accumtraits3.hpp

C++ Templates 完全导引范例

/* 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 T>
class AccumulationTraits;

template<>
class AccumulationTraits<char> {
  public:
    typedef int AccT;
    static AccT const zero = 0;
};

template<>
class AccumulationTraits<short> {
  public:
    typedef int AccT;
    static AccT const zero = 0;
};

template<>
class AccumulationTraits<int> {
  public:
    typedef long AccT;
    static AccT const zero = 0;
};
//...