boost/vmd/is_empty_list.hpp

0001
0002 //  (C) Copyright Edward Diener 2011-2015
0003 //  Use, modification and distribution are subject to the Boost Software License,
0004 //  Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
0005 //  http://www.boost.org/LICENSE_1_0.txt).
0006
0007 #if !defined(BOOST_VMD_IS_EMPTY_LIST_HPP)
0008 #define BOOST_VMD_IS_EMPTY_LIST_HPP
0009
0010 #include <boost/vmd/detail/setup.hpp>
0011
0012 #if BOOST_PP_VARIADICS
0013
0014 #include <boost/vmd/detail/is_list.hpp>
0015
0016 /*
0017
0018   The succeeding comments in this file are in doxygen format.
0019
0020 */
0021
0022 /** \file
0023 */
0024
0025 /** \def BOOST_VMD_IS_EMPTY_LIST(sequence)
0026
0027     \brief Tests whether a sequence is an empty Boost PP list.
0028
0029     An empty Boost PP list consists of the single identifier 'BOOST_PP_NIL'.
0030     This identifier also serves as a list terminator for a non-empty list.
0031
0032     sequence = a preprocessor parameter
0033
0034     returns = 1 if the sequence is an empty Boost PP list,
0035               0 if it is not.
0036
0037     The macro will generate a preprocessing error if the input
0038     as an empty list marker, instead of being an identifier, is
0039     a preprocessor token which VMD cannot parse, as in the
0040     example '&BOOST_PP_NIL'.
0041
0042 */
0043
0044 #define BOOST_VMD_IS_EMPTY_LIST(sequence) \
0045     BOOST_VMD_DETAIL_IS_LIST_IS_EMPTY_LIST_PROCESS(sequence) \
0046 /**/
0047
0048 /** \def BOOST_VMD_IS_EMPTY_LIST_D(d,sequence)
0049
0050     \brief Tests whether a sequence is an empty Boost PP list. Re-entrant version.
0051
0052     An empty Boost PP list consists of the single identifier 'BOOST_PP_NIL'.
0053     This identifier also serves as a list terminator for a non-empty list.
0054
0055     d        = The next available BOOST_PP_WHILE iteration <br/>
0056     sequence = a preprocessor parameter
0057
0058     returns = 1 if the sequence is an empty Boost PP list,
0059               0 if it is not.
0060
0061     The macro will generate a preprocessing error if the input
0062     as an empty list marker, instead of being an identifier, is
0063     a preprocessor token which VMD cannot parse, as in the
0064     example '&BOOST_PP_NIL'.
0065
0066 */
0067
0068 #define BOOST_VMD_IS_EMPTY_LIST_D(d,sequence) \
0069     BOOST_VMD_DETAIL_IS_LIST_IS_EMPTY_LIST_PROCESS_D(d,sequence) \
0070 /**/
0071
0072 #endif /* BOOST_PP_VARIADICS */
0073 #endif /* BOOST_VMD_IS_EMPTY_LIST_HPP */