ceph/src/boost/libs/intrusive/include/boost/intrusive/detail/default_header_holder.hpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 //
   3 // (C) Copyright Ion Gaztanaga  2014-2014
   4 //
   5 // Distributed under the Boost Software License, Version 1.0.
   6 //    (See accompanying file LICENSE_1_0.txt or copy at
   7 //          http://www.boost.org/LICENSE_1_0.txt)
   8 //
   9 // See http://www.boost.org/libs/intrusive for documentation.
  10 //
  11 /////////////////////////////////////////////////////////////////////////////
  12
  13 #ifndef BOOST_INTRUSIVE_DETAIL_DEFAULT_HEADER_HOLDER_HPP
  14 #define BOOST_INTRUSIVE_DETAIL_DEFAULT_HEADER_HOLDER_HPP
  15
  16 #ifndef BOOST_CONFIG_HPP
  17 #  include <boost/config.hpp>
  18 #endif
  19
  20 #if defined(BOOST_HAS_PRAGMA_ONCE)
  21 #  pragma once
  22 #endif
  23
  24 #include <boost/intrusive/detail/workaround.hpp>
  25 #include <boost/intrusive/pointer_traits.hpp>
  26 #include <boost/intrusive/detail/to_raw_pointer.hpp>
  27
  28 namespace boost {
  29 namespace intrusive {
  30 namespace detail {
  31
  32 // trivial header node holder
  33 template < typename NodeTraits >
  34 struct default_header_holder : public NodeTraits::node
  35 {
  36    typedef NodeTraits node_traits;
  37    typedef typename node_traits::node node;
  38    typedef typename node_traits::node_ptr node_ptr;
  39    typedef typename node_traits::const_node_ptr const_node_ptr;
  40
  41    default_header_holder() : node() {}
  42
  43    BOOST_INTRUSIVE_FORCEINLINE const_node_ptr get_node() const
  44    { return pointer_traits< const_node_ptr >::pointer_to(*static_cast< const node* >(this)); }
  45
  46    BOOST_INTRUSIVE_FORCEINLINE node_ptr get_node()
  47    { return pointer_traits< node_ptr >::pointer_to(*static_cast< node* >(this)); }
  48
  49    // (unsafe) downcast used to implement container-from-iterator
  50    BOOST_INTRUSIVE_FORCEINLINE static default_header_holder* get_holder(const node_ptr &p)
  51    { return static_cast< default_header_holder* >(boost::intrusive::detail::to_raw_pointer(p)); }
  52 };
  53
  54 // type function producing the header node holder
  55 template < typename ValueTraits, typename HeaderHolder >
  56 struct get_header_holder_type
  57 {
  58    typedef HeaderHolder type;
  59 };
  60 template < typename ValueTraits >
  61 struct get_header_holder_type< ValueTraits, void >
  62 {
  63    typedef default_header_holder< typename ValueTraits::node_traits > type;
  64 };
  65
  66 } //namespace detail
  67 } //namespace intrusive
  68 } //namespace boost
  69
  70 #endif //BOOST_INTRUSIVE_DETAIL_DEFAULT_HEADER_HOLDER_HPP