1 files changed, 40 insertions, 0 deletions
diff --git a/tests/ui/deref/pin-impl-deref.rs b/tests/ui/deref/pin-impl-deref.rs
new file mode 100644
index 00000000000..b1dc8dea3f2
--- /dev/null
+++ b/tests/ui/deref/pin-impl-deref.rs
@@ -0,0 +1,40 @@
+// The purpose of this file is to track the error messages from Pin and DerefMut interacting.
+
+//@ check-fail
+
+use std::ops::DerefMut;
+use std::pin::Pin;
+
+struct MyUnpinType {}
+
+impl MyUnpinType {
+    fn at_self(&self) {}
+    fn at_mut_self(&mut self) {}
+}
+
+struct MyPinType(core::marker::PhantomPinned);
+
+impl MyPinType {
+    fn at_self(&self) {}
+    fn at_mut_self(&mut self) {}
+}
+
+fn impl_deref_mut(_: impl DerefMut) {}
+fn unpin_impl_ref(r_unpin: Pin<&MyUnpinType>) {
+    impl_deref_mut(r_unpin)
+    //~^ ERROR: the trait bound `Pin<&MyUnpinType>: DerefMut` is not satisfied
+}
+fn unpin_impl_mut(r_unpin: Pin<&mut MyUnpinType>) {
+    impl_deref_mut(r_unpin)
+}
+fn pin_impl_ref(r_pin: Pin<&MyPinType>) {
+    impl_deref_mut(r_pin)
+    //~^ ERROR: `PhantomPinned` cannot be unpinned
+    //~| ERROR: the trait bound `Pin<&MyPinType>: DerefMut` is not satisfied
+}
+fn pin_impl_mut(r_pin: Pin<&mut MyPinType>) {
+    impl_deref_mut(r_pin)
+    //~^ ERROR: `PhantomPinned` cannot be unpinned
+}
+
+fn main() {}