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

   1 /////////////////////////////////////////////////////////////////////////////
   2 //
   3 // (C) Copyright Ion Gaztanaga 2010-2013
   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 //[doc_recursive_member
  13 #include <boost/intrusive/list.hpp>
  14 #include <boost/intrusive/parent_from_member.hpp>
  15
  16 using namespace boost::intrusive;
  17
  18 class Recursive;
  19
  20 //Declaration of the functor that converts betwen the Recursive
  21 //class and the hook
  22 struct Functor
  23 {
  24    //Required types
  25    typedef list_member_hook<>    hook_type;
  26    typedef hook_type*            hook_ptr;
  27    typedef const hook_type*      const_hook_ptr;
  28    typedef Recursive             value_type;
  29    typedef value_type*           pointer;
  30    typedef const value_type*     const_pointer;
  31
  32    //Required static functions
  33    static hook_ptr to_hook_ptr (value_type &value);
  34    static const_hook_ptr to_hook_ptr(const value_type &value);
  35    static pointer to_value_ptr(hook_ptr n);
  36    static const_pointer to_value_ptr(const_hook_ptr n);
  37 };
  38
  39 //Define the recursive class
  40 class Recursive
  41 {
  42    private:
  43    Recursive(const Recursive&);
  44    Recursive & operator=(const Recursive&);
  45
  46    public:
  47    Recursive() : hook(), children() {}
  48    list_member_hook<> hook;
  49    list< Recursive, function_hook< Functor> > children;
  50 };
  51
  52 //Definition of Functor functions
  53 inline Functor::hook_ptr Functor::to_hook_ptr (Functor::value_type &value)
  54    {  return &value.hook; }
  55 inline Functor::const_hook_ptr Functor::to_hook_ptr(const Functor::value_type &value)
  56    {  return &value.hook; }
  57 inline Functor::pointer Functor::to_value_ptr(Functor::hook_ptr n)
  58    {  return get_parent_from_member<Recursive>(n, &Recursive::hook);  }
  59 inline Functor::const_pointer Functor::to_value_ptr(Functor::const_hook_ptr n)
  60    {  return get_parent_from_member<Recursive>(n, &Recursive::hook);  }
  61
  62 int main()
  63 {
  64    Recursive f, f2;
  65    //A recursive list of Recursive
  66    list< Recursive, function_hook< Functor> > l;
  67
  68    //Insert a node in parent list
  69    l.insert(l.begin(), f);
  70
  71    //Insert a node in child list
  72    l.begin()->children.insert(l.begin()->children.begin(), f2);
  73
  74    //Objects properly inserted
  75    assert(l.size() == l.begin()->children.size());
  76    assert(l.size() == 1);
  77
  78    //Clear both lists
  79    l.begin()->children.clear();
  80    l.clear();
  81    return 0;
  82 }
  83 //]