33 /// * If the list is empty, then `first` is null. Otherwise, `first` points at the `ListLinks`
34 ///   field of the first element in the list.
264     first: *mut ListLinksFields,  field
470             first: ptr::null_mut(),  in new()
477         self.first.is_null()  in is_empty()
482     /// Returns a pointer to the newly inserted element. Never changes `self.first` unless the list
514             self.first = item;  in insert_inner()
536         // * `self.first` is null or in the list.  in push_back()
537         // * `self.first` is only null if the list is empty.  in push_back()
538         unsafe { self.insert_inner(item, self.first) };  in push_back()
544         // * `self.first` is null or in the list.  in push_front()
545         // * `self.first` is only null if the list is empty.  in push_front()
546         let new_elem = unsafe { self.insert_inner(item, self.first) };  in push_front()
549         self.first = new_elem;  in push_front()
559         let last = unsafe { (*self.first).prev };  in pop_back()
564     /// Removes the first item from this list.
570         // SAFETY: The first item of this list is in this list.  in pop_front()
571         Some(unsafe { self.remove_internal(self.first) })  in pop_front()
666         //  * If `item` was not the first item, then `self.first` should remain unchanged.  in remove_internal_inner()
667         //  * If `item` was the first item and there is another item, then we just updated  in remove_internal_inner()
668         //    `prev->next` to `next`, which is the new first item, and setting `item->next` to null  in remove_internal_inner()
671         //    `item->next` to null, so this correctly sets `first` to null now that the list is  in remove_internal_inner()
673         if self.first == item {  in remove_internal_inner()
677             self.first = unsafe { (*prev).next };  in remove_internal_inner()
694         // First, we insert the elements into `self`. At the end, we make `other` empty.  in push_all_back()
697             self.first = other.first;  in push_all_back()
699             let other_first = other.first;  in push_all_back()
702             let self_first = self.first;  in push_all_back()
708             // update `self.first` because the first element of `self` does not change.  in push_all_back()
718         other.first = ptr::null_mut();  in push_all_back()
721     /// Returns a cursor that points before the first element of the list.
723         // INVARIANT: `self.first` is in this list.  in cursor_front()
725             next: self.first,  in cursor_front()
742         // at the first element of the same list.  in iter()
744             current: self.first,  in iter()
745             stop: self.first,  in iter()
771 /// * The `stop` pointer is equal to the `first` field of that [`List`].
848 /// // Use a cursor to remove the first element with the given value.
960         let first = self.list.first;  in prev_ptr()  localVariable
961         if next == first {  in prev_ptr()
962             // We are before the first element.  in prev_ptr()
968             // the same as `(*first).prev`.  in prev_ptr()
969             next = first;  in prev_ptr()
972         // SAFETY: `next` can't be null, because then `first` must also be null, but in that case  in prev_ptr()
973         // we would have exited at the `next == first` check. Thus, `next` is an element in the  in prev_ptr()
1023         if next == self.list.first {  in move_next()
1034     /// If the cursor is before the first element, then this call does nothing. This call returns
1037         if self.next == self.list.first {  in move_prev()
1049             self.list.first  in insert_inner()
1055         // * if `ptr` is null, then `self.list.first` is null so the list is empty.  in insert_inner()
1057         if self.next == self.list.first {  in insert_inner()
1059             self.list.first = item;  in insert_inner()
1136         //   access requires first releasing the immutable borrow on the `CursorPeek`.  in arc()
1162         // requires first releasing the immutable borrow on the `CursorPeek`.  in deref()