traits/accumtraits4.hpp

The following code example is taken from the book
C++ Templates - The Complete Guide
by David Vandevoorde and Nicolai M. Josuttis, Addison-Wesley, 2002
© Copyright David Vandevoorde and Nicolai M. Josuttis 2002


template<typename T>
class AccumulationTraits;

template<>
class AccumulationTraits<char> {
  public:
    typedef int AccT;
    static AccT zero() {
        return 0;
    }
};

template<>
class AccumulationTraits<short> {
  public:
    typedef int AccT;
    static AccT zero() {
        return 0;
    }
};

template<>
class AccumulationTraits<int> {
  public:
    typedef long AccT;
    static AccT zero() {
        return 0;
    }
};

template<>
class AccumulationTraits<unsigned int> {
  public:
    typedef unsigned long AccT;
    static AccT zero() {
        return 0;
    }
};

template<>
class AccumulationTraits<float> {
  public:
    typedef double AccT;
    static AccT zero() {
        return 0;
    }
};
//...