Add a test for cloned side effects

rust-lang · Dec 5, 2018 · a964307 · a964307
1 parent 3eddc74
commit a964307
Showing 1 changed file with 17 additions and 0 deletions.
diff --git a/src/libcore/tests/iter.rs b/src/libcore/tests/iter.rs
@@ -1249,6 +1249,23 @@ fn test_cloned() {
     assert_eq!(it.next_back(), None);
 }
 
+#[test]
+fn test_cloned_side_effects() {
+    let mut count = 0;
+    {
+        let iter = [1, 2, 3]
+            .iter()
+            .map(|x| {
+                count += 1;
+                x
+            })
+            .cloned()
+            .zip(&[1]);
+        for _ in iter {}
+    }
+    assert_eq!(count, 2);
+}
+
 #[test]
 fn test_double_ended_map() {
     let xs = [1, 2, 3, 4, 5, 6];