Re: [Boost-Users] Regex: matching either of 2 fields, in any order

From: John Maddock (john_maddock_at_[hidden])
Date: 2003-05-31 05:25:38

> That's it exactly.  And your explanation was a lot more succinct than
> mine, too!  Thanks.
> > I could be wrong, but I interpreted the OP's question to mean: is it
> > possible to have the regex generate an error if more than one 
> > sub-field of a
> > specific type is found, i.e. the following would be invalid:
> > 
> > ~C123~C345

OK, negative forward lookahead asserts can be used for that:

"~C\\d+(?!.*~C\\d)"

John.