Return a reference providing non‐modifiable access to the day of week value referenced by this iterator. The behavior is undefined unless the iterator refers to a valid day of the week, specifically, the behavior is undefined if *this == end().
Return a reference providing non‐modifiable access to the day of week value referenced by this iterator. The behavior is undefined unless the iterator refers to a valid day of the week, specifically, the behavior is undefined if *this == end().