fixed gnu compiler incompatibility

src/cas/example/directoryService/directoryServer.cc

@@ -70,6 +70,14 @@ directoryServer::directoryServer(const char * const pvPrefix, unsigned pvCount,
 	}
 }
 
+
+//
+// directoryServer::~directoryServer()
+//
+directoryServer::~directoryServer()
+{
+}
+
 //
 // directoryServer::installAliasName()
 //

src/cas/example/directoryService/directoryServer.h

@@ -93,6 +93,7 @@ private:
 class directoryServer : public caServer {
 public:
 	directoryServer (const char * const pvPrefix, unsigned pvCount, unsigned aliasCount);
+	~directoryServer();
         void show (unsigned level) const;
         pvExistReturn pvExistTest (const casCtx&, const char *pPVName);