error[E0597]: `*cell` does not live long enough
  --> $DIR/dropck.rs:10:40
   |
LL |     let (mut gen, cell);
   |                   ---- binding `cell` declared here
LL |     cell = Box::new(RefCell::new(0));
LL |     let ref_ = Box::leak(Box::new(Some(cell.borrow_mut())));
   |                                        ^^^^ borrowed value does not live long enough
...
LL | }
   | -
   | |
   | `*cell` dropped here while still borrowed
   | borrow might be used here, when `gen` is dropped and runs the destructor for coroutine
   |
   = note: values in a scope are dropped in the opposite order they are defined

error[E0597]: `ref_` does not live long enough
  --> $DIR/dropck.rs:15:18
   |
LL |     gen = || {
   |           -- value captured here by coroutine
LL |         // but the coroutine can use it to drop a `Ref<'a, i32>`.
LL |         let _d = ref_.take();
   |                  ^^^^ borrowed value does not live long enough
...
LL | }
   | -
   | |
   | `ref_` dropped here while still borrowed
   | borrow might be used here, when `gen` is dropped and runs the destructor for coroutine
   |
   = note: values in a scope are dropped in the opposite order they are defined

error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0597`.