vmd/detail/is_empty_tuple.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_DETAIL_IS_EMPTY_TUPLE_HPP)
0008 #define BOOST_VMD_DETAIL_IS_EMPTY_TUPLE_HPP
0009
0010 #include <boost/preprocessor/comparison/equal.hpp>
0011 #include <boost/preprocessor/control/iif.hpp>
0012 #include <boost/preprocessor/tuple/elem.hpp>
0013 #include <boost/preprocessor/tuple/size.hpp>
0014 #include <boost/vmd/identity.hpp>
0015 #include <boost/vmd/is_empty.hpp>
0016 #include <boost/vmd/is_tuple.hpp>
0017
0018 #define BOOST_VMD_DETAIL_IS_EMPTY_TUPLE_CEM(tuple) \
0019     BOOST_VMD_IS_EMPTY(BOOST_PP_TUPLE_ELEM(0,tuple)) \
0020 /**/
0021
0022 #define BOOST_VMD_DETAIL_IS_EMPTY_TUPLE_SIZE(tuple) \
0023     BOOST_VMD_IDENTITY_RESULT \
0024         ( \
0025         BOOST_PP_IIF \
0026             ( \
0027             BOOST_PP_EQUAL(BOOST_PP_TUPLE_SIZE(tuple),1), \
0028             BOOST_VMD_DETAIL_IS_EMPTY_TUPLE_CEM, \
0029             BOOST_VMD_IDENTITY(0) \
0030             ) \
0031         (tuple) \
0032         ) \
0033 /**/
0034
0035 #define BOOST_VMD_DETAIL_IS_EMPTY_TUPLE_SIZE_D(d,tuple) \
0036     BOOST_VMD_IDENTITY_RESULT \
0037         ( \
0038         BOOST_PP_IIF \
0039             ( \
0040             BOOST_PP_EQUAL_D(d,BOOST_PP_TUPLE_SIZE(tuple),1), \
0041             BOOST_VMD_DETAIL_IS_EMPTY_TUPLE_CEM, \
0042             BOOST_VMD_IDENTITY(0) \
0043             ) \
0044         (tuple) \
0045         ) \
0046 /**/
0047
0048 #define BOOST_VMD_DETAIL_IS_EMPTY_TUPLE(tuple) \
0049     BOOST_VMD_IDENTITY_RESULT \
0050         ( \
0051         BOOST_PP_IIF \
0052             ( \
0053             BOOST_VMD_IS_TUPLE(tuple), \
0054             BOOST_VMD_DETAIL_IS_EMPTY_TUPLE_SIZE, \
0055             BOOST_VMD_IDENTITY(0) \
0056             ) \
0057         (tuple) \
0058         ) \
0059 /**/
0060
0061 #define BOOST_VMD_DETAIL_IS_EMPTY_TUPLE_D(d,tuple) \
0062     BOOST_VMD_IDENTITY_RESULT \
0063         ( \
0064         BOOST_PP_IIF \
0065             ( \
0066             BOOST_VMD_IS_TUPLE(tuple), \
0067             BOOST_VMD_DETAIL_IS_EMPTY_TUPLE_SIZE_D, \
0068             BOOST_VMD_IDENTITY(0) \
0069             ) \
0070         (d,tuple) \
0071         ) \
0072 /**/
0073
0074 #endif /* BOOST_VMD_DETAIL_IS_EMPTY_TUPLE_HPP */