they are exactly the same type for C++ and Objective-C++ code. This allows
them to be used as arguments to functions, especially virtuals, because
the C++ name mangling will be the same.
git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@20162 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775