3rdparty/boost/boost/fusion/algorithm/query/detail/segmented_find.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_FIND_HPP_INCLUDED)
   8 #define BOOST_FUSION_SEGMENTED_FIND_HPP_INCLUDED
   9
  10 #include <boost/fusion/support/config.hpp>
  11 #include <boost/mpl/eval_if.hpp>
  12 #include <boost/mpl/identity.hpp>
  13 #include <boost/fusion/algorithm/query/find_fwd.hpp>
  14 #include <boost/fusion/iterator/equal_to.hpp>
  15 #include <boost/fusion/sequence/intrinsic/end.hpp>
  16 #include <boost/fusion/support/segmented_fold_until.hpp>
  17
  18 namespace boost { namespace fusion { namespace detail
  19 {
  20     template <typename T>
  21     struct segmented_find_fun
  22     {
  23         template <typename Sequence, typename State, typename Context>
  24         struct apply
  25         {
  26             typedef
  27                 typename result_of::find<Sequence, T>::type
  28             iterator_type;
  29
  30             typedef
  31                 typename result_of::equal_to<
  32                     iterator_type
  33                   , typename result_of::end<Sequence>::type
  34                 >::type
  35             continue_type;
  36
  37             typedef
  38                 typename mpl::eval_if<
  39                     continue_type
  40                   , mpl::identity<State>
  41                   , result_of::make_segmented_iterator<
  42                         iterator_type
  43                       , Context
  44                     >
  45                 >::type
  46             type;
  47
  48             BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  49             static type call(Sequence& seq, State const&state, Context const& context, segmented_find_fun)
  50             {
  51                 return call_impl(seq, state, context, continue_type());
  52             }
  53
  54             BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  55             static type call_impl(Sequence&, State const&state, Context const&, mpl::true_)
  56             {
  57                 return state;
  58             }
  59
  60             BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  61             static type call_impl(Sequence& seq, State const&, Context const& context, mpl::false_)
  62             {
  63                 return fusion::make_segmented_iterator(fusion::find<T>(seq), context);
  64             }
  65         };
  66     };
  67
  68     template <typename Sequence, typename T>
  69     struct result_of_segmented_find
  70     {
  71         struct filter
  72         {
  73             typedef
  74                 typename result_of::segmented_fold_until<
  75                     Sequence
  76                   , typename result_of::end<Sequence>::type
  77                   , segmented_find_fun<T>
  78                 >::type
  79             type;
  80
  81             BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  82             static type call(Sequence& seq)
  83             {
  84                 return fusion::segmented_fold_until(
  85                     seq
  86                   , fusion::end(seq)
  87                   , detail::segmented_find_fun<T>());
  88             }
  89         };
  90
  91         typedef typename filter::type type;
  92     };
  93 }}}
  94
  95 #endif