do not lower patterns in impl Trait

1 files changed, 14 insertions, 0 deletions

diff --git a/src/test/ui/impl-trait/closure-in-impl-trait.rs b/src/test/ui/impl-trait/closure-in-impl-trait.rs
new file mode 100644
index 00000000000..3593a1d5c8d
--- /dev/null
+++ b/src/test/ui/impl-trait/closure-in-impl-trait.rs
@@ -0,0 +1,14 @@
+// run-pass
+#![allow(unused_must_use)]
+fn bug<T>() -> impl Iterator<Item = [(); { |x: u32| { x }; 4 }]> {
+    std::iter::empty()
+}
+
+fn ok<T>() -> Box<dyn Iterator<Item = [(); { |x: u32| { x }; 4 }]>> {
+    Box::new(std::iter::empty())
+}
+
+fn main() {
+    for _item in ok::<u32>() {}
+    for _item in bug::<u32>() {}
+}