| trait Noisy { |
| fn speak(&mut self); |
| } |
| |
| struct Cat { |
| meows : usize, |
| |
| how_hungry : isize, |
| name : String, |
| } |
| |
| impl Cat { |
| pub fn eat(&mut 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(&mut self) { self.meow(); } |
| |
| } |
| |
| impl Cat { |
| fn meow(&mut 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<dyn Noisy> = Box::new(cat(0, 2, "nyan".to_string())) as Box<dyn Noisy>; |
| nyan.eat(); //~ ERROR no method named `eat` found |
| } |