SPLAY_ASSEMBLE
SPLAY_ASSEMBLE(head, &__node, __left, __right, field); \
SPLAY_ASSEMBLE(head, &__node, __left, __right, field); \
SPLAY_ASSEMBLE(head, &__node, __left, __right, field); \
SPLAY_ASSEMBLE(head, &__node, __left, __right, field); \