1 files changed, 31 insertions, 0 deletions
diff --git a/tests/ui/impl-trait/recursive-type-alias-impl-trait-declaration-too-subtle.rs b/tests/ui/impl-trait/recursive-type-alias-impl-trait-declaration-too-subtle.rs
new file mode 100644
index 000000000..91f1ed481
--- /dev/null
+++ b/tests/ui/impl-trait/recursive-type-alias-impl-trait-declaration-too-subtle.rs
@@ -0,0 +1,31 @@
+#![feature(type_alias_impl_trait)]
+
+mod a {
+    type Foo = impl PartialEq<(Foo, i32)>;
+    //~^ ERROR: unconstrained opaque type
+
+    struct Bar;
+
+    impl PartialEq<(Bar, i32)> for Bar {
+        fn eq(&self, _other: &(Foo, i32)) -> bool {
+            //~^ ERROR: `eq` has an incompatible type for trait
+            true
+        }
+    }
+}
+
+mod b {
+    type Foo = impl PartialEq<(Foo, i32)>;
+    //~^ ERROR: unconstrained opaque type
+
+    struct Bar;
+
+    impl PartialEq<(Foo, i32)> for Bar {
+        fn eq(&self, _other: &(Bar, i32)) -> bool {
+            //~^ ERROR: `eq` has an incompatible type for trait
+            true
+        }
+    }
+}
+
+fn main() {}