1038     typedef typename difference_type_of<interval_traits<Type> >::type DiffT;  in length()  typedef
1039     return icl::is_empty(object) ? identity_element<DiffT>::value()  in length()
1048     typedef typename difference_type_of<interval_traits<Type> >::type DiffT;  in length()  typedef
1049     return icl::is_empty(object) ? identity_element<DiffT>::value()  in length()
1058     typedef typename difference_type_of<interval_traits<Type> >::type DiffT;  in length()  typedef
1059     return icl::is_empty(object) ? identity_element<DiffT>::value()  in length()
1068     typedef typename difference_type_of<interval_traits<Type> >::type DiffT;  in length()  typedef
1069     return icl::is_empty(object) ? identity_element<DiffT>::value()  in length()
1405     typedef typename difference_type_of<interval_traits<Type> >::type DiffT;  in distance()  typedef
1408         return icl::identity_element<DiffT>::value();  in distance()
1414         return icl::identity_element<DiffT>::value();  in distance()