error[E0303]: pattern bindings are not allowed after an `@` --> $DIR/pattern-bindings-after-at.rs:8:31 | LL | ref mut z @ &mut Some(ref a) => { | ^^^^^ not allowed after `@` error[E0502]: cannot borrow `_` as immutable because it is also borrowed as mutable --> $DIR/pattern-bindings-after-at.rs:8:31 | LL | ref mut z @ &mut Some(ref a) => { | ----------------------^^^^^- | | | | | immutable borrow occurs here | mutable borrow occurs here ... LL | **z = None; | ---------- mutable borrow later used here error: aborting due to 2 previous errors Some errors have detailed explanations: E0303, E0502. For more information about an error, try `rustc --explain E0303`.