Code Fragment: UnionMerger

template <typename Object, typename Sequence>		// set union
class UnionMerger : public Merger<Object, Sequence> {
protected:
  virtual void aIsLess(const Object& a, Sequence& C)
    { C.insertLast(a); }				// add a
  virtual void bothEqual(const Object& a, const Object& b, Sequence& C)
    { C.insertLast(a); }    				// add a only
  virtual void bIsLess(const Object& b, Sequence& C)
    { C.insertLast(b); }   				// add b
public:
  UnionMerger() { }
};