correct fix for ticket 10676. this is a temporary fix until we overhaul the fold implementation.

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

@@ -47,7 +47,7 @@ namespace boost { namespace fusion
     {
         template<typename State, typename It, typename F>
         struct BOOST_PP_CAT(BOOST_FUSION_FOLD_NAME, _lvalue_state)
-          : boost::tr1_result_of<
+          : fusion::detail::result_of_with_decltype<
                 F(
                 typename add_reference<typename add_const<State>::type>::type,
                 BOOST_FUSION_FOLD_IMPL_INVOKE_IT_META_TRANSFORM(It))
@@ -327,7 +327,7 @@ namespace boost { namespace fusion
         {
             typedef typename
                 BOOST_PP_CAT(result_of_unrolled_,BOOST_FUSION_FOLD_NAME)<
-                    typename boost::tr1_result_of<
+                    typename fusion::detail::result_of_with_decltype<
                         F(
                             StateRef,
                             BOOST_FUSION_FOLD_IMPL_INVOKE_IT_META_TRANSFORM(

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

@@ -14,7 +14,7 @@ namespace boost { namespace fusion
     {
         template<typename State, typename It, typename F>
         struct fold_lvalue_state
-          : boost::result_of<
+          : fusion::detail::result_of_with_decltype<
                 F(
                 typename add_reference<typename add_const<State>::type>::type,
                 typename fusion::result_of::deref<It>::type)
@@ -273,7 +273,7 @@ namespace boost { namespace fusion
         {
             typedef typename
                 result_of_unrolled_fold<
-                    typename boost::tr1_result_of<
+                    typename fusion::detail::result_of_with_decltype<
                         F(
                             StateRef,
                             typename fusion::result_of::deref< It0 const>::type

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

@@ -10,6 +10,7 @@
 #define BOOST_FUSION_ALGORITHM_ITERATION_FOLD_HPP
 
 #include <boost/fusion/support/config.hpp>
+#include <boost/fusion/support/detail/result_of.hpp>
 #include <boost/fusion/algorithm/iteration/fold_fwd.hpp>
 #include <boost/config.hpp>
 #include <boost/fusion/sequence/intrinsic/begin.hpp>

include/boost/fusion/support/detail/result_of.hpp

@@ -0,0 +1,42 @@
+/*=============================================================================
+    Copyright (c) 2001-2014 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_RESULT_OF_10272014_0654)
+#define FUSION_RESULT_OF_10272014_0654
+
+#include <boost/utility/result_of.hpp>
+
+namespace boost { namespace fusion { namespace detail
+{
+    // This is a temporary workaround for result_of before we make fusion fully
+    // sfinae result_of friendy, which will require some heavy lifting for some
+    // low level code. So far this is used only in the fold algorithm. This will
+    // be removed once we overhaul fold.
+
+#if defined(BOOST_NO_CXX11_DECLTYPE)
+
+    template <typename Sig>
+    struct result_of_with_decltype : boost::tr1_result_of<Sig> {};
+
+#else
+
+    BOOST_MPL_HAS_XXX_TRAIT_DEF(result_type)
+    BOOST_MPL_HAS_XXX_TEMPLATE_DEF(result)
+
+    template <typename Sig>
+    struct result_of_with_decltype;
+
+    template <typename F, typename... Args>
+    struct result_of_with_decltype<F(Args...)>
+        : mpl::if_<mpl::or_<has_result_type<F>, detail::has_result<F>>,
+            boost::tr1_result_of<F(Args...)>,
+            boost::detail::cpp0x_result_of<F(Args...)>>::type {};
+
+#endif
+
+}}}
+
+#endif