1 files changed, 24 insertions, 0 deletions
diff --git a/tests/ui/traits/object/enforce-supertrait-projection.rs b/tests/ui/traits/object/enforce-supertrait-projection.rs
new file mode 100644
index 000000000..2c9b41eea
--- /dev/null
+++ b/tests/ui/traits/object/enforce-supertrait-projection.rs
@@ -0,0 +1,24 @@
+trait SuperTrait {
+    type A;
+    type B;
+}
+
+trait Trait: SuperTrait<A = <Self as SuperTrait>::B> {}
+
+fn transmute<A, B>(x: A) -> B {
+    foo::<A, B, dyn Trait<A = A, B = B>>(x)
+    //~^ ERROR type mismatch resolving `<dyn Trait<B = B, A = A> as SuperTrait>::A == B`
+}
+
+fn foo<A, B, T: ?Sized>(x: T::A) -> B
+where
+    T: Trait<B = B>,
+{
+    x
+}
+
+static X: u8 = 0;
+fn main() {
+    let x = transmute::<&u8, &[u8; 1_000_000]>(&X);
+    println!("{:?}", x[100_000]);
+}