// fwd decl
class WXDLLEXPORT wxImageList;
class WXDLLEXPORT wxDragImage;
-struct WXDLLEXPORT wxTreeViewItem;
+struct WXDLLIMPEXP_FWD_CORE wxTreeViewItem;
// a callback function used for sorting tree items, it should return -1 if the
// first item precedes the second, +1 if the second precedes the first or 0 if