1 files changed, 15 insertions, 0 deletions
diff --git a/library/core/tests/iter/adapters/enumerate.rs b/library/core/tests/iter/adapters/enumerate.rs
index 0e6033878..ff57973a6 100644
--- a/library/core/tests/iter/adapters/enumerate.rs
+++ b/library/core/tests/iter/adapters/enumerate.rs
@@ -1,4 +1,5 @@
 use core::iter::*;
+use core::num::NonZeroUsize;
 
 #[test]
 fn test_iterator_enumerate() {
@@ -56,6 +57,20 @@ fn test_iterator_enumerate_count() {
 }
 
 #[test]
+fn test_iterator_enumerate_advance_by() {
+    let xs = [0, 1, 2, 3, 4, 5];
+    let mut it = xs.iter().enumerate();
+    assert_eq!(it.advance_by(0), Ok(()));
+    assert_eq!(it.next(), Some((0, &0)));
+    assert_eq!(it.advance_by(1), Ok(()));
+    assert_eq!(it.next(), Some((2, &2)));
+    assert_eq!(it.advance_by(2), Ok(()));
+    assert_eq!(it.next(), Some((5, &5)));
+    assert_eq!(it.advance_by(1), Err(NonZeroUsize::new(1).unwrap()));
+    assert_eq!(it.next(), None);
+}
+
+#[test]
 fn test_iterator_enumerate_fold() {
     let xs = [0, 1, 2, 3, 4, 5];
     let mut it = xs.iter().enumerate();