Function lerp 

pub fn lerp<'out, T, F>(
    out: &'out mut [T; 3],
    a: &[T; 3],
    b: &[T; 3],
    t: &F,
) -> &'out mut [T; 3]
where
    for<'a> T: Clone + Cast<F> + AddAssign<&'a T>,
    for<'a> F: Clone + Cast<T> + MulAssign<&'a F>,
    for<'a, 'b> &'a T: Sub<&'b T, Output = T>,

Example

let mut v = vec3::new_zero();
vec3::lerp(&mut v, &vec3::new_zero(), &[100; 3], &0.5);
assert_eq!(v, [50; 3]);