ceph/src/boost/libs/hana/include/boost/hana/detail/type_foldr1.hpp

   1 /*!
   2 @file
   3 Defines `boost::hana::detail::type_foldr1`.
   4
   5 @copyright Louis Dionne 2013-2016
   6 Distributed under the Boost Software License, Version 1.0.
   7 (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
   8  */
   9
  10 #ifndef BOOST_HANA_DETAIL_TYPE_FOLDR1_HPP
  11 #define BOOST_HANA_DETAIL_TYPE_FOLDR1_HPP
  12
  13 #include <boost/hana/config.hpp>
  14
  15
  16 BOOST_HANA_NAMESPACE_BEGIN namespace detail {
  17     template <unsigned n>
  18     struct type_foldr1_t;
  19
  20     template <>
  21     struct type_foldr1_t<0> {
  22         template <
  23             template <typename ...> class f,
  24             typename state
  25         >
  26         using result = state;
  27     };
  28
  29     template <>
  30     struct type_foldr1_t<1> {
  31         template <
  32             template <typename ...> class f,
  33             typename x1,
  34             typename state
  35         >
  36         using result = typename f<x1, state>::type;
  37     };
  38
  39     template <>
  40     struct type_foldr1_t<2> {
  41         template <
  42             template <typename ...> class f,
  43             typename x1, typename x2,
  44             typename state
  45         >
  46         using result = typename f<x1, typename f<x2, state>::type>::type;
  47     };
  48
  49     template <>
  50     struct type_foldr1_t<3> {
  51         template <
  52             template <typename ...> class f,
  53             typename x1, typename x2, typename x3,
  54             typename state
  55         >
  56         using result = typename f<
  57             x1,
  58             typename f<
  59                 x2,
  60                 typename f<
  61                     x3,
  62                     state
  63                 >::type
  64             >::type
  65         >::type;
  66     };
  67
  68     template <>
  69     struct type_foldr1_t<4> {
  70         template <
  71             template <typename ...> class f,
  72             typename x1, typename x2, typename x3, typename x4,
  73             typename state
  74         >
  75         using result = typename f<
  76             x1,
  77             typename f<
  78                 x2,
  79                 typename f<
  80                     x3,
  81                     typename f<
  82                         x4,
  83                         state
  84                     >::type
  85                 >::type
  86             >::type
  87         >::type;
  88     };
  89
  90     template <>
  91     struct type_foldr1_t<5> {
  92         template <
  93             template <typename ...> class f,
  94             typename x1, typename x2, typename x3, typename x4, typename x5,
  95             typename state
  96         >
  97         using result = typename f<
  98             x1,
  99             typename f<
 100                 x2,
 101                 typename f<
 102                     x3,
 103                     typename f<
 104                         x4,
 105                         typename f<
 106                             x5,
 107                             state
 108                         >::type
 109                     >::type
 110                 >::type
 111             >::type
 112         >::type;
 113     };
 114
 115     template <>
 116     struct type_foldr1_t<6> {
 117         template <
 118             template <typename ...> class f,
 119             typename x1, typename x2, typename x3, typename x4, typename x5, typename x6,
 120             typename ...xs
 121         >
 122         using result =
 123         typename f<
 124             x1,
 125             typename f<
 126                 x2,
 127                 typename f<
 128                     x3,
 129                     typename f<
 130                         x4,
 131                         typename f<
 132                             x5,
 133                             typename type_foldr1_t<(sizeof...(xs) > 6 ? 6 : sizeof...(xs))>::
 134                             template result<f, x6, xs...>
 135                         >::type
 136                     >::type
 137                 >::type
 138             >::type
 139         >::type;
 140     };
 141
 142     template <template <typename ...> class f, typename x1, typename ...xn>
 143     struct type_foldr1 {
 144         using type = typename type_foldr1_t<(sizeof...(xn) > 6 ? 6 : sizeof...(xn))>
 145                      ::template result<f, x1, xn...>;
 146     };
 147 } BOOST_HANA_NAMESPACE_END
 148
 149 #endif // !BOOST_HANA_DETAIL_TYPE_FOLDR1_HPP