+ // Normal iterators need to be comparable with the const_iterators so
+ // declare the comparison operators and implement them below after the
+ // full const_iterator declaration.
+ bool operator==(const const_iterator& i) const;
+ bool operator!=(const const_iterator& i) const;
+ bool operator<(const const_iterator& i) const;
+ bool operator>(const const_iterator& i) const;
+ bool operator<=(const const_iterator& i) const;
+ bool operator>=(const const_iterator& i) const;
+