Hey all, I'm new to Spirit and trying to put a parser together for a very simple language of S expressions. [Note: while I'm new to Spirit, I'm not new to parsers or parser combinators.] This is sort of an obnoxious email because it's basically "here, solve my problem for me even though I haven't read the docs as well as I could", but I figured I'd ask anyway; so if you take a look, I'm much appreciative. I define some tokens template <typename Lexer> struct tokens : lex::lexer<Lexer> { tokens() { this->self.add ("(", Tokens::L_Paren) (")", Tokens::R_Paren) ("\"...\"", Tokens::String_Literal) ("[0-9]+", Tokens::Integer_Literal) ("[a-zA-Z]+", Tokens::Symbol) ; } }; Then a grammar: template <typename Iterator> struct sexp_grammar : qi::grammar { qi::rule sexp; qi::ruleSExp::Ptr(), space_type> sexp_list; sexp_grammar() : sexp_grammar::base_type(sexp) { using qi::token; using namespace Tokens; sexp_list = *sexp; sexp = token(String_Literal) | token(Integer_Literal) | token(Symbol) | (token(L_Paren) >> sexp_list >> token(R_Paren) ); } }; (SExp is a class, and SExp::Ptr is a typedef to shared_ptr<SExp>.) If I change the also tried removing the template parameters other than Iterator in the rules, and that let it compile (albeit with a warning). I get oodles of errors (compiling with GCC 4.6 with g++ -o src/parser.os -c -std=c++0x -g -Wall -Wextra -Wnon-virtual-dtor -fPIC -Iinclude src/parser.cc) which I'm not even going to try to paste into this email and you can look at pastebin instead: http://pastebin.com/R5Hk9gJ0 The full code can be seen at https://github.com/EvanED/simple_sexp/blob/master/src/parser.cc Evan