[...]没有内置的Cocoa方法来转换[...]。这是
吗？

[...] there is no built-in Cocoa methods to convert [...]. Is this correct?

这不正确。

您可能对 CFStringTransform 感兴趣，它的功能。这是一个完全成熟的ICU转换引擎，可以（也）执行您所要求的转换。

You might be interested in CFStringTransform and it's capabilities. It is a full blown ICU transformation engine, which can (also) perform your requested transformation.

请参阅使用目标C / Cocoa解除unicode unicode字符，即\\\ሴ