I may be wrong, and I hope I am. If a character is guaranteed never to consist of more than X code-points, it would be simple to offer a fixed-width character type, even if the width is huge by comparison to the eight-bit char type. But from what I've seen, I don't think that's the case.
I assume there is some limit but who know which? Even in Hebrew (the language I speak) you can easily create a letter with 4 code points: - shin-basic, shin/sin mark, vovel, dagesh - Now I can also add some biblical marks (I think there may be two or three of them) And Hebrew is relatively simple one. Now I have no idea about what happens in other languages and what happens with Unicode points that are going to be added in future Unicode releases. So I would suggest not assume that there is a certain limit. Artyom