, arg};
fn main() {
let matches = app().get_matches();
// Note, it's safe to call unwrap() because the arg is required
let port: usize = matches
.value_of_t("PORT")
.expect("'PORT' is required and parsing will fail if its missing");
println!("PORT = {}", port);
}
fn app() -> clap::App<'static> {
app_from_crate!().arg(
arg!(<PORT>)
.help("Network port to use")
.validator(|s| s.parse::<usize>()),
)
}
#[test]
fn verify_app() {
app().debug_assert();
}