RingIterator<C> operator +(int i) {
RingIterator<C> p;
p.org = org;
p.cur = &(cur->next());
return p;
};
C& first() { return ROOT.next(); };
C& head() { return ROOT.next(); };
bool empty() { return ( &(ROOT.next()) == &ROOT ); };
RingIterator<C>& operator ++(int) {
cur = &(cur->next());
return *this;
};