I want to use clap_app!
macro to define an argument which should have a default value. Unfortunately, there is nothing in the docs, and my naive attempt didn't work:
#[macro_use]
extern crate clap;
fn main() {
let matches = clap_app!(myapp =>
(@arg seconds: -u +takes_value +default_value("1.0") "Update time")
).get_matches();
println!("{}", matches.value_of("seconds").unwrap())
}
How can I specify a default value for an argument within clap_app!
macro?
This is currently impossible with number, https://github.com/kbknapp/clap-rs/issues/1035.
But it's should be:
(@arg seconds: -u +takes_value default_value[1.0] "Update time")