1# /* **************************************************************************
2# * *
3# * (C) Copyright Edward Diener 2013.
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_TUPLE_POP_FRONT_HPP
13# define BOOST_PREPROCESSOR_TUPLE_POP_FRONT_HPP
14#
15# include <boost/preprocessor/config/config.hpp>
16#
17# if BOOST_PP_VARIADICS
18#
19# include <boost/preprocessor/array/pop_front.hpp>
20# include <boost/preprocessor/array/to_tuple.hpp>
21# include <boost/preprocessor/comparison/greater.hpp>
22# include <boost/preprocessor/control/iif.hpp>
23# include <boost/preprocessor/tuple/size.hpp>
24# include <boost/preprocessor/tuple/to_array.hpp>
25#
26#
27# /* BOOST_PP_TUPLE_POP_FRONT */
28#
29# define BOOST_PP_TUPLE_POP_FRONT(tuple) \
30 BOOST_PP_IIF \
31 ( \
32 BOOST_PP_GREATER(BOOST_PP_TUPLE_SIZE(tuple),1), \
33 BOOST_PP_TUPLE_POP_FRONT_EXEC, \
34 BOOST_PP_TUPLE_POP_FRONT_RETURN \
35 ) \
36 (tuple) \
37/**/
38#
39# define BOOST_PP_TUPLE_POP_FRONT_EXEC(tuple) \
40 BOOST_PP_ARRAY_TO_TUPLE(BOOST_PP_ARRAY_POP_FRONT(BOOST_PP_TUPLE_TO_ARRAY(tuple))) \
41/**/
42#
43# define BOOST_PP_TUPLE_POP_FRONT_RETURN(tuple) tuple
44#
45# /* BOOST_PP_TUPLE_POP_FRONT_Z */
46#
47# define BOOST_PP_TUPLE_POP_FRONT_Z(z, tuple) \
48 BOOST_PP_IIF \
49 ( \
50 BOOST_PP_GREATER(BOOST_PP_TUPLE_SIZE(tuple),1), \
51 BOOST_PP_TUPLE_POP_FRONT_Z_EXEC, \
52 BOOST_PP_TUPLE_POP_FRONT_Z_RETURN \
53 ) \
54 (z, tuple) \
55/**/
56#
57# define BOOST_PP_TUPLE_POP_FRONT_Z_EXEC(z, tuple) \
58 BOOST_PP_ARRAY_TO_TUPLE(BOOST_PP_ARRAY_POP_FRONT_Z(z, BOOST_PP_TUPLE_TO_ARRAY(tuple))) \
59/**/
60#
61# define BOOST_PP_TUPLE_POP_FRONT_Z_RETURN(z, tuple) tuple
62#
63# endif // BOOST_PP_VARIADICS
64#
65# endif // BOOST_PREPROCESSOR_TUPLE_POP_FRONT_HPP
66

source code of boost/boost/preprocessor/tuple/pop_front.hpp