CHN_LINK
#define CHN_NEXT(elm, list) SLIST_NEXT((elm), CHN_LINK(list))
SLIST_FOREACH(x, CHN_HEAD(y, z), CHN_LINK(z))
SLIST_FOREACH_SAFE(w, CHN_HEAD(x, z), CHN_LINK(z), y)
SLIST_INSERT_HEAD(CHN_HEAD(x, z), y, CHN_LINK(z))
SLIST_INSERT_AFTER(x, y, CHN_LINK(z))
SLIST_REMOVE_HEAD(CHN_HEAD(holder, list), CHN_LINK(list)); \
SLIST_REMOVE_AFTER(t, CHN_LINK(list)); \