skiplist/item.go
func CompareInt(this, that unsafe.Pointer) int {
	thisItem := (*intKeyItem)(this)
	thatItem := (*intKeyItem)(that)
	return int(*thisItem - *thatItem)
}
func CompareInt(this, that unsafe.Pointer) int {
	thisItem := (*intKeyItem)(this)
	thatItem := (*intKeyItem)(that)
	return int(*thisItem - *thatItem)
}
// CompareInt is a helper integer item comparator