1 files changed, 28 insertions, 0 deletions
diff --git a/src/test/ui/traits/object/with-self-in-projection-output-good.rs b/src/test/ui/traits/object/with-self-in-projection-output-good.rs
new file mode 100644
index 000000000..d1b7bf6c2
--- /dev/null
+++ b/src/test/ui/traits/object/with-self-in-projection-output-good.rs
@@ -0,0 +1,28 @@
+// build-pass (FIXME(62277): could be check-pass?)
+
+// Regression test related to #56288. Check that a supertrait projection (of
+// `Output`) that references `Self` can be ok if it is referencing a projection (of
+// `Self::Target`, in this case). Note that we still require the user to manually
+// specify both `Target` and `Output` for now.
+
+trait Base {
+    type Output;
+}
+
+trait Helper: Base<Output=<Self as Helper>::Target> {
+    type Target;
+}
+
+impl Base for u32
+{
+    type Output = i32;
+}
+
+impl Helper for u32
+{
+    type Target = i32;
+}
+
+fn main() {
+    let _x: Box<dyn Helper<Target=i32, Output=i32>> = Box::new(2u32);
+}