error[E0505]: cannot move out of `x` because it is borrowed
  --> $DIR/borrowck-issue-2657-1.rs:9:18
   |
LL |       Some(ref _y) => {
   |            ------ borrow of `x.0` occurs here
LL |         let _a = x;
   |                  ^ move out of `x` occurs here
LL |         _y.use_ref();
   |         -- borrow later used here

error: aborting due to 1 previous error

For more information about this error, try `rustc --explain E0505`.