Inheritance in Rust in Rust

struct Puppy {
    dog: Dog,
}
impl Puppy {
    fn new(name: &str) -> Puppy {
        Puppy { dog: Dog::new(name) }
    }
    fn whine(&self) { println!("whimper"); }
}

Full lesson:

Inheritance is one of the four classic OOP pillars (along with encapsulation, polymorphism, and abstraction). The idea is simple: most real-world things are kinds of other things — a Puppy is a Dog, a Car is a Vehicle, a Manager is an Employee. When you model that "is-a" relationship in code, the child class gets the parent's data and behavior automatically.

What gets inherited?

• Fields — the Puppy has a name field even though we only declared it on Dog.
• Methods — the Puppy can call bark() even though we only defined it on Dog.
• The contract — anywhere code expects a Dog, you can pass a Puppy (we'll see this when we cover polymorphism).

What you still write

• The constructor usually has to forward arguments up to the parent's constructor (because the parent's fields need initializing).
• Any new methods or new fields specific to the child.

Your task

Below the Dog struct, create a Puppy struct that wraps a Dog and adds one new method, whine(), that prints "whimper". The harness creates a Puppy named "Buddy", calls its inherited bark(), and then its new whine().

Expected output:

Woof! I am Buddy
whimper