Convert a String into an Array of Characters - mul

问题:

Assuming that in 2019 every solution which is not UNICODE-safe is wrong. What is the best way to convert a string to array of UNICODE characters in PHP?

Obviously this means that accessing the bytes with the brace syntax is wrong, as well as using str_split:

$arr = str_split($text);

From sample input like:

$string = '先éé€