1# /* **************************************************************************
2# * *
3# * (C) Copyright Paul Mensonides 2002.
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_SEQ_FILTER_HPP
13# define BOOST_PREPROCESSOR_SEQ_FILTER_HPP
14#
15# include <boost/preprocessor/config/config.hpp>
16# include <boost/preprocessor/control/expr_if.hpp>
17# include <boost/preprocessor/facilities/empty.hpp>
18# include <boost/preprocessor/seq/fold_left.hpp>
19# include <boost/preprocessor/seq/seq.hpp>
20# include <boost/preprocessor/tuple/elem.hpp>
21# include <boost/preprocessor/tuple/rem.hpp>
22#
23# /* BOOST_PP_SEQ_FILTER */
24#
25# if ~BOOST_PP_CONFIG_FLAGS() & BOOST_PP_CONFIG_EDG()
26# define BOOST_PP_SEQ_FILTER(pred, data, seq) BOOST_PP_SEQ_TAIL(BOOST_PP_TUPLE_ELEM(3, 2, BOOST_PP_SEQ_FOLD_LEFT(BOOST_PP_SEQ_FILTER_O, (pred, data, (nil)), seq)))
27# else
28# define BOOST_PP_SEQ_FILTER(pred, data, seq) BOOST_PP_SEQ_FILTER_I(pred, data, seq)
29# define BOOST_PP_SEQ_FILTER_I(pred, data, seq) BOOST_PP_SEQ_TAIL(BOOST_PP_TUPLE_ELEM(3, 2, BOOST_PP_SEQ_FOLD_LEFT(BOOST_PP_SEQ_FILTER_O, (pred, data, (nil)), seq)))
30# endif
31#
32# if BOOST_PP_CONFIG_FLAGS() & BOOST_PP_CONFIG_STRICT()
33# define BOOST_PP_SEQ_FILTER_O(s, st, elem) BOOST_PP_SEQ_FILTER_O_IM(s, BOOST_PP_TUPLE_REM_3 st, elem)
34# define BOOST_PP_SEQ_FILTER_O_IM(s, im, elem) BOOST_PP_SEQ_FILTER_O_I(s, im, elem)
35# else
36# define BOOST_PP_SEQ_FILTER_O(s, st, elem) BOOST_PP_SEQ_FILTER_O_I(s, BOOST_PP_TUPLE_ELEM(3, 0, st), BOOST_PP_TUPLE_ELEM(3, 1, st), BOOST_PP_TUPLE_ELEM(3, 2, st), elem)
37# endif
38#
39# if ~BOOST_PP_CONFIG_FLAGS() & BOOST_PP_CONFIG_DMC()
40# define BOOST_PP_SEQ_FILTER_O_I(s, pred, data, res, elem) (pred, data, res BOOST_PP_EXPR_IF(pred(s, data, elem), (elem)))
41# else
42# define BOOST_PP_SEQ_FILTER_O_I(s, pred, data, res, elem) (pred, data, res BOOST_PP_EXPR_IF(pred##(s, data, elem), (elem)))
43# endif
44#
45# /* BOOST_PP_SEQ_FILTER_S */
46#
47# if ~BOOST_PP_CONFIG_FLAGS() & BOOST_PP_CONFIG_EDG()
48# define BOOST_PP_SEQ_FILTER_S(s, pred, data, seq) BOOST_PP_SEQ_TAIL(BOOST_PP_TUPLE_ELEM(3, 2, BOOST_PP_SEQ_FOLD_LEFT_ ## s(BOOST_PP_SEQ_FILTER_O, (pred, data, (nil)), seq)))
49# else
50# define BOOST_PP_SEQ_FILTER_S(s, pred, data, seq) BOOST_PP_SEQ_FILTER_S_I(s, pred, data, seq)
51# define BOOST_PP_SEQ_FILTER_S_I(s, pred, data, seq) BOOST_PP_SEQ_TAIL(BOOST_PP_TUPLE_ELEM(3, 2, BOOST_PP_SEQ_FOLD_LEFT_ ## s(BOOST_PP_SEQ_FILTER_O, (pred, data, (nil)), seq)))
52# endif
53#
54# endif
55

source code of boost/boost/preprocessor/seq/filter.hpp