This is NOT an issue and just to let you know that a new "absent operator" has been implemented on Ruby's regexp lib named Onigmo. Sorry for this if this'd disturb you.
I recognize that your Regexp2 is based upon .NET Framework and extending your lib like that might not be good in some cases.
Note that I don't mean I need the operator right now.
I just wrote that for the case you'd have any interests in the new operator.
This is NOT an issue and just to let you know that a new "absent operator" has been implemented on Ruby's regexp lib named Onigmo. Sorry for this if this'd disturb you.
Note that the implementation of the operator has a rigid background theory: https://staff.aist.go.jp/tanaka-akira/pub/prosym49-akr-paper.pdf
Cheers,