counting.cpp

#include <boost/iterator/counting_iterator.hpp>
#include <boost/iterator/indirect_iterator.hpp>
#include <boost/cstdlib.hpp>
#include <algorithm>
#include <iostream>
#include <iterator>
#include <vector>

using namespace std;
using namespace boost;

int main(int, char*[])
{
  // Example of using counting_iterator
  cout << "counting from 0 to 4:" << endl;
  counting_iterator<int> first(0), last(4);
  copy(first, last, ostream_iterator<int>(cout, " "));
  cout << endl;

  // Example of using make_counting_iterator()
  cout << "counting from -5 to 4:" << endl;
  copy(make_counting_iterator(-5), make_counting_iterator(5),
       ostream_iterator<int>(cout, " "));
  cout << endl;

  // Example of using counting iterator to create an array of pointers.
  int N = 7;
  vector<int> numbers;
  // Fill "numbers" array with [0,N)
  copy(counting_iterator<int>(0), counting_iterator<int>(N), 
      back_inserter(numbers));

  vector<vector<int>::iterator> pointers;

  // Use counting iterator to fill in the array of pointers.
  // causes an ICE with MSVC6
  copy(make_counting_iterator(numbers.begin()),
       make_counting_iterator(numbers.end()),
       back_inserter(pointers));

  // Use indirect iterator to print out numbers by accessing
  // them through the array of pointers.
  cout << "indirectly printing out the numbers from 0 to " 
       << N << endl;

  copy(make_indirect_iterator(pointers.begin()),
      make_indirect_iterator(pointers.end()),
      ostream_iterator<int>(cout, " "));

  cout << endl;

  return boost::exit_success;
}