quest – Rust: Traits & generics

Core Intermediate

10 Traits & generics

Traits are Rust's interfaces; generics let one function serve many types. Give a trait a default method, then write a generic 'largest'.

Step 1 / 2

Give the Animal trait a default greet body returning "Hi, I'm <name>".

Hints

A trait can supply a default body that impls inherit for free.
format!("Hi, I'm {}", self.name()).

10_traits_generics.rs

trait Animal {
    fn name(&self) -> String;

    // default body: returns "Hi, I'm <name>"
    fn greet(&self) -> String {
        todo!()
    }
}

struct Dog;
impl Animal for Dog {
    fn name(&self) -> String { String::from("Rex") }
}

Reset to starterCompiled in a sandbox; hidden checks must pass.

Reveal solution

trait Animal {
    fn name(&self) -> String;

    fn greet(&self) -> String {
        format!("Hi, I'm {}", self.name())
    }
}

struct Dog;
impl Animal for Dog {
    fn name(&self) -> String { String::from("Rex") }
}