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use core::iter::{self};
use super::*;
#[test]
fn test_iterator_array_chunks_infer() {
let xs = [1, 1, 2, -2, 6, 0, 3, 1];
for [a, b, c] in xs.iter().copied().array_chunks() {
assert_eq!(a + b + c, 4);
}
}
#[test]
fn test_iterator_array_chunks_clone_and_drop() {
let count = Cell::new(0);
let mut it = (0..5).map(|_| CountDrop::new(&count)).array_chunks::<3>();
assert_eq!(it.by_ref().count(), 1);
assert_eq!(count.get(), 3);
let mut it2 = it.clone();
assert_eq!(count.get(), 3);
assert_eq!(it.into_remainder().unwrap().len(), 2);
assert_eq!(count.get(), 5);
assert!(it2.next().is_none());
assert_eq!(it2.into_remainder().unwrap().len(), 2);
assert_eq!(count.get(), 7);
}
#[test]
fn test_iterator_array_chunks_remainder() {
let mut it = (0..11).array_chunks::<4>();
assert_eq!(it.next(), Some([0, 1, 2, 3]));
assert_eq!(it.next(), Some([4, 5, 6, 7]));
assert_eq!(it.next(), None);
assert_eq!(it.into_remainder().unwrap().as_slice(), &[8, 9, 10]);
}
#[test]
fn test_iterator_array_chunks_size_hint() {
let it = (0..6).array_chunks::<1>();
assert_eq!(it.size_hint(), (6, Some(6)));
let it = (0..6).array_chunks::<3>();
assert_eq!(it.size_hint(), (2, Some(2)));
let it = (0..6).array_chunks::<5>();
assert_eq!(it.size_hint(), (1, Some(1)));
let it = (0..6).array_chunks::<7>();
assert_eq!(it.size_hint(), (0, Some(0)));
let it = (1..).array_chunks::<2>();
assert_eq!(it.size_hint(), (usize::MAX / 2, None));
let it = (1..).filter(|x| x % 2 != 0).array_chunks::<2>();
assert_eq!(it.size_hint(), (0, None));
}
#[test]
fn test_iterator_array_chunks_count() {
let it = (0..6).array_chunks::<1>();
assert_eq!(it.count(), 6);
let it = (0..6).array_chunks::<3>();
assert_eq!(it.count(), 2);
let it = (0..6).array_chunks::<5>();
assert_eq!(it.count(), 1);
let it = (0..6).array_chunks::<7>();
assert_eq!(it.count(), 0);
let it = (0..6).filter(|x| x % 2 == 0).array_chunks::<2>();
assert_eq!(it.count(), 1);
let it = iter::empty::<i32>().array_chunks::<2>();
assert_eq!(it.count(), 0);
let it = [(); usize::MAX].iter().array_chunks::<2>();
assert_eq!(it.count(), usize::MAX / 2);
}
#[test]
fn test_iterator_array_chunks_next_and_next_back() {
let mut it = (0..11).array_chunks::<3>();
assert_eq!(it.next(), Some([0, 1, 2]));
assert_eq!(it.next_back(), Some([6, 7, 8]));
assert_eq!(it.next(), Some([3, 4, 5]));
assert_eq!(it.next_back(), None);
assert_eq!(it.next(), None);
assert_eq!(it.next_back(), None);
assert_eq!(it.next(), None);
assert_eq!(it.into_remainder().unwrap().as_slice(), &[9, 10]);
}
#[test]
fn test_iterator_array_chunks_rev_remainder() {
let mut it = (0..11).array_chunks::<4>();
{
let mut it = it.by_ref().rev();
assert_eq!(it.next(), Some([4, 5, 6, 7]));
assert_eq!(it.next(), Some([0, 1, 2, 3]));
assert_eq!(it.next(), None);
assert_eq!(it.next(), None);
}
assert_eq!(it.into_remainder().unwrap().as_slice(), &[8, 9, 10]);
}
#[test]
fn test_iterator_array_chunks_try_fold() {
let count = Cell::new(0);
let mut it = (0..10).map(|_| CountDrop::new(&count)).array_chunks::<3>();
let result: Result<_, ()> = it.by_ref().try_fold(0, |acc, _item| Ok(acc + 1));
assert_eq!(result, Ok(3));
assert_eq!(count.get(), 9);
drop(it);
assert_eq!(count.get(), 10);
let count = Cell::new(0);
let mut it = (0..10).map(|_| CountDrop::new(&count)).array_chunks::<3>();
let result = it.by_ref().try_fold(0, |acc, _item| if acc < 2 { Ok(acc + 1) } else { Err(acc) });
assert_eq!(result, Err(2));
assert_eq!(count.get(), 9);
drop(it);
assert_eq!(count.get(), 9);
}
#[test]
fn test_iterator_array_chunks_fold() {
let result = (1..11).array_chunks::<3>().fold(0, |acc, [a, b, c]| {
assert_eq!(acc + 1, a);
assert_eq!(acc + 2, b);
assert_eq!(acc + 3, c);
acc + 3
});
assert_eq!(result, 9);
let count = Cell::new(0);
let result =
(0..10).map(|_| CountDrop::new(&count)).array_chunks::<3>().fold(0, |acc, _item| acc + 1);
assert_eq!(result, 3);
// fold impls may or may not process the remainder
assert!(count.get() <= 10 && count.get() >= 9);
}
#[test]
fn test_iterator_array_chunks_try_rfold() {
let count = Cell::new(0);
let mut it = (0..10).map(|_| CountDrop::new(&count)).array_chunks::<3>();
let result: Result<_, ()> = it.try_rfold(0, |acc, _item| Ok(acc + 1));
assert_eq!(result, Ok(3));
assert_eq!(count.get(), 9);
drop(it);
assert_eq!(count.get(), 10);
let count = Cell::new(0);
let mut it = (0..10).map(|_| CountDrop::new(&count)).array_chunks::<3>();
let result = it.try_rfold(0, |acc, _item| if acc < 2 { Ok(acc + 1) } else { Err(acc) });
assert_eq!(result, Err(2));
assert_eq!(count.get(), 9);
drop(it);
assert_eq!(count.get(), 10);
}
#[test]
fn test_iterator_array_chunks_rfold() {
let result = (1..11).array_chunks::<3>().rfold(0, |acc, [a, b, c]| {
assert_eq!(10 - (acc + 1), c);
assert_eq!(10 - (acc + 2), b);
assert_eq!(10 - (acc + 3), a);
acc + 3
});
assert_eq!(result, 9);
let count = Cell::new(0);
let result =
(0..10).map(|_| CountDrop::new(&count)).array_chunks::<3>().rfold(0, |acc, _item| acc + 1);
assert_eq!(result, 3);
assert_eq!(count.get(), 10);
}
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