1 files changed, 25 insertions, 0 deletions
diff --git a/src/test/ui/traits/cycle-type-trait.rs b/src/test/ui/traits/cycle-type-trait.rs
new file mode 100644
index 000000000..c62d01403
--- /dev/null
+++ b/src/test/ui/traits/cycle-type-trait.rs
@@ -0,0 +1,25 @@
+// run-pass
+#![allow(dead_code)]
+// Test a case where a supertrait references a type that references
+// the original trait. This poses no problem at the moment.
+
+// pretty-expanded FIXME #23616
+
+trait Chromosome: Get<Struct<i32>> {
+}
+
+trait Get<A> {
+    fn get(&self) -> A;
+}
+
+struct Struct<C:Chromosome> { c: C }
+
+impl Chromosome for i32 { }
+
+impl Get<Struct<i32>> for i32 {
+    fn get(&self) -> Struct<i32> {
+        Struct { c: *self }
+    }
+}
+
+fn main() { }