trait Dimension {
   fn volume(&self) -> f64;
 }

 struct Sphere {
   radius: f64
 }

 impl Dimension for Sphere {
   fn volume(&self) -> f64 {
     4.0/3.0 * std::f64::consts::PI * cubic(self.radius)
   }
 }

 struct Cube {
   side: f64
 }

 impl Dimension for Cube {
   fn volume(&self) -> f64 {
     cubic(self.side)
   }
 }

 fn print_volume<T: Dimension>(obj: T) {
   println!("Das Objekt hat das Volumen von {}", obj.volume());
 }

 fn cubic(x: f64) -> f64 {
   x * x * x
 }

 fn main() {
   print_volume(Sphere { radius: 1.0});
   print_volume(Cube { side: 1.0 });
 }