examples/manual/advance.cpp

/**************************************************************************
 *
 * advance.cpp - Example program for advancing iterators. 
 *
 * $Id$
 *
 ***************************************************************************
 *
 * Licensed to the Apache Software  Foundation (ASF) under one or more
 * contributor  license agreements.  See  the NOTICE  file distributed
 * with  this  work  for  additional information  regarding  copyright
 * ownership.   The ASF  licenses this  file to  you under  the Apache
 * License, Version  2.0 (the  "License"); you may  not use  this file
 * except in  compliance with the License.   You may obtain  a copy of
 * the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the  License is distributed on an  "AS IS" BASIS,
 * WITHOUT  WARRANTIES OR CONDITIONS  OF ANY  KIND, either  express or
 * implied.   See  the License  for  the  specific language  governing
 * permissions and limitations under the License.
 *
 * Copyright 1994-2006 Rogue Wave Software.
 * 
 **************************************************************************/

#include <iterator>   // for advance
#include <iostream>   // for cout, endl
#include <list>       // for list

#include <examples.h>


int main ()
{
    // Typedefs for convenience.
    typedef std::list<long, std::allocator<long> > List;
    typedef std::ostream_iterator<List::value_type,
                                  char, std::char_traits<char> > os_iter;

    // Initialize a list using an array.
    const List::value_type arr [] = { 3, 4, 5, 6, 7, 8 };
    List l (arr + 0, arr + sizeof arr / sizeof *arr);

    // Declare a list iterator, s.b. a ForwardIterator.
    List::iterator itr = l.begin ();

    // Output the original list.
    std::cout << "For the list: ";
    std::copy (l.begin (), l.end (), os_iter (std::cout, " "));

    std::cout << std::endl << std::endl
              << "When the iterator is initialized to l.begin ()," 
              << "\nit points to " << *itr << std::endl;

    // operator+ is not available for a ForwardIterator, so use advance.
    std::advance (itr, 4);
    std::cout << "\nAfter advance (itr, 4), the iterator points to "
              << *itr << std::endl;

    return 0;
}