seq/detail/is_empty.hpp

0001 # /* **************************************************************************
0002 #  *                                                                          *
0003 #  *     (C) Copyright Edward Diener 2015.
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 ">#
0011 # /* See http://www.boost.org for most recent version. */
0012 0013 ">#
0014 # ifndef BOOST_PREPROCESSOR_SEQ_DETAIL_IS_EMPTY_HPP
0015 # define BOOST_PREPROCESSOR_SEQ_DETAIL_IS_EMPTY_HPP
0016 0017 ">#
0018 # include <boost/preprocessor/config/config.hpp>
0019 # include <boost/preprocessor/arithmetic/dec.hpp>
0020 # include <boost/preprocessor/logical/bool.hpp>
0021 # include <boost/preprocessor/logical/compl.hpp>
0022 # include <boost/preprocessor/seq/size.hpp>
0023 0024 ">#
0025 /* An empty seq is one that is just BOOST_PP_SEQ_NIL */
0026 0027 ">#
0028 # define BOOST_PP_SEQ_DETAIL_IS_EMPTY(seq) \
0029     BOOST_PP_COMPL \
0030         ( \
0031         BOOST_PP_SEQ_DETAIL_IS_NOT_EMPTY(seq) \
0032         ) \
0033 /**/
0034 0035 ">#
0036 # define BOOST_PP_SEQ_DETAIL_IS_EMPTY_SIZE(size) \
0037     BOOST_PP_COMPL \
0038         ( \
0039         BOOST_PP_SEQ_DETAIL_IS_NOT_EMPTY_SIZE(size) \
0040         ) \
0041 /**/
0042 0043 ">#
0044 # define BOOST_PP_SEQ_DETAIL_IS_NOT_EMPTY(seq) \
0045     BOOST_PP_SEQ_DETAIL_IS_NOT_EMPTY_SIZE(BOOST_PP_SEQ_DETAIL_EMPTY_SIZE(seq)) \
0046 /**/
0047 0048 ">#
0049 # define BOOST_PP_SEQ_DETAIL_IS_NOT_EMPTY_SIZE(size) \
0050     BOOST_PP_BOOL(size) \
0051 /**/
0052 0053 ">#
0054 # define BOOST_PP_SEQ_DETAIL_EMPTY_SIZE(seq) \
0055     BOOST_PP_DEC(BOOST_PP_SEQ_SIZE(seq (nil))) \
0056 /**/
0057 0058 ">#
0059 # endif