struct sAC_ColumnSort : public ValueOrder {
	bool              descending;
	const ValueOrder *order;
	int             (*cmp)(const Value& a, const Value& b);

	virtual bool operator()(const Value& a, const Value& b) const {
		return descending ? cmp ? (*cmp)(b, a) < 0 : (*order)(b, a)
		                  : cmp ? (*cmp)(a, b) < 0 : (*order)(a, b);
	}
};