Updated boost to v1.55.0

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

diff --git a/boost/fusion/sequence/intrinsic/begin.hpp b/boost/fusion/sequence/intrinsic/begin.hpp
index 5dbe0c408db32903143f33bbdec28e8ab8d32039..7a7ecf6afdd007e64cd5ee6f549de956cb576c29 100644 (file)
--- a/boost/fusion/sequence/intrinsic/begin.hpp
+++ b/boost/fusion/sequence/intrinsic/begin.hpp
@@ -1,5 +1,5 @@
 /*=============================================================================
-    Copyright (c) 2001-2006 Joel de Guzman
+    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)
@@ -7,7 +7,14 @@
 #if !defined(FUSION_BEGIN_04052005_1132)
 #define FUSION_BEGIN_04052005_1132
 
+#include <boost/blank.hpp>
+#include <boost/utility/enable_if.hpp>
+#include <boost/mpl/if.hpp>
+#include <boost/fusion/sequence/intrinsic_fwd.hpp>
 #include <boost/fusion/support/tag_of.hpp>
+#include <boost/fusion/support/is_sequence.hpp>
+#include <boost/fusion/support/is_segmented.hpp>
+#include <boost/fusion/sequence/intrinsic/detail/segmented_begin.hpp>
 
 namespace boost { namespace fusion
 {
@@ -24,7 +31,13 @@ namespace boost { namespace fusion
         struct begin_impl
         {
             template <typename Sequence>
-            struct apply;
+            struct apply
+              : mpl::if_<
+                    traits::is_segmented<Sequence>
+                  , detail::segmented_begin<Sequence>
+                  , blank
+                >::type
+            {};
         };
 
         template <>
@@ -57,14 +70,22 @@ namespace boost { namespace fusion
     }
 
     template <typename Sequence>
-    inline typename result_of::begin<Sequence>::type const
+    inline typename
+        lazy_enable_if<
+            traits::is_sequence<Sequence>
+          , result_of::begin<Sequence>
+        >::type const
     begin(Sequence& seq)
     {
         return result_of::begin<Sequence>::call(seq);
     }
 
     template <typename Sequence>
-    inline typename result_of::begin<Sequence const>::type const
+    inline typename
+        lazy_enable_if<
+            traits::is_sequence<Sequence>
+          , result_of::begin<Sequence const>
+        >::type const
     begin(Sequence const& seq)
     {
         return result_of::begin<Sequence const>::call(seq);