Initial move from Spirit CVS

[SVN r34896]

include/boost/fusion/iterator/advance.hpp

@@ -0,0 +1,72 @@
+/*=============================================================================
+    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_ADVANCE_09172005_1146)
+#define FUSION_ADVANCE_09172005_1146
+
+#include <boost/fusion/iterator/detail/advance.hpp>
+#include <boost/fusion/support/category_of.hpp>
+
+#include <boost/mpl/int.hpp>
+#include <boost/mpl/assert.hpp>
+#include <boost/type_traits/is_same.hpp>
+#include <boost/fusion/support/tag_of.hpp>
+
+namespace boost { namespace fusion
+{
+    struct random_access_traversal_tag;
+
+    namespace extension
+    {
+        template <typename Tag>
+        struct advance_impl
+        {
+            // default implementation
+            template <typename Iterator, typename N>
+            struct apply :
+                mpl::if_c<
+                    (N::value > 0)
+                  , advance_detail::forward<Iterator, N::value>
+                  , advance_detail::backward<Iterator, N::value>
+                >::type
+            {
+                typedef typename traits::category_of<Iterator>::type category;
+                BOOST_MPL_ASSERT_NOT((is_same<category, random_access_traversal_tag>));
+            };
+        };
+    }
+    
+    namespace result_of
+    {
+        template <typename Iterator, int N>
+        struct advance_c
+            : extension::advance_impl<typename detail::tag_of<Iterator>::type>::template apply<Iterator, mpl::int_<N> >
+        {};
+
+        template <typename Iterator, typename N>
+        struct advance
+            : extension::advance_impl<typename detail::tag_of<Iterator>::type>::template apply<Iterator, N>
+        {};
+    }
+
+    template <int N, typename Iterator>
+    inline typename result_of::advance_c<Iterator, N>::type
+    advance_c(Iterator const& i)
+    {
+        return result_of::advance_c<Iterator, N>::call(i);
+    }
+
+    template<typename N, typename Iterator>
+    inline typename result_of::advance<Iterator, N>::type
+    advance(Iterator const& i)
+    {
+        return result_of::advance<Iterator, N>::call(i);
+    }
+
+}} // namespace boost::fusion
+
+#endif