| // run-pass |
| #![allow(dead_code)] |
| // Check that drop elaboration clears the "master" discriminant |
| // drop flag even if it protects no fields. |
| |
| struct Good(usize); |
| impl Drop for Good { |
| #[inline(never)] |
| fn drop(&mut self) { |
| println!("dropping Good({})", self.0); |
| } |
| } |
| |
| struct Void; |
| impl Drop for Void { |
| #[inline(never)] |
| fn drop(&mut self) { |
| panic!("Suddenly, a Void appears."); |
| } |
| } |
| |
| enum E { |
| Never(Void), |
| Fine(Good) |
| } |
| |
| fn main() { |
| let mut go = true; |
| |
| loop { |
| let next; |
| match go { |
| true => next = E::Fine(Good(123)), |
| false => return, |
| } |
| |
| match next { |
| E::Never(_) => return, |
| E::Fine(_good) => go = false, |
| } |
| |
| // `next` is dropped and StorageDead'd here. We must reset the |
| // discriminant's drop flag to avoid random variants being |
| // dropped. |
| } |
| } |
