1 files changed, 14 insertions, 0 deletions
diff --git a/tests/ui/impl-trait/issue-49579.rs b/tests/ui/impl-trait/issue-49579.rs
new file mode 100644
index 00000000000..98de014e90b
--- /dev/null
+++ b/tests/ui/impl-trait/issue-49579.rs
@@ -0,0 +1,14 @@
+// check-pass
+
+fn fibs(n: u32) -> impl Iterator<Item=u128> {
+    (0 .. n)
+    .scan((0, 1), |st, _| {
+        *st = (st.1, st.0 + st.1);
+        Some(*st)
+    })
+    .map(&|(f, _)| f)
+}
+
+fn main() {
+    println!("{:?}", fibs(10).collect::<Vec<_>>());
+}