Macro bail_out::ensure

macro_rules! ensure {
    ($cond:expr, $error:expr) => { ... };
}

Return early with an error if the condition is false. This ensures the condition is met. This macro is equivalent to if !cond { return Err(error) }. Example:

use bail_out::*;
fn test_err() -> Result<(), &'static str> {
   ensure!(false, "error");
   Ok(())
}
assert_eq!(test_err(), Err("error"));

fn test_ok() -> Result<(), &'static str> {
   ensure!(true, "ok");
   Ok(())
}
assert_eq!(test_ok(), Ok(()));