Super Search is your friend (as is oft said). A SoPW only search for nodes containing the words "regex zero width assertion" gets you a pile of examples. Just picking a few from the first page:

Similar searches for related key words would get a pile more.

DWIM is Perl's answer to Gödel

In reply to Re: real world extended regex examples by GrandFather
in thread real world extended regex examples by szabgab

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