boost/mpl/iter_fold_if.hpp

   1
   2 #ifndef BOOST_MPL_ITER_FOLD_IF_HPP_INCLUDED
   3 #define BOOST_MPL_ITER_FOLD_IF_HPP_INCLUDED
   4
   5 // Copyright Aleksey Gurtovoy 2003-2004
   6 // Copyright Eric Friedman 2003
   7 //
   8 // Distributed under the Boost Software License, Version 1.0.
   9 // (See accompanying file LICENSE_1_0.txt or copy at
  10 // http://www.boost.org/LICENSE_1_0.txt)
  11 //
  12 // See http://www.boost.org/libs/mpl for documentation.
  13
  14 // $Id: iter_fold_if.hpp 49267 2008-10-11 06:19:02Z agurtovoy $
  15 // $Date: 2008-10-10 23:19:02 -0700 (Fri, 10 Oct 2008) $
  16 // $Revision: 49267 $
  17
  18 #include <boost/mpl/begin_end.hpp>
  19 #include <boost/mpl/logical.hpp>
  20 #include <boost/mpl/always.hpp>
  21 #include <boost/mpl/eval_if.hpp>
  22 #include <boost/mpl/if.hpp>
  23 #include <boost/mpl/pair.hpp>
  24 #include <boost/mpl/apply.hpp>
  25 #include <boost/mpl/aux_/iter_fold_if_impl.hpp>
  26 #include <boost/mpl/aux_/na_spec.hpp>
  27 #include <boost/mpl/aux_/lambda_support.hpp>
  28 #include <boost/mpl/aux_/config/forwarding.hpp>
  29 #include <boost/mpl/aux_/config/workaround.hpp>
  30
  31 #include <boost/type_traits/is_same.hpp>
  32
  33 namespace boost { namespace mpl {
  34
  35 namespace aux {
  36
  37 template< typename Predicate, typename LastIterator >
  38 struct iter_fold_if_pred
  39 {
  40     template< typename State, typename Iterator > struct apply
  41 #if !defined(BOOST_MPL_CFG_NO_NESTED_FORWARDING)
  42         : and_<
  43               not_< is_same<Iterator,LastIterator> >
  44             , apply1<Predicate,Iterator>
  45             >
  46     {
  47 #else
  48     {
  49         typedef and_<
  50               not_< is_same<Iterator,LastIterator> >
  51             , apply1<Predicate,Iterator>
  52             > type;
  53 #endif
  54     };
  55 };
  56
  57 } // namespace aux
  58
  59 template<
  60       typename BOOST_MPL_AUX_NA_PARAM(Sequence)
  61     , typename BOOST_MPL_AUX_NA_PARAM(State)
  62     , typename BOOST_MPL_AUX_NA_PARAM(ForwardOp)
  63     , typename BOOST_MPL_AUX_NA_PARAM(ForwardPredicate)
  64     , typename BOOST_MPL_AUX_NA_PARAM(BackwardOp)
  65     , typename BOOST_MPL_AUX_NA_PARAM(BackwardPredicate)
  66     >
  67 struct iter_fold_if
  68 {
  69
  70     typedef typename begin<Sequence>::type first_;
  71     typedef typename end<Sequence>::type last_;
  72
  73     typedef typename eval_if<
  74           is_na<BackwardPredicate>
  75         , if_< is_na<BackwardOp>, always<false_>, always<true_> >
  76         , identity<BackwardPredicate>
  77         >::type backward_pred_;
  78
  79 // cwpro8 doesn't like 'cut-off' type here (use typedef instead)
  80 #if !BOOST_WORKAROUND(__MWERKS__, BOOST_TESTED_AT(0x3003)) && !BOOST_WORKAROUND(__IBMCPP__, BOOST_TESTED_AT(600))
  81     struct result_ :
  82 #else
  83     typedef
  84 #endif
  85         aux::iter_fold_if_impl<
  86           first_
  87         , State
  88         , ForwardOp
  89         , protect< aux::iter_fold_if_pred< ForwardPredicate,last_ > >
  90         , BackwardOp
  91         , backward_pred_
  92         >
  93 #if !BOOST_WORKAROUND(__MWERKS__, BOOST_TESTED_AT(0x3003)) && !BOOST_WORKAROUND(__IBMCPP__, BOOST_TESTED_AT(600))
  94     { };
  95 #else
  96     result_;
  97 #endif
  98
  99 public:
 100
 101     typedef pair<
 102           typename result_::state
 103         , typename result_::iterator
 104         > type;
 105
 106     BOOST_MPL_AUX_LAMBDA_SUPPORT(
 107           6
 108         , iter_fold_if
 109         , (Sequence,State,ForwardOp,ForwardPredicate,BackwardOp,BackwardPredicate)
 110         )
 111 };
 112
 113 BOOST_MPL_AUX_NA_SPEC(6, iter_fold_if)
 114
 115 }}
 116
 117 #endif // BOOST_MPL_ITER_FOLD_IF_HPP_INCLUDED