using the latest regex patch and vc7.1 i've accidentally encountered the following:
... regex re("([^\n]*\\n+\\s+)+NEEDEDSUBITEM2:[^\\s]"); bool matched = regex_search(text, re); // bad_expression
I think the problem is that the first repeated section: ([^\n]*\\n+\\s+)+ starts and ends with repeats either of which can match repeated whitespace - this is what causes the matcher to thrash trying to find a match, eventually leading to it giving up and throwing an exception, I think you could make your expression much more precise by using: regex re("([^\n]*\\n+)+\\s+NEEDEDSUBITEM2:[^\\s]"); By moving the \s+ out side of the repeat like this the expression is now much more deterministic - it can only do one thing for any given input character.
and one question: having "DATA.*?ITEM1(ITEM2)?" and an input like "DATA ITEM1 ITEM1ITEM2" should ITEM2 be extracted? i think it would be good to make a note on this case in the doc.
No for Perl regexes, not sure for POSIX regexes (non-greedy repeats don't sit will with POSIX semantics in cases like this, I'd advise using Perl regexes only with non-greedy repeats). John.