Michael McLaughlin:
> It's relatively easy to just add a glyph collection type (with each glyph
> collection object containing one or more Unicode glyph values that defines
> what will be rendered as a single character). A collection of objects of
> that type could then be passed as a pair of iterators or an
> initializer_list to the draw_text member function for the surface types.

Well in my design that I'm about to propose there will be separate
std::unicode::grapheme_cluster type and something that is returned by
iterators of std::unicode::grapheme_cluster_sequence which is a grapheme
cluster but uses reference semantics so it is possible to replace
grapheme clusters inside a sequence.