1 files changed, 25 insertions, 0 deletions
diff --git a/tests/ui/consts/const-eval/ub-uninhabit.rs b/tests/ui/consts/const-eval/ub-uninhabit.rs
new file mode 100644
index 000000000..4c4ef216d
--- /dev/null
+++ b/tests/ui/consts/const-eval/ub-uninhabit.rs
@@ -0,0 +1,25 @@
+// Strip out raw byte dumps to make comparison platform-independent:
+// normalize-stderr-test "(the raw bytes of the constant) \(size: [0-9]*, align: [0-9]*\)" -> "$1 (size: $$SIZE, align: $$ALIGN)"
+// normalize-stderr-test "([0-9a-f][0-9a-f] |╾─*a(lloc)?[0-9]+(\+[a-z0-9]+)?─*╼ )+ *│.*" -> "HEX_DUMP"
+
+use std::mem;
+
+#[derive(Copy, Clone)]
+enum Bar {}
+
+#[repr(C)]
+union MaybeUninit<T: Copy> {
+    uninit: (),
+    init: T,
+}
+
+const BAD_BAD_BAD: Bar = unsafe { MaybeUninit { uninit: () }.init };
+//~^ ERROR it is undefined behavior to use this value
+
+const BAD_BAD_REF: &Bar = unsafe { mem::transmute(1usize) };
+//~^ ERROR it is undefined behavior to use this value
+
+const BAD_BAD_ARRAY: [Bar; 1] = unsafe { MaybeUninit { uninit: () }.init };
+//~^ ERROR it is undefined behavior to use this value
+
+fn main() {}