ceph/src/boost/libs/spirit/include/boost/spirit/home/support/detail/as_variant.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 #ifndef BOOST_PP_IS_ITERATING
   8 #if !defined(BOOST_SPIRIT_AS_VARIANT_NOVEMBER_16_2007_0420PM)
   9 #define BOOST_SPIRIT_AS_VARIANT_NOVEMBER_16_2007_0420PM
  10
  11 #include <boost/preprocessor/iterate.hpp>
  12 #include <boost/preprocessor/repetition/enum_params.hpp>
  13 #include <boost/preprocessor/repetition/enum_binary_params.hpp>
  14 #include <boost/preprocessor/repetition/enum_params_with_a_default.hpp>
  15 #include <boost/preprocessor/repetition/repeat_from_to.hpp>
  16 #include <boost/variant/variant_fwd.hpp>
  17 #include <boost/fusion/include/size.hpp>
  18 #include <boost/fusion/include/begin.hpp>
  19 #include <boost/fusion/include/next.hpp>
  20 #include <boost/fusion/include/value_of.hpp>
  21 #include <boost/mpl/fold.hpp>
  22 #include <boost/mpl/vector.hpp>
  23 #include <boost/mpl/push_back.hpp>
  24 #include <boost/mpl/equal_to.hpp>
  25 #include <boost/mpl/contains.hpp>
  26 #include <boost/mpl/limits/list.hpp>
  27 #include <boost/type_traits/is_same.hpp>
  28
  29 namespace boost { namespace spirit { namespace detail
  30 {
  31     template <int size>
  32     struct as_variant_impl;
  33
  34 #if !defined(BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES)
  35 #else
  36     template <>
  37     struct as_variant_impl<0>
  38     {
  39         template <typename Iterator>
  40         struct apply
  41         {
  42             typedef variant<> type;
  43         };
  44     };
  45 #endif
  46
  47 #define BOOST_FUSION_NEXT_ITERATOR(z, n, data)                                  \
  48     typedef typename fusion::result_of::next<BOOST_PP_CAT(I, n)>::type          \
  49         BOOST_PP_CAT(I, BOOST_PP_INC(n));
  50
  51 #define BOOST_FUSION_NEXT_CALL_ITERATOR(z, n, data)                             \
  52     typename gen::BOOST_PP_CAT(I, BOOST_PP_INC(n))                              \
  53         BOOST_PP_CAT(i, BOOST_PP_INC(n)) = fusion::next(BOOST_PP_CAT(i, n));
  54
  55 #define BOOST_FUSION_VALUE_OF_ITERATOR(z, n, data)                              \
  56     typedef typename fusion::result_of::value_of<BOOST_PP_CAT(I, n)>::type      \
  57         BOOST_PP_CAT(T, n);
  58
  59 #define BOOST_PP_FILENAME_1 <boost/spirit/home/support/detail/as_variant.hpp>
  60
  61 #if !defined(BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES)
  62 #define BOOST_PP_ITERATION_LIMITS (1, BOOST_MPL_LIMIT_LIST_SIZE)
  63 #else
  64 #define BOOST_PP_ITERATION_LIMITS (1, BOOST_VARIANT_LIMIT_TYPES)
  65 #endif
  66
  67 #include BOOST_PP_ITERATE()
  68
  69 #undef BOOST_FUSION_NEXT_ITERATOR
  70 #undef BOOST_FUSION_NEXT_CALL_ITERATOR
  71 #undef BOOST_FUSION_VALUE_OF_ITERATOR
  72
  73     template <typename Sequence>
  74     struct as_variant
  75     {
  76         // build a variant generator being able to generate a variant holding
  77         // all of the types as given in the typelist
  78         typedef typename
  79             detail::as_variant_impl<fusion::result_of::size<Sequence>::value>
  80         gen;
  81
  82         // use this generator to create the actual variant
  83         typedef typename gen::template apply<
  84                 typename fusion::result_of::begin<Sequence>::type
  85             >::type
  86         type;
  87     };
  88 }}}
  89
  90 #endif
  91 #else // defined(BOOST_PP_IS_ITERATING)
  92 ///////////////////////////////////////////////////////////////////////////////
  93 //
  94 //  Preprocessor vertical repetition code
  95 //
  96 ///////////////////////////////////////////////////////////////////////////////
  97
  98 #define N BOOST_PP_ITERATION()
  99
 100     template <>
 101     struct as_variant_impl<N>
 102     {
 103         template <typename I0>
 104         struct apply
 105         {
 106             BOOST_PP_REPEAT(N, BOOST_FUSION_NEXT_ITERATOR, _)
 107             BOOST_PP_REPEAT(N, BOOST_FUSION_VALUE_OF_ITERATOR, _)
 108             typedef variant<BOOST_PP_ENUM_PARAMS(N, T)> type;
 109         };
 110     };
 111
 112 #undef N
 113 #endif // defined(BOOST_PP_IS_ITERATING)
 114