Chris@102: /*=============================================================================
Chris@102:     Copyright (c) 2001-2014 Joel de Guzman
Chris@102: 
Chris@102:     Distributed under the Boost Software License, Version 1.0. (See accompanying
Chris@102:     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
Chris@102: ==============================================================================*/
Chris@102: #if !defined(FUSION_RESULT_OF_10272014_0654)
Chris@102: #define FUSION_RESULT_OF_10272014_0654
Chris@102: 
Chris@102: #include <boost/config.hpp>
Chris@102: #include <boost/utility/result_of.hpp>
Chris@102: 
Chris@102: #if !defined(BOOST_RESULT_OF_USE_DECLTYPE) || defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES)
Chris@102: #define BOOST_FUSION_NO_DECLTYPE_BASED_RESULT_OF
Chris@102: #endif
Chris@102: 
Chris@102: #if !defined(BOOST_FUSION_NO_DECLTYPE_BASED_RESULT_OF)
Chris@102: #include <boost/mpl/if.hpp>
Chris@102: #include <boost/mpl/or.hpp>
Chris@102: #include <boost/mpl/has_xxx.hpp>
Chris@102: #endif
Chris@102: 
Chris@102: namespace boost { namespace fusion { namespace detail
Chris@102: {
Chris@102:     // This is a temporary workaround for result_of before we make fusion fully
Chris@102:     // sfinae result_of friendy, which will require some heavy lifting for some
Chris@102:     // low level code. So far this is used only in the fold algorithm. This will
Chris@102:     // be removed once we overhaul fold.
Chris@102: 
Chris@102: #if defined(BOOST_FUSION_NO_DECLTYPE_BASED_RESULT_OF)
Chris@102: 
Chris@102:     template <typename Sig>
Chris@102:     struct result_of_with_decltype : boost::tr1_result_of<Sig> {};
Chris@102: 
Chris@102: #else // defined(BOOST_FUSION_NO_DECLTYPE_BASED_RESULT_OF)
Chris@102: 
Chris@102:     BOOST_MPL_HAS_XXX_TRAIT_DEF(result_type)
Chris@102:     BOOST_MPL_HAS_XXX_TEMPLATE_DEF(result)
Chris@102: 
Chris@102:     template <typename Sig>
Chris@102:     struct result_of_with_decltype;
Chris@102: 
Chris@102:     template <typename F, typename... Args>
Chris@102:     struct result_of_with_decltype<F(Args...)>
Chris@102:         : mpl::if_<mpl::or_<has_result_type<F>, detail::has_result<F> >,
Chris@102:             boost::tr1_result_of<F(Args...)>,
Chris@102:             boost::detail::cpp0x_result_of<F(Args...)> >::type {};
Chris@102: 
Chris@102: #endif // defined(BOOST_FUSION_NO_DECLTYPE_BASED_RESULT_OF)
Chris@102: 
Chris@102: }}}
Chris@102: 
Chris@102: #endif