24     tail: *const Node<T>,  field
34             tail: null(),  in new()
57             node.prev = self.tail;  in push_back()
61             if self.tail.is_null() {  in push_back()
64                 (*(self.tail as *mut Node<T>)).next = node;  in push_back()
67             self.tail = node;  in push_back()
74         if self.tail.is_null() {  in pop_back()
78                 let node = Box::from_raw(self.tail as *mut Node<T>);  in pop_back()
79                 self.tail = node.prev;  in pop_back()
81                 if self.tail.is_null() {  in pop_back()
84                     (*(self.tail as *mut Node<T>)).next = null();  in pop_back()
98             tail: self.tail,  in iter()
109             tail: self.tail,  in iter_mut()
141             current: self.tail,  in cursor_back()
152             current: self.tail,  in cursor_back_mut()
161         if self.tail.is_null() {  in back()
164             unsafe { Some(&(*self.tail).element) }  in back()
171         if self.tail.is_null() {  in back_mut()
174             unsafe { Some(&mut (*(self.tail as *mut Node<T>)).element) }  in back_mut()
182         if self.tail.is_null() {  in back_node()
185             unsafe { Some(&(*self.tail)) }  in back_node()
193         if self.tail.is_null() {  in back_node_mut()
198                 let node = &mut *(self.tail as *mut Node<T>);  in back_node_mut()
216             self.tail = node.prev;  in unlink_node()
325     tail: *const Node<T>,  field
360         if self.len == 0 || self.tail.is_null() {  in next_back()
363             let node = unsafe { &*(self.tail as *mut Node<T>) };  in next_back()
365             self.tail = node.prev;  in next_back()
374     tail: *const Node<T>,  field
410         if self.len == 0 || self.tail.is_null() {  in next_back()
413             let node = unsafe { &mut *(self.tail as *mut Node<T>) };  in next_back()
415             self.tail = node.prev;  in next_back()
457             self.current = self.list.tail;  in move_prev()
525             self.current = self.list.tail;  in move_prev()