error[E0609]: no field `f` on type `*const Rec`
  --> $DIR/unsafe-fn-autoderef.rs:19:14
   |
LL |     return p.f;
   |              ^ unknown field
   |
help: `p` is a raw pointer; try dereferencing it
   |
LL |     return (*p).f;
   |            ++ +

error: aborting due to 1 previous error

For more information about this error, try `rustc --explain E0609`.