1 files changed, 20 insertions, 0 deletions
diff --git a/tests/ui/consts/const-eval/promoted_const_fn_fail.rs b/tests/ui/consts/const-eval/promoted_const_fn_fail.rs
new file mode 100644
index 000000000..656dd33e1
--- /dev/null
+++ b/tests/ui/consts/const-eval/promoted_const_fn_fail.rs
@@ -0,0 +1,20 @@
+#[repr(C)]
+union Bar {
+    a: &'static u8,
+    b: usize,
+}
+
+const fn bar() -> u8 {
+    unsafe {
+        // this will error as long as this test
+        // is run on a system whose pointers need more
+        // than 8 bits
+        Bar { a: &42 }.b as u8
+    }
+}
+
+fn main() {
+    let x: &'static u8 = &(bar() + 1); //~ ERROR temporary value dropped while borrowed
+    let y = *x;
+    unreachable!();
+}