boost/mpl/aux_/advance_backward.hpp

   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: advance_backward.hpp 49267 2008-10-11 06:19:02Z agurtovoy $
  18 // $Date: 2008-10-10 23:19:02 -0700 (Fri, 10 Oct 2008) $
  19 // $Revision: 49267 $
  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
  44 namespace boost { namespace mpl { namespace aux {
  45
  46 // forward declaration
  47 template< 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
  54 template< BOOST_MPL_AUX_NTTP_DECL(long, N) >
  55 struct 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
  88 template<>
  89 struct 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