#include <set>

namespace AAA {
   class ISoul {
   public:
      ISoul(){}

      ClassDef(ISoul,0)
   };

   namespace BBB {
      template<typename T> class IConst : public AAA::ISoul {
      public:
	 IConst() {}
	 virtual IConst* Create( IConst* /*parent*/, T /*value*/ ) { return NULL; }
	 virtual void    Set( T /*value*/ ) {}
	 ClassDef(IConst,0)
      };


      template<typename T> class Const;
      

      template<typename T> class Value : public AAA::BBB::IConst<T> {
      public:
         Value( Const<T>* cnst ) : AAA::BBB::IConst<T>() { fConst = cnst; }
	 virtual IConst<T>* Create( IConst<T>* parent, T value ) {
	    if( parent == NULL )
	       return fConst->Create(this,value);
	    return fConst->Create(parent,value);
	 }
	 virtual void    Set( T value ) { fValue = value; }
	 
      protected:
	 Const<T>* fConst;
	 T fValue;

	 ClassDef(Value,0)
      };


      template<typename T> class Const : public AAA::BBB::IConst<T> {

	 typedef std::set< AAA::BBB::IConst<T> * > ConstSet;
	 typedef typename ConstSet::iterator ConstSetIterator;

      public:
	 Const() : AAA::BBB::IConst<T>()  {}
	 virtual IConst<T>* Create( IConst<T>* parent, T value ) {
	    ConstSetIterator it  = fConstValues.find( parent );
	    if( it != fConstValues.end() ){
	       return (*it);
	    }
	    IConst<T>* cnst = new Value<T>(this);
	    cnst->Set( value );
	    fConstValues.insert( cnst );
	    return cnst;
	 }
	 
      protected:
	 ConstSet fConstValues;

	 ClassDef(Const,0)
      };



   }
}


int main(){
   AAA::BBB::Const<Float_t>* cnst = new AAA::BBB::Const<Float_t>();
   AAA::ISoul* s = cnst->Create(NULL,33.3);

}