rust/src/test/ui/class-cast-to-trait.rs

65 lines
1.3 KiB
Rust

// Copyright 2012 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.
#![feature(box_syntax)]
trait noisy {
fn speak(&self);
}
struct cat {
meows : usize,
how_hungry : isize,
name : String,
}
impl cat {
pub fn eat(&self) -> bool {
if self.how_hungry > 0 {
println!("OM NOM NOM");
self.how_hungry -= 2;
return true;
}
else {
println!("Not hungry!");
return false;
}
}
}
impl noisy for cat {
fn speak(&self) { self.meow(); }
}
impl cat {
fn meow(&self) {
println!("Meow");
self.meows += 1;
if self.meows % 5 == 0 {
self.how_hungry += 1;
}
}
}
fn cat(in_x : usize, in_y : isize, in_name: String) -> cat {
cat {
meows: in_x,
how_hungry: in_y,
name: in_name
}
}
fn main() {
let nyan: Box<noisy> = box cat(0, 2, "nyan".to_string()) as Box<noisy>;
nyan.eat(); //~ ERROR no method named `eat` found
}