Macro assert_float_eq 

macro_rules! assert_float_eq {
    ($left:expr, $right:expr, $eq1:ident <= $tol_1:expr, $eq2:ident <= $tol_2:expr, $eq3:ident <= $tol_3:expr) => { ... };
    ($left:expr, $right:expr, $eq1:ident <= $tol_1:expr, $eq2:ident <= $tol_2:expr) => { ... };
    ($left:expr, $right:expr, $eq1:ident <= $tol_1:expr) => { ... };
    ($left:expr, $right:expr, $($eq:ident <= $tol:expr,)+) => { ... };
    ($left:expr, $right:expr, $eq1:ident <= $tol_1:expr, $eq2:ident <= $tol_2:expr, $eq3:ident <= $tol_3:expr, $($arg:tt)+) => { ... };
    ($left:expr, $right:expr, $eq1:ident <= $tol_1:expr, $eq2:ident <= $tol_2:expr, $($arg:tt)+) => { ... };
    ($left:expr, $right:expr, $eq1:ident <= $tol_1:expr, $($arg:tt)+) => { ... };
}

Asserts that two floating point expressions are equal to each other.

See the top level documentation for a list of available comparison algorithms.

On panic, this macro will print the values of the expressions with their debug representations, with additional information from the comparison operations. Like assert!, this macro has a second form, where a custom panic message can be provided.

Examples

let a: f32 = 4.0;
let b: f32 = 4.000_002_5;

assert_float_eq!(a, b, ulps <= 10);
assert_float_eq!(a, 3.999_999_6, rmax <= 2.0 * f32::EPSILON);
assert_float_eq!(a - b, 0.0, abs <= 0.000_01, "Checking that {} == {}", a, b);