[handrous]

Me, reading the link at the top of this thread: oh wow, those are really cool.

Me, reading this example: oh no, those all need to be added to our project's lint rules to make sure no-one uses them.

[chana_masala]

Why would you prevent their usage? They're incredibly helpful

[handrous]

I guess it'd be OK as long as everyone always accompanied such lines with a comment, with at least one line per symbol or character it's identifying & explaining. As all but the most trivial regexes warrant.