1 files changed, 46 insertions, 29 deletions
diff --git a/boost/parameter/aux_/result_of0.hpp b/boost/parameter/aux_/result_of0.hpp
index e0096148b4..f8cbea3c3a 100644
--- a/boost/parameter/aux_/result_of0.hpp
+++ b/boost/parameter/aux_/result_of0.hpp
@@ -1,36 +1,53 @@
-// Copyright David Abrahams 2005. 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)
-#ifndef BOOST_PARAMETER_AUX_RESULT_OF0_DWA2005511_HPP
-# define BOOST_PARAMETER_AUX_RESULT_OF0_DWA2005511_HPP
-
-# include <boost/utility/result_of.hpp>
-
-// A metafunction returning the result of invoking a nullary function
-// object of the given type.
+// Copyright David Abrahams 2005.
+// 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)
 
-#ifndef BOOST_NO_RESULT_OF
-
-# include <boost/utility/result_of.hpp>
-namespace boost { namespace parameter { namespace aux { 
-template <class F>
-struct result_of0 : result_of<F()>
-{};
+#ifndef BOOST_PARAMETER_AUX_RESULT_OF0_DWA2005511_HPP
+#define BOOST_PARAMETER_AUX_RESULT_OF0_DWA2005511_HPP
 
-}}} // namespace boost::parameter::aux_
+#include <boost/parameter/aux_/use_default_tag.hpp>
+#include <boost/parameter/config.hpp>
+#include <boost/utility/result_of.hpp>
 
+#if defined(BOOST_PARAMETER_CAN_USE_MP11)
+#include <boost/mp11/utility.hpp>
+#include <type_traits>
 #else
+#include <boost/mpl/if.hpp>
+#include <boost/type_traits/is_void.hpp>
+#endif
+
+namespace boost { namespace parameter { namespace aux {
+
+    // A metafunction returning the result of invoking
+    // a nullary function object of the given type.
+    template <typename F>
+    class result_of0
+    {
+#if defined(BOOST_NO_RESULT_OF)
+        typedef typename F::result_type result_of_F;
+#else
+        typedef typename ::boost::result_of<F()>::type result_of_F;
+#endif
 
-namespace boost { namespace parameter { namespace aux { 
-template <class F>
-struct result_of0
-{
-    typedef typename F::result_type type;
-};
-
-}}} // namespace boost::parameter::aux_
-
-#endif 
+     public:
+#if defined(BOOST_PARAMETER_CAN_USE_MP11)
+        using type = ::boost::mp11::mp_if<
+            ::std::is_void<result_of_F>
+#else
+        typedef typename ::boost::mpl::if_<
+            ::boost::is_void<result_of_F>
+#endif
+          , ::boost::parameter::aux::use_default_tag
+          , result_of_F
+#if defined(BOOST_PARAMETER_CAN_USE_MP11)
+        >;
+#else
+        >::type type;
+#endif
+    };
+}}} // namespace boost::parameter::aux
 
+#endif  // include guard
 
-#endif // BOOST_PARAMETER_AUX_RESULT_OF0_DWA2005511_HPP