boost/intrusive/detail/node_to_value.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_NODE_TO_VALUE_HPP
  14 #define BOOST_INTRUSIVE_DETAIL_NODE_TO_VALUE_HPP
  15
  16 #if defined(_MSC_VER)
  17 #  pragma once
  18 #endif
  19
  20 #include <boost/intrusive/pointer_traits.hpp>
  21 #include <boost/intrusive/detail/mpl.hpp>
  22 #include <boost/intrusive/detail/is_stateful_value_traits.hpp>
  23
  24 namespace boost {
  25 namespace intrusive {
  26 namespace detail {
  27
  28 template<class VoidPointer>
  29 struct dummy_constptr
  30 {
  31    typedef typename boost::intrusive::pointer_traits<VoidPointer>::
  32       template rebind_pointer<const void>::type ConstVoidPtr;
  33
  34    explicit dummy_constptr(ConstVoidPtr)
  35    {}
  36
  37    dummy_constptr()
  38    {}
  39
  40    ConstVoidPtr get_ptr() const
  41    {  return ConstVoidPtr();  }
  42 };
  43
  44 template<class VoidPointer>
  45 struct constptr
  46 {
  47    typedef typename boost::intrusive::pointer_traits<VoidPointer>::
  48       template rebind_pointer<const void>::type ConstVoidPtr;
  49
  50    constptr()
  51    {}
  52
  53    explicit constptr(const ConstVoidPtr &ptr)
  54       :  const_void_ptr_(ptr)
  55    {}
  56
  57    const void *get_ptr() const
  58    {  return boost::intrusive::detail::to_raw_pointer(const_void_ptr_);  }
  59
  60    ConstVoidPtr const_void_ptr_;
  61 };
  62
  63 template <class VoidPointer, bool store_ptr>
  64 struct select_constptr
  65 {
  66    typedef typename if_c
  67       < store_ptr
  68       , constptr<VoidPointer>
  69       , dummy_constptr<VoidPointer>
  70       >::type type;
  71 };
  72
  73
  74 template<class ValueTraits, bool IsConst>
  75 struct node_to_value
  76    :  public select_constptr
  77       < typename pointer_traits
  78             <typename ValueTraits::pointer>::template rebind_pointer<void>::type
  79       , is_stateful_value_traits<ValueTraits>::value
  80       >::type
  81 {
  82    static const bool stateful_value_traits = is_stateful_value_traits<ValueTraits>::value;
  83    typedef typename select_constptr
  84       < typename pointer_traits
  85             <typename ValueTraits::pointer>::
  86                template rebind_pointer<void>::type
  87       , stateful_value_traits >::type                 Base;
  88
  89    typedef ValueTraits                                 value_traits;
  90    typedef typename value_traits::value_type           value_type;
  91    typedef typename value_traits::node_traits::node    node;
  92    typedef typename add_const_if_c
  93          <value_type, IsConst>::type                   vtype;
  94    typedef typename add_const_if_c
  95          <node, IsConst>::type                         ntype;
  96    typedef typename pointer_traits
  97       <typename ValueTraits::pointer>::
  98          template rebind_pointer<ntype>::type          npointer;
  99    typedef typename pointer_traits<npointer>::
 100       template rebind_pointer<const ValueTraits>::type const_value_traits_ptr;
 101
 102    node_to_value(const const_value_traits_ptr &ptr)
 103       :  Base(ptr)
 104    {}
 105
 106    typedef vtype &                                 result_type;
 107    typedef ntype &                                 first_argument_type;
 108
 109    const_value_traits_ptr get_value_traits() const
 110    {  return pointer_traits<const_value_traits_ptr>::static_cast_from(Base::get_ptr());  }
 111
 112    result_type to_value(first_argument_type arg, false_) const
 113    {  return *(value_traits::to_value_ptr(pointer_traits<npointer>::pointer_to(arg)));  }
 114
 115    result_type to_value(first_argument_type arg, true_) const
 116    {  return *(this->get_value_traits()->to_value_ptr(pointer_traits<npointer>::pointer_to(arg))); }
 117
 118    result_type operator()(first_argument_type arg) const
 119    {  return this->to_value(arg, bool_<stateful_value_traits>()); }
 120 };
 121
 122 }  //namespace detail{
 123 }  //namespace intrusive{
 124 }  //namespace boost{
 125
 126 #endif //BOOST_INTRUSIVE_DETAIL_NODE_TO_VALUE_HPP