166   Segment *Tail;  variable
264     DCHECK_EQ(Tail, &SentinelSegment);  in InitHeadAndTail()
272     Tail = S;  in InitHeadAndTail()
273     DCHECK_EQ(Head, Tail);  in InitHeadAndTail()
274     DCHECK_EQ(Tail->Next, &SentinelSegment);  in InitHeadAndTail()
275     DCHECK_EQ(Tail->Prev, &SentinelSegment);  in InitHeadAndTail()
283     DCHECK_NE(Tail, &SentinelSegment);  in AppendNewSegment()
284     DCHECK_EQ(Tail->Next, &SentinelSegment);  in AppendNewSegment()
287     S->Prev = Tail;  in AppendNewSegment()
288     Tail->Next = S;  in AppendNewSegment()
289     Tail = S;  in AppendNewSegment()
291     DCHECK_EQ(Tail->Next, &SentinelSegment);  in AppendNewSegment()
299         Tail(&SentinelSegment),  in Array()
305                                   Tail(&SentinelSegment),  in Array()
314                                            Tail(O.Tail),  in Array()
319     O.Tail = &SentinelSegment;  in Array()
329     Tail = O.Tail;
330     O.Tail = &SentinelSegment;
354     DCHECK((Size == 0 && Head == &SentinelSegment && Head == Tail) ||  in AppendEmplace()
355            (Size != 0 && Head != &SentinelSegment && Tail != &SentinelSegment));  in AppendEmplace()
363     DCHECK_NE(Tail, &SentinelSegment);  in AppendEmplace()
370     DCHECK_NE(Tail, &SentinelSegment);  in AppendEmplace()
371     auto Base = &Tail->Data;  in AppendEmplace()
386     DCHECK((Size == 0 && Head == &SentinelSegment && Head == Tail) ||  in Append()
387            (Size != 0 && Head != &SentinelSegment && Tail != &SentinelSegment));  in Append()
395     DCHECK_NE(Tail, &SentinelSegment);  in Append()
402     DCHECK_NE(Tail, &SentinelSegment);  in Append()
403     auto Base = &Tail->Data;  in Append()
406               reinterpret_cast<unsigned char *>(Tail) + SegmentSize);  in Append()
436     DCHECK_NE(Tail, &SentinelSegment);  in back()
516       DCHECK_NE(Tail, &SentinelSegment);  in trim()
517       DCHECK_EQ(Tail->Next, &SentinelSegment);  in trim()
556         auto SPT = Tail->Prev;  in trim()
558         Tail->Prev = &SentinelSegment;  in trim()
559         Tail->Next = Freelist;  in trim()
560         Freelist = Tail;  in trim()
561         Tail = SPT;  in trim()
564         DCHECK_EQ(Tail->Next, &SentinelSegment);  in trim()
596         auto SPT = Tail->Prev;  in trim()
597         auto ST = Tail;  in trim()
602         Tail = SPT;  in trim()
606         DCHECK_EQ(Tail->Next, &SentinelSegment);  in trim()
615     if (Tail == &SentinelSegment)  in trim()
616       Head = Tail;  in trim()
619         (Size == 0 && Head == &SentinelSegment && Tail == &SentinelSegment) ||  in trim()
620         (Size != 0 && Head != &SentinelSegment && Tail != &SentinelSegment));  in trim()
623         (Freelist == &SentinelSegment && Tail->Next == &SentinelSegment));  in trim()
631     return Iterator<T>(Tail, Size, Size);  in end()
637     return Iterator<const T>(Tail, Size, Size);  in cend()