forked from cawka/ndn.cxx
diff --git a/ndn-cpp/trie/detail/multi-policy-container.h b/ndn-cpp/trie/detail/multi-policy-container.h
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+/* -*-  Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil; -*- */
+/*
+ * Copyright (c) 2011 University of California, Los Angeles
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation;
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ * Author: Alexander Afanasyev <alexander.afanasyev@ucla.edu>
+ */
+
+#ifndef MULTI_POLICY_CONTAINER_H_
+#define MULTI_POLICY_CONTAINER_H_
+
+#include <boost/mpl/inherit_linearly.hpp>
+#include <boost/mpl/at.hpp>
+
+namespace ns3 {
+namespace ndn {
+namespace ndnSIM {
+namespace detail {
+
+template< class Base, class Value >
+struct policy_wrap
+{
+  policy_wrap (Base &base) : value_ (base) { }
+  Value value_;
+};
+
+template< class Base, class Super/*empy_wrap/previous level*/, class Value/*policy_wrap< element in vector >*/ >
+struct inherit_with_base : Super, Value
+{
+  inherit_with_base (Base &base) : Super (base), Value (base) { }
+
+  void
+  update (typename Base::iterator item)
+  {
+    Value::value_.update (item);
+    Super::update (item);
+  }
+
+  bool
+  insert (typename Base::iterator item)
+  {
+    bool ok = Value::value_.insert (item);
+    if (!ok)
+      return false;
+
+    ok = Super::insert (item);
+    if (!ok)
+      {
+        Value::value_.erase (item);
+        return false;
+      }
+    return true;
+  }
+
+  void
+  lookup (typename Base::iterator item)
+  {
+    Value::value_.lookup (item);
+    Super::lookup (item);
+  }
+
+  void
+  erase (typename Base::iterator item)
+  {
+    Value::value_.erase (item);
+    Super::erase (item);
+  }  
+
+  void
+  clear ()
+  {
+    Value::value_.clear ();
+    Super::clear ();
+  }
+};
+
+template< class Base >
+struct empty_policy_wrap
+{
+  empty_policy_wrap (Base &base) { }
+
+  void update (typename Base::iterator item) {}
+  bool insert (typename Base::iterator item) { return true; }
+  void lookup (typename Base::iterator item) {}
+  void erase (typename Base::iterator item) {}
+  void clear () {}
+};
+
+template< class Base, class Vector >
+struct multi_policy_container
+  : public boost::mpl::fold< Vector,
+                      empty_policy_wrap<Base>,
+                      inherit_with_base<Base,
+                                        boost::mpl::_1/*empty/previous*/,
+                                        policy_wrap<Base, boost::mpl::_2>/*element in vector*/>
+                      >::type
+{
+  typedef typename boost::mpl::fold< Vector,
+                              empty_policy_wrap<Base>,
+                              inherit_with_base<Base,
+                                                boost::mpl::_1/*empty/previous*/,
+                                                policy_wrap<Base, boost::mpl::_2>/*element in vector*/>
+                              >::type super;
+
+  typedef typename boost::mpl::at_c<Vector, 0>::type::iterator iterator;
+  typedef typename boost::mpl::at_c<Vector, 0>::type::const_iterator const_iterator;
+
+  iterator begin ()             { return this->get<0> ().begin (); }
+  const_iterator begin () const { return this->get<0> ().begin (); }
+
+  iterator end ()             { return this->get<0> ().end (); }
+  const_iterator end () const { return this->get<0> ().end (); }
+
+  size_t size () const { return this->get<0> ().size (); }
+  
+  multi_policy_container (Base &base)
+  : super (base)
+  { }
+
+  template<int N>
+  struct index
+  {
+    typedef typename boost::mpl::at_c<Vector, N>::type type;
+  };
+  
+  template<class T>
+  T &
+  get ()
+  {
+    return static_cast< policy_wrap<Base, T> &> (*this).value_;
+  }
+
+  template<class T>
+  const T &
+  get () const
+  {
+    return static_cast< const policy_wrap<Base, T> &> (*this).value_;
+  }
+
+  template<int N>
+  typename boost::mpl::at_c<Vector, N>::type &
+  get ()
+  {
+    typedef typename boost::mpl::at_c<Vector, N>::type T;
+    return static_cast< policy_wrap<Base, T> &> (*this).value_;
+  }
+
+  template<int N>
+  const typename boost::mpl::at_c<Vector, N>::type &
+  get () const
+  {
+    typedef typename boost::mpl::at_c<Vector, N>::type T;
+    return static_cast< const policy_wrap<Base, T> &> (*this).value_;
+  }
+};
+
+
+} // detail
+} // ndnSIM
+} // ndn
+} // ns3
+
+#endif // MULTI_POLICY_CONTAINER_H_