1# /* **************************************************************************
2# * *
3# * (C) Copyright Edward Diener 2014.
4# * Distributed under the Boost Software License, Version 1.0. (See
5# * accompanying file LICENSE_1_0.txt or copy at
6# * http://www.boost.org/LICENSE_1_0.txt)
7# * *
8# ************************************************************************** */
9#
10# /* See http://www.boost.org for most recent version. */
11#
12#ifndef BOOST_PREPROCESSOR_DETAIL_IS_EMPTY_HPP
13#define BOOST_PREPROCESSOR_DETAIL_IS_EMPTY_HPP
14
15#include <boost/preprocessor/punctuation/is_begin_parens.hpp>
16
17#if BOOST_PP_VARIADICS_MSVC
18
19# pragma warning(once:4002)
20
21#define BOOST_PP_DETAIL_IS_EMPTY_IIF_0(t, b) b
22#define BOOST_PP_DETAIL_IS_EMPTY_IIF_1(t, b) t
23
24#else
25
26#define BOOST_PP_DETAIL_IS_EMPTY_IIF_0(t, ...) __VA_ARGS__
27#define BOOST_PP_DETAIL_IS_EMPTY_IIF_1(t, ...) t
28
29#endif
30
31#if BOOST_PP_VARIADICS_MSVC && _MSC_VER <= 1400
32
33#define BOOST_PP_DETAIL_IS_EMPTY_PROCESS(param) \
34 BOOST_PP_IS_BEGIN_PARENS \
35 ( \
36 BOOST_PP_DETAIL_IS_EMPTY_NON_FUNCTION_C param () \
37 ) \
38/**/
39
40#else
41
42#define BOOST_PP_DETAIL_IS_EMPTY_PROCESS(...) \
43 BOOST_PP_IS_BEGIN_PARENS \
44 ( \
45 BOOST_PP_DETAIL_IS_EMPTY_NON_FUNCTION_C __VA_ARGS__ () \
46 ) \
47/**/
48
49#endif
50
51#define BOOST_PP_DETAIL_IS_EMPTY_PRIMITIVE_CAT(a, b) a ## b
52#define BOOST_PP_DETAIL_IS_EMPTY_IIF(bit) BOOST_PP_DETAIL_IS_EMPTY_PRIMITIVE_CAT(BOOST_PP_DETAIL_IS_EMPTY_IIF_,bit)
53#define BOOST_PP_DETAIL_IS_EMPTY_NON_FUNCTION_C(...) ()
54
55#endif /* BOOST_PREPROCESSOR_DETAIL_IS_EMPTY_HPP */
56

source code of include/boost/preprocessor/facilities/detail/is_empty.hpp