progress with integrating the segmented Fusion work

[SVN r73831]

include/boost/fusion/support/is_segmented.hpp

@@ -0,0 +1,51 @@
+/*=============================================================================
+    Copyright (c) 2006 Eric Niebler
+
+    Distributed under 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_IS_SEGMENTED_03202006_0015)
+#define FUSION_IS_SEGMENTED_03202006_0015
+
+#include <boost/fusion/support/tag_of.hpp>
+
+namespace boost { namespace fusion 
+{
+    // Special tags:
+    struct sequence_facade_tag;
+    struct iterator_range_tag;
+
+    namespace extension
+    {
+        template <typename Tag>
+        struct is_segmented_impl
+        {
+            template <typename Sequence>
+            struct apply
+              : mpl::false_
+            {};
+        };
+
+        template <>
+        struct is_segmented_impl<sequence_facade_tag>
+        {
+            template <typename Sequence>
+            struct apply : Sequence::is_segmented {};
+        };
+
+        template <>
+        struct is_segmented_impl<iterator_range_tag>;
+    }
+
+    namespace traits
+    {
+        template <typename Sequence>
+        struct is_segmented
+          : extension::is_segmented_impl<typename traits::tag_of<Sequence>::type>::
+                template apply<Sequence>
+        {
+        };
+    }
+}}
+
+#endif