boost/intrusive/derivation_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_DERIVATION_VALUE_TRAITS_HPP
  14 #define BOOST_INTRUSIVE_DERIVATION_VALUE_TRAITS_HPP
  15
  16 #include <boost/intrusive/link_mode.hpp>
  17 #include <iterator>
  18
  19 namespace boost {
  20 namespace intrusive {
  21
  22 //!This value traits template is used to create value traits
  23 //!from user defined node traits where value_traits::value_type will
  24 //!derive from node_traits::node
  25 template<class T, class NodeTraits, link_mode_type LinkMode = safe_link>
  26 struct derivation_value_traits
  27 {
  28    public:
  29    typedef NodeTraits                                                node_traits;
  30    typedef T                                                         value_type;
  31    typedef typename node_traits::node                                node;
  32    typedef typename node_traits::node_ptr                            node_ptr;
  33    typedef typename node_traits::const_node_ptr                      const_node_ptr;
  34    typedef typename boost::pointer_to_other<node_ptr, T>::type       pointer;
  35    typedef typename boost::pointer_to_other<node_ptr, const T>::type const_pointer;
  36    typedef typename std::iterator_traits<pointer>::reference         reference;
  37    typedef typename std::iterator_traits<const_pointer>::reference   const_reference;
  38    static const link_mode_type link_mode = LinkMode;
  39
  40    static node_ptr to_node_ptr(reference value)
  41    { return node_ptr(&value); }
  42
  43    static const_node_ptr to_node_ptr(const_reference value)
  44    { return node_ptr(&value); }
  45
  46    static pointer to_value_ptr(node_ptr n)
  47    {  return pointer(static_cast<T*>(detail::get_pointer(n))); }
  48
  49    static const_pointer to_value_ptr(const_node_ptr n)
  50    {  return const_pointer(static_cast<T*>(detail::get_pointer(n))); }
  51 };
  52
  53 } //namespace intrusive
  54 } //namespace boost
  55
  56 #endif //BOOST_INTRUSIVE_DERIVATION_VALUE_TRAITS_HPP