error[E0517]: attribute should be applied to a struct or union
 --> $DIR/packed-enum.rs:3:8
  |
3 |   #[repr(packed)] //~ ERROR E0517
  |          ^^^^^^
4 | / enum E1 {
5 | |     V(()),
6 | | }
  | |_- not a struct or union

error[E0517]: attribute should be applied to a struct or union
  --> $DIR/packed-enum.rs:9:8
   |
9  |   #[repr(packed)] //~ ERROR E0517
   |          ^^^^^^
10 | / enum E2 {
11 | |     V(()),
12 | | }
   | |_- not a struct or union

error[E0517]: attribute should be applied to a struct or union
  --> $DIR/packed-enum.rs:14:8
   |
14 |   #[repr(packed)] //~ ERROR E0517
   |          ^^^^^^
15 |   #[pin_project]
16 | / enum E3 {
17 | |     V(()),
18 | | }
   | |_- not a struct or union