The good point (in my opinion) is not that "ASCII takes 1 byte, BMP takes 2 bytes, everything else 4 bytes", but rather that the exposed API hides this from you, and exposes to you a sequence of code points. This, I hope, will reduce errors, as code points, not code units, is often a better abstraction to be working with. (For some random string processing function.)

So far as I know, Haskell is the only other language that I know of that exposes, as the defaultish-native interface, Unicode strings as a sequence or iterable of code points (by just using UTF-32). Java, C#, your-language-here all do code units. C++'s template are powerful enough that someone could make unicode_str<encoding_to_store_as>, but I've not seen one.

See: http://www.unicode.org/glossary/#code_point http://www.unicode.org/glossary/#code_unit