error[E0308]: mismatched types
  --> $DIR/match-struct.rs:17:9
   |
LL |         E::C(_) => (),
   |         ^^^^^^^ expected struct `S`, found enum `E`
   |
   = note: expected type `S`
              found type `E`

error: aborting due to previous error

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