Macro assert_relative_eq 

macro_rules! assert_relative_eq {
    ($left:expr, $right:expr) => { ... };
    ($left:expr, $right:expr, $epsilon:expr) => { ... };
}

This macros assert that two values are close to each other.

Examples

assert_relative_eq!(1.0_f64, 1.0);
assert_relative_eq!(1.0_f64, 1.000000001, 1e-7);

assert_relative_eq!(2.0_f64, 1.0);

assert_relative_eq!(1.0_f64, 1.000001, 1e-7);