40   T *back() { return Last; }  in back()
41   const T *back() const { return Last; }  in back()
44     First = Last = nullptr;  in clear()
62   T *Last = nullptr;  member
68     CHECK_EQ(Last, nullptr);  in checkConsistency()
73       if (I == Last)  in checkConsistency()
77     CHECK_EQ(Last->Next, nullptr);  in checkConsistency()
83   using IntrusiveList<T>::Last;
92       Last->Next = X;  in push_back()
93     Last = X;  in push_back()
99       Last = X;  in push_front()
109       Last = nullptr;  in pop_front()
120     if (Last == Prev)  in insert()
121       Last = X;  in insert()
131     if (Last == X)  in extract()
132       Last = Prev;  in extract()
143       Last->Next = L->First;  in append_back()
144       Last = L->Last;  in append_back()
153   using IntrusiveList<T>::Last;
160       Last = X;  in push_front()
190       DCHECK_EQ(Last->Next, nullptr);  in push_back()
191       Last->Next = X;  in push_back()
193     X->Prev = Last;  in push_back()
194     Last = X;  in push_back()
202       Last = nullptr;  in pop_front()
228     if (Last == X) {  in remove()
230       Last = Prev;  in remove()