1 files changed, 24 insertions, 0 deletions
diff --git a/library/core/tests/iter/adapters/mod.rs b/library/core/tests/iter/adapters/mod.rs
index 567d9fe49..ffd5f3857 100644
--- a/library/core/tests/iter/adapters/mod.rs
+++ b/library/core/tests/iter/adapters/mod.rs
@@ -1,3 +1,5 @@
+mod array_chunks;
+mod by_ref_sized;
 mod chain;
 mod cloned;
 mod copied;
@@ -183,3 +185,25 @@ impl Clone for CountClone {
         ret
     }
 }
+
+#[derive(Debug, Clone)]
+struct CountDrop<'a> {
+    dropped: bool,
+    count: &'a Cell<usize>,
+}
+
+impl<'a> CountDrop<'a> {
+    pub fn new(count: &'a Cell<usize>) -> Self {
+        Self { dropped: false, count }
+    }
+}
+
+impl Drop for CountDrop<'_> {
+    fn drop(&mut self) {
+        if self.dropped {
+            panic!("double drop");
+        }
+        self.dropped = true;
+        self.count.set(self.count.get() + 1);
+    }
+}