File: class-cast-to-trait.rs

package info (click to toggle)
rustc-web 1.78.0%2Bdfsg1-2~deb12u3
  • links: PTS, VCS
  • area: main
  • in suites: bookworm
  • size: 1,245,420 kB
  • sloc: xml: 147,985; javascript: 18,022; sh: 11,083; python: 10,265; ansic: 6,172; cpp: 5,023; asm: 4,390; makefile: 4,269
file content (60 lines) | stat: -rw-r--r-- 988 bytes parent folder | download | duplicates (6)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
//@ run-pass
#![allow(dead_code)]
#![allow(unused_mut)]
#![allow(non_camel_case_types)]

//@ ignore-freebsd FIXME fails on BSD


trait noisy {
  fn speak(&mut self);
}

struct cat {
  meows: usize,
  how_hungry: isize,
  name: String,
}

impl noisy for cat {
  fn speak(&mut self) { self.meow(); }
}

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 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
    }
}


pub fn main() {
    let mut nyan = cat(0, 2, "nyan".to_string());
    let mut nyan: &mut dyn noisy = &mut nyan;
    nyan.speak();
}