boost/intrusive/member_value_traits.hpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 //
   3 // (C) Copyright Ion Gaztanaga  2006-2008
   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_MEMBER_VALUE_TRAITS_HPP
  14 #define BOOST_INTRUSIVE_MEMBER_VALUE_TRAITS_HPP
  15
  16 #include <boost/intrusive/link_mode.hpp>
  17 #include <iterator>
  18 #include <boost/intrusive/detail/parent_from_member.hpp>
  19
  20 namespace boost {
  21 namespace intrusive {
  22
  23 //!This value traits template is used to create value traits
  24 //!from user defined node traits where value_traits::value_type will
  25 //!store a node_traits::node
  26 template< class T, class NodeTraits
  27         , typename NodeTraits::node T::* PtrToMember
  28         , link_mode_type LinkMode = safe_link>
  29 struct member_value_traits
  30 {
  31    public:
  32    typedef NodeTraits                                                node_traits;
  33    typedef T                                                         value_type;
  34    typedef typename node_traits::node                                node;
  35    typedef typename node_traits::node_ptr                            node_ptr;
  36    typedef typename node_traits::const_node_ptr                      const_node_ptr;
  37    typedef typename boost::pointer_to_other<node_ptr, T>::type       pointer;
  38    typedef typename boost::pointer_to_other<node_ptr, const T>::type const_pointer;
  39    typedef typename std::iterator_traits<pointer>::reference         reference;
  40    typedef typename std::iterator_traits<const_pointer>::reference   const_reference;
  41    static const link_mode_type link_mode = LinkMode;
  42
  43    static node_ptr to_node_ptr(reference value)
  44    {  return node_ptr(&(value.*PtrToMember));   }
  45
  46    static const_node_ptr to_node_ptr(const_reference value)
  47    {  return node_ptr(&(value.*PtrToMember));   }
  48
  49    static pointer to_value_ptr(node_ptr n)
  50    {
  51       return pointer(detail::parent_from_member<value_type, node>
  52          (detail::get_pointer(n), PtrToMember));
  53    }
  54
  55    static const_pointer to_value_ptr(const_node_ptr n)
  56    {
  57       return pointer(detail::parent_from_member<value_type, node>
  58          (detail::get_pointer(n), PtrToMember));
  59    }
  60 };
  61
  62 } //namespace intrusive
  63 } //namespace boost
  64
  65 #endif //BOOST_INTRUSIVE_MEMBER_VALUE_TRAITS_HPP