Hi, I'm seeking help for the following problem, using the regex library: the following line of code is meant to assist in parsing urls: boost::regex exp("(?is)(https?)://([^:/?#]+):?(\\d{1,5})?/?([^?#]*)?\ \??([^#]+)?#?(\\w*)"); It runs fine in a linux environment, however if compiled with VC9 on windows, it fails with: First-chance exception at 0x7c812aeb in test.exe: Microsoft C++ exception: boost ::exception_detail ::clone_impl <boost::exception_detail::error_info_injector<boost::regex_error> > at memory location 0x0012f768.. I thought that the expression might be too long, and indeed if I shorten the above line to: boost regex exp("(?is)(https?)://([^:/?#]+):?(\\d{1,5})?/?"); it runs fine on windows as well. Any help on what the cause of this can be, would be appreciated. Regards, ==Adam