]>
Commit | Line | Data |
---|---|---|
7c673cae FG |
1 | |
2 | #ifndef BOOST_MPL_EMPTY_BASE_HPP_INCLUDED | |
3 | #define BOOST_MPL_EMPTY_BASE_HPP_INCLUDED | |
4 | ||
5 | // Copyright Aleksey Gurtovoy 2001-2004 | |
6 | // | |
7 | // Distributed under the Boost Software License, Version 1.0. | |
8 | // (See accompanying file LICENSE_1_0.txt or copy at | |
9 | // http://www.boost.org/LICENSE_1_0.txt) | |
10 | // | |
11 | // See http://www.boost.org/libs/mpl for documentation. | |
12 | ||
13 | // $Id$ | |
14 | // $Date$ | |
15 | // $Revision$ | |
16 | ||
17 | #include <boost/mpl/bool.hpp> | |
18 | #include <boost/mpl/aux_/config/msvc.hpp> | |
19 | #include <boost/mpl/aux_/config/workaround.hpp> | |
20 | #include <boost/mpl/aux_/lambda_support.hpp> | |
21 | ||
22 | #include <boost/type_traits/integral_constant.hpp> | |
23 | #include <boost/type_traits/is_empty.hpp> | |
24 | ||
25 | namespace boost { namespace mpl { | |
26 | ||
27 | // empty base class, guaranteed to have no members; inheritance from | |
28 | // 'empty_base' through the 'inherit' metafunction is a no-op - see | |
29 | // "mpl/inherit.hpp> header for the details | |
30 | struct empty_base {}; | |
31 | ||
32 | template< typename T > | |
33 | struct is_empty_base | |
34 | : false_ | |
35 | { | |
36 | #if BOOST_WORKAROUND(BOOST_MSVC, < 1300) | |
37 | using false_::value; | |
38 | #endif | |
39 | }; | |
40 | ||
41 | template<> | |
42 | struct is_empty_base<empty_base> | |
43 | : true_ | |
44 | { | |
45 | #if BOOST_WORKAROUND(BOOST_MSVC, < 1300) | |
46 | using true_::value; | |
47 | #endif | |
48 | }; | |
49 | ||
50 | }} | |
51 | ||
52 | namespace boost { | |
53 | ||
54 | template<> struct is_empty< mpl::empty_base > | |
55 | : public ::boost::integral_constant<bool,true> | |
56 | { | |
57 | public: | |
58 | BOOST_MPL_AUX_LAMBDA_SUPPORT_SPEC(1,is_empty,(mpl::empty_base)) | |
59 | }; | |
60 | ||
61 | } | |
62 | ||
63 | #endif // BOOST_MPL_EMPTY_BASE_HPP_INCLUDED |