src/test/run-pass/bug-7183-generics.rs

   1 // Copyright 2013 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 trait Speak : Sized {
  12     fn say(&self, s:&str) -> String;
  13     fn hi(&self) -> String { hello(self) }
  14 }
  15
  16 fn hello<S:Speak>(s:&S) -> String{
  17     s.say("hello")
  18 }
  19
  20 impl Speak for int {
  21     fn say(&self, s:&str) -> String {
  22         format!("{}: {}", s, *self)
  23     }
  24 }
  25
  26 impl<T: Speak> Speak for Option<T> {
  27     fn say(&self, s:&str) -> String {
  28         match *self {
  29             None => format!("{} - none", s),
  30             Some(ref x) => { format!("something!{}", x.say(s)) }
  31         }
  32     }
  33 }
  34
  35
  36 pub fn main() {
  37     assert_eq!(3.hi(), "hello: 3".to_string());
  38     assert_eq!(Some(Some(3)).hi(),
  39                "something!something!hello: 3".to_string());
  40     assert_eq!(None::<int>.hi(), "hello - none".to_string());
  41
  42     assert_eq!(Some(None::<int>).hi(), "something!hello - none".to_string());
  43     assert_eq!(Some(3).hi(), "something!hello: 3".to_string());
  44 }