trait Vehicle  {
    fn test(&self) {
        println!("Test {}", 
            std::any::type_name::<Self>())
    }
}

struct Car;
struct Truck;

impl Vehicle for Car{}
impl Vehicle for Truck{}

let rows: [Box<dyn Vehicle>; 2] = [
    Box::new(Car{}),
    Box::new(Truck{})
];

for vehicle in rows {
    vehicle.test();
}