boost/fusion/sequence/intrinsic/detail/segmented_begin_impl.hpp

   1 /*=============================================================================
   2     Copyright (c) 2011 Eric Niebler
   3
   4     Distributed under the Boost Software License, Version 1.0. (See accompanying
   5     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   6 ==============================================================================*/
   7 #if !defined(BOOST_FUSION_SEGMENTED_BEGIN_IMPL_HPP_INCLUDED)
   8 #define BOOST_FUSION_SEGMENTED_BEGIN_IMPL_HPP_INCLUDED
   9
  10 #include <boost/type_traits/remove_const.hpp>
  11 #include <boost/fusion/container/list/cons_fwd.hpp>
  12 #include <boost/fusion/sequence/intrinsic_fwd.hpp>
  13 #include <boost/fusion/support/is_segmented.hpp>
  14 #include <boost/fusion/sequence/intrinsic/detail/segmented_end_impl.hpp>
  15 #include <boost/fusion/support/detail/segmented_fold_until_impl.hpp>
  16
  17 namespace boost { namespace fusion
  18 {
  19     template <typename First, typename Last>
  20     struct iterator_range;
  21 }}
  22
  23 namespace boost { namespace fusion { namespace detail
  24 {
  25     struct segmented_begin_fun
  26     {
  27         template <typename Sequence, typename State, typename Context>
  28         struct apply
  29         {
  30             typedef
  31                 iterator_range<
  32                     typename fusion::result_of::begin<Sequence>::type
  33                   , typename fusion::result_of::end<Sequence>::type
  34                 >
  35             range_type;
  36
  37             typedef cons<range_type, Context> type;
  38             typedef mpl::false_ continue_type;
  39
  40             static type call(Sequence& seq, State const&, Context const& context, segmented_begin_fun)
  41             {
  42                 return type(range_type(fusion::begin(seq), fusion::end(seq)), context);
  43             }
  44         };
  45     };
  46
  47     template <typename Sequence, typename Stack, bool IsSegmented = traits::is_segmented<Sequence>::type::value>
  48     struct segmented_begin_impl_aux
  49     {
  50         typedef
  51             segmented_end_impl<Sequence, Stack>
  52         end_impl;
  53
  54         typedef
  55             segmented_fold_until_impl<
  56                 Sequence
  57               , typename end_impl::type
  58               , Stack
  59               , segmented_begin_fun
  60             >
  61         fold_impl;
  62
  63         typedef typename fold_impl::type type;
  64
  65         static type call(Sequence& seq, Stack const& stack)
  66         {
  67             return fold_impl::call(seq, end_impl::call(seq, stack), stack, segmented_begin_fun());
  68         }
  69     };
  70
  71     template <typename Sequence, typename Stack>
  72     struct segmented_begin_impl_aux<Sequence, Stack, false>
  73     {
  74         typedef typename result_of::begin<Sequence>::type  begin_type;
  75         typedef typename result_of::end<Sequence>::type    end_type;
  76         typedef iterator_range<begin_type, end_type>    pair_type;
  77         typedef cons<pair_type, Stack>                  type;
  78
  79         static type call(Sequence& seq, Stack stack)
  80         {
  81             return type(pair_type(fusion::begin(seq), fusion::end(seq)), stack);
  82         }
  83     };
  84
  85     template <typename Sequence, typename Stack>
  86     struct segmented_begin_impl
  87       : segmented_begin_impl_aux<Sequence, Stack>
  88     {};
  89
  90 }}}
  91
  92 #endif