What? No. Parent comment is comparing C++ to modern programming languages, showcasing how they provide commonly used utilities out-of-the-box instead of making every programmer re-implement them again and again and again and again and again.
So it is NOT built-in and the code example shown above is dishonest - @SuperV1234 compares how "lean" two languages are but conveniently hides half of the code in their preferred language to make it seem simpler that it actually is, as otherwise it would look bad in the comparison!
So finally, it's NOT built-in, and the parent comment was showing that in other languages - it IS built-in. So your code example is NOT correct and comparison is NOT correct, because you just hid the most important part of it, which is the implementation, that the user has to either: a) write themselves, b) find somewhere on the Internet.
You won't have to care about ^^ and [:X:] if you just want to consume reflection-based utils, which was the whole point of my comment.