Code shared from the Rust Playground

playground.rs

extern crate rand;
use rand::Rng;
// use std::str;
// use std::string; // .to_string() is already impl on u8

fn main() {
    let mut rng = rand::thread_rng();
    let robot = rng.gen::<u8>().to_string();
    let greeting: &str = &(format!("Hello, {}!", robot));
    print(greeting);
}

fn print(input_string: &str) {
    println!("{}", input_string);
}