Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 203 insertions, 0 deletions

diff --git a/library/core/tests/iter/adapters/skip.rs b/library/core/tests/iter/adapters/skip.rs
new file mode 100644
index 000000000..65f235e86
--- /dev/null
+++ b/library/core/tests/iter/adapters/skip.rs
@@ -0,0 +1,203 @@
+use core::iter::*;
+
+use super::Unfuse;
+
+#[test]
+fn test_iterator_skip() {
+    let xs = [0, 1, 2, 3, 5, 13, 15, 16, 17, 19, 20, 30];
+    let ys = [13, 15, 16, 17, 19, 20, 30];
+    let mut it = xs.iter().skip(5);
+    let mut i = 0;
+    while let Some(&x) = it.next() {
+        assert_eq!(x, ys[i]);
+        i += 1;
+        assert_eq!(it.len(), xs.len() - 5 - i);
+    }
+    assert_eq!(i, ys.len());
+    assert_eq!(it.len(), 0);
+}
+
+#[test]
+fn test_iterator_skip_doubleended() {
+    let xs = [0, 1, 2, 3, 5, 13, 15, 16, 17, 19, 20, 30];
+    let mut it = xs.iter().rev().skip(5);
+    assert_eq!(it.next(), Some(&15));
+    assert_eq!(it.by_ref().rev().next(), Some(&0));
+    assert_eq!(it.next(), Some(&13));
+    assert_eq!(it.by_ref().rev().next(), Some(&1));
+    assert_eq!(it.next(), Some(&5));
+    assert_eq!(it.by_ref().rev().next(), Some(&2));
+    assert_eq!(it.next(), Some(&3));
+    assert_eq!(it.next(), None);
+    let mut it = xs.iter().rev().skip(5).rev();
+    assert_eq!(it.next(), Some(&0));
+    assert_eq!(it.rev().next(), Some(&15));
+    let mut it_base = xs.iter();
+    {
+        let mut it = it_base.by_ref().skip(5).rev();
+        assert_eq!(it.next(), Some(&30));
+        assert_eq!(it.next(), Some(&20));
+        assert_eq!(it.next(), Some(&19));
+        assert_eq!(it.next(), Some(&17));
+        assert_eq!(it.next(), Some(&16));
+        assert_eq!(it.next(), Some(&15));
+        assert_eq!(it.next(), Some(&13));
+        assert_eq!(it.next(), None);
+    }
+    // make sure the skipped parts have not been consumed
+    assert_eq!(it_base.next(), Some(&0));
+    assert_eq!(it_base.next(), Some(&1));
+    assert_eq!(it_base.next(), Some(&2));
+    assert_eq!(it_base.next(), Some(&3));
+    assert_eq!(it_base.next(), Some(&5));
+    assert_eq!(it_base.next(), None);
+    let it = xs.iter().skip(5).rev();
+    assert_eq!(it.last(), Some(&13));
+}
+
+#[test]
+fn test_iterator_skip_nth() {
+    let xs = [0, 1, 2, 3, 5, 13, 15, 16, 17, 19, 20, 30];
+
+    let mut it = xs.iter().skip(0);
+    assert_eq!(it.nth(0), Some(&0));
+    assert_eq!(it.nth(1), Some(&2));
+
+    let mut it = xs.iter().skip(5);
+    assert_eq!(it.nth(0), Some(&13));
+    assert_eq!(it.nth(1), Some(&16));
+
+    let mut it = xs.iter().skip(12);
+    assert_eq!(it.nth(0), None);
+}
+
+#[test]
+fn test_skip_advance_by() {
+    assert_eq!((0..0).skip(10).advance_by(0), Ok(()));
+    assert_eq!((0..0).skip(10).advance_by(1), Err(0));
+    assert_eq!((0u128..(usize::MAX as u128) + 1).skip(usize::MAX).advance_by(usize::MAX), Err(1));
+    assert_eq!((0u128..u128::MAX).skip(usize::MAX).advance_by(1), Ok(()));
+
+    assert_eq!((0..2).skip(1).advance_back_by(10), Err(1));
+    assert_eq!((0..0).skip(1).advance_back_by(0), Ok(()));
+}
+
+#[test]
+fn test_iterator_skip_count() {
+    let xs = [0, 1, 2, 3, 5, 13, 15, 16, 17, 19, 20, 30];
+
+    assert_eq!(xs.iter().skip(0).count(), 12);
+    assert_eq!(xs.iter().skip(1).count(), 11);
+    assert_eq!(xs.iter().skip(11).count(), 1);
+    assert_eq!(xs.iter().skip(12).count(), 0);
+    assert_eq!(xs.iter().skip(13).count(), 0);
