src/test/run-pass-valgrind/cast-enum-with-dtor.rs

   1 // Copyright 2015 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 // no-prefer-dynamic
  12
  13 #![allow(dead_code)]
  14 #![feature(const_atomic_usize_new)]
  15
  16 // check dtor calling order when casting enums.
  17
  18 use std::sync::atomic;
  19 use std::sync::atomic::Ordering;
  20 use std::mem;
  21
  22 enum E {
  23     A = 0,
  24     B = 1,
  25     C = 2
  26 }
  27
  28 static FLAG: atomic::AtomicUsize = atomic::AtomicUsize::new(0);
  29
  30 impl Drop for E {
  31     fn drop(&mut self) {
  32         // avoid dtor loop
  33         unsafe { mem::forget(mem::replace(self, E::B)) };
  34
  35         FLAG.store(FLAG.load(Ordering::SeqCst)+1, Ordering::SeqCst);
  36     }
  37 }
  38
  39 fn main() {
  40     assert_eq!(FLAG.load(Ordering::SeqCst), 0);
  41     {
  42         let e = E::C;
  43         assert_eq!(e as u32, 2);
  44         assert_eq!(FLAG.load(Ordering::SeqCst), 0);
  45     }
  46     assert_eq!(FLAG.load(Ordering::SeqCst), 0);
  47 }