| error[E0596]: cannot borrow `y.0` as mutable, as it is immutable for the pattern guard | |
| --> $DIR/guard-mutability-1.rs:8:33 | |
| | | |
| LL | Some(mut y) if let Some(ref mut z) = y => { | |
| | ^^^^^^^^^ cannot borrow as mutable | |
| | | |
| = note: variables bound in patterns are immutable until the end of the pattern guard | |
| error: aborting due to 1 previous error | |
| For more information about this error, try `rustc --explain E0596`. |