ceph/src/boost/libs/multi_index/include/boost/multi_index/detail/base_type.hpp

   1 /* Copyright 2003-2013 Joaquin M Lopez Munoz.
   2  * Distributed under the Boost Software License, Version 1.0.
   3  * (See accompanying file LICENSE_1_0.txt or copy at
   4  * http://www.boost.org/LICENSE_1_0.txt)
   5  *
   6  * See http://www.boost.org/libs/multi_index for library home page.
   7  */
   8
   9 #ifndef BOOST_MULTI_INDEX_DETAIL_BASE_TYPE_HPP
  10 #define BOOST_MULTI_INDEX_DETAIL_BASE_TYPE_HPP
  11
  12 #if defined(_MSC_VER)
  13 #pragma once
  14 #endif
  15
  16 #include <boost/config.hpp> /* keep it first to prevent nasty warns in MSVC */
  17 #include <boost/detail/workaround.hpp>
  18 #include <boost/mpl/at.hpp>
  19 #include <boost/mpl/apply.hpp>
  20 #include <boost/mpl/size.hpp>
  21 #include <boost/multi_index/detail/index_base.hpp>
  22 #include <boost/multi_index/detail/is_index_list.hpp>
  23 #include <boost/static_assert.hpp>
  24
  25 namespace boost{
  26
  27 namespace multi_index{
  28
  29 namespace detail{
  30
  31 /* MPL machinery to construct a linear hierarchy of indices out of
  32  * a index list.
  33  */
  34
  35 struct index_applier
  36 {
  37   template<typename IndexSpecifierMeta,typename SuperMeta>
  38   struct apply
  39   {
  40     typedef typename IndexSpecifierMeta::type            index_specifier;
  41     typedef typename index_specifier::
  42       BOOST_NESTED_TEMPLATE index_class<SuperMeta>::type type;
  43   };
  44 };
  45
  46 template<int N,typename Value,typename IndexSpecifierList,typename Allocator>
  47 struct nth_layer
  48 {
  49   BOOST_STATIC_CONSTANT(int,length=mpl::size<IndexSpecifierList>::value);
  50
  51   typedef typename  mpl::eval_if_c<
  52     N==length,
  53     mpl::identity<index_base<Value,IndexSpecifierList,Allocator> >,
  54     mpl::apply2<
  55       index_applier,
  56       mpl::at_c<IndexSpecifierList,N>,
  57       nth_layer<N+1,Value,IndexSpecifierList,Allocator>
  58     >
  59   >::type type;
  60 };
  61
  62 template<typename Value,typename IndexSpecifierList,typename Allocator>
  63 struct multi_index_base_type:nth_layer<0,Value,IndexSpecifierList,Allocator>
  64 {
  65   BOOST_STATIC_ASSERT(detail::is_index_list<IndexSpecifierList>::value);
  66 };
  67
  68 } /* namespace multi_index::detail */
  69
  70 } /* namespace multi_index */
  71
  72 } /* namespace boost */
  73
  74 #endif