xisf/
Math.rs

1pub fn RoundInt(x: f64) -> i32 {
2    union MyUnion {
3        d: f64,
4        i: i32,
5    }
6
7    assert!(x >= (i32::MIN as f64) && x <= (i32::MAX as f64));
8    let v = MyUnion {
9        d: x + 6755399441055744.0,
10    };
11    unsafe { v.i } // ### NB: Assuming little-endian architecture.
12}
13
14pub fn IsFinite(x: f64) -> bool {
15    x.is_finite()
16}
17
18pub fn IsNegativeZero(x: f64) -> bool {
19    x == -0.0
20}
21
22#[cfg(test)]
23mod tests {
24    use crate::Math::RoundInt;
25
26    #[test]
27    fn test_round_int() {
28        assert!(RoundInt(0.5) == 0);
29        assert!(RoundInt(0.2) == 0);
30        assert!(RoundInt(0.7) == 1);
31        assert!(RoundInt(1.5) == 2); // Note round to even
32    }
33}
xisf/Math.rs

xisf/
Math.rs
