Sorry, fat-fingered things and the message was sent too early. trying again: Hi all, I am new to spirit, and my only source of information has been the current spirit documentation. I am running into a curious problem in which the manual suggests some code should compile, yet it does not. Test case: ---------------------------------------------------------------------------------------------- #include <boost/spirit/core.hpp> using namespace boost::spirit; int main() { const char *s = "(1)"; rule<> r = ch_p('(') >> int_p >> ch_p(')'); parse(s, r); // compiles OK parse(s, r, space_p); // does NOT compile parse(s, ch_p('(') >> int_p >> ch_p(')'), space_p); // compiles OK } ---------------------------------------------------------------------------------------------- Why does the third parse() compile, but not the second? Does the rule require some kind of adaptor to work in this context? Thanks, -Gabe