istriter.cpp

stl自带源码

/* The following code example is taken from the book
 * "The C++ Standard Library - A Tutorial and Reference"
 * by Nicolai M. Josuttis, Addison-Wesley, 1999
 *
 * (C) Copyright Nicolai M. Josuttis 1999.
 * 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>
#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;
    }
}