#![allow(dead_code, deprecated, unused_variables, unused_mut)]
fn main() {
    let mut s = Some(String::from("Hello"));
    let o: Option<&mut String> = Option::from(&mut s);
    match o {
        Some(t) => *t = String::from("Hello, Rustaceans!"),
        None => {}
    }
    assert_eq!(s, Some(String::from("Hello, Rustaceans!")));
}