enum/struct practice in rust

zoo.rs

#[derive(Debug)]
struct Dog {
  name: String
}

#[derive(Debug)]
struct Cat {
  name: String
}

#[derive(Debug)]
struct Human {
  name: String
}

impl Dog {
  fn new(name: &str) -> Dog {
    Dog {
      name: String::from(name)
    }
  }

  fn speak(&self) {
    println!("woof!");
  }
}

impl Cat {
  fn new(name: &str) -> Cat {
    Cat {
      name: String::from(name)
    }
  }

  fn speak(&self) {
    println!("meow!");
  }
}

impl Human {
  fn new(name: &str) -> Human {
    Human {
      name: String::from(name)
    }
  }

  fn speak(&self) {
    println!("hello!");
  }
}

#[derive(Debug)]
enum Animal {
  Dog(Dog),
  Cat(Cat),
  Human(Human)
}

impl Animal {
  fn speak(&self) {
    match self {
      Animal::Dog(d) => d.speak(),
      Animal::Cat(c) => c.speak(),
      Animal::Human(h) => h.speak()
    }
  }
}

fn main() {
  let spot = Animal::Dog(Dog::new("Spot"));
  let kitty_purry = Animal::Cat(Cat::new("Kitty Purry"));
  let alice = Animal::Human(Human::new("Alice"));
  spot.speak();
  kitty_purry.speak();
  alice.speak();
}