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diff --git a/moses/src/ChartTrellisDetourQueue.h b/moses/src/ChartTrellisDetourQueue.h
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+/***********************************************************************
+ Moses - statistical machine translation system
+ Copyright (C) 2006-2011 University of Edinburgh
+ 
+ This library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+ 
+ This library 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
+ Lesser General Public License for more details.
+ 
+ You should have received a copy of the GNU Lesser General Public
+ License along with this library; if not, write to the Free Software
+ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+***********************************************************************/
+
+#pragma once
+
+#include "ChartTrellisDetour.h"
+
+#include <set>
+
+namespace Moses {
+
+// A bounded priority queue of ChartTrellisDetour pointers.  The top item is
+// the best scoring detour.  The queue assumes ownership of pushed items and
+// relinquishes ownership when they are popped.  Any remaining items at the
+// time of the queue's destruction are deleted.
+class ChartTrellisDetourQueue {
+ public:
+  // Create empty queue with fixed capacity of c.  Capacity 0 means unbounded.
+  ChartTrellisDetourQueue(size_t c) : m_capacity(c) {}
+  ~ChartTrellisDetourQueue();
+
+  bool Empty() const { return m_queue.empty(); }
+
+  // Add the detour to the queue or delete it if the queue is full and the
+  // score is no better than the queue's worst score.
+  void Push(const ChartTrellisDetour *detour);
+
+  // Remove the best-scoring detour from the queue and return it.  The
+  // caller is responsible for deleting the object.
+  const ChartTrellisDetour *Pop();
+
+ private:
+  struct DetourOrderer {
+    bool operator()(const ChartTrellisDetour* a,
+                    const ChartTrellisDetour* b) const {
+      return (a->GetTotalScore() > b->GetTotalScore());
+    }
+  };
+
+  typedef std::multiset<const ChartTrellisDetour *, DetourOrderer> QueueType;
+
+  QueueType m_queue;
+  const size_t m_capacity;
+};
+
+}  // namespace Moses