37 #define TREE_INSERT_CHILD(treeelm, elm, field) do { \  argument
38 	(elm)->field.tn_parent = (treeelm); \
39 	if ((treeelm)->field.tn_last != NULL) { \
40 		(treeelm)->field.tn_last->field.tn_younger = (elm); \
41 		(elm)->field.tn_older = (treeelm)->field.tn_last; \
43 	(treeelm)->field.tn_last = (elm); \
44 	if ((treeelm)->field.tn_first == NULL) \
45 		(treeelm)->field.tn_first = (elm); \
48 #define TREE_INSERT_YOUNGER(treeelm, elm, field) do { \  argument
49 	(elm)->field.tn_parent = (treeelm)->field.tn_parent; \
50 	if ((treeelm)->field.tn_younger != NULL) { \
51 		(elm)->field.tn_younger = (treeelm)->field.tn_younger; \
54 	else if ((treeelm)->field.tn_parent != NULL) \
55 		(treeelm)->field.tn_parent->field.tn_last = (elm); \
56 	(treeelm)->field.tn_younger = (elm); \
57 	(elm)->field.tn_older = (treeelm); \
60 #define TREE_INSERT_OLDER(treeelm, elm, field) do { \  argument
61 	(elm)->field.tn_parent = (treeelm)->field.tn_parent; \
62 	if ((treeelm)->field.tn_older != NULL) { \
63 		(elm)->field.tn_older = (treeelm)->field.tn_older; \
66 	else if ((treeelm)->field.tn_parent != NULL) \
67 		(treeelm)->field.tn_parent->field.tn_first = (elm); \
68 	(treeelm)->field.tn_older = (elm); \
69 	(elm)->field.tn_younger = (treeelm); \