//InvalidQuality.h

#ifndef InvalidQuality_H
#define InvalidQuality_H

// Invalid Quality is a concrete subclass of Quality.  It behaves 
// like any unacceptable quality: any acceptable quality will be found
// better in comparison.
//

#include "Quality.h"

class InvalidQuality : public Quality {

private:  // attributes

  // define the type
  static void* _mytype;

private:  // methods

  // return the type
  void* get_type() const { return _mytype; };

  // comparison
  bool _is_better_than(const Quality& quality) const
    { return false; };

public:

  bool is_valid() const;

};

#endif