Polymorphism with function calls in Rust

polymorphism-boxes.rs

struct Chat;
struct Chien;

trait Bruiteur {
  fn bruit(&self) -> &str;
}

impl Bruiteur for Chat {
  fn bruit(&self) -> &str {
    "Nyan"
  }
}

impl Bruiteur for Chien {
  fn bruit(&self) -> &str {
    "Woof"
  }
}

fn main() {
  let animaux : Vec<Box<dyn Bruiteur>> = vec![Box::new(Chat), Box::new(Chien)];
  
  for x in animaux {
    println!("{}", x.bruit());
  }
}

polymorphism-enum.rs

enum Animal {
  Chat(String),
  Chien(String, i32)
}

fn describe(x: Animal) -> String {
  match x {
    Animal::Chat(name) => format!("{} is a cat", name),
    Animal::Chien(name, weight) => format!("{} is a dog and weights {} pounds", name, weight),
  }
}

fn main() {
  let mut v: Vec<Animal> = Vec::new();

  v.push(Animal::Chat(String::from("Oreo")));
  v.push(Animal::Chien(String::from("Spot"), 20));
  
  for x in v {
    println!("{}", describe(x));
  }
}

polymorphism-references.rs

struct Chat;
struct Chien;

trait Bruiteur {
  fn bruit(&self) -> &str;
}

impl Bruiteur for Chat {
  fn bruit(&self) -> &str {
    "Nyan"
  }
}

impl Bruiteur for Chien {
  fn bruit(&self) -> &str {
    "Woof"
  }
}

fn main() {
  let mut v: Vec<&mut Bruiteur> = Vec::new();
  let mut chat = Chat;
  let mut chien = Chien;
  v.push(&mut chat);
  v.push(&mut chien);
  
  for x in v {
    println!("{}", x.bruit());
  }
}