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
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
|
use core::iter::*;
#[test]
fn test_fuse_nth() {
let xs = [0, 1, 2];
let mut it = xs.iter();
assert_eq!(it.len(), 3);
assert_eq!(it.nth(2), Some(&2));
assert_eq!(it.len(), 0);
assert_eq!(it.nth(2), None);
assert_eq!(it.len(), 0);
}
#[test]
fn test_fuse_last() {
let xs = [0, 1, 2];
let it = xs.iter();
assert_eq!(it.len(), 3);
assert_eq!(it.last(), Some(&2));
}
#[test]
fn test_fuse_count() {
let xs = [0, 1, 2];
let it = xs.iter();
assert_eq!(it.len(), 3);
assert_eq!(it.count(), 3);
// Can't check len now because count consumes.
}
#[test]
fn test_fuse_fold() {
let xs = [0, 1, 2];
let it = xs.iter(); // `FusedIterator`
let i = it.fuse().fold(0, |i, &x| {
assert_eq!(x, xs[i]);
i + 1
});
assert_eq!(i, xs.len());
let it = xs.iter(); // `FusedIterator`
let i = it.fuse().rfold(xs.len(), |i, &x| {
assert_eq!(x, xs[i - 1]);
i - 1
});
assert_eq!(i, 0);
let it = xs.iter().scan((), |_, &x| Some(x)); // `!FusedIterator`
let i = it.fuse().fold(0, |i, x| {
assert_eq!(x, xs[i]);
i + 1
});
assert_eq!(i, xs.len());
}
#[test]
fn test_fuse() {
let mut it = 0..3;
assert_eq!(it.len(), 3);
assert_eq!(it.next(), Some(0));
assert_eq!(it.len(), 2);
assert_eq!(it.next(), Some(1));
assert_eq!(it.len(), 1);
assert_eq!(it.next(), Some(2));
assert_eq!(it.len(), 0);
assert_eq!(it.next(), None);
assert_eq!(it.len(), 0);
assert_eq!(it.next(), None);
assert_eq!(it.len(), 0);
assert_eq!(it.next(), None);
assert_eq!(it.len(), 0);
}
|
