| error[E0301]: cannot mutably borrow in a pattern guard | |
| --> $DIR/E0301.rs:4:19 | |
| | | |
| LL | option if option.take().is_none() => {}, | |
| | ^^^^^^ borrowed mutably in pattern guard | |
| | | |
| = help: add #![feature(bind_by_move_pattern_guards)] to the crate attributes to enable | |
| error: aborting due to previous error | |
| For more information about this error, try `rustc --explain E0301`. |