From 3a4fe97052cf9d3f244fcab885e338a6384cefa6 Mon Sep 17 00:00:00 2001
From: Yuki Okushi <huyuumi.dev@gmail.com>
Date: Fri, 9 Oct 2020 18:32:33 +0900
Subject: [PATCH] Add a regression test for issue-65581

---
 src/test/ui/impl-trait/issues/issue-65581.rs | 33 ++++++++++++++++++++
 1 file changed, 33 insertions(+)
 create mode 100644 src/test/ui/impl-trait/issues/issue-65581.rs

diff --git a/src/test/ui/impl-trait/issues/issue-65581.rs b/src/test/ui/impl-trait/issues/issue-65581.rs
new file mode 100644
index 000000000000..af65b79d3e83
--- /dev/null
+++ b/src/test/ui/impl-trait/issues/issue-65581.rs
@@ -0,0 +1,33 @@
+// check-pass
+
+#![allow(dead_code)]
+
+trait Trait1<T, U> {
+    fn f1(self) -> U;
+}
+
+trait Trait2 {
+    type T;
+    type U: Trait2<T = Self::T>;
+    fn f2(f: impl FnOnce(&Self::U));
+}
+
+fn f3<T: Trait2>() -> impl Trait1<T, T::T> {
+    Struct1
+}
+
+struct Struct1;
+
+impl<T: Trait2> Trait1<T, T::T> for Struct1 {
+    fn f1(self) -> T::T {
+        unimplemented!()
+    }
+}
+
+fn f4<T: Trait2>() {
+    T::f2(|_| {
+        f3::<T::U>().f1();
+    });
+}
+
+fn main() {}