+}
+
+#[test]
+fn test_iterator_skip_last() {
+    let xs = [0, 1, 2, 3, 5, 13, 15, 16, 17, 19, 20, 30];
+
+    assert_eq!(xs.iter().skip(0).last(), Some(&30));
+    assert_eq!(xs.iter().skip(1).last(), Some(&30));
+    assert_eq!(xs.iter().skip(11).last(), Some(&30));
+    assert_eq!(xs.iter().skip(12).last(), None);
+    assert_eq!(xs.iter().skip(13).last(), None);
+
+    let mut it = xs.iter().skip(5);
+    assert_eq!(it.next(), Some(&13));
+    assert_eq!(it.last(), Some(&30));
+}
+
+#[test]
+fn test_iterator_skip_fold() {
+    let xs = [0, 1, 2, 3, 5, 13, 15, 16, 17, 19, 20, 30];
+    let ys = [13, 15, 16, 17, 19, 20, 30];
+
+    let it = xs.iter().skip(5);
+    let i = it.fold(0, |i, &x| {
+        assert_eq!(x, ys[i]);
+        i + 1
+    });
+    assert_eq!(i, ys.len());
+
+    let mut it = xs.iter().skip(5);
+    assert_eq!(it.next(), Some(&ys[0])); // process skips before folding
+    let i = it.fold(1, |i, &x| {
+        assert_eq!(x, ys[i]);
+        i + 1
+    });
+    assert_eq!(i, ys.len());
+
+    let it = xs.iter().skip(5);
+    let i = it.rfold(ys.len(), |i, &x| {
+        let i = i - 1;
+        assert_eq!(x, ys[i]);
+        i
+    });
+    assert_eq!(i, 0);
+
+    let mut it = xs.iter().skip(5);
+    assert_eq!(it.next(), Some(&ys[0])); // process skips before folding
+    let i = it.rfold(ys.len(), |i, &x| {
+        let i = i - 1;
+        assert_eq!(x, ys[i]);
+        i
+    });
+    assert_eq!(i, 1);
+}
+
+#[test]
+fn test_skip_try_folds() {
+    let f = &|acc, x| i32::checked_add(2 * acc, x);
+    assert_eq!((1..20).skip(9).try_fold(7, f), (10..20).try_fold(7, f));
+    assert_eq!((1..20).skip(9).try_rfold(7, f), (10..20).try_rfold(7, f));
+
+    let mut iter = (0..30).skip(10);
+    assert_eq!(iter.try_fold(0, i8::checked_add), None);
+    assert_eq!(iter.next(), Some(20));
+    assert_eq!(iter.try_rfold(0, i8::checked_add), None);
+    assert_eq!(iter.next_back(), Some(24));
+}
+
+#[test]
+fn test_skip_nth_back() {
+    let xs = [0, 1, 2, 3, 4, 5];
+    let mut it = xs.iter().skip(2);
+    assert_eq!(it.nth_back(0), Some(&5));
+    assert_eq!(it.nth_back(1), Some(&3));
+    assert_eq!(it.nth_back(0), Some(&2));
+    assert_eq!(it.nth_back(0), None);
+
+    let ys = [2, 3, 4, 5];
+    let mut ity = ys.iter();
+    let mut it = xs.iter().skip(2);
+    assert_eq!(it.nth_back(1), ity.nth_back(1));
+    assert_eq!(it.clone().nth(0), ity.clone().nth(0));
+    assert_eq!(it.nth_back(0), ity.nth_back(0));
+    assert_eq!(it.clone().nth(0), ity.clone().nth(0));
+    assert_eq!(it.nth_back(0), ity.nth_back(0));
+    assert_eq!(it.clone().nth(0), ity.clone().nth(0));
+    assert_eq!(it.nth_back(0), ity.nth_back(0));
+    assert_eq!(it.clone().nth(0), ity.clone().nth(0));
+
+    let mut it = xs.iter().skip(2);
+    assert_eq!(it.nth_back(4), None);
+    assert_eq!(it.nth_back(0), None);
+
+    let mut it = xs.iter();
+    it.by_ref().skip(2).nth_back(3);
+    assert_eq!(it.next_back(), Some(&1));
+
+    let mut it = xs.iter();
+    it.by_ref().skip(2).nth_back(10);
+    assert_eq!(it.next_back(), Some(&1));
+}
+
+#[test]
+fn test_skip_non_fused() {
+    let non_fused = Unfuse::new(0..10);
+
+    // `Skip` would previously exhaust the iterator in this `next` call and then erroneously try to
+    // advance it further. `Unfuse` tests that this doesn't happen by panicking in that scenario.
+    let _ = non_fused.skip(20).next();
+}