Macro assertables::assertable_f_lt

macro_rules! assertable_f_lt {
    ($function:path, $left:expr, $right:expr $(,)?) => { ... };
    ($function:path, $left:expr, $right:expr, $($arg:tt)+) => { ... };
}

Assert one function output is less than anoter.

• When true, return Ok(()).

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

Examples

let x = assertable_f_lt!(i32::abs, 1 as i32, -2 as i32);
//-> Ok(())
assert_eq!(x.unwrap(), ());

let x = assertable_f_lt!(i32::abs, -2 as i32, 1 as i32);
//-> Err("…")
// assertable failed: `assertable_f_lt!(function, left, right)`
//      function: `\"i32::abs\"`,
//    left input: `-2`,
//   right input: `1`,
//   left output: `2`,
//  right output: `1`
assert_eq!(x.unwrap_err(), "assertable failed: `assertable_f_lt!(function, left, right)`\n     function: `\"i32::abs\"`,\n   left input: `-2`,\n  right input: `1`,\n  left output: `2`,\n right output: `1`".to_string());

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