Cast.h

//-*-C++-*-
/***************************************************************************
 *
 *   Copyright (C) 2011 by Willem van Straten
 *   Licensed under the Academic Free License version 2.1
 *
 ***************************************************************************/
 
// psrchive/More/MEAL/MEAL/Cast.h
 
#ifndef __MEAL_Cast_H
#define __MEAL_Cast_H
 
namespace MEAL {
 
 
  template<class To, class From>
  class Cast : public To
  {
 
  public:
 
    typedef typename To::Result Result;
 
    Cast (From* _from)
    {
      from = _from;  
      this->copy_parameter_policy  (from);
    }
 
    std::string get_name () const
    { return std::string("Cast")
        + "<To=" + To::Name + ",From=" + From::Name + ">"; }
 
  protected:
 
    void calculate (Result& result, std::vector<Result>* gradient)
    {
      std::vector<typename From::Result> from_grad;
      std::vector<typename From::Result>* from_gradptr = &from_grad;
      if (!gradient)
        from_gradptr = 0;
 
      typename From::Result from_result = from->evaluate (from_gradptr);
 
      result = static_cast<Result> (from_result);
 
      if (!gradient)
        return;
 
      gradient->resize( from_grad.size() );
      for (unsigned igrad=0; igrad<from_grad.size(); igrad++)
        (*gradient)[igrad] = static_cast<Result> (from_grad[igrad]);
    }
 
    Reference::To<From> from;
 
  };
 
  template<class To, class From>
  To* cast (From* from)
  { return new Cast<To, From> (from); }
 
  template<class To, class From>
  To* cast (Reference::To<From>& from)
  { return new Cast<To, From> (from.get()); }
 
}
 
#endif