// https://google.github.io/comprehensive-rust/smart-pointers/trait-objects.html

struct Dog {
    name: String,
    age: i8,
}
struct Cat {
    lives: i8,
}

trait Pet {
    fn talk(&self) -> String;
}

impl Pet for Dog {
    fn talk(&self) -> String {
        format!("Woof, my name is {}!", self.name)
    }
}

impl Pet for Cat {
    fn talk(&self) -> String {
        String::from("Miau!")
    }
}

pub fn run() {
    println!("\ntrait_obj (Google Kurs comprehensive-rust)");
    println!(
        "{} {}",
        std::mem::size_of::<Dog>(),
        std::mem::size_of::<Cat>()
    );
    println!(
        "{} {}",
        std::mem::size_of::<&Dog>(),
        std::mem::size_of::<&Cat>()
    );
    println!("{}", std::mem::size_of::<&dyn Pet>());
    println!("{}", std::mem::size_of::<Box<dyn Pet>>());
    let pets: Vec<Box<dyn Pet>> = vec![
        Box::new(Cat { lives: 9 }),
        Box::new(Dog {
            name: String::from("Fido"),
            age: 5,
        }),
    ];
    for pet in pets {
        println!("Hello, who are you? {}", pet.talk());
    }
}