trait Foo {
    fn something(&self) {
        self.method();
    }

    fn method(&self);
}

impl Foo for String {
    fn method(&self) {
        println!("In String");
    }
}

impl Foo for i32 {
    fn method(&self) {
        println!("In i32");
    }
}

fn main() {
    let x = String::new();
    use_impl_trait(&x);
    use_trait_object(&x);
    use_trait_object_by_box(Box::new(&x));
    use_trait_object_by_dyn(&x);

    let x: i32 = 0;
    use_impl_trait(&x);
    use_trait_object(&x);
    use_trait_object_by_box(Box::new(&x));
    use_trait_object_by_dyn(&x);
}

fn use_impl_trait(f: &impl Foo) {
    println!("Use Impl Trait");
    f.something();
}

fn use_trait_object(f: &Foo) {
    println!("Use Trait Object");
    f.something();
}

fn use_trait_object_by_box(b: Box<&Foo>) {
    println!("Use Trait Object By Box");
    b.something();
}

fn use_trait_object_by_dyn(f: &dyn Foo) {
    println!("Use Trait Object By Dyn");
    f.something();
}