libs/iterator/example/counting_iterator_example.cpp
// (C) Copyright Jeremy Siek 2000-2004.
// Distributed under the Boost Software License, Version 1.0. (See
// accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
#include <boost/config.hpp>
#include <algorithm>
#include <iostream>
#include <iterator>
#include <vector>
#include <boost/iterator/counting_iterator.hpp>
#include <boost/iterator/indirect_iterator.hpp>
#include <boost/cstdlib.hpp>
int main(int, char*[])
{
// Example of using counting_iterator
std::cout << "counting from 0 to 4:" << std::endl;
boost::counting_iterator<int> first(0), last(4);
std::copy(first, last, std::ostream_iterator<int>(std::cout, " "));
std::cout << std::endl;
// Example of using counting iterator to create an array of pointers.
int N = 7;
std::vector<int> numbers;
typedef std::vector<int>::iterator n_iter;
// Fill "numbers" array with [0,N)
std::copy(
boost::counting_iterator<int>(0)
, boost::counting_iterator<int>(N)
, std::back_inserter(numbers));
std::vector<std::vector<int>::iterator> pointers;
// Use counting iterator to fill in the array of pointers.
// causes an ICE with MSVC6
std::copy(boost::make_counting_iterator(numbers.begin()),
boost::make_counting_iterator(numbers.end()),
std::back_inserter(pointers));
// Use indirect iterator to print out numbers by accessing
// them through the array of pointers.
std::cout << "indirectly printing out the numbers from 0 to "
<< N << std::endl;
std::copy(boost::make_indirect_iterator(pointers.begin()),
boost::make_indirect_iterator(pointers.end()),
std::ostream_iterator<int>(std::cout, " "));
std::cout << std::endl;
return boost::exit_success;
}