regex_replace("XX",regex("X", boost::regex::literal), "Y")

returns "YXY" instead of "YY" whereas the (even more) trivial case

regex_replace("X",regex("X", boost::regex::literal), "Y")

returns "Y" as expected.

I am using boost_1_31_0 compiled with VC6(SP5). In addition, I have applied the patches from the package boost-1.31.0-regex-patch-20040503.

What is going wrong here?

Well it's a bug, here's the patch that's going into cvs now: RCS file: /cvsroot/boost/boost/boost/regex/v4/perl_matcher_common.hpp,v retrieving revision 1.18.2.3 diff -u -r1.18.2.3 perl_matcher_common.hpp --- boost/regex/v4/perl_matcher_common.hpp 3 May 2004 11:31:15 -00001.18.2. 3 +++ boost/regex/v4/perl_matcher_common.hpp 12 Jun 2004 10:04:47 -0000 @@ -54,7 +54,7 @@ estimate_max_state_count(static_cast(0)); if(!(m_match_flags & (match_perl|match_posix))) { - if(re.flags() & regex_constants::perlex) + if((re.flags() & regex_constants::perlex) || (re.flags() & regex_constants::literal)) m_match_flags |= match_perl; else m_match_flags |= match_posix; John.