src/test/ui/issues/issue-6892.rs

   1 // run-pass
   2 #![allow(dead_code)]
   3 // Ensures that destructors are run for expressions of the form "let _ = e;"
   4 // where `e` is a type which requires a destructor.
   5
   6
   7 struct Foo;
   8 struct Bar { x: isize }
   9 struct Baz(isize);
  10 enum FooBar { _Foo(Foo), _Bar(usize) }
  11
  12 static mut NUM_DROPS: usize = 0;
  13
  14 impl Drop for Foo {
  15     fn drop(&mut self) {
  16         unsafe { NUM_DROPS += 1; }
  17     }
  18 }
  19 impl Drop for Bar {
  20     fn drop(&mut self) {
  21         unsafe { NUM_DROPS += 1; }
  22     }
  23 }
  24 impl Drop for Baz {
  25     fn drop(&mut self) {
  26         unsafe { NUM_DROPS += 1; }
  27     }
  28 }
  29 impl Drop for FooBar {
  30     fn drop(&mut self) {
  31         unsafe { NUM_DROPS += 1; }
  32     }
  33 }
  34
  35 fn main() {
  36     assert_eq!(unsafe { NUM_DROPS }, 0);
  37     { let _x = Foo; }
  38     assert_eq!(unsafe { NUM_DROPS }, 1);
  39     { let _x = Bar { x: 21 }; }
  40     assert_eq!(unsafe { NUM_DROPS }, 2);
  41     { let _x = Baz(21); }
  42     assert_eq!(unsafe { NUM_DROPS }, 3);
  43     { let _x = FooBar::_Foo(Foo); }
  44     assert_eq!(unsafe { NUM_DROPS }, 5);
  45     { let _x = FooBar::_Bar(42); }
  46     assert_eq!(unsafe { NUM_DROPS }, 6);
  47
  48     { let _ = Foo; }
  49     assert_eq!(unsafe { NUM_DROPS }, 7);
  50     { let _ = Bar { x: 21 }; }
  51     assert_eq!(unsafe { NUM_DROPS }, 8);
  52     { let _ = Baz(21); }
  53     assert_eq!(unsafe { NUM_DROPS }, 9);
  54     { let _ = FooBar::_Foo(Foo); }
  55     assert_eq!(unsafe { NUM_DROPS }, 11);
  56     { let _ = FooBar::_Bar(42); }
  57     assert_eq!(unsafe { NUM_DROPS }, 12);
  58 }