mini_math/
nearly_equal.rs

1/// Compare floating-point values using an epsilon
2pub trait NearlyEqual {
3    fn nearly_equals(self, rhs: Self) -> bool;
4}
5
6impl NearlyEqual for f32 {
7    fn nearly_equals(self, rhs: Self) -> bool {
8        (self - rhs).abs() < std::f32::EPSILON
9    }
10}
11
12impl<T> NearlyEqual for Option<T>
13where
14    T: NearlyEqual,
15{
16    fn nearly_equals(self, rhs: Self) -> bool {
17        match (self, rhs) {
18            (Some(a), Some(b)) => a.nearly_equals(b),
19            (None, None) => true,
20            _ => false,
21        }
22    }
23}
24
25/// Asserts that two expressions are nearly equal to each other (using [`NearlyEqual`]).
26#[macro_export]
27macro_rules! assert_nearly_eq {
28    ($left:expr, $right:expr) => {{
29        if !($left.nearly_equals($right)) {
30            panic!(
31                "assertion failed: `(left == right)`\nleft: `{:?}`,\nright: `{:?}`",
32                $left, $right
33            )
34        }
35    }};
36}