enum Shape {
    Rectangle,
    Square,
}

struct Quadrilateral<T> {
    width: T,
    height: T,
    shape: Shape,
}

fn main(){
    // Instanciamos un struct Quadrilateral
    let rectangle_one = Quadrilateral{width: 200, height: 200, shape: Shape::Rectangle};
    let rectangle_two = Quadrilateral{width: -100, height: -200, shape: Shape::Square };
}