move destroyable.h from pvDataCPP

src/utils/Makefile

@@ -12,6 +12,7 @@ INC += pv/configuration.h
 INC += pv/likely.h
 INC += pv/wildcard.h
 INC += pv/fairQueue.h
+INC += pv/destroyable.h
 
 LIBSRCS += hexDump.cpp
 LIBSRCS += inetAddressUtil.cpp

src/utils/pv/destroyable.h

@@ -0,0 +1,59 @@
+/* destroyable.h */
+/*
+ * Copyright information and license terms for this software can be
+ * found in the file LICENSE that is included with the distribution
+ */
+/**
+ *  @author mse
+ */
+#ifndef DESTROYABLE_H
+#define DESTROYABLE_H
+
+#include <pv/sharedPtr.h>
+
+#include <shareLib.h>
+
+namespace epics { namespace pvData { 
+
+
+        /**
+         * @brief Instance declaring destroy method.
+         * 
+         * @author mse
+         */
+        class epicsShareClass Destroyable {
+        public:
+            POINTER_DEFINITIONS(Destroyable);
+            /**
+             * Destroy this instance.
+             */
+            virtual void destroy() = 0;
+            
+        protected:
+            /**
+             * Do not allow delete on this instance and derived classes, destroy() must be used instead.
+             */ 
+            virtual ~Destroyable() {};
+        public:
+
+            /** for use with shared_ptr<> when wrapping
+             *
+             @code
+               shared_ptr<foo> inner(new foo),
+                               outer(inner.get, Destroyable::cleaner(inner));
+             @endcode
+             */
+            class cleaner {
+                Destroyable::shared_pointer ptr;
+            public:
+                cleaner(const Destroyable::shared_pointer& ptr) :ptr(ptr) {}
+                void operator()(Destroyable*) {
+                    Destroyable::shared_pointer P;
+                    P.swap(ptr);
+                    P->destroy();
+                }
+            };
+        };
+
+}}
+#endif  /* DESTROYABLE_H */