1 files changed, 22 insertions, 0 deletions

diff --git a/tests/ui/impl-trait/issues/issue-78722-2.rs b/tests/ui/impl-trait/issues/issue-78722-2.rs
new file mode 100644
index 000000000..cf5361e1e
--- /dev/null
+++ b/tests/ui/impl-trait/issues/issue-78722-2.rs
@@ -0,0 +1,22 @@
+//! test that we cannot register hidden types for opaque types
+//! declared outside an anonymous constant.
+// edition:2018
+
+#![feature(type_alias_impl_trait)]
+
+type F = impl core::future::Future<Output = u8>;
+
+struct Bug {
+    V1: [(); {
+        fn concrete_use() -> F {
+            //~^ ERROR future that resolves to `u8`, but it resolves to `()`
+            async {}
+        }
+        let f: F = async { 1 };
+        //~^ ERROR item constrains opaque type that is not in its signature
+        //~| ERROR `async` blocks are not allowed in constants
+        1
+    }],
+}
+
+fn main() {}