This allows to avoid problems with hiding all but the overridden overloads of Insert() in wxSizer-derived classes, see #11616, without having to explicitly write any using statements. Keep Insert(size_t, wxSizerItem) virtual to allow the existing code overriding it to keep working. git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@63230 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775