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

Bogdan Harjoc wrote:

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.

You need to escape the escape. "\\?" will match a literal '?' character. Ditto for "\\(" and "\\+". That's because the C++ compiler will eat one level of escape even before the regex engine sees it. Surely you have to use an extra slash with PCRE, too, right? -- Eric Niebler Boost Consulting www.boost-consulting.com