boost/fusion/view/zip_view/detail/advance_impl.hpp

   1 /*=============================================================================
   2     Copyright (c) 2001-2011 Joel de Guzman
   3     Copyright (c) 2006 Dan Marsden
   4
   5     Distributed under the Boost Software License, Version 1.0. (See accompanying
   6     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   7 ==============================================================================*/
   8 #if !defined(FUSION_ADVANCE_IMPL_20061024_2021)
   9 #define FUSION_ADVANCE_IMPL_20061024_2021
  10
  11 #include <boost/fusion/support/config.hpp>
  12 #include <boost/fusion/view/zip_view/zip_view_iterator_fwd.hpp>
  13 #include <boost/fusion/iterator/advance.hpp>
  14 #include <boost/fusion/algorithm/transformation/transform.hpp>
  15 #include <boost/type_traits/remove_reference.hpp>
  16
  17 namespace boost { namespace fusion {
  18
  19     struct zip_view_iterator_tag;
  20
  21     namespace detail
  22     {
  23         template<typename N>
  24         struct poly_advance
  25         {
  26             template<typename Sig>
  27             struct result;
  28
  29             template<typename N1, typename It>
  30             struct result<poly_advance<N1>(It)>
  31             {
  32                 typedef typename remove_reference<It>::type it;
  33                 typedef typename result_of::advance<it,N>::type type;
  34             };
  35
  36             template<typename It>
  37             BOOST_FUSION_GPU_ENABLED
  38             typename result<poly_advance(It)>::type
  39             operator()(const It& it) const
  40             {
  41                 return fusion::advance<N>(it);
  42             }
  43         };
  44     }
  45
  46     namespace extension
  47     {
  48         template<typename Tag>
  49         struct advance_impl;
  50
  51         template<>
  52         struct advance_impl<zip_view_iterator_tag>
  53         {
  54             template<typename It, typename N>
  55             struct apply
  56             {
  57                 typedef zip_view_iterator<
  58                     typename result_of::transform<typename It::iterators, detail::poly_advance<N> >::type> type;
  59
  60                 BOOST_FUSION_GPU_ENABLED
  61                 static type
  62                 call(It const& it)
  63                 {
  64                     return type(
  65                         fusion::transform(it.iterators_, detail::poly_advance<N>()));
  66                 }
  67             };
  68         };
  69     }
  70 }}
  71
  72 #endif