src/bin/tut4.rs

// Generic Programming: Dynamic Polymorphism

#![allow(dead_code)]
#![allow(unused_imports)]

use rust_tutorial::*;

fn stringify_all(xs: Vec<&dyn ToString>) -> String {
    let strings: Vec<String> =
        xs.iter().map(|x| x.to_string()).collect();

    strings.join(", ")
}

fn main() {
    let mut stringlike_things: Vec<&dyn ToString> = Vec::new();

    let x1 = "abc";
    let x2 = 100;
    let x3 = Person { age: 30, name: "Mary".to_string() };

    stringlike_things.push(&x1);
    stringlike_things.push(&x2);
    stringlike_things.push(&x3);

    println!("{}", stringify_all(stringlike_things));
}