1 files changed, 24 insertions, 0 deletions
diff --git a/src/test/ui/consts/const-eval/promoted_const_fn_fail_deny_const_err.rs b/src/test/ui/consts/const-eval/promoted_const_fn_fail_deny_const_err.rs
new file mode 100644
index 000000000..c53424664
--- /dev/null
+++ b/src/test/ui/consts/const-eval/promoted_const_fn_fail_deny_const_err.rs
@@ -0,0 +1,24 @@
+#![deny(const_err)]
+
+#[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() {
+    // This will compile, but then hard-abort at runtime.
+    // FIXME(oli-obk): this should instead panic (not hard-abort) at runtime.
+    let x: &'static u8 = &(bar() + 1);
+    //~^ ERROR temporary value dropped while borrowed
+    let y = *x;
+    unreachable!();
+}