Rust traits

Traits are similar to interfaces except they can have a default implementation.

Basics

struct Cat { name: String }
struct Dog { name: String, breed: String }

// all implementors of 'Pet' must have method 'play' with this method signature
trait Pet {
    fn play(&self);
}


impl Pet for Cat {
    fn play(&self) {
        println!("you give a ball of yarn to {}", self.name)
    }
}

// use trait as param type
fn play_with_pet(pet: &impl Pet) {
    pet.play();
}

fn main(){
    let cat = Cat{name: "maize".to_string()};
    let dog = Dog{name: "midnight".to_string(), breed: "?".to_string()};
    play_with_pet(&cat);
    play_with_pet(&dog);
}