1
2// (C) Copyright Edward Diener 2011-2015
3// Use, modification and distribution are subject to the Boost Software License,
4// Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
5// http://www.boost.org/LICENSE_1_0.txt).
6
7#if !defined(BOOST_VMD_IS_EMPTY_LIST_HPP)
8#define BOOST_VMD_IS_EMPTY_LIST_HPP
9
10#include <boost/vmd/detail/setup.hpp>
11
12#if BOOST_PP_VARIADICS
13
14#include <boost/vmd/detail/is_list.hpp>
15
16/*
17
18 The succeeding comments in this file are in doxygen format.
19
20*/
21
22/** \file
23*/
24
25/** \def BOOST_VMD_IS_EMPTY_LIST(sequence)
26
27 \brief Tests whether a sequence is an empty Boost PP list.
28
29 An empty Boost PP list consists of the single identifier 'BOOST_PP_NIL'.
30 This identifier also serves as a list terminator for a non-empty list.
31
32 sequence = a preprocessor parameter
33
34 returns = 1 if the sequence is an empty Boost PP list
35 0 if it is not.
36
37 The macro will generate a preprocessing error if the input
38 as an empty list marker, instead of being an identifier, is
39 a preprocessor token which VMD cannot parse, as in the
40 example '&BOOST_PP_NIL'.
41
42*/
43
44#define BOOST_VMD_IS_EMPTY_LIST(sequence) \
45 BOOST_VMD_DETAIL_IS_LIST_IS_EMPTY_LIST_PROCESS(sequence) \
46/**/
47
48/** \def BOOST_VMD_IS_EMPTY_LIST_D(d,sequence)
49
50 \brief Tests whether a sequence is an empty Boost PP list. Re-entrant version.
51
52 An empty Boost PP list consists of the single identifier 'BOOST_PP_NIL'.
53 This identifier also serves as a list terminator for a non-empty list.
54
55 d = The next available BOOST_PP_WHILE iteration
56 sequence = a preprocessor parameter
57
58 returns = 1 if the sequence is an empty Boost PP list
59 0 if it is not.
60
61 The macro will generate a preprocessing error if the input
62 as an empty list marker, instead of being an identifier, is
63 a preprocessor token which VMD cannot parse, as in the
64 example '&BOOST_PP_NIL'.
65
66*/
67
68#define BOOST_VMD_IS_EMPTY_LIST_D(d,sequence) \
69 BOOST_VMD_DETAIL_IS_LIST_IS_EMPTY_LIST_PROCESS_D(d,sequence) \
70/**/
71
72#endif /* BOOST_PP_VARIADICS */
73#endif /* BOOST_VMD_IS_EMPTY_LIST_HPP */
74

source code of boost/boost/vmd/is_empty_list.hpp