1 files changed, 25 insertions, 0 deletions
diff --git a/src/test/ui/type-alias-impl-trait/inference-cycle.rs b/src/test/ui/type-alias-impl-trait/inference-cycle.rs
new file mode 100644
index 000000000..79caddf79
--- /dev/null
+++ b/src/test/ui/type-alias-impl-trait/inference-cycle.rs
@@ -0,0 +1,25 @@
+#![feature(type_alias_impl_trait)]
+#![allow(dead_code)]
+
+mod m {
+    type Foo = impl std::fmt::Debug;
+    //~^ ERROR cycle detected
+
+    // Cycle: error today, but it'd be nice if it eventually worked
+
+    pub fn foo() -> Foo {
+        is_send(bar())
+    }
+
+    pub fn bar() {
+        is_send(foo()); // Today: error
+    }
+
+    fn baz() {
+        let f: Foo = 22_u32;
+    }
+
+    fn is_send<T: Send>(_: T) {}
+}
+
+fn main() {}