Test that maplike FromIter satisfies uniqueness

2 files changed, 6 insertions, 2 deletions

diff --git a/src/libstd/collections/hash/map.rs b/src/libstd/collections/hash/map.rs
index 2925d8362c8..1e28ee8da26 100644
--- a/src/libstd/collections/hash/map.rs
+++ b/src/libstd/collections/hash/map.rs
@@ -3138,13 +3138,15 @@ mod test_map {
 
     #[test]
     fn test_from_iter() {
-        let xs = [(1, 1), (2, 2), (3, 3), (4, 4), (5, 5), (6, 6)];
+        let xs = [(1, 1), (2, 2), (2, 2), (3, 3), (4, 4), (5, 5), (6, 6)];
 
         let map: HashMap<_, _> = xs.iter().cloned().collect();
 
         for &(k, v) in &xs {
             assert_eq!(map.get(&k), Some(&v));
         }
+
+        assert_eq!(map.iter().len(), xs.len() - 1);
     }
 
     #[test]
diff --git a/src/libstd/collections/hash/set.rs b/src/libstd/collections/hash/set.rs
index 403914c0707..d243412405a 100644
--- a/src/libstd/collections/hash/set.rs
+++ b/src/libstd/collections/hash/set.rs
@@ -1782,13 +1782,15 @@ mod test_set {
 
     #[test]
     fn test_from_iter() {
-        let xs = [1, 2, 3, 4, 5, 6, 7, 8, 9];
+        let xs = [1, 2, 2, 3, 4, 5, 6, 7, 8, 9];
 
         let set: HashSet<_> = xs.iter().cloned().collect();
 
         for x in &xs {
             assert!(set.contains(x));
         }
+
+        assert_eq!(set.iter().len(), xs.len() - 1);
     }
 
     #[test]