src/test/run-pass/class-impl-very-parameterized-trait.rs

   1 // Copyright 2012-2014 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
  12 use std::cmp;
  13
  14 #[derive(Copy, Debug)]
  15 enum cat_type { tuxedo, tabby, tortoiseshell }
  16
  17 impl cmp::PartialEq for cat_type {
  18     fn eq(&self, other: &cat_type) -> bool {
  19         ((*self) as uint) == ((*other) as uint)
  20     }
  21     fn ne(&self, other: &cat_type) -> bool { !(*self).eq(other) }
  22 }
  23
  24 // Very silly -- this just returns the value of the name field
  25 // for any int value that's less than the meows field
  26
  27 // ok: T should be in scope when resolving the trait ref for map
  28 struct cat<T> {
  29     // Yes, you can have negative meows
  30     meows : int,
  31
  32     how_hungry : int,
  33     name : T,
  34 }
  35
  36 impl<T> cat<T> {
  37     pub fn speak(&mut self) { self.meow(); }
  38
  39     pub fn eat(&mut self) -> bool {
  40         if self.how_hungry > 0 {
  41             println!("OM NOM NOM");
  42             self.how_hungry -= 2;
  43             return true;
  44         } else {
  45             println!("Not hungry!");
  46             return false;
  47         }
  48     }
  49     fn len(&self) -> uint { self.meows as uint }
  50     fn is_empty(&self) -> bool { self.meows == 0 }
  51     fn clear(&mut self) {}
  52     fn contains_key(&self, k: &int) -> bool { *k <= self.meows }
  53
  54     fn find(&self, k: &int) -> Option<&T> {
  55         if *k <= self.meows {
  56             Some(&self.name)
  57         } else {
  58             None
  59         }
  60     }
  61     fn insert(&mut self, k: int, _: T) -> bool {
  62         self.meows += k;
  63         true
  64     }
  65
  66     fn find_mut(&mut self, _k: &int) -> Option<&mut T> { panic!() }
  67
  68     fn remove(&mut self, k: &int) -> bool {
  69         if self.find(k).is_some() {
  70             self.meows -= *k; true
  71         } else {
  72             false
  73         }
  74     }
  75
  76     fn pop(&mut self, _k: &int) -> Option<T> { panic!() }
  77
  78     fn swap(&mut self, _k: int, _v: T) -> Option<T> { panic!() }
  79 }
  80
  81 impl<T> cat<T> {
  82     pub fn get(&self, k: &int) -> &T {
  83         match self.find(k) {
  84           Some(v) => { v }
  85           None    => { panic!("epic fail"); }
  86         }
  87     }
  88
  89     pub fn new(in_x: int, in_y: int, in_name: T) -> cat<T> {
  90         cat{meows: in_x, how_hungry: in_y, name: in_name }
  91     }
  92 }
  93
  94 impl<T> cat<T> {
  95     fn meow(&mut self) {
  96         self.meows += 1;
  97         println!("Meow {}", self.meows);
  98         if self.meows % 5 == 0 {
  99             self.how_hungry += 1;
 100         }
 101     }
 102 }
 103
 104 pub fn main() {
 105     let mut nyan: cat<String> = cat::new(0, 2, "nyan".to_string());
 106     for _ in 1_usize..5 { nyan.speak(); }
 107     assert!(*nyan.find(&1).unwrap() == "nyan".to_string());
 108     assert_eq!(nyan.find(&10), None);
 109     let mut spotty: cat<cat_type> = cat::new(2, 57, cat_type::tuxedo);
 110     for _ in 0_usize..6 { spotty.speak(); }
 111     assert_eq!(spotty.len(), 8);
 112     assert!((spotty.contains_key(&2)));
 113     assert_eq!(spotty.get(&3), &cat_type::tuxedo);
 114 }