%!demo
%! ## `sort` orders an ordinal array by its category *ranking*, not alphabetically
%! ## by label.
%!
%! C = categorical ({'L'; 'S'; 'M'; 'S'; 'L'}, {'S', 'M', 'L'}, 'Ordinal', true)
%! sort (C)
%!
%! ## Any `<undefined>` values sort to the end by default.
