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diff --git a/qpid/cpp/src/qpid/cluster/exp/UniqueIds.h b/qpid/cpp/src/qpid/cluster/exp/UniqueIds.h
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+++ b/qpid/cpp/src/qpid/cluster/exp/UniqueIds.h
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+#ifndef QPID_CLUSTER_EXP_UNIQUEIDS_H
+#define QPID_CLUSTER_EXP_UNIQUEIDS_H
+
+/*
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ *
+ */
+
+#include "qpid/sys/Mutex.h"
+#include <set>
+
+namespace qpid {
+namespace cluster {
+
+/**
+ * Assign ID numbers, ensuring that all the assigned IDs are unique
+ * T is the numeric type - actually any type with >, == and ++ will do.
+ */
+template <class T> class UniqueIds
+{
+  public:
+    /** Get an ID that is different from all other active IDs.
+     *@return the ID, which is now considered active.
+     */
+    T get() {
+        sys::Mutex::ScopedLock l(lock);
+        T old = mark;
+        while (active.find(++mark) != active.end() && mark != old)
+            ;
+        assert(mark != old);      // check wrap-around
+        active.insert(mark);
+        return mark;
+    }
+    /** Release an ID, so it is inactive and available for re-use */
+    void release(T id) {
+        sys::Mutex::ScopedLock l(lock);
+        active.erase(id);
+    }
+    /** Allocate an ID, release automatically at end of scope */
+    struct Scope {
+        UniqueIds& ids;
+        T id;
+        Scope(UniqueIds& ids_) : ids(ids_), id(ids.get()) {}
+        ~Scope() { ids.release(id); }
+    };
+
+  private:
+    sys::Mutex lock;
+    std::set<T> active;
+    T mark;
+};
+}} // namespace qpid::cluster
+
+#endif  /*!QPID_CLUSTER_EXP_UNIQUEIDS_H*/