23 pub struct ListHead {  struct
30 impl ListHead {  impl
41     pub fn insert_next(list: &ListHead) -> impl PinInit<Self, Infallible> + '_ {  in insert_next()
50     pub fn insert_prev(list: &ListHead) -> impl PinInit<Self, Infallible> + '_ {  in insert_prev()
80 impl PinnedDrop for ListHead {  implementation
94 struct Link(Cell<NonNull<ListHead>>);
104     unsafe fn new_unchecked(ptr: NonNull<ListHead>) -> Self {  in new_unchecked()
119     fn cur(&self) -> &ListHead {  in cur()  argument
129     fn as_ptr(&self) -> *const ListHead {  in as_ptr()  argument
142     let a = Box::pin_init(ListHead::new())?;  in main()
143     stack_pin_init!(let b = ListHead::insert_next(&a));  in main()
144     stack_pin_init!(let c = ListHead::insert_next(&a));  in main()
145     stack_pin_init!(let d = ListHead::insert_next(&b));  in main()
146     let e = Box::pin_init(ListHead::insert_next(&b))?;  in main()