1 files changed, 27 insertions, 0 deletions
diff --git a/tests/ui/impl-trait/in-assoc-type-unconstrained.rs b/tests/ui/impl-trait/in-assoc-type-unconstrained.rs
new file mode 100644
index 00000000000..c395b4195a0
--- /dev/null
+++ b/tests/ui/impl-trait/in-assoc-type-unconstrained.rs
@@ -0,0 +1,27 @@
+#![feature(impl_trait_in_assoc_type)]
+
+mod compare_ty {
+    trait Trait {
+        type Ty: IntoIterator<Item = ()>;
+    }
+    impl Trait for () {
+        type Ty = Option<impl Sized>;
+        //~^ ERROR: unconstrained opaque type
+        //~| ERROR: type mismatch resolving `<Option<<() as Trait>::Ty::{opaque#0}> as IntoIterator>::Item == ()`
+    }
+}
+
+mod compare_method {
+    trait Trait {
+        type Ty;
+        fn method() -> Self::Ty;
+    }
+    impl Trait for () {
+        type Ty = impl Sized;
+        //~^ ERROR: unconstrained opaque type
+        fn method() -> () {}
+        //~^ ERROR: method `method` has an incompatible type for trait
+    }
+}
+
+fn main() {}