error: generic `Self` types are currently not permitted in anonymous constants
  --> $DIR/self-ty-in-const-2.rs:17:41
   |
LL |         let _: [u8; std::mem::size_of::<Self>()];
   |                                         ^^^^
   |
note: not a concrete type
  --> $DIR/self-ty-in-const-2.rs:15:1
   |
LL | / impl<T> Baz for Bar<T> {
LL | |     fn hey() {
LL | |         let _: [u8; std::mem::size_of::<Self>()];
LL | |     }
LL | | }
   | |_^

error: aborting due to previous error