Hi folks, The following code demonstrates the problem I'm having. I'm using Boost 1.33.1 (Debian), but IIRC this worked last year with the same version because I tested it; possibly a Debian-specific regression? I expect both regular expressions here to match with the value string. They certainly to with egrep. However, I only get the second to match: % g++ -c regex.cc -o regex.o && g++ -o regex regex.o -lboost_regex % ./regex It didn't match the first It matched the second Am I correct in my expectation that expression1 will match? If not, what should I be doing to make it match? Many thanks, Roger -- .''`. Roger Leigh : :' : Debian GNU/Linux http://people.debian.org/~rleigh/ `. `' Printing on GNU/Linux? http://gutenprint.sourceforge.net/ `- GPG Public Key: 0x25BFB848 Please GPG sign your mail.