virtual RangeCondition<T> *clone() const;
virtual bool can_merge(const Condition &, const CompoundCondition &) const;
virtual RangeCondition<T> *merge(const std::vector<Condition *> &, const CompoundCondition &) const;
+ virtual bool is_viable() const { return min<=max; }
virtual void add_lines(std::list<FilterStatement> &) const;
};