1 files changed, 51 insertions, 0 deletions
diff --git a/src/test/ui/invalid_dispatch_from_dyn_impls.rs b/src/test/ui/invalid_dispatch_from_dyn_impls.rs
new file mode 100644
index 000000000..b7bc766fb
--- /dev/null
+++ b/src/test/ui/invalid_dispatch_from_dyn_impls.rs
@@ -0,0 +1,51 @@
+#![feature(unsize, dispatch_from_dyn)]
+
+use std::{
+    ops::DispatchFromDyn,
+    marker::{Unsize, PhantomData},
+};
+
+struct WrapperWithExtraField<T>(T, i32);
+
+impl<T, U> DispatchFromDyn<WrapperWithExtraField<U>> for WrapperWithExtraField<T>
+where
+    T: DispatchFromDyn<U>,
+{} //~^^^ ERROR [E0378]
+
+
+struct MultiplePointers<T: ?Sized>{
+    ptr1: *const T,
+    ptr2: *const T,
+}
+
+impl<T: ?Sized, U: ?Sized> DispatchFromDyn<MultiplePointers<U>> for MultiplePointers<T>
+where
+    T: Unsize<U>,
+{} //~^^^ ERROR [E0378]
+
+
+struct NothingToCoerce<T: ?Sized> {
+    data: PhantomData<T>,
+}
+
+impl<T: ?Sized, U: ?Sized> DispatchFromDyn<NothingToCoerce<T>> for NothingToCoerce<U> {}
+//~^ ERROR [E0378]
+
+#[repr(C)]
+struct HasReprC<T: ?Sized>(Box<T>);
+
+impl<T: ?Sized, U: ?Sized> DispatchFromDyn<HasReprC<U>> for HasReprC<T>
+where
+    T: Unsize<U>,
+{} //~^^^ ERROR [E0378]
+
+#[repr(align(64))]
+struct OverAlignedZst;
+struct OverAligned<T: ?Sized>(Box<T>, OverAlignedZst);
+
+impl<T: ?Sized, U: ?Sized> DispatchFromDyn<OverAligned<U>> for OverAligned<T>
+    where
+        T: Unsize<U>,
+{} //~^^^ ERROR [E0378]
+
+fn main() {}