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;
+}

example/filter_iterator_example.cpp

@@ -0,0 +1,60 @@
+//  (C) Copyright Jeremy Siek 1999-2004.
+//  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 <functional>
+#include <iostream>
+#include <boost/iterator/filter_iterator.hpp>
+#include <boost/cstdlib.hpp> // for exit_success
+
+struct is_positive_number {
+  bool operator()(int x) { return 0 < x; }
+};
+
+int main()
+{
+  int numbers_[] = { 0, -1, 4, -3, 5, 8, -2 };
+  const int N = sizeof(numbers_)/sizeof(int);
+  
+  typedef int* base_iterator;
+  base_iterator numbers(numbers_);
+  
+  // Example using make_filter_iterator()
+  std::copy(boost::make_filter_iterator<is_positive_number>(numbers, numbers + N),
+            boost::make_filter_iterator<is_positive_number>(numbers + N, numbers + N),
+            std::ostream_iterator<int>(std::cout, " "));
+  std::cout << std::endl;
+
+  // Example using filter_iterator
+  typedef boost::filter_iterator<is_positive_number, base_iterator>
+    FilterIter;
+  
+  is_positive_number predicate;
+  FilterIter filter_iter_first(predicate, numbers, numbers + N);
+  FilterIter filter_iter_last(predicate, numbers + N, numbers + N);
+
+  std::copy(filter_iter_first, filter_iter_last, std::ostream_iterator<int>(std::cout, " "));
+  std::cout << std::endl;
+
+  // Another example using make_filter_iterator()
+  std::copy(
+      boost::make_filter_iterator(
+          std::bind2nd(std::greater<int>(), -2)
+        , numbers, numbers + N)
+            
+    , boost::make_filter_iterator(
+          std::bind2nd(std::greater<int>(), -2)
+        , numbers + N, numbers + N)
+      
+    , std::ostream_iterator<int>(std::cout, " ")
+  );
+  
+  std::cout << std::endl;
+  
+  return boost::exit_success;
+}

example/reverse_iterator_example.cpp

@@ -0,0 +1,43 @@
+// (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 <iostream>
+#include <algorithm>
+#include <boost/iterator/reverse_iterator.hpp>
+#include <boost/cstdlib.hpp>
+
+int main(int, char*[])
+{
+  char letters_[] = "hello world!";
+  const int N = sizeof(letters_)/sizeof(char) - 1;
+  typedef char* base_iterator;
+  base_iterator letters(letters_);
+  
+  std::cout << "original sequence of letters:\t\t\t"
+            << letters_ << std::endl;
+
+  // Use reverse_iterator to print a sequence of letters in reverse
+  // order.
+  
+  boost::reverse_iterator<base_iterator>
+    reverse_letters_first(letters + N),
+    reverse_letters_last(letters);
+
+  std::cout << "sequence in reverse order:\t\t\t";
+  std::copy(reverse_letters_first, reverse_letters_last,
+            std::ostream_iterator<char>(std::cout));
+  std::cout << std::endl;
+
+  std::cout << "sequence in double-reversed (normal) order:\t";
+  std::copy(boost::make_reverse_iterator(reverse_letters_last),
+            boost::make_reverse_iterator(reverse_letters_first),
+            std::ostream_iterator<char>(std::cout));
+  std::cout << std::endl;
+
+  return boost::exit_success;
+}