Updated boost to v1.55.0

[rsem.git] / boost / fusion / sequence / intrinsic / empty.hpp

diff --git a/boost/fusion/sequence/intrinsic/empty.hpp b/boost/fusion/sequence/intrinsic/empty.hpp
new file mode 100644 (file)
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+++ b/boost/fusion/sequence/intrinsic/empty.hpp
@@ -0,0 +1,61 @@
+/*=============================================================================
+    Copyright (c) 2001-2011 Joel de Guzman
+
+    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_EMPTY_09162005_0335)
+#define FUSION_EMPTY_09162005_0335
+
+#include <boost/fusion/sequence/intrinsic_fwd.hpp>
+#include <boost/fusion/sequence/intrinsic/size.hpp>
+#include <boost/mpl/bool.hpp>
+#include <boost/fusion/support/tag_of.hpp>
+
+namespace boost { namespace fusion
+{
+    // Special tags:
+    struct sequence_facade_tag;
+    struct mpl_sequence_tag; // mpl sequence tag
+
+    namespace extension
+    {
+        template <typename Tag>
+        struct empty_impl
+        {
+            template <typename Sequence>
+            struct apply 
+                : mpl::bool_<(result_of::size<Sequence>::value == 0)>
+            {};
+        };
+
+        template <>
+        struct empty_impl<sequence_facade_tag>
+        {
+            template <typename Sequence>
+            struct apply : Sequence::template empty<Sequence> {};
+        };
+
+        template <>
+        struct empty_impl<mpl_sequence_tag>;
+    }
+
+    namespace result_of
+    {
+        template <typename Sequence>
+        struct empty 
+            : extension::empty_impl<typename detail::tag_of<Sequence>::type>::
+                template apply<Sequence>
+        {};
+    }
+
+    template <typename Sequence>
+    inline typename result_of::empty<Sequence>::type
+    empty(Sequence const&)
+    {
+        typedef typename result_of::empty<Sequence>::type result;
+        return result();
+    }
+}}
+
+#endif