1
2#if !defined(BOOST_PP_IS_ITERATING)
3
4///// header body
5
6#ifndef BOOST_MPL_AUX778076_ADVANCE_BACKWARD_HPP_INCLUDED
7#define BOOST_MPL_AUX778076_ADVANCE_BACKWARD_HPP_INCLUDED
8
9// Copyright Aleksey Gurtovoy 2000-2004
10//
11// Distributed under the Boost Software License, Version 1.0.
12// (See accompanying file LICENSE_1_0.txt or copy at
13// http://www.boost.org/LICENSE_1_0.txt)
14//
15// See http://www.boost.org/libs/mpl for documentation.
16
17// $Id$
18// $Date$
19// $Revision$
20
21#if !defined(BOOST_MPL_PREPROCESSING_MODE)
22# include <boost/mpl/prior.hpp>
23# include <boost/mpl/apply_wrap.hpp>
24#endif
25
26#include <boost/mpl/aux_/config/use_preprocessed.hpp>
27
28#if !defined(BOOST_MPL_CFG_NO_PREPROCESSED_HEADERS) \
29 && !defined(BOOST_MPL_PREPROCESSING_MODE)
30
31# define BOOST_MPL_PREPROCESSED_HEADER advance_backward.hpp
32# include <boost/mpl/aux_/include_preprocessed.hpp>
33
34#else
35
36# include <boost/mpl/limits/unrolling.hpp>
37# include <boost/mpl/aux_/nttp_decl.hpp>
38# include <boost/mpl/aux_/config/eti.hpp>
39
40# include <boost/preprocessor/iterate.hpp>
41# include <boost/preprocessor/cat.hpp>
42# include <boost/preprocessor/inc.hpp>
43
44namespace boost { namespace mpl { namespace aux {
45
46// forward declaration
47template< BOOST_MPL_AUX_NTTP_DECL(long, N) > struct advance_backward;
48
49# define BOOST_PP_ITERATION_PARAMS_1 \
50 (3,(0, BOOST_MPL_LIMIT_UNROLLING, <boost/mpl/aux_/advance_backward.hpp>))
51# include BOOST_PP_ITERATE()
52
53// implementation for N that exceeds BOOST_MPL_LIMIT_UNROLLING
54template< BOOST_MPL_AUX_NTTP_DECL(long, N) >
55struct advance_backward
56{
57 template< typename Iterator > struct apply
58 {
59 typedef typename apply_wrap1<
60 advance_backward<BOOST_MPL_LIMIT_UNROLLING>
61 , Iterator
62 >::type chunk_result_;
63
64 typedef typename apply_wrap1<
65 advance_backward<(
66 (N - BOOST_MPL_LIMIT_UNROLLING) < 0
67 ? 0
68 : N - BOOST_MPL_LIMIT_UNROLLING
69 )>
70 , chunk_result_
71 >::type type;
72 };
73};
74
75}}}
76
77#endif // BOOST_MPL_CFG_NO_PREPROCESSED_HEADERS
78#endif // BOOST_MPL_AUX778076_ADVANCE_BACKWARD_HPP_INCLUDED
79
80///// iteration, depth == 1
81
82// For gcc 4.4 compatability, we must include the
83// BOOST_PP_ITERATION_DEPTH test inside an #else clause.
84#else // BOOST_PP_IS_ITERATING
85#if BOOST_PP_ITERATION_DEPTH() == 1
86#define i_ BOOST_PP_FRAME_ITERATION(1)
87
88template<>
89struct advance_backward< BOOST_PP_FRAME_ITERATION(1) >
90{
91 template< typename Iterator > struct apply
92 {
93 typedef Iterator iter0;
94
95#if i_ > 0
96# define BOOST_PP_ITERATION_PARAMS_2 \
97 (3,(1, BOOST_PP_FRAME_ITERATION(1), <boost/mpl/aux_/advance_backward.hpp>))
98# include BOOST_PP_ITERATE()
99#endif
100
101 typedef BOOST_PP_CAT(iter,BOOST_PP_FRAME_ITERATION(1)) type;
102 };
103
104#if defined(BOOST_MPL_CFG_MSVC_60_ETI_BUG)
105 /// ETI workaround
106 template<> struct apply<int>
107 {
108 typedef int type;
109 };
110#endif
111};
112
113#undef i_
114
115///// iteration, depth == 2
116
117#elif BOOST_PP_ITERATION_DEPTH() == 2
118
119# define AUX778076_ITER_0 BOOST_PP_CAT(iter,BOOST_PP_DEC(BOOST_PP_FRAME_ITERATION(2)))
120# define AUX778076_ITER_1 BOOST_PP_CAT(iter,BOOST_PP_FRAME_ITERATION(2))
121
122 typedef typename prior<AUX778076_ITER_0>::type AUX778076_ITER_1;
123
124# undef AUX778076_ITER_1
125# undef AUX778076_ITER_0
126
127#endif // BOOST_PP_ITERATION_DEPTH()
128#endif // BOOST_PP_IS_ITERATING
129

source code of boost/boost/mpl/aux_/advance_backward.hpp