Does the 'o' modifier for Perl regular expressions still provide any benefit?

Question

It used to be considered beneficial to include the \'o\' modifier at the end of Perl regular expressions. The current Perl documentation does not even seem to list it, cert

Answer 1

This is an optimization in the case that the regex includes a variable reference. It indicates that the regex does not change even though it has a variable within it. This allows for optimizations that would not be possible otherwise.