+typedef struct DBusAllocatedSlot DBusAllocatedSlot;
+
+/** An allocated slot for storing data
+ */
+struct DBusAllocatedSlot
+{
+ dbus_int32_t slot_id; /**< ID of this slot */
+ int refcount; /**< Number of uses of the slot */
+};
+
+/**
+ * An allocator that tracks a set of slot IDs.
+ */