added asserts to Clone/CreateRefData()

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@13980 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/common/object.cpp

@@ -276,11 +276,17 @@ void wxObject::AllocExclusive()
 
 wxObjectRefData *wxObject::CreateRefData() const
 {
+    // if you use AllocExclusive() you must override this method
+    wxFAIL_MSG( _T("CreateRefData() must be overridden if called!") );
+
     return NULL;
 }
 
 wxObjectRefData *wxObject::CloneRefData(wxObjectRefData * WXUNUSED(data)) const
 {
+    // if you use AllocExclusive() you must override this method
+    wxFAIL_MSG( _T("CloneRefData() must be overridden if called!") );
+
     return NULL;
 }