error: this method is named `iter` but its return type does not implement `Iterator`
  --> $DIR/iter_not_returning_iterator.rs:30:5
   |
LL |     fn iter(&self) -> Counter2 {
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: `-D clippy::iter-not-returning-iterator` implied by `-D warnings`

error: this method is named `iter_mut` but its return type does not implement `Iterator`
  --> $DIR/iter_not_returning_iterator.rs:34:5
   |
LL |     fn iter_mut(&self) -> Counter2 {
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error: this method is named `iter` but its return type does not implement `Iterator`
  --> $DIR/iter_not_returning_iterator.rs:50:5
   |
LL |     fn iter(&self) -> Self::I;
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^

error: aborting due to 3 previous errors