+#ifndef _WX_DDE_H_BASE_
+#define _WX_DDE_H_BASE_
+
+#include "wx/list.h"
+
+class wxDDEClient;
+class wxDDEServer;
+class wxDDEConnection;
+
+WX_DECLARE_USER_EXPORTED_LIST(wxDDEClient, wxDDEClientList, WXDLLIMPEXP_BASE);
+WX_DECLARE_USER_EXPORTED_LIST(wxDDEServer, wxDDEServerList, WXDLLIMPEXP_BASE);
+WX_DECLARE_USER_EXPORTED_LIST(wxDDEConnection, wxDDEConnectionList, WXDLLIMPEXP_BASE);
+
+#if defined(__WXMSW__)
+ #include "wx/msw/dde.h"
+#else
+ #error DDE is only supported on MSW