error[E0046]: not all trait items implemented, missing: `Item` --> $DIR/issue-23729.rs:10:9 | LL | impl Iterator for Recurrence { | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ missing `Item` in implementation | = help: implement the missing item: `type Item = /* Type */;` error: aborting due to previous error For more information about this error, try `rustc --explain E0046`.