The following code is a simplified version of what I'm trying to do. Basically, I have a struct (int_holder in the toy code), with a container data element. I want to insert an object (int in this case) and return to the parent qi :: rule a pointer to the newly inserted object.
I pass the int_holder to the grammar by reference to fill it with values when parsing, so the int_holder will be an inherited attribute of the grammar. The code:
#include <boost/spirit/include/qi.hpp> #include <boost/spirit/include/phoenix_core.hpp> #include <boost/spirit/include/phoenix_operator.hpp> #include <boost/spirit/include/phoenix_function.hpp> #include <vector> namespace qi=boost::spirit::qi; namespace phoenix=boost::phoenix; struct int_holder { int_holder() {} std::vector<int> ints; }; struct insert_impl { template<class, class> struct result { typedef int* type; }; int* operator() (int_holder& holder, int i) const { holder.ints.push_back (i); return &holder.ints.back(); } }; template<class Iterator> struct my_grammar : qi::grammar<Iterator, int*(int_holder&)> { my_grammar () : my_grammar::base_type (start) , insert (insert_impl()) { using qi::_val; using qi::int_; using qi::_r1; using qi::_1; using phoenix::ref; start = +next(_val) [_val = _1]; next = int_ [_val = insert(_r1, _1)]; } qi::rule<Iterator, int*(int_holder&)> start, next; phoenix::function<insert_impl> insert; }; int main () { using phoenix::ref; const char* p="1"; int* last; int_holder holder; my_grammar<const char*> g; qi::parse (p, p+1, g(ref(holder)), last); }
The code does not compile with the following error message:
In file included from /opt/local/include/boost/fusion/sequence/intrinsic/detail/segmented_begin.hpp:16:0, from /opt/local/include/boost/fusion/sequence/intrinsic/begin.hpp:17, from /opt/local/include/boost/fusion/iterator/segmented_iterator.hpp:12, from /opt/local/include/boost/fusion/sequence/intrinsic/detail/segmented_end.hpp:11, from /opt/local/include/boost/fusion/sequence/intrinsic/end.hpp:17, from /opt/local/include/boost/fusion/sequence/intrinsic/back.hpp:11, from /opt/local/include/boost/fusion/sequence/intrinsic.hpp:11, from /opt/local/include/boost/fusion/include/intrinsic.hpp:10, from /opt/local/include/boost/proto/fusion.hpp:22, from /opt/local/include/boost/proto/core.hpp:21, from /opt/local/include/boost/proto/proto.hpp:12, from /opt/local/include/boost/spirit/home/support/meta_compiler.hpp:19, from /opt/local/include/boost/spirit/home/qi/meta_compiler.hpp:14, from /opt/local/include/boost/spirit/home/qi/action/action.hpp:14, from /opt/local/include/boost/spirit/home/qi/action.hpp:14, from /opt/local/include/boost/spirit/home/qi.hpp:14, from /opt/local/include/boost/spirit/include/qi.hpp:16, from test_qi.cpp:1: /opt/local/include/boost/fusion/container/list/cons.hpp: In instantiation of 'boost::fusion::cons<Car, Cdr>::cons(const boost::fusion::cons<Car2, Cdr2>&) [with Car2 = int*&; Cdr2 = boost::fusion::nil; Car = int_holder&; Cdr = boost::fusion::nil]': /opt/local/include/boost/spirit/home/support/context.hpp:117:20: required from 'boost::spirit::context<Attributes, Locals>::context(typename Attributes::car_type, const Args&, Context&) [with Args = boost::fusion::vector<boost::phoenix::actor<boost::spirit::attribute<0> >, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_>; Context = boost::spirit::context<boost::fusion::cons<int*&, boost::fusion::cons<int_holder&, boost::fusion::nil> >, boost::fusion::vector0<> >; Attributes = boost::fusion::cons<int*&, boost::fusion::cons<int_holder&, boost::fusion::nil> >; Locals = boost::fusion::vector0<>; typename Attributes::car_type = int*&]' /opt/local/include/boost/spirit/home/qi/nonterminal/rule.hpp:343:67: required from 'bool boost::spirit::qi::rule<Iterator, T1, T2, T3, T4>::parse(Iterator&, const Iterator&, Context&, const Skipper&, Attribute&, const Params&) const [with Context = boost::spirit::context<boost::fusion::cons<int*&, boost::fusion::cons<int_holder&, boost::fusion::nil> >, boost::fusion::vector0<> >; Skipper = boost::spirit::unused_type; Attribute = int*; Params = boost::fusion::vector<boost::phoenix::actor<boost::spirit::attribute<0> >, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_>; Iterator = const char*; T1 = int*(int_holder&); T2 = boost::spirit::unused_type; T3 = boost::spirit::unused_type; T4 = boost::spirit::unused_type]' /opt/local/include/boost/spirit/home/qi/nonterminal/detail/parameterized.hpp:48:79: required from 'bool boost::spirit::qi::parameterized_nonterminal<Subject, Params>::parse(Iterator&, const