src/test/ui/error-codes/E0301.nll.stderr

   1 error[E0301]: cannot mutably borrow in a pattern guard
   2   --> $DIR/E0301.rs:14:19
   3    |
   4 LL |         option if option.take().is_none() => {}, //~ ERROR E0301
   5    |                   ^^^^^^ borrowed mutably in pattern guard
   6    |
   7    = help: add #![feature(bind_by_move_pattern_guards)] to the crate attributes to enable
   8
   9 error: aborting due to previous error
  10
  11 For more information about this error, try `rustc --explain E0301`.