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/intrinsics.hpp>
15#include <boost/type_traits/integral_constant.hpp>
16
17namespace boost {
18
19#ifdef BOOST_IS_UNION
20template <class T> struct is_union : public integral_constant<bool, BOOST_IS_UNION(T)> {};
21#else
22template <class T> struct is_union : public integral_constant<bool, false> {};
23#endif
24
25template <class T> struct is_union<T const> : public is_union<T>{};
26template <class T> struct is_union<T volatile const> : public is_union<T>{};
27template <class T> struct is_union<T volatile> : public is_union<T>{};
28
29} // namespace boost
30
31#endif // BOOST_TT_IS_UNION_HPP_INCLUDED
32

source code of boost/boost/type_traits/is_union.hpp