1 files changed, 57 insertions, 0 deletions
diff --git a/tests/ui/traits/issue-52893.rs b/tests/ui/traits/issue-52893.rs
new file mode 100644
index 00000000000..d72598d5d59
--- /dev/null
+++ b/tests/ui/traits/issue-52893.rs
@@ -0,0 +1,57 @@
+// check-fail
+//
+// regression test for issue 52893
+trait At<Name> {
+    type AtRes;
+    fn at(self) -> Self::AtRes;
+}
+
+trait Push<T> {
+    type PushRes;
+    fn push(self, other: T) -> Self::PushRes;
+}
+
+trait AddClass<Name, F> {
+    type AddRes;
+    fn init(self, func: F);
+}
+
+trait ToRef {
+    type RefRes;
+    fn to_ref(&self) -> Self::RefRes;
+}
+
+struct Class<P>(P);
+
+impl<P> Class<P> {
+    fn with<Name, F>(self) -> <Self as AddClass<Name, F>>::AddRes
+    where
+        Self: AddClass<Name, F>,
+    {
+        todo!()
+    }
+
+    fn from<F>(self) -> <Self as AddClass<P, F>>::AddRes
+    where
+        Self: AddClass<P, F>,
+    {
+        todo!()
+    }
+}
+
+impl<F, Name, P> AddClass<Name, F> for Class<P>
+where
+    Self: At<Name>,
+    <Self as At<Name>>::AtRes: Push<F>,
+    <<Self as At<Name>>::AtRes as Push<F>>::PushRes: ToRef<RefRes = Self> + Push<F>,
+{
+    type AddRes = ();
+
+    fn init(self, func: F) {
+        let builder = self.at().push(func);
+        let output = builder.to_ref();
+        builder.push(output); //~ ERROR mismatched types [E0308]
+    }
+}
+
+fn main() {}