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
|
use core::iter::*;
#[test]
fn test_cloned() {
let xs = [2, 4, 6, 8];
let mut it = xs.iter().cloned();
assert_eq!(it.len(), 4);
assert_eq!(it.next(), Some(2));
assert_eq!(it.len(), 3);
assert_eq!(it.next(), Some(4));
assert_eq!(it.len(), 2);
assert_eq!(it.next_back(), Some(8));
assert_eq!(it.len(), 1);
assert_eq!(it.next_back(), Some(6));
assert_eq!(it.len(), 0);
assert_eq!(it.next_back(), None);
}
#[test]
fn test_cloned_side_effects() {
let mut count = 0;
{
let iter = [1, 2, 3]
.iter()
.map(|x| {
count += 1;
x
})
.cloned()
.zip(&[1]);
for _ in iter {}
}
assert_eq!(count, 2);
}
#[test]
fn test_cloned_try_folds() {
let a = [1, 2, 3, 4, 5, 6, 7, 8, 9];
let f = &|acc, x| i32::checked_add(2 * acc, x);
let f_ref = &|acc, &x| i32::checked_add(2 * acc, x);
assert_eq!(a.iter().cloned().try_fold(7, f), a.iter().try_fold(7, f_ref));
assert_eq!(a.iter().cloned().try_rfold(7, f), a.iter().try_rfold(7, f_ref));
let a = [10, 20, 30, 40, 100, 60, 70, 80, 90];
let mut iter = a.iter().cloned();
assert_eq!(iter.try_fold(0_i8, |acc, x| acc.checked_add(x)), None);
assert_eq!(iter.next(), Some(60));
let mut iter = a.iter().cloned();
assert_eq!(iter.try_rfold(0_i8, |acc, x| acc.checked_add(x)), None);
assert_eq!(iter.next_back(), Some(70));
}
|
