1 files changed, 9 insertions, 0 deletions
diff --git a/src/test/ui/impl-trait/fallback.rs b/src/test/ui/impl-trait/fallback.rs
new file mode 100644
index 000000000..1e6eb5bb3
--- /dev/null
+++ b/src/test/ui/impl-trait/fallback.rs
@@ -0,0 +1,9 @@
+// check-pass
+
+fn take_edge_counters(
+    x: &mut Option<Vec<i32>>,
+) -> Option<impl Iterator<Item = i32>> {
+    x.take().map_or(None, |m| Some(m.into_iter()))
+}
+
+fn main() {}