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Diffstat (limited to 'boost/fusion/support/detail/result_of.hpp')
-rw-r--r-- | boost/fusion/support/detail/result_of.hpp | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/boost/fusion/support/detail/result_of.hpp b/boost/fusion/support/detail/result_of.hpp new file mode 100644 index 0000000000..e53ea9e354 --- /dev/null +++ b/boost/fusion/support/detail/result_of.hpp @@ -0,0 +1,53 @@ +/*============================================================================= + 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/config.hpp> +#include <boost/utility/result_of.hpp> + +#if !defined(BOOST_RESULT_OF_USE_DECLTYPE) || defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES) +#define BOOST_FUSION_NO_DECLTYPE_BASED_RESULT_OF +#endif + +#if !defined(BOOST_FUSION_NO_DECLTYPE_BASED_RESULT_OF) +#include <boost/mpl/if.hpp> +#include <boost/mpl/or.hpp> +#include <boost/mpl/has_xxx.hpp> +#endif + +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_FUSION_NO_DECLTYPE_BASED_RESULT_OF) + + template <typename Sig> + struct result_of_with_decltype : boost::tr1_result_of<Sig> {}; + +#else // defined(BOOST_FUSION_NO_DECLTYPE_BASED_RESULT_OF) + + 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 // defined(BOOST_FUSION_NO_DECLTYPE_BASED_RESULT_OF) + +}}} + +#endif |