added make_xxx functions for some of the iterators

[SVN r21611]

example/counting_iterator_example.cpp

@@ -0,0 +1,54 @@
+// (C) Copyright Jeremy Siek 2000-2004.
+// 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 <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;
+}