Swift's String class (https://developer.apple.com/library/ios/documentation/Swift/...) uses extended grapheme clusters as characters. If you need the raw Unicode scalars or UTF-16/UTF-8 code units, there are separate "views" into the string that let you iterate over these.

Using extended grapheme clusters as characters means truncation, concatenation, length measurement and transformations like reversal all work in the expected way, even in the presence of combining characters. More standard libraries should consider adopting this model!