/* 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. */template<typename T1, typename T2>class Promotion<Array<T1>, Array<T2> > {  public:    typedef Array<typename Promotion<T1,T2>::ResultT> ResultT;};template<typename T>class Promotion<Array<T>, Array<T> > {  public:    typedef Array<typename Promotion<T,T>::ResultT> ResultT;};