library/core/tests/manually_drop.rs

   1 use core::mem::ManuallyDrop;
   2
   3 #[test]
   4 fn smoke() {
   5     #[derive(Clone)]
   6     struct TypeWithDrop;
   7     impl Drop for TypeWithDrop {
   8         fn drop(&mut self) {
   9             unreachable!("Should not get dropped");
  10         }
  11     }
  12
  13     let x = ManuallyDrop::new(TypeWithDrop);
  14     drop(x);
  15
  16     // also test unsizing
  17     let x: Box<ManuallyDrop<[TypeWithDrop]>> =
  18         Box::new(ManuallyDrop::new([TypeWithDrop, TypeWithDrop]));
  19     drop(x);
  20
  21     // test clone and clone_from implementations
  22     let mut x = ManuallyDrop::new(TypeWithDrop);
  23     let y = x.clone();
  24     x.clone_from(&y);
  25     drop(x);
  26     drop(y);
  27 }