[Boost-users] Regex trouble (compiling a simple expression fails)

Hi, I've looked at replacing the pcre library with boost regex,mainly because the C++ interface seems more usable than the plain C functions from pcre. The trouble is, I'm wasn't able to adjust regular expressions to the format boost regex uses. For instance, while pcre and others seem to like the expression "\?", boost throws bad_expression. The same goes for "\(", "\+" and others I'm using. So, I suppose the question is, is there a flag that can be set for the regex constructor that enables compatibility with a certain regex specification or should the regexp I gave as an example not be accepted ? Any hints would be kindly appreciated. Thanks, Bogdan.