rust/library/core/tests/iter/adapters/inspect.rs
2021-01-22 16:58:21 -05:00

39 lines
791 B
Rust

use core::iter::*;
#[test]
fn test_inspect() {
let xs = [1, 2, 3, 4];
let mut n = 0;
let ys = xs.iter().cloned().inspect(|_| n += 1).collect::<Vec<usize>>();
assert_eq!(n, xs.len());
assert_eq!(&xs[..], &ys[..]);
}
#[test]
fn test_inspect_fold() {
let xs = [1, 2, 3, 4];
let mut n = 0;
{
let it = xs.iter().inspect(|_| n += 1);
let i = it.fold(0, |i, &x| {
assert_eq!(x, xs[i]);
i + 1
});
assert_eq!(i, xs.len());
}
assert_eq!(n, xs.len());
let mut n = 0;
{
let it = xs.iter().inspect(|_| n += 1);
let i = it.rfold(xs.len(), |i, &x| {
assert_eq!(x, xs[i - 1]);
i - 1
});
assert_eq!(i, 0);
}
assert_eq!(n, xs.len());
}