ceph/src/boost/libs/fusion/include/boost/fusion/view/nview/nview.hpp

   1 /*=============================================================================
   2     Copyright (c) 2009 Hartmut Kaiser
   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
   8 #if !defined(BOOST_FUSION_NVIEW_SEP_23_2009_0948PM)
   9 #define BOOST_FUSION_NVIEW_SEP_23_2009_0948PM
  10
  11 #include <boost/fusion/support/config.hpp>
  12 #include <boost/mpl/if.hpp>
  13
  14 #include <boost/type_traits/add_reference.hpp>
  15 #include <boost/type_traits/add_const.hpp>
  16
  17 #include <boost/fusion/support/is_view.hpp>
  18 #include <boost/fusion/support/sequence_base.hpp>
  19 #include <boost/fusion/container/vector.hpp>
  20 #include <boost/fusion/sequence/intrinsic/size.hpp>
  21 #include <boost/fusion/view/transform_view.hpp>
  22
  23 #include <boost/config.hpp>
  24
  25 namespace boost { namespace fusion
  26 {
  27     namespace detail
  28     {
  29         struct addref
  30         {
  31             template<typename Sig>
  32             struct result;
  33
  34             template<typename U>
  35             struct result<addref(U)> : add_reference<U> {};
  36
  37 #ifdef BOOST_NO_CXX11_RVALUE_REFERENCES
  38             template <typename T>
  39             BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  40             typename add_reference<T>::type
  41             operator()(T& x) const
  42             {
  43                 return x;
  44             }
  45 #else
  46             template <typename T>
  47             BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  48             typename result<addref(T)>::type
  49             operator()(T&& x) const
  50             {
  51                 return x;
  52             }
  53 #endif
  54         };
  55
  56         struct addconstref
  57         {
  58             template<typename Sig>
  59             struct result;
  60
  61             template<typename U>
  62             struct result<addconstref(U)>
  63               : add_reference<typename add_const<U>::type>
  64             {};
  65
  66             template <typename T>
  67             BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  68             typename add_reference<typename add_const<T>::type>::type
  69             operator()(T& x) const
  70             {
  71                 return x;
  72             }
  73
  74             template <typename T>
  75             BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  76             typename add_reference<typename add_const<T>::type>::type
  77             operator()(T const& x) const
  78             {
  79                 return x;
  80             }
  81         };
  82     }
  83
  84     struct nview_tag;
  85     struct random_access_traversal_tag;
  86     struct fusion_sequence_tag;
  87
  88     template<typename Sequence, typename Indicies>
  89     struct nview
  90       : sequence_base<nview<Sequence, Indicies> >
  91     {
  92         typedef nview_tag fusion_tag;
  93         typedef fusion_sequence_tag tag; // this gets picked up by MPL
  94         typedef random_access_traversal_tag category;
  95
  96         typedef mpl::true_ is_view;
  97         typedef Indicies index_type;
  98         typedef typename result_of::size<Indicies>::type size;
  99
 100         typedef typename mpl::if_<
 101             is_const<Sequence>, detail::addconstref, detail::addref
 102         >::type transform_type;
 103         typedef transform_view<Sequence, transform_type> transform_view_type;
 104         typedef typename result_of::as_vector<transform_view_type>::type
 105             sequence_type;
 106
 107         BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
 108         explicit nview(Sequence& val)
 109           : seq(sequence_type(transform_view_type(val, transform_type())))
 110         {}
 111
 112         sequence_type seq;
 113     };
 114
 115 }}
 116
 117 // define the nview() generator functions
 118 #include <boost/fusion/view/nview/detail/nview_impl.hpp>
 119
 120 #endif
 121
 122