Iterator&, Context&, const Skipper&, Attribute&) const [with Iterator = const char*; Context = boost::spirit::context<boost::fusion::cons<int*&, boost::fusion::cons<int_holder&, boost::fusion::nil> >, boost::fusion::vector0<> >; Skipper = boost::spirit::unused_type; Attribute = int*; Subject = boost::spirit::qi::rule<const char*, int*(int_holder&), boost::spirit::unused_type, boost::spirit::unused_type, boost::spirit::unused_type>; Params = boost::fusion::vector<boost::phoenix::actor<boost::spirit::attribute<0> >, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_>]' /opt/local/include/boost/spirit/home/qi/action/action.hpp:65:13: required from 'bool boost::spirit::qi::action<Subject, Action>::parse(Iterator&, const Iterator&, Context&, const Skipper&, Attribute&) const [with Iterator = const char*; Context = boost::spirit::context<boost::fusion::cons<int*&, boost::fusion::cons<int_holder&, boost::fusion::nil> >, boost::fusion::vector0<> >; Skipper = boost::spirit::unused_type; Attribute = boost::spirit::unused_type; Subject = boost::spirit::qi::parameterized_nonterminal<boost::spirit::qi::rule<const char*, int*(int_holder&), boost::spirit::unused_type, boost::spirit::unused_type, boost::spirit::unused_type>, boost::fusion::vector<boost::phoenix::actor<boost::spirit::attribute<0> >, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_> >; Action = boost::phoenix::actor<boost::phoenix::composite<boost::phoenix::assign_eval, boost::fusion::vector<boost::spirit::attribute<0>, boost::spirit::argument<0>, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_> > >]' /opt/local/include/boost/spirit/home/qi/detail/fail_function.hpp:38:72: required from 'bool boost::spirit::qi::detail::fail_function<Iterator, Context, Skipper>::operator()(const Component&, Attribute&) const [with Component = boost::spirit::qi::action<boost::spirit::qi::parameterized_nonterminal<boost::spirit::qi::rule<const char*, int*(int_holder&), boost::spirit::unused_type, boost::spirit::unused_type, boost::spirit::unused_type>, boost::fusion::vector<boost::phoenix::actor<boost::spirit::attribute<0> >, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_> >, boost::phoenix::actor<boost::phoenix::composite<boost::phoenix::assign_eval, boost::fusion::vector<boost::spirit::attribute<0>, boost::spirit::argument<0>, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_> > > >; Attribute = boost::spirit::unused_type; Iterator = const char*; Context = boost::spirit::context<boost::fusion::cons<int*&, boost::fusion::cons<int_holder&, boost::fusion::nil> >, boost::fusion::vector0<> >; Skipper = boost::spirit::unused_type]' /opt/local/include/boost/spirit/home/qi/detail/pass_container.hpp:263:38: [ skipping 10 instantiation contexts ] /opt/local/include/boost/function/function_template.hpp:1042:16: required from 'boost::function<R(T0, T1, T2, T3)>::function(Functor, typename boost::enable_if_c<boost::type_traits::ice_not<boost::is_integral<Functor>::value>::value, int>::type) [with Functor = boost::spirit::qi::detail::parser_binder<boost::spirit::qi::plus<boost::spirit::qi::action<boost::spirit::qi::parameterized_nonterminal<boost::spirit::qi::rule<const char*, int*(int_holder&), boost::spirit::unused_type, boost::spirit::unused_type, boost::spirit::unused_type>, boost::fusion::vector<boost::phoenix::actor<boost::spirit::attribute<0> >, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_> >, boost::phoenix::actor<boost::phoenix::composite<boost::phoenix::assign_eval, boost::fusion::vector<boost::spirit::attribute<0>, boost::spirit::argument<0>, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_> > > > >, mpl_::bool_<false> >; R = bool; T0 = const char*&; T1 = const char* const&; T2 = boost::spirit::context<boost::fusion::cons<int*&, boost::fusion::cons<int_holder&, boost::fusion::nil> >, boost::fusion::vector0<> >&; T3 = const boost::spirit::unused_type&; typename boost::enable_if_c<boost::type_traits::ice_not<boost::is_integral<Functor>::value>::value, int>::type = int]' /opt/local/include/boost/function/function_template.hpp:1083:5: required from 'typename boost::enable_if_c<boost::type_traits::ice_not<boost::is_integral<Functor>::value>::value, boost::function<R(T0, T1, T2, T3)>&>::type boost::function<R(T0, T1, T2, T3)>::operator=(Functor) [with Functor = boost::spirit::qi::detail::parser_binder<boost::spirit::qi::plus<boost::spirit::qi::action<boost::spirit::qi::parameterized_nonterminal<boost::spirit::qi::rule<const