1 files changed, 29 insertions, 0 deletions
diff --git a/tests/ui/closures/issue-23012-supertrait-signature-inference.rs b/tests/ui/closures/issue-23012-supertrait-signature-inference.rs
new file mode 100644
index 000000000..5899b703e
--- /dev/null
+++ b/tests/ui/closures/issue-23012-supertrait-signature-inference.rs
@@ -0,0 +1,29 @@
+// check-pass
+// Checks that we can infer a closure signature even if the `FnOnce` bound is
+// a supertrait of the obligations we have currently registered for the Ty var.
+
+pub trait Receive<T, E>: FnOnce(Result<T, E>) {
+    fn receive(self, res: Result<T, E>);
+}
+
+impl<T, E, F: FnOnce(Result<T, E>)> Receive<T, E> for F {
+    fn receive(self, res: Result<T, E>) {
+        self(res)
+    }
+}
+
+pub trait Async<T, E> {
+    fn receive<F: Receive<T, E>>(self, f: F);
+}
+
+impl<T, E> Async<T, E> for Result<T, E> {
+    fn receive<F: Receive<T, E>>(self, f: F) {
+        f(self)
+    }
+}
+
+pub fn main() {
+    Ok::<u32, ()>(123).receive(|res| {
+        res.unwrap();
+    });
+}