ceph/src/boost/libs/intrusive/example/doc_derivation_value_traits.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 //
   3 // (C) Copyright Ion Gaztanaga  2006-2014
   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 #include <boost/intrusive/link_mode.hpp>
  13 #include <boost/intrusive/list.hpp>
  14 #include <boost/intrusive/derivation_value_traits.hpp>
  15 #include <vector>
  16
  17 struct simple_node
  18 {
  19    simple_node *prev_;
  20    simple_node *next_;
  21 };
  22
  23 //Define the node traits. A single node_traits will be enough.
  24 struct simple_node_traits
  25 {
  26    typedef simple_node                             node;
  27    typedef node *                                  node_ptr;
  28    typedef const node *                            const_node_ptr;
  29    static node *get_next(const node *n)            {  return n->next_;  }
  30    static void set_next(node *n, node *next)       {  n->next_ = next;  }
  31    static node *get_previous(const node *n)        {  return n->prev_;  }
  32    static void set_previous(node *n, node *prev)   {  n->prev_ = prev;  }
  33 };
  34
  35 //[doc_derivation_value_traits_value_traits
  36 class base_1{};
  37 class base_2{};
  38
  39 struct value_1 :  public base_1, public simple_node
  40 {
  41    int   id_;
  42    simple_node node_;
  43 };
  44
  45 struct value_2 :  public base_1, public base_2, public simple_node
  46 {
  47    simple_node node_;
  48    float id_;
  49 };
  50
  51 using namespace boost::intrusive;
  52
  53 //Now define the needed value traits using derivation_value_traits
  54 typedef derivation_value_traits<value_1, simple_node_traits, normal_link> ValueTraits1;
  55 typedef derivation_value_traits<value_2, simple_node_traits, normal_link> ValueTraits2;
  56
  57 //Now define two intrusive lists. Both lists will use the same algorithms:
  58 // circular_list_algorithms<simple_node_traits>
  59 typedef list <value_1, value_traits<ValueTraits1> > Value1List;
  60 typedef list <value_2, value_traits<ValueTraits2> > Value2List;
  61 //]
  62
  63 //[doc_derivation_value_traits_test
  64 int main()
  65 {
  66    typedef std::vector<value_1> Vect1;
  67    typedef std::vector<value_2> Vect2;
  68
  69    //Create values, with a different internal number
  70    Vect1 values1;
  71    Vect2 values2;
  72    for(int i = 0; i < 100; ++i){
  73       value_1 v1;    v1.id_ = i;          values1.push_back(v1);
  74       value_2 v2;    v2.id_ = (float)i;   values2.push_back(v2);
  75    }
  76
  77    //Create the lists with the objects
  78    Value1List list1(values1.begin(), values1.end());
  79    Value2List list2(values2.begin(), values2.end());
  80
  81    //Now test both lists
  82    Value1List::const_iterator bit1(list1.begin()), bitend1(list1.end());
  83    Value2List::const_iterator bit2(list2.begin()), bitend2(list2.end());
  84
  85    Vect1::const_iterator it1(values1.begin()), itend1(values1.end());
  86    Vect2::const_iterator it2(values2.begin()), itend2(values2.end());
  87
  88    //Test the objects inserted in our lists
  89    for(; it1 != itend1; ++it1, ++bit1,  ++it2, ++bit2){
  90       if(&*bit1 != &*it1 || &*bit2 != &*it2) return false;
  91    }
  92    return 0;
  93 }
  94 //]