Initial move from Spirit CVS

[SVN r34896]

include/boost/fusion/support/sequence_base.hpp

@@ -0,0 +1,34 @@
+/*=============================================================================
+    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_SEQUENCE_BASE_04182005_0737)
+#define FUSION_SEQUENCE_BASE_04182005_0737
+
+#include <boost/fusion/support/detail/compiler_config.hpp>
+
+namespace boost { namespace fusion
+{
+    struct sequence_root {};
+
+    template <typename Sequence>
+    struct sequence_base : sequence_root
+    {
+        Sequence const&
+        derived() const
+        {
+            return static_cast<Sequence const&>(*this);
+        }
+
+        Sequence&
+        derived()
+        {
+            return static_cast<Sequence&>(*this);
+        }
+    };
+}}
+
+#endif