The following code example is taken from the book
The C++ Standard Library - A Tutorial and Reference, 2nd Edition
by Nicolai M. Josuttis, Addison Wesley Longman, 2012
Copyright © 2012 by Pearson Education, Inc. and Nicolai M. Josuttis
#include <iterator>
#include <iostream>
#include <string>
#include <algorithm>
using namespace std;
int main()
{
istream_iterator<string> cinPos(cin);
ostream_iterator<string> coutPos(cout," ");
// while input is not at the end of the file
// - write every third string
while (cinPos != istream_iterator<string>()) {
// ignore the following two strings
advance (cinPos, 2);
// read and write the third string
if (cinPos != istream_iterator<string>()) {
*coutPos++ = *cinPos++;
}
}
cout << endl;
}