src/test/ui/range_inclusive.rs

   1 // run-pass
   2 // Test inclusive range syntax.
   3 #![feature(range_is_empty)]
   4 #![allow(unused_braces)]
   5 #![allow(unused_comparisons)]
   6
   7 use std::ops::RangeToInclusive;
   8
   9 fn foo() -> isize { 42 }
  10
  11 // Test that range syntax works in return statements
  12 pub fn return_range_to() -> RangeToInclusive<i32> { return ..=1; }
  13
  14 #[derive(Debug)]
  15 struct P(u8);
  16
  17 pub fn main() {
  18     let mut count = 0;
  19     for i in 0_usize..=10 {
  20         assert!(i >= 0 && i <= 10);
  21         count += i;
  22     }
  23     assert_eq!(count, 55);
  24
  25     let mut count = 0;
  26     let range = 0_usize..=10;
  27     for i in range {
  28         assert!(i >= 0 && i <= 10);
  29         count += i;
  30     }
  31     assert_eq!(count, 55);
  32
  33     let mut count = 0;
  34     for i in (0_usize..=10).step_by(2) {
  35         assert!(i >= 0 && i <= 10 && i % 2 == 0);
  36         count += i;
  37     }
  38     assert_eq!(count, 30);
  39
  40     let _ = 0_usize..=4+4-3;
  41     let _ = 0..=foo();
  42
  43     let _ = { &42..=&100 }; // references to literals are OK
  44     let _ = ..=42_usize;
  45
  46     // Test we can use two different types with a common supertype.
  47     let x = &42;
  48     {
  49         let y = 42;
  50         let _ = x..=&y;
  51     }
  52
  53     // test collection indexing
  54     let vec = (0..=10).collect::<Vec<_>>();
  55     let slice: &[_] = &*vec;
  56     let string = String::from("hello world");
  57     let stir = "hello world";
  58
  59     assert_eq!(&vec[3..=6], &[3, 4, 5, 6]);
  60     assert_eq!(&vec[ ..=6], &[0, 1, 2, 3, 4, 5, 6]);
  61
  62     assert_eq!(&slice[3..=6], &[3, 4, 5, 6]);
  63     assert_eq!(&slice[ ..=6], &[0, 1, 2, 3, 4, 5, 6]);
  64
  65     assert_eq!(&string[3..=6], "lo w");
  66     assert_eq!(&string[ ..=6], "hello w");
  67
  68     assert_eq!(&stir[3..=6], "lo w");
  69     assert_eq!(&stir[ ..=6], "hello w");
  70
  71     // test the size hints and emptying
  72     let mut long = 0..=255u8;
  73     let mut short = 42..=42u8;
  74     assert_eq!(long.size_hint(), (256, Some(256)));
  75     assert_eq!(short.size_hint(), (1, Some(1)));
  76     long.next();
  77     short.next();
  78     assert_eq!(long.size_hint(), (255, Some(255)));
  79     assert_eq!(short.size_hint(), (0, Some(0)));
  80     assert!(short.is_empty());
  81
  82     assert_eq!(long.len(), 255);
  83     assert_eq!(short.len(), 0);
  84
  85     // test iterating backwards
  86     assert_eq!(long.next_back(), Some(255));
  87     assert_eq!(long.next_back(), Some(254));
  88     assert_eq!(long.next_back(), Some(253));
  89     assert_eq!(long.next(), Some(1));
  90     assert_eq!(long.next(), Some(2));
  91     assert_eq!(long.next_back(), Some(252));
  92     for i in 3..=251 {
  93         assert_eq!(long.next(), Some(i));
  94     }
  95     assert!(long.is_empty());
  96
  97     // check underflow
  98     let mut narrow = 1..=0;
  99     assert_eq!(narrow.next_back(), None);
 100     assert!(narrow.is_empty());
 101     let mut zero = 0u8..=0;
 102     assert_eq!(zero.next_back(), Some(0));
 103     assert_eq!(zero.next_back(), None);
 104     assert!(zero.is_empty());
 105     let mut high = 255u8..=255;
 106     assert_eq!(high.next_back(), Some(255));
 107     assert_eq!(high.next_back(), None);
 108     assert!(high.is_empty());
 109
 110     // what happens if you have a nonsense range?
 111     let mut nonsense = 10..=5;
 112     assert_eq!(nonsense.next(), None);
 113     assert!(nonsense.is_empty());
 114
 115     // output
 116     assert_eq!(format!("{:?}", 0..=10), "0..=10");
 117     assert_eq!(format!("{:?}", ..=10), "..=10");
 118     assert_eq!(format!("{:?}", 9..=6), "9..=6");
 119
 120     // ensure that constructing a RangeInclusive does not need PartialOrd bound
 121     assert_eq!(format!("{:?}", P(1)..=P(2)), "P(1)..=P(2)");
 122 }