// 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_DETAIL_IS_XXX_DWA20051011_HPP

 # define BOOST_DETAIL_IS_XXX_DWA20051011_HPP

 # include <boost/config.hpp>

 # include <boost/mpl/bool.hpp>

 # include <boost/preprocessor/enum_params.hpp>

 # if defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION)

 # include <boost/type_traits/is_reference.hpp>

 # include <boost/type_traits/add_reference.hpp>

 #  define BOOST_DETAIL_IS_XXX_DEF(name, qualified_name, nargs)          \

 template <class X_>                                                     \

 struct is_##name                                                        \

 {                                                                       \

     typedef char yes;                                                   \

     typedef char (&no)[2];                                              \

                                                                         \

     static typename add_reference<X_>::type dummy;                      \

                                                                         \

     struct helpers                                                      \

     {                                                                   \

         template < BOOST_PP_ENUM_PARAMS_Z(1, nargs, class U) >          \

         static yes test(                                                \

            qualified_name< BOOST_PP_ENUM_PARAMS_Z(1, nargs, U) >&, int  \

         );                                                              \

                                                                         \

         template <class U>                                              \

         static no test(U&, ...);                                        \

     };                                                                  \

                                                                         \

     BOOST_STATIC_CONSTANT(                                              \

         bool, value                                                     \

         = !is_reference<X_>::value                                      \

         & (sizeof(helpers::test(dummy, 0)) == sizeof(yes)));            \

                                                                         \

     typedef mpl::bool_<value> type;                                     \

 };

 # else

 #  define BOOST_DETAIL_IS_XXX_DEF(name, qualified_name, nargs)  \

 template <class T>                                              \

 struct is_##name : mpl::false_                                  \

 {                                                               \

 };                                                              \

                                                                 \

 template < BOOST_PP_ENUM_PARAMS_Z(1, nargs, class T) >          \

 struct is_##name<                                               \

    qualified_name< BOOST_PP_ENUM_PARAMS_Z(1, nargs, T) >        \

 >                                                               \

    : mpl::true_                                                 \

 {                                                               \

 };

 # endif

 #endif // BOOST_DETAIL_IS_XXX_DWA20051011_HPP