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// Copyright 2013 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
trait Speak {
fn say(&self, s:&str) -> String;
fn hi(&self) -> String { hello(self) }
}
fn hello<S:Speak>(s:&S) -> String{
s.say("hello")
}
impl Speak for int {
fn say(&self, s:&str) -> String {
format!("{}: {}", s, *self)
}
}
impl<T: Speak> Speak for Option<T> {
fn say(&self, s:&str) -> String {
match *self {
None => format!("{} - none", s),
Some(ref x) => { format!("something!{}", x.say(s)) }
}
}
}
pub fn main() {
assert_eq!(3i.hi(), "hello: 3".to_string());
assert_eq!(Some(Some(3i)).hi(),
"something!something!hello: 3".to_string());
assert_eq!(None::<int>.hi(), "hello - none".to_string());
assert_eq!(Some(None::<int>).hi(), "something!hello - none".to_string());
assert_eq!(Some(3i).hi(), "something!hello: 3".to_string());
}
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