error[E0369]: binary operation `%` cannot be applied to type `&&{integer}` --> $DIR/binary-op-on-double-ref.rs:14:9 | LL | x % 2 == 0 | ^^^^^ | = note: this is a reference to a type that `%` can be applied to; you need to dereference this variable once for this operation to work = note: an implementation of `std::ops::Rem` might be missing for `&&{integer}` error: aborting due to previous error For more information about this error, try `rustc --explain E0369`.