Macro vector 

macro_rules! vector {
    ($x:expr, $y:expr $(,)?) => { ... };
    ($x:expr, $y:expr, $z:expr $(,)?) => { ... };
    ($x:expr, $y:expr, $z:expr, $w:expr $(,)?) => { ... };
}

Creates new vector If number of elements is 2 => Vector2 is created. If number of elements is 3 => Vector3 is created. If number of elements is 4 => Vector4 is created.