bjoernager/rust
bjoernager/rust
1
Fork 0
Code Activity

add core::iter::repeat_with

Browse source
This commit is contained in:
Mazdak Farrokhzad 2018-02-12 08:05:46 +01:00
parent b8398d947d
commit 0f789aad2b
2 changed files with 148 additions and 0 deletions
Download patch file Download diff file Expand all files Collapse all files

44
src/libcore/tests/iter.rs
View file

@ -1549,6 +1549,50 @@ fn test_repeat_take_collect() {
assert_eq!(v, vec![42, 42, 42]);
}
#[test]
fn test_repeat_with() {
struct NotClone(usize);
let mut it = repeat_with(|| NotClone(42));
assert_eq!(it.next(), Some(NotClone(42)));
assert_eq!(it.next(), Some(NotClone(42)));
assert_eq!(it.next(), Some(NotClone(42)));
assert_eq!(repeat_with(|| NotClone(42)).size_hint(), (usize::MAX, None));
}
#[test]
fn test_repeat_with_rev() {
let mut curr = 1;
let mut pow2 = repeat_with(|| { let tmp = curr; curr *= 2; tmp })
.rev().take(4);
assert_eq!(it.next(), Some(1));
assert_eq!(it.next(), Some(2));
assert_eq!(it.next(), Some(4));
assert_eq!(it.next(), Some(8));
assert_eq!(it.next(), None);
}
#[test]
fn test_repeat_with_take() {
let mut it = repeat_with(|| 42).take(3);
assert_eq!(it.next(), Some(42));
assert_eq!(it.next(), Some(42));
assert_eq!(it.next(), Some(42));
assert_eq!(it.next(), None);
is_trusted_len(repeat_with(|| 42).take(3));
assert_eq!(repeat_with(|| 42).take(3).size_hint(), (3, Some(3)));
assert_eq!(repeat_with(|| 42).take(0).size_hint(), (0, Some(0)));
assert_eq!(repeat_with(|| 42).take(usize::MAX).size_hint(),
(usize::MAX, Some(usize::MAX)));
}
#[test]
fn test_repeat_take_collect() {
let mut curr = 1;
let v: Vec<_> = repeat_with(|| { let tmp = curr; curr *= 2; tmp })
.take(5).collect();
assert_eq!(v, vec![1, 2, 4, 8, 16]);
}
#[test]
fn test_fuse() {
let mut it = 0..3;