src/test/ui/issues/issue-16492.rs

   1 // run-pass
   2 #![allow(non_snake_case)]
   3
   4 use std::rc::Rc;
   5 use std::cell::Cell;
   6
   7 struct Field {
   8     number: usize,
   9     state: Rc<Cell<usize>>
  10 }
  11
  12 impl Field {
  13     fn new(number: usize, state: Rc<Cell<usize>>) -> Field {
  14         Field {
  15             number: number,
  16             state: state
  17         }
  18     }
  19 }
  20
  21 impl Drop for Field {
  22     fn drop(&mut self) {
  23         println!("Dropping field {}", self.number);
  24         assert_eq!(self.state.get(), self.number);
  25         self.state.set(self.state.get()+1);
  26     }
  27 }
  28
  29 struct NoDropImpl {
  30     _one: Field,
  31     _two: Field,
  32     _three: Field
  33 }
  34
  35 struct HasDropImpl {
  36     _one: Field,
  37     _two: Field,
  38     _three: Field
  39 }
  40
  41 impl Drop for HasDropImpl {
  42     fn drop(&mut self) {
  43         println!("HasDropImpl.drop()");
  44         assert_eq!(self._one.state.get(), 0);
  45         self._one.state.set(1);
  46     }
  47 }
  48
  49 pub fn main() {
  50     let state = Rc::new(Cell::new(1));
  51     let noImpl = NoDropImpl {
  52         _one: Field::new(1, state.clone()),
  53         _two: Field::new(2, state.clone()),
  54         _three: Field::new(3, state.clone())
  55     };
  56     drop(noImpl);
  57     assert_eq!(state.get(), 4);
  58
  59     state.set(0);
  60     let hasImpl = HasDropImpl {
  61         _one: Field::new(1, state.clone()),
  62         _two: Field::new(2, state.clone()),
  63         _three: Field::new(3, state.clone())
  64     };
  65     drop(hasImpl);
  66     assert_eq!(state.get(), 4);
  67 }