error[E0382]: use of moved value: `x`
  --> $DIR/borrowck-reinit.rs:6:16
   |
LL |     let mut x = Box::new(0);
   |         ----- move occurs because `x` has type `Box<i32>`, which does not implement the `Copy` trait
...
LL |     drop(x);
   |          - value moved here
LL |     let _ = (1,x);
   |                ^ value used here after move
   |
help: consider cloning the value if the performance cost is acceptable
   |
LL |     drop(x.clone());
   |           ++++++++

error: aborting due to previous error

For more information about this error, try `rustc --explain E0382`.