1 files changed, 17 insertions, 0 deletions
diff --git a/src/test/ui/consts/const-eval/ub-enum-overwrite.rs b/src/test/ui/consts/const-eval/ub-enum-overwrite.rs
new file mode 100644
index 00000000000..c5677849229
--- /dev/null
+++ b/src/test/ui/consts/const-eval/ub-enum-overwrite.rs
@@ -0,0 +1,17 @@
+#![feature(const_mut_refs)]
+
+enum E {
+    A(u8),
+    B,
+}
+
+const _: u8 = {
+    //~^ ERROR is undefined behavior
+    let mut e = E::A(1);
+    let p = if let E::A(x) = &mut e { x as *mut u8 } else { unreachable!() };
+    // Make sure overwriting `e` uninitializes other bytes
+    e = E::B;
+    unsafe { *p }
+};
+
+fn main() {}