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`.