#![allow(dead_code, cenum_impl_drop_cast)] // check dtor calling order when casting enums. use std::sync::atomic; use std::sync::atomic::Ordering; use std::mem; enum E { A = 0, B = 1, C = 2 } static FLAG: atomic::AtomicUsize = atomic::AtomicUsize::new(0); impl Drop for E { fn drop(&mut self) { // avoid dtor loop unsafe { mem::forget(mem::replace(self, E::B)) }; FLAG.store(FLAG.load(Ordering::SeqCst)+1, Ordering::SeqCst); } } fn main() { assert_eq!(FLAG.load(Ordering::SeqCst), 0); { let e = E::C; assert_eq!(e as u32, 2); assert_eq!(FLAG.load(Ordering::SeqCst), 1); } assert_eq!(FLAG.load(Ordering::SeqCst), 1); }