>>652
String.initに格差があってね
この差も疑問なんだけど

let ca:[Character] = ["a", "b", "c"]
let ua:[UnicodeScalar] = ["a", "b", "c"]

let cs = String(ca)
let us = String(ua) //これが出来ない

let us = String(ua.map(Character.init)) //これは出来る