From ab44e46345653803e86e6e05358fdb1bb1a6d07b Mon Sep 17 00:00:00 2001
From: samlich <1349989+samlich@users.noreply.github.com>
Date: Wed, 20 Oct 2021 22:51:31 +0000
Subject: [PATCH] Add test for issue #78561

---
 src/test/ui/nll/issue-78561.rs | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)
 create mode 100644 src/test/ui/nll/issue-78561.rs

diff --git a/src/test/ui/nll/issue-78561.rs b/src/test/ui/nll/issue-78561.rs
new file mode 100644
index 0000000000000..55147fcd1bd27
--- /dev/null
+++ b/src/test/ui/nll/issue-78561.rs
@@ -0,0 +1,23 @@
+// check-pass
+#![feature(type_alias_impl_trait)]
+
+pub trait Trait {
+    type A;
+
+    fn f() -> Self::A;
+}
+
+pub trait Tr2<'a, 'b> {}
+
+pub struct A<T>(T);
+pub trait Tr {
+    type B;
+}
+
+impl<'a, 'b, T: Tr<B = dyn Tr2<'a, 'b>>> Trait for A<T> {
+    type A = impl core::fmt::Debug;
+
+    fn f() -> Self::A {}
+}
+
+fn main() {}