error[E0046]: not all trait items implemented, missing: `Unit`
  --> $DIR/associated-type2.rs:11:1
   |
LL |     type Unit;
   |     --------- `Unit` from trait
...
LL | impl<T> ToUnit for *const T {}
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ missing `Unit` in implementation

error: aborting due to 1 previous error

For more information about this error, try `rustc --explain E0046`.