error[E0503]: cannot use `value` because it was mutably borrowed
  --> $DIR/E0503.rs:4:16
   |
LL |     let _borrow = &mut value;
   |                        ----- borrow of `value` occurs here
LL |     let _sum = value + 1;
   |                ^^^^^ use of borrowed `value`

error: aborting due to previous error

For more information about this error, try `rustc --explain E0503`.