It&#x27;s hard but needed to differentiate between UTF-16 and UChar byte array. UChar byte array are not essentially an well-formed UTF-16 string. Beyond, why bother use UnicodeString? It&#x27;s fairly easy to use. It covers the detail from your sight.<p>It&#x27;s indeed super cool to see a modern Unicode C++ library. But anyway, is it really useful for production usage? The answer could be no. In contrast, ICU was old, battle-tested, compact and well-tested.