error[E0308]: mismatched types
  --> $DIR/wrong_ser.rs:18:10
   |
18 | #[derive(Serialize)]
   |          ^^^^^^^^^ expected u8, found u16
   |
   = note: expected type `&u8`
              found type `&u16`

error: aborting due to previous error

For more information about this error, try `rustc --explain E0308`.