Initial move from Spirit CVS

[SVN r34896]

include/boost/fusion/iterator/deref.hpp

@@ -0,0 +1,52 @@
+/*=============================================================================
+    Copyright (c) 2001-2006 Joel de Guzman
+
+    Use, modification and distribution is subject to 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)
+==============================================================================*/
+#if !defined(FUSION_DEREF_05042005_1019)
+#define FUSION_DEREF_05042005_1019
+
+#include <boost/fusion/support/iterator_base.hpp>
+#include <boost/fusion/support/tag_of.hpp>
+
+namespace boost { namespace fusion
+{
+    namespace extension
+    {
+        template <typename Tag>
+        struct deref_impl
+        {
+            template <typename Iterator>
+            struct apply {};
+        };
+    }
+
+    namespace result_of
+    {
+        template <typename Iterator>
+        struct deref
+            : extension::deref_impl<typename detail::tag_of<Iterator>::type>::
+                template apply<Iterator>
+        {};
+    }
+
+    template <typename Iterator>
+    typename result_of::deref<Iterator>::type
+    deref(Iterator const& i)
+    {
+        typedef result_of::deref<Iterator> deref_meta;
+        typename deref_meta::type result(deref_meta::call(i));
+        return result;
+    }
+
+    template <typename Iterator>
+    typename result_of::deref<Iterator>::type
+    operator*(iterator_base<Iterator> const& i)
+    {
+        return fusion::deref(i.cast());
+    }
+}}
+
+#endif