assertables

Macro assert_fn_err_lt

source 
macro_rules! assert_fn_err_lt {
    ($a_function:path, $a_param:expr, $b_function:path, $b_param:expr $(,)?) => { ... };
    ($a_function:path, $a_param:expr, $b_function:path, $b_param:expr, $($message:tt)+) => { ... };
    ($a_function:path, $b_function:path) => { ... };
    ($a_function:path, $b_function:path, $($message:tt)+) => { ... };
}
Expand description

Assert a function error is less than another.

  • If true, return ().

  • Otherwise, call panic! with a message and the values of the expressions with their debug representations.

§Examples

fn f(i: i8) -> Result<String, String> {
    match i {
        0..=9 => Ok(format!("{}", i)),
        _ => Err(format!("{:?} is out of range", i)),
    }
}

let a: i8 = 10;
let b: i8 = 20;
assert_fn_err_lt!(f, a, f, b);

let a: i8 = 20;
let b: i8 = 10;
assert_fn_err_lt!(f, a, f, b);
// assertion failed: `assert_fn_err_lt!(a_function, a_param, b_function, b_param)`
// https://docs.rs/assertables/8.9.0/assertables/macro.assert_fn_err_lt.html
//  a_function label: `f`,
//     a_param label: `a`,
//     a_param debug: `20`,
//  b_function label: `f`,
//     b_param label: `b`,
//     b_param debug: `10`,
//                 a: `\"20 is out of range\"`,
//                 b: `\"10 is out of range\"`

§Module macros