1 2 // (C) Copyright Dave Abrahams, Steve Cleary, Beman Dawes, Howard 3 // Hinnant & John Maddock 2000. 4 // Use, modification and distribution are subject to the Boost Software License, 5 // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at 6 // http://www.boost.org/LICENSE_1_0.txt). 7 // 8 // See http://www.boost.org/libs/type_traits for most recent version including documentation. 9 10 11 #ifndef BOOST_TT_IS_UNION_HPP_INCLUDED 12 #define BOOST_TT_IS_UNION_HPP_INCLUDED 13 14 #include <boost/type_traits/remove_cv.hpp> 15 #include <boost/type_traits/config.hpp> 16 #include <boost/type_traits/intrinsics.hpp> 17 18 // should be the last #include 19 #include <boost/type_traits/detail/bool_trait_def.hpp> 20 21 namespace boost { 22 23 namespace detail { 24 #ifndef __GNUC__ 25 template <typename T> struct is_union_impl 26 { 27 typedef typename remove_cv<T>::type cvt; 28 #ifdef BOOST_IS_UNION 29 BOOST_STATIC_CONSTANT(bool, value = BOOST_IS_UNION(cvt)); 30 #else 31 BOOST_STATIC_CONSTANT(bool, value = false); 32 #endif 33 }; 34 #else 35 // 36 // using remove_cv here generates a whole load of needless 37 // warnings with gcc, since it doesn't do any good with gcc 38 // in any case (at least at present), just remove it: 39 // 40 template <typename T> struct is_union_impl 41 { 42 #ifdef BOOST_IS_UNION 43 BOOST_STATIC_CONSTANT(bool, value = BOOST_IS_UNION(T)); 44 #else 45 BOOST_STATIC_CONSTANT(bool, value = false); 46 #endif 47 }; 48 #endif 49 } // namespace detail 50 51 BOOST_TT_AUX_BOOL_TRAIT_DEF1(is_union,T,::boost::detail::is_union_impl<T>::value) 52 53 } // namespace boost 54 55 #include <boost/type_traits/detail/bool_trait_undef.hpp> 56 57 #endif // BOOST_TT_IS_UNION_HPP_INCLUDED 58