This is still simpler than std::stack<> which can be used with any container
and not just wxVector<> but better than the WX_DECLARE_STACK() macro which was
all that we had before.
git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@67047 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775