#ifndef ROOT_ASTRO_TFitsKeyValue
#define ROOT_ASTRO_TFitsKeyValue

#ifndef ROOT_TObject
#include "TObject.h"
#endif

class TFitsPlaceHolder : public TObject {
public:
  TFitsPlaceHolder() : TObject() {}
  TFitsPlaceHolder(const TFitsPlaceHolder&) : TObject() {}
  TFitsPlaceHolder& operator=(const TFitsPlaceHolder& rhs);
  virtual ~TFitsPlaceHolder() {}

  virtual Bool_t                 AsBool() const = 0;
  virtual Int_t                  AsInt() const = 0;
  virtual Bool_t                 IsBool() const = 0;
  virtual Bool_t                 IsInt() const = 0;

  ClassDef(TFitsPlaceHolder,0)
};

template<typename T>
class TFitsHolder : public TFitsPlaceHolder {
private:
  TFitsHolder& operator=(const TFitsHolder& rhs); // hidden

public:
  T fHeld;

  TFitsHolder(const T& value = T()) : fHeld(value) {}
  virtual ~TFitsHolder() {}

  virtual Bool_t                 AsBool() const;
  virtual Int_t                  AsInt() const;
  virtual Bool_t                 IsBool() const {return typeid(T) == typeid(Bool_t);}
  virtual Bool_t                 IsInt() const {return typeid(T) == typeid(Int_t);}

  ClassDef(TFitsHolder,1)
};

class TFitsKeyValue : public TObject {
private:
  TFitsPlaceHolder* fContent; //->

public:
  TFitsKeyValue() : TObject(), fContent(0) {}
  TFitsKeyValue(const TFitsKeyValue& value);
  template<typename T> TFitsKeyValue(const T& value);
  TFitsKeyValue& operator=(const TFitsKeyValue& rhs);
  virtual ~TFitsKeyValue() {SafeDelete(fContent);}

  virtual Bool_t                 AsBool() const {return fContent ? fContent->AsBool() : 0;}
  virtual Int_t                  AsInt() const {return fContent ? fContent->AsInt() : 0;}
  virtual Bool_t                 IsBool() const {return fContent ? fContent->IsBool() : kFALSE;}
  virtual Bool_t                 IsInt() const {return fContent ? fContent->IsInt() : kFALSE;}

  virtual operator Bool_t() {return AsBool();}
  virtual operator Int_t() {return AsInt();}

  ClassDef(TFitsKeyValue,1) // FITS card value
};

#endif