ceph/src/boost/libs/multi_index/include/boost/multi_index/tag.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_TAG_HPP
  10 #define BOOST_MULTI_INDEX_TAG_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/multi_index/detail/no_duplicate_tags.hpp>
  18 #include <boost/mpl/identity.hpp>
  19 #include <boost/mpl/transform.hpp>
  20 #include <boost/mpl/vector.hpp>
  21 #include <boost/preprocessor/facilities/intercept.hpp>
  22 #include <boost/preprocessor/repetition/enum_binary_params.hpp>
  23 #include <boost/preprocessor/repetition/enum_params.hpp>
  24 #include <boost/static_assert.hpp>
  25 #include <boost/type_traits/is_base_and_derived.hpp>
  26
  27 /* A wrapper of mpl::vector used to hide MPL from the user.
  28  * tag contains types used as tag names for indices in get() functions.
  29  */
  30
  31 /* This user_definable macro limits the number of elements of a tag;
  32  * useful for shortening resulting symbol names (MSVC++ 6.0, for instance,
  33  * has problems coping with very long symbol names.)
  34  */
  35
  36 #if !defined(BOOST_MULTI_INDEX_LIMIT_TAG_SIZE)
  37 #define BOOST_MULTI_INDEX_LIMIT_TAG_SIZE BOOST_MPL_LIMIT_VECTOR_SIZE
  38 #endif
  39
  40 #if BOOST_MULTI_INDEX_LIMIT_TAG_SIZE<BOOST_MPL_LIMIT_VECTOR_SIZE
  41 #define BOOST_MULTI_INDEX_TAG_SIZE BOOST_MULTI_INDEX_LIMIT_TAG_SIZE
  42 #else
  43 #define BOOST_MULTI_INDEX_TAG_SIZE BOOST_MPL_LIMIT_VECTOR_SIZE
  44 #endif
  45
  46 namespace boost{
  47
  48 namespace multi_index{
  49
  50 namespace detail{
  51
  52 struct tag_marker{};
  53
  54 template<typename T>
  55 struct is_tag
  56 {
  57   BOOST_STATIC_CONSTANT(bool,value=(is_base_and_derived<tag_marker,T>::value));
  58 };
  59
  60 } /* namespace multi_index::detail */
  61
  62 template<
  63   BOOST_PP_ENUM_BINARY_PARAMS(
  64     BOOST_MULTI_INDEX_TAG_SIZE,
  65     typename T,
  66     =mpl::na BOOST_PP_INTERCEPT)
  67 >
  68 struct tag:private detail::tag_marker
  69 {
  70   /* The mpl::transform pass produces shorter symbols (without
  71    * trailing mpl::na's.)
  72    */
  73
  74   typedef typename mpl::transform<
  75     mpl::vector<BOOST_PP_ENUM_PARAMS(BOOST_MULTI_INDEX_TAG_SIZE,T)>,
  76     mpl::identity<mpl::_1>
  77   >::type type;
  78
  79   BOOST_STATIC_ASSERT(detail::no_duplicate_tags<type>::value);
  80 };
  81
  82 } /* namespace multi_index */
  83
  84 } /* namespace boost */
  85
  86 #undef BOOST_MULTI_INDEX_TAG_SIZE
  87
  88 #endif