You need to escape the backslash in your exp variable. Here's (1) that works. #include <iostream> #include <string> #include using namespace std; using namespace boost; int main() { regex exp("\\s(ab)*", regbase::perl); // note the escaped \s here cmatch what; if ( regex_match(" ababab", what, exp) ) { string str = what[0]; cout << str << endl; } } Regards, James -----Original Message----- From: Javier de Acha [mailto:jdeacha@corest.com] Sent: Wednesday, July 23, 2003 10:50 AM To: Boost-Users@yahoogroups.com Subject: [Boost-Users] Problem with regular expression Hello, The next few lines doesn't work (1) with \s. But (2) works well [[:space:]] regbase::escape_in_lists dont func? Someone it knows because? Thanks Javier --------------------------------------------------------------------- (1) void main() { regex exp("\s(ab)*",regbase::perl); cmatch what; if(regex_match(" ababab", what, exp)) { string str = what[0]; //this fail } } ---------------------------------------------------------------------------- ---- (2) void main() { regex exp("[[:space:]](ab)*",regbase::perl); cmatch what; if(regex_match(" ababab", what, exp)) { string str = what[0]; //this succesfully match } } [Non-text portions of this message have been removed] ------------------------ Yahoo! Groups Sponsor ---------------------~--> Buy Ink Cartridges & Refill Kits for Your Epson at Myinks.com Free shipping on orders $50 or more to the US and Canada. http://www.c1tracking.com/l.asp?cid=5705&lp=home/epson.asp http://us.click.yahoo.com/brYXfA/_xWGAA/ySSFAA/EbFolB/TM ---------------------------------------------------------------------~-> Info: http://www.boost.org Wiki: http://www.crystalclearsoftware.com/cgi-bin/boost_wiki/wiki.pl Unsubscribe: mailto:boost-users-unsubscribe@yahoogroups.com Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/