Macro axerrno::ensure

macro_rules! ensure {
    ($predicate:expr, $context_selector:expr $(,)?) => { ... };
}

Ensure a condition is true. If it is not, return from the function with an error.

Examples

fn example(user_id: i32) -> AxResult {
    ensure!(user_id > 0, ax_err!(InvalidInput));
    // After this point, we know that `user_id` is positive.
    let user_id = user_id as u32;
    Ok(())
}