boost/fusion/view/transform_view/detail/begin_impl.hpp

   1 /*=============================================================================
   2     Copyright (c) 2001-2011 Joel de Guzman
   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(FUSION_BEGIN_IMPL_07162005_1031)
   8 #define FUSION_BEGIN_IMPL_07162005_1031
   9
  10 #include <boost/fusion/support/config.hpp>
  11 #include <boost/fusion/view/transform_view/transform_view_fwd.hpp>
  12
  13 namespace boost { namespace fusion
  14 {
  15     template <typename First, typename F>
  16     struct transform_view_iterator;
  17
  18     template <typename First1, typename First2, typename F>
  19     struct transform_view_iterator2;
  20
  21     namespace extension
  22     {
  23         template <typename Tag>
  24         struct begin_impl;
  25
  26         // Unary Version
  27         template <>
  28         struct begin_impl<transform_view_tag>
  29         {
  30             template <typename Sequence>
  31             struct apply
  32             {
  33                 typedef typename Sequence::first_type first_type;
  34                 typedef typename Sequence::transform_type transform_type;
  35                 typedef transform_view_iterator<first_type, transform_type> type;
  36
  37                 BOOST_FUSION_GPU_ENABLED
  38                 static type
  39                 call(Sequence& s)
  40                 {
  41                     return type(s.first(), s.f);
  42                 }
  43             };
  44         };
  45
  46         // Binary Version
  47         template <>
  48         struct begin_impl<transform_view2_tag>
  49         {
  50             template <typename Sequence>
  51             struct apply
  52             {
  53                 typedef typename Sequence::first1_type first1_type;
  54                 typedef typename Sequence::first2_type first2_type;
  55                 typedef typename Sequence::transform_type transform_type;
  56                 typedef transform_view_iterator2<first1_type, first2_type, transform_type> type;
  57
  58                 BOOST_FUSION_GPU_ENABLED
  59                 static type
  60                 call(Sequence& s)
  61                 {
  62                     return type(s.first1(), s.first2(), s.f);
  63                 }
  64             };
  65         };
  66     }
  67 }}
  68
  69 #endif
  70
  71