template function with pointer parameter : template pointer parameter « template « C++ Tutorial

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2. template
3. template pointer parameter

/* 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.
 */

#include <iostream>


template <typename T>
inline
T accum (T const* beg, T const* end)
{
    T total = T();  // assume T() actually creates a zero value
    while (beg != end) {
        total += *beg;
        ++beg;
    }
    return total;
}


int main()
{
    // create array of 5 integer values
    int num[] = { 1, 2, 3, 4, 5 };

    // print average value
    std::cout << "the average value of the integer values is "
              << accum(&num[0], &num[5]) / 5
              << '\n';

    // create array of character values
    char name[] = "templates";
    int length = sizeof(name)-1;

    // (try to) print average character value
    std::cout << "the average value of the characters in \""
              << name << "\" is "
              << accum(&name[0], &name[length]) / length
              << '\n';
}

the average value of the integer values is 3
the average value of the characters in "templates" is -5