Initial move from Spirit CVS

[SVN r34896]

include/boost/fusion/algorithm/iteration/fold.hpp

@@ -0,0 +1,67 @@
+/*=============================================================================
+    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_FOLD_05052005_1214)
+#define FUSION_FOLD_05052005_1214
+
+#include <boost/fusion/algorithm/iteration/detail/fold.hpp>
+#include <boost/fusion/sequence/intrinsic/size.hpp>
+#include <boost/static_assert.hpp>
+
+namespace boost { namespace fusion
+{
+    struct void_;
+
+    namespace result_of
+    {
+        template <typename Sequence, typename State, typename F>
+        struct fold
+        {
+            typedef typename
+                detail::static_fold<
+                    typename result_of::begin<Sequence>::type
+                  , typename result_of::end<Sequence>::type
+                  , State
+                  , F
+                >::type
+            type;
+        };
+    }
+
+    template <typename Sequence, typename State, typename F>
+    inline typename result_of::fold<Sequence, State, F>::type
+    fold(Sequence& seq, State const& state, F const& f)
+    {
+        return detail::fold(
+            fusion::begin(seq)
+          , fusion::end(seq)
+          , state
+          , f
+          , is_same<
+                typename result_of::begin<Sequence>::type
+              , typename result_of::end<Sequence>::type>()
+        );
+    }
+
+    template <typename Sequence, typename State, typename F>
+    inline typename result_of::fold<Sequence const, State, F>::type
+    fold(Sequence const& seq, State const& state, F const& f)
+    {
+        return detail::fold(
+            fusion::begin(seq)
+          , fusion::end(seq)
+          , state
+          , f
+          , is_same<
+                typename result_of::begin<Sequence const>::type
+              , typename result_of::end<Sequence const>::type>()
+        );
+    }
+}}
+
+#endif
+