Macro bail 

macro_rules! bail {
    ($($arg:tt)*) => { ... };
}

Return early with an XXError

This macro is equivalent to return Err(error!(...)).

Example

use xx::bail;

fn validate(value: i32) -> xx::XXResult<()> {
    if value < 0 {
        bail!("Value must be non-negative, got {}", value);
    }
    Ok(())
}