gistfile1.rs

#[allow(default_methods)]
trait Speak {
    fn say(&self, s:&str);
    fn hi(&self) { hello(self); }
}

fn hello<S:Speak>(s:&S) {
    s.say("hello");
}

impl Speak for int {
    fn say(&self, s:&str) {
        println(fmt!("%s: %d", s, *self));
    }
}

impl<T: Speak> Speak for Option<T> {
    fn say(&self, s:&str) {
        match *self {
            None => println(fmt!("%s to nobody", s)),
            Some(ref x) => { println("something!"); x.say(s); }
        }
    }
}


fn main() {
    3.hi();
    Some(3).hi();
}