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 <iostream>
#include <iterator>
using namespace std;
int main()
{
// create istream iterator that reads integers from cin
istream_iterator<int> intReader(cin);
// create end-of-stream iterator
istream_iterator<int> intReaderEOF;
// while able to read tokens with istream iterator
// - write them twice
while (intReader != intReaderEOF) {
cout << "once: " << *intReader << endl;
cout << "once again: " << *intReader << endl;
++intReader;
}
}