eg.rs

impl<'a> std::ops::Sub<Vec3> for &'a Vec3 {
    type Output = Vec3;
    fn sub(self, other: Vec3) -> Vec3 {
        let mut output = Vec3::new([0f64; 3]);
        for index in 0..3 {
            output.vector[index] = self.vector[index] - other.vector[index];
        }
        return output;
    }
}
impl<'a> std::ops::Sub<&'a Vec3> for Vec3 {
    type Output = Vec3;
    fn sub(self, other: &'a Vec3) -> Vec3 {
        let mut output = Vec3::new([0f64; 3]);
        for index in 0..3 {
            output.vector[index] = self.vector[index] - other.vector[index];
        }
        return output;
    }
}