progress with integrating the segmented Fusion work

[SVN r73831]

include/boost/fusion/sequence/intrinsic/segments.hpp

@@ -0,0 +1,69 @@
+/*=============================================================================
+    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(BOOST_FUSION_SEGMENTS_04052005_1141)
+#define BOOST_FUSION_SEGMENTS_04052005_1141
+
+#include <boost/fusion/support/tag_of.hpp>
+
+namespace boost { namespace fusion
+{
+    // Special tags:
+    struct sequence_facade_tag;
+    struct iterator_range_tag;
+
+    // segments: returns a sequence of sequences
+    namespace extension
+    {
+        template <typename Tag>
+        struct segments_impl
+        {
+            template <typename Sequence>
+            struct apply {};
+        };
+
+        template <>
+        struct segments_impl<sequence_facade_tag>
+        {
+            template <typename Sequence>
+            struct apply : Sequence::template segments<Sequence> {};
+        }; 
+
+        template <>
+        struct segments_impl<iterator_range_tag>;
+    }
+
+    namespace result_of
+    {
+        template <typename Sequence>
+        struct segments
+        {
+            typedef typename traits::tag_of<Sequence>::type tag_type;
+
+            typedef typename
+                extension::segments_impl<tag_type>::template apply<Sequence>::type
+            type;
+        };
+    }
+
+    template <typename Sequence>
+    typename result_of::segments<Sequence>::type
+    segments(Sequence & seq)
+    {
+        typedef typename traits::tag_of<Sequence>::type tag_type;
+        return extension::segments_impl<tag_type>::template apply<Sequence>::call(seq);
+    }
+
+    template <typename Sequence>
+    typename result_of::segments<Sequence const>::type
+    segments(Sequence const& seq)
+    {
+        typedef typename traits::tag_of<Sequence const>::type tag_type;
+        return extension::segments_impl<tag_type>::template apply<Sequence const>::call(seq);
+    }
+}}
+
+#endif