1 files changed, 23 insertions, 0 deletions
diff --git a/tests/ui/async-await/in-trait/missing-feature-flag.rs b/tests/ui/async-await/in-trait/missing-feature-flag.rs
new file mode 100644
index 000000000..6481f4a70
--- /dev/null
+++ b/tests/ui/async-await/in-trait/missing-feature-flag.rs
@@ -0,0 +1,23 @@
+// edition:2018
+// [next] compile-flags: -Zlower-impl-trait-in-trait-to-assoc-ty
+// revisions: current next
+
+#![feature(async_fn_in_trait)]
+#![feature(min_specialization)]
+
+struct MyStruct;
+
+trait MyTrait<T> {
+    async fn foo(_: T) -> &'static str;
+}
+
+impl<T> MyTrait<T> for MyStruct {}
+//~^ ERROR: not all trait items implemented, missing: `foo` [E0046]
+
+impl MyTrait<i32> for MyStruct {
+    async fn foo(_: i32) -> &'static str {}
+    //~^ ERROR: `foo` specializes an item from a parent `impl`, but that item is not marked `default` [E0520]
+    //~| ERROR: mismatched types [E0308]
+}
+
+fn main() {}