accum4.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.
 */
#ifndef ACCUM_HPP
#define ACCUM_HPP

#include "accumtraits4.hpp"

template <typename T>
inline
typename AccumulationTraits<T>::AccT accum (T const* beg,
                                            T const* end) 
{
    // return type is traits of the element type
    typedef typename AccumulationTraits<T>::AccT AccT;

    AccT total = AccumulationTraits<T>::zero();
    while (beg != end) {
        total += *beg;
        ++beg;
    }
    return total;
}

#endif // ACCUM_HPP