The following code example is taken from the book
C++ Templates - The Complete Guide, 2nd Edition
by David Vandevoorde, Nicolai M. Josuttis, and Douglas Gregor,
Addison-Wesley, 2017
© Copyright David Vandevoorde, Nicolai M. Josuttis, Douglas Gregor 2017
#include "accum1.hpp"
#include <iostream>
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, 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, name+length) / length
<< '\n';
}