Code shared from the Rust Playground

str.rs

// https://play.rust-lang.org/?version=nightly&mode=debug&edition=2018&gist=09a4f12d1c599376037d00f054ac359f
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);
}