char*, int*(int_holder&), boost::spirit::unused_type, boost::spirit::unused_type, boost::spirit::unused_type>, boost::fusion::vector<boost::phoenix::actor<boost::spirit::attribute<0> >, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_> >, boost::phoenix::actor<boost::phoenix::composite<boost::phoenix::assign_eval, boost::fusion::vector<boost::spirit::attribute<0>, boost::spirit::argument<0>, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_> > > > >, mpl_::bool_<false> >; R = bool; T0 = const char*&; T1 = const char* const&; T2 = boost::spirit::context<boost::fusion::cons<int*&, boost::fusion::cons<int_holder&, boost::fusion::nil> >, boost::fusion::vector0<> >&; T3 = const boost::spirit::unused_type&; typename boost::enable_if_c<boost::type_traits::ice_not<boost::is_integral<Functor>::value>::value, boost::function<R(T0, T1, T2, T3)>&>::type = boost::function<bool(const char*&, const char* const&, boost::spirit::context<boost::fusion::cons<int*&, boost::fusion::cons<int_holder&, boost::fusion::nil> >, boost::fusion::vector0<> >&, const boost::spirit::unused_type&)>&]' /opt/local/include/boost/spirit/home/qi/nonterminal/rule.hpp:182:13: required from 'static void boost::spirit::qi::rule<Iterator, T1, T2, T3, T4>::define(boost::spirit::qi::rule<Iterator, T1, T2, T3, T4>&, const Expr&, mpl_::true_) [with Auto = mpl_::bool_<false>; Expr = boost::proto::exprns_::expr<boost::proto::tagns_::tag::unary_plus, boost::proto::argsns_::list1<const boost::proto::exprns_::expr<boost::proto::tagns_::tag::subscript, boost::proto::argsns_::list2<boost::proto::exprns_::expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::spirit::qi::parameterized_nonterminal<boost::spirit::qi::rule<const char*, int*(int_holder&), boost::spirit::unused_type, boost::spirit::unused_type, boost::spirit::unused_type>, boost::fusion::vector<boost::phoenix::actor<boost::spirit::attribute<0> >, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_> > >, 0l>&, boost::proto::exprns_::expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<const boost::phoenix::actor<boost::phoenix::composite<boost::phoenix::assign_eval, boost::fusion::vector<boost::spirit::attribute<0>, boost::spirit::argument<0>, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_> > >&>, 0l> >, 2l>&>, 1l>; Iterator = const char*; T1 = int*(int_holder&); T2 = boost::spirit::unused_type; T3 = boost::spirit::unused_type; T4 = boost::spirit::unused_type; boost::spirit::qi::rule<Iterator, T1, T2, T3, T4> = boost::spirit::qi::rule<const char*, int*(int_holder&), boost::spirit::unused_type, boost::spirit::unused_type, boost::spirit::unused_type>; mpl_::true_ = mpl_::bool_<true>]' /opt/local/include/boost/spirit/home/qi/nonterminal/rule.hpp:220:13: required from 'boost::spirit::qi::rule<Iterator, T1, T2, T3, T4>& boost::spirit::qi::rule<Iterator, T1, T2, T3, T4>::operator=(const Expr&) [with Expr = boost::proto::exprns_::expr<boost::proto::tagns_::tag::unary_plus, boost::proto::argsns_::list1<const boost::proto::exprns_::expr<boost::proto::tagns_::tag::subscript, boost::proto::argsns_::list2<boost::proto::exprns_::expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::spirit::qi::parameterized_nonterminal<boost::spirit::qi::rule<const char*, int*(int_holder&), boost::spirit::unused_type, boost::spirit::unused_type, boost::spirit::unused_type>, boost::fusion::vector<boost::phoenix::actor<boost::spirit::attribute<0> >, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_> > >, 0l>&, boost::proto::exprns_::expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<const boost::phoenix::actor<boost::phoenix::composite<boost::phoenix::assign_eval, boost::fusion::vector<boost::spirit::attribute<0>, boost::spirit::argument<0>, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_> > >&>, 0l> >, 2l>&>, 1l>; Iterator = const char*; T1 = int*(int_holder&); T2 = boost::spirit::unused_type; T3 = boost::spirit::unused_type; T4 = boost::spirit::unused_type; boost::spirit::qi::rule<Iterator, T1, T2, T3, T4> = boost::spirit::qi::rule<const char*, int*(int_holder&), boost::spirit::unused_type, boost::spirit::unused_type, boost::spirit::unused_type>]' test_qi.cpp:41:3: required from 'my_grammar<Iterator>::my_grammar() [with Iterator = const char*]' test_qi.cpp:57:26: required from here /opt/local/include/boost/fusion/container/list/cons.hpp:83:40: error: invalid initialization of reference of type 'boost::fusion::cons<int_holder&, boost::fusion::nil>::car_type {aka int_holder&}' from expression of type 'int*'
Obviously there is a problem passing _r1 to the phoenix :: function, but I have no idea how to solve it. Thanks in advance.