1st draft

[SVN r8939]

development/boost/iterator_traits.hpp

@@ -0,0 +1,60 @@
+#ifndef BOOST_ITERATOR_TRAITS_HPP
+#define BOOST_ITERATOR_TRAITS_HPP
+
+#include <boost/config.hpp>
+#include <boost/type_traits.hpp>
+
+namespace boost {
+  
+  template <typename Iterator>
+  struct iterator_traits {
+    typedef typename Iterator::value_type value_type;
+    typedef typename Iterator::reference reference;
+    typedef typename Iterator::pointer pointer;
+    typedef typename Iterator::difference_type difference_type;
+    typedef typename Iterator::return_category return_category;
+    typedef typename Iterator::motion_category motion_category;
+  };
+
+  // Motion Categories
+  struct single_pass_iterator_tag { };
+  struct forward_iterator_tag : public single_pass_iterator_tag { };
+  struct bidirectional_iterator_tag : public forward_iterator_tag { };
+  struct random_access_iterator_tag : public bidirectional_iterator_tag { };
+  
+  // Return Type Categories
+  struct readable_iterator_tag { };
+  struct writable_iterator_tag { };
+  struct mutable_lvalue_iterator_tag : virtual public writable_iterator_tag,
+    virtual public readable_iterator_tag { };
+  struct constant_lvalue_iterator_tag : public readable_iterator_tag { };
+  
+#if !defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION)
+
+  namespace detail {
+    template <bool IsConst>
+    struct pointer_return_category {
+      typedef constant_lvalue_iterator_tag type;
+    };
+    template <>
+    struct pointer_return_category<false> {
+      typedef mutable_lvalue_iterator_tag type;
+    };
+  } // namespace detail
+
+  template <typename T>
+  struct iterator_traits<T*> {
+    typedef T value_type;
+    typedef T& reference;
+    typedef T* pointer;
+    typedef std::ptrdiff_t difference_type;
+    typedef typename detail::pointer_return_category<is_const<T>::value>::type
+      return_category;
+    typedef random_access_iterator_tag motion_category;
+  };
+
+#endif
+
+} // namespace boost
+
+#endif // BOOST_ITERATOR_TRAITS_HPP