This is needed to at least silence g++ warnings but may actually even fix a real problem as these classes can be inherited from and are deleted via a pointer (to "this" itself, in Release() implementation). git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@74492 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775