Code shared from the Rust Playground

playground.rs

trait A {
    fn greet(&self) {
        println!("Hi! I am {}!", self.name());
    }
    
    fn name(&self) -> &str {
        "A"
    }
}

trait B: A {
    fn name(&self) -> &str {
        "B"
    } 
}

struct X {
    name: &'static str,
}

struct Y {}

impl A for X {}
impl B for X {
    fn name(&self) -> &str {
        self.name
    } 
}

impl A for Y {}
impl B for Y {}

fn greet<T: B>(t: &T) {
    t.greet();
}

fn main() {
    let x = X { name: "X" };
    let y = Y {};
    
    greet(&x);
    greet(&y);
    
    println!("{}", A::name(&x));
    println!("{}", B::name(&x));

    println!("{}", A::name(&y));
    println!("{}", B::name(&y));
}