Code shared from the Rust Playground

playground.rs

trait Show {
    fn show(&self) -> String;
}

impl Show for i32 {
    fn show(&self) -> String {
        format!("4 byte signed: {}", self)
    }
}

impl Show for f64 {
    fn show(&self) -> String {
        format!("8 byte float: {}", self)
    }
}


fn main() {
    let answer = Box::new(42);
    let maybe_pi = Box::new(3.14);
    let show_list: Vec<Box<dyn Show>> = vec![answer, maybe_pi];
    for d in show_list.iter() {
        println!("show {}", d.show());
    }
}