ObservedValue.h

// Main class (represents a single observed value)
class ObservedValue : public CSGObject
{
  ObservedValue();
  ObservedValue(int64_t step, std::string name, Any v);
  ~ObservedValue();
  
  int64_t get_step();
  std::string get_name();
  Any get_value();
  
  char * get_name() const
  {
    return "ObservedValue";
  }
  
  protected:
    int64_t step;
    std::string name;
    Any value;
  
};

// ObservedValue which store CrossValidation types
class CrossValidationObservedValue() : public ObservedValue
{
  // Cross Validation specific values
}

class CSGObject
{
.....

  void observe(ObservedValue& value);
  
}