@Rocky_Wei I'm not a big fan of the ?? followed by !!, it's very confusing to me to read because the ! is known to be a "force unwrapping" operator and this feels like an unsafe feature. Also, all developers would need to learn the precedence (that ?? is higher than !!).
The problem you're trying to solve reminds me of the also function in Kotlin:
Applying the same idea to Swift would look somewhat like this:
I'm not saying this is "better" or anything, just another approach to consider. And I believe you could just add this global function to your app and use it right now without any changes to the language (source):