Macro diverge::diverge

macro_rules! diverge {
    ($e:expr) => { ... };
}

Aborts the outer function if given Some by returning its value, or continues the function if given None. This is particularly useful for understandable extension injection site specification.

Example

fn reject_if_wrong_password(password: &str) -> Option<bool> {
    match password {
        "let_me_in" => None,
        _ => {
            // Hide the responsibility of recording the failure from `test_password()`
            record_failed_login_attempt();
            Some(false)
        },
    }
}

fn test_password(password: &str) -> bool {
    diverge!(reject_if_wrong_password(password));
    true
}