/* The following code example is taken from the book * "C++ Templates - The Complete Guide" * by David Vandevoorde and Nicolai M. Josuttis, Addison-Wesley, 2002 * * (C) Copyright David Vandevoorde and Nicolai M. Josuttis 2002. * Permission to copy, use, modify, sell and distribute this software * is granted provided this copyright notice appears in all copies. * This software is provided "as is" without express or implied * warranty, and with no claim as to its suitability for any purpose. */#include "ifthenelse.hpp"template <typename F, int N>class UsedFunctorParam;template <typename F, int N>class FunctorParam {  private:    class Unused {      private:        class Private {};      public:        typedef Private Type;    };  public:    typedef typename IfThenElse<F::NumParams>=N,                                UsedFunctorParam<F,N>,                                 Unused>::ResultT::Type            Type;};template <typename F>class UsedFunctorParam<F, 1> {  public:    typedef typename F::Param1T Type;};