/* 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. */#define FunctorParamSpec(N)                           \        template<typename F>                          \        class UsedFunctorParam<F, N> {                \          public:                                     \            typedef typename F::Param##N##T Type;     \        }//...FunctorParamSpec(2);FunctorParamSpec(3);//...FunctorParamSpec(20);#undef FunctorParamSpec