Enum to represent exit status

• We define a type called ExitCode that has two variants: Success and Failure.

• We can then, based on the results of our porgram set the value of exit.

• However, this is a bit limited as we can only indicate failure without the details we are used to - which is a number.

• By default Rust does not implement the Debug trait for an arbitrary enum so we derive from the Debug trait to be able to print the values using the :? placeholder.

• We can also observe that if-statements can have a return value.

#[derive(Debug)]
enum ExitCode {
    Success,
    Failure,
}

fn main() {
    let args = std::env::args().collect::<Vec<_>>();
    let exit = if args.len() > 1 {
        ExitCode::Success
    } else {
        ExitCode::Failure
    };

    println!("{exit:?}");
}