facilities/detail/is_empty.hpp

0001 # /* **************************************************************************
0002 #  *                                                                          *
0003 #  *     (C) Copyright Edward Diener 2014.
0004 #  *     Distributed under the Boost Software License, Version 1.0. (See
0005 #  *     accompanying file LICENSE_1_0.txt or copy at
0006 #  *     http://www.boost.org/LICENSE_1_0.txt)
0007 #  *                                                                          *
0008 #  ************************************************************************** */
0009 #
0010 # /* See http://www.boost.org for most recent version. */
0011 #
0012 #ifndef BOOST_PREPROCESSOR_DETAIL_IS_EMPTY_HPP
0013 #define BOOST_PREPROCESSOR_DETAIL_IS_EMPTY_HPP
0014
0015 #include <boost/preprocessor/punctuation/is_begin_parens.hpp>
0016
0017 #if BOOST_PP_VARIADICS_MSVC
0018
0019 # pragma warning(once:4002)
0020
0021 #define BOOST_PP_DETAIL_IS_EMPTY_IIF_0(t, b) b
0022 #define BOOST_PP_DETAIL_IS_EMPTY_IIF_1(t, b) t
0023
0024 #else
0025
0026 #define BOOST_PP_DETAIL_IS_EMPTY_IIF_0(t, ...) __VA_ARGS__
0027 #define BOOST_PP_DETAIL_IS_EMPTY_IIF_1(t, ...) t
0028
0029 #endif
0030
0031 #if BOOST_PP_VARIADICS_MSVC && _MSC_VER <= 1400
0032
0033 #define BOOST_PP_DETAIL_IS_EMPTY_PROCESS(param) \
0034     BOOST_PP_IS_BEGIN_PARENS \
0035         ( \
0036         BOOST_PP_DETAIL_IS_EMPTY_NON_FUNCTION_C param () \
0037         ) \
0038 /**/
0039
0040 #else
0041
0042 #define BOOST_PP_DETAIL_IS_EMPTY_PROCESS(...) \
0043     BOOST_PP_IS_BEGIN_PARENS \
0044         ( \
0045         BOOST_PP_DETAIL_IS_EMPTY_NON_FUNCTION_C __VA_ARGS__ () \
0046         ) \
0047 /**/
0048
0049 #endif
0050
0051 #define BOOST_PP_DETAIL_IS_EMPTY_PRIMITIVE_CAT(a, b) a ## b
0052 #define BOOST_PP_DETAIL_IS_EMPTY_IIF(bit) BOOST_PP_DETAIL_IS_EMPTY_PRIMITIVE_CAT(BOOST_PP_DETAIL_IS_EMPTY_IIF_,bit)
0053 #define BOOST_PP_DETAIL_IS_EMPTY_NON_FUNCTION_C(...) ()
0054
0055 #endif /* BOOST_PREPROCESSOR_DETAIL_IS_EMPTY_HPP */