Re: [boost] Re: Regex-User: ISBN validation

From: John Maddock (john_at_[hidden])
Date: 2005-04-11 04:32:01

> Have you tried \2 instead of \1 for the long expression? AFAICS from the 
> documentation <http://www.boost.org/libs/regex/doc/syntax.html>, the first 
> "Forward Lookahead Assert" is still a match, but you want to refer to the 
> second parenthesis, right?

I don't think so: $2 appears after the last backreference, so would be an 
invalid expression, (forward lookahead asserts don't count as marked 
sub-expressions - nothing that begins (? does ).

John.