Hello, when using the regular expression parser with the Spirit library, I get the following compilation error (I've edited the g++-output somewhat): g++ -c -o TestSpirit.o -ansi -g -Iboost-1_33/include/boost-1_33/ TestSpirit.cpp In file included from boost-1_33/include/boost-1_33/boost/spirit/utility/regex.hpp:46, boost-1_33/include/boost-1_33/boost/spirit/utility/impl/regex.ipp:65: error: wrong number of template arguments (1, should be 2) Command exited with non-zero status 1 I edited the file boost-1_33/include/boost-1_33/boost/spirit/utility/impl/regex.ipp, replacing line 65 boost::reg_expression<CharT> rxstr; // regular expression to match with boost::basic_regex<CharT> rxstr; // regular expression to match , and now it seems to work (at least my application). So I guess the Spirit library needs to be updated (according to the new regex-library standard). Oliver P.S. I tried it out with g++ 3.4.3 and 4.0.1, but it doesn't matter.