Macro assertables::assertable

macro_rules! assertable {
    ($x:expr $(,)?) => { ... };
    ($x:expr, $($arg:tt)+) => { ... };
}

Assert a condition is true.

• When true, return Ok(()).

• Otherwise, return Err with a message and the values of the expressions with their debug representations.

Examples

let x = assertable!(true);
//-> Ok(())
assert_eq!(x.unwrap(), ());

let x = assertable!(false);
//-> Err("…")
// assertable failed: `assertable!(condition)`
//  condition: `false`
assert_eq!(x.unwrap_err(), "assertable failed: `assertable!(condition)`\n condition: `false`".to_string());

This macro has a second form where a custom message can be provided.