72       return (tail - head == o.tail - o.head)  in operator ==()
74 	  && 0 == hb_memcmp (head, o.head, tail - head)  in operator ==()
79       return hb_bytes_t (head, tail - head).hash () ^  in hash()
93     char *head;  member
101     char *head;  member
108   { return snapshot_t { head, tail, current, current->links.length }; }  in snapshot()
151     this->head = this->start;  in reset()
205 		     (unsigned) (this->head - this->start),  in end_serialize()
241       obj->head = head;  in push()
255     revert (obj->head, obj->tail);  in pop_discard()
271     obj->tail = head;  in pop_pack()
273     unsigned len = obj->tail - obj->head;  in pop_pack()
274     head = obj->head; /* Rewind head. */  in pop_pack()
294     memmove (tail, obj->head, len);  in pop_pack()
296     obj->head = tail;  in pop_pack()
323     revert (snap.head, snap.tail);  in revert()
330     assert (snap_head <= head);  in revert()
332     head = snap_head;  in revert()
341 	   packed.tail ()->head < tail)  in discard_stale_objects()
349       assert (packed.tail ()->head == tail);  in discard_stale_objects()
364     assert (current->head <= (const char *) &ofs);  in add_link()
371     link.position = (const char *) &ofs - current->head;  in add_link()
381     assert (current->head <= (const char *) base);  in to_bias()
382     return (const char *) base - current->head;  in to_bias()
399 	case Head:     offset = child->head - parent->head; break;  in resolve_links()
400 	case Tail:     offset = child->head - parent->tail; break;  in resolve_links()
401 	case Absolute: offset = (head - start) + (child->head - tail); break;  in resolve_links()
426     return this->head - current->head;  in length()
438   { return reinterpret_cast<Type *> (this->head); }  in start_embed()
453     if (this->tail - this->head < ptrdiff_t (size))  in allocate_size()
458     memset (this->head, 0, size);  in allocate_size()
459     char *ret = this->head;  in allocate_size()
460     this->head += size;  in allocate_size()
518     assert ((char *) obj <= this->head);  in extend_size()
519     assert ((char *) obj + size >= this->head);  in extend_size()
520     if (unlikely (!this->allocate_size<Type> (((char *) obj) + size - this->head))) return nullptr;  in extend_size()
544     unsigned int len = (this->head - this->start)  in copy_bytes()
550     memcpy (p, this->start, this->head - this->start);  in copy_bytes()
551     memcpy (p + (this->head - this->start), this->tail, this->end - this->tail);  in copy_bytes()
572     auto &off = * ((BEInt<T> *) (parent->head + link.position));  in assign_offset()
578   char *start, *head, *tail, *end;  member