The library no loger guarantees nor relies on the direct presence of advance / distance / next / prior / type members in iterator types; the following table summarises the new requirements:
Before Now i::type deref<i>::type i::next next<i>::type i::prior prior<i>::type i::advance<n>::type advance<i,n>::type i::distance<j>::type distance<i,j>::type i::category i::category