src/test/run-fail/mir_dynamic_drops_3.rs

   1 // Copyright 2016 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 // error-pattern:unwind happens
  12 // error-pattern:drop 3
  13 // error-pattern:drop 2
  14 // error-pattern:drop 1
  15
  16
  17 /// Structure which will not allow to be dropped twice.
  18 struct Droppable<'a>(&'a mut bool, u32);
  19 impl<'a> Drop for Droppable<'a> {
  20     fn drop(&mut self) {
  21         if *self.0 {
  22             eprintln!("{} dropped twice", self.1);
  23             ::std::process::exit(1);
  24         }
  25         eprintln!("drop {}", self.1);
  26         *self.0 = true;
  27     }
  28 }
  29
  30 fn may_panic<'a>() -> Droppable<'a> {
  31     panic!("unwind happens");
  32 }
  33
  34 fn mir<'a>(d: Droppable<'a>) {
  35     let (mut a, mut b) = (false, false);
  36     let y = Droppable(&mut a, 2);
  37     let x = [Droppable(&mut b, 1), y, d, may_panic()];
  38 }
  39
  40 fn main() {
  41     let mut c = false;
  42     mir(Droppable(&mut c, 3));
  43 }