boost spirit compilation error

Question

I'm trying to use boost::spirit for the first time and I'm running in some compilation errors that I don't understand how to solve.

It seems to hint that it is about the Skipper that I'm using but I'm using the same Skipper everywhere and I tried lots of different Skipper configuration, none of them worked :(

My sample file is the following:

#include <boost/spirit/include/qi.hpp> 

namespace qi = boost::spirit::qi;
namespace ascii = boost::spirit::ascii;

template <typename Iterator>
struct Grammar: qi::grammar<Iterator, std::vector<std::string>, ascii::space_type>
{
    Grammar(): Grammar::base_type(ident_list)
    {
        ident = qi::lexeme[*qi::alnum];
        ident_list = *ident;
    }

    qi::rule<Iterator, std::vector<std::string>, ascii::space_type> ident_list;                                                                                                                                       
    qi::rule<Iterator, std::string, ascii::space_type> ident;
};

int main()
{
    Grammar<std::string::const_iterator> grammar;
    std::vector<std::string> result;

    std::string string_to_parse = "My list of ident";

    std::string::const_iterator start = string_to_parse.begin();
    std::string::const_iterator end = string_to_parse.end();

    phrase_parse(
        start,
        end,
        grammar,
        ascii::space,
        result
    );

    return 0;
}

and here is the compilation error:

In file included from /usr/local/include/boost/spirit/home/qi/nonterminal.hpp:14:0,
                 from /usr/local/include/boost/spirit/home/qi.hpp:21,
                 from /usr/local/include/boost/spirit/include/qi.hpp:16,
                 from main.cpp:1:
/usr/local/include/boost/spirit/home/qi/nonterminal/rule.hpp: In instantiation of 'bool boost::spirit::qi::rule<Iterator, T1, T2, T3, T4>::parse(Iterator&, const Iterator&, Context&, const Skipper&, Attribute&) const [with Context = boost::spirit::context<boost::fusion::cons<std::vector<std::__cxx11::basic_string<char> >&, boost::fusion::nil_>, boost::fusion::vector<> >; Skipper = boost::spirit::qi::char_class<boost::spirit::tag::char_code<boost::spirit::tag::space, boost::spirit::char_encoding::ascii> >; Attribute = const boost::spirit::unused_type; Iterator = __gnu_cxx::__normal_iterator<const char*, std::__cxx11::basic_string<char> >; T1 = std::__cxx11::basic_string<char>; T2 = boost::proto::exprns_::expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::spirit::tag::char_code<boost::spirit::tag::space, boost::spirit::char_encoding::ascii> >, 0l>; T3 = boost::spirit::unused_type; T4 = boost::spirit::unused_type]':
/usr/local/include/boost/spirit/home/qi/reference.hpp:43:72:   required from 'bool boost::spirit::qi::reference<Subject>::parse(Iterator&, const Iterator&, Context&, const Skipper&, Attribute&) const [with Iterator = __gnu_cxx::__normal_iterator<const char*, std::__cxx11::basic_string<char> >; Context = boost::spirit::context<boost::fusion::cons<std::vector<std::__cxx11::basic_string<char> >&, boost::fusion::nil_>, boost::fusion::vector<> >; Skipper = boost::spirit::qi::char_class<boost::spirit::tag::char_code<boost::spirit::tag::space, boost::spirit::char_encoding::ascii> >; Attribute = const boost::spirit::unused_type; Subject = const boost::spirit::qi::rule<__gnu_cxx::__normal_iterator<const char*, std::__cxx11::basic_string<char> >, std::__cxx11::basic_string<char>, boost::proto::exprns_::expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::spirit::tag::char_code<boost::spirit::tag::space, boost::spirit::char_encoding::ascii> >, 0l>, boost::spirit::unused_type, boost::spirit::unused_type>]'
/usr/local/include/boost/spirit/home/qi/detail/fail_function.hpp:38:20:   required from 'bool boost::spirit::qi::detail::fail_function<Iterator, Context, Skipper>::operator()(const Component&, Attribute&) const [with Component = boost::spirit::qi::reference<const boost::spirit::qi::rule<__gnu_cxx::__normal_iterator<const char*, std::__cxx11::basic_string<char> >, std::__cxx11::basic_string<char>, boost::proto::exprns_::expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::spirit::tag::char_code<boost::spirit::tag::space, boost::spirit::char_encoding::ascii> >, 0l>, boost::spirit::unused_type, boost::spirit::unused_type> >; Attribute = const boost::spirit::unused_type; Iterator = __gnu_cxx::__normal_iterator<const char*, std::__cxx11::basic_string<char> >; Context = boost::spirit::context<boost::fusion::cons<std::vector<std::__cxx11::basic_string<char> >&, boost::fusion::nil_>, boost::fusion::vector<> >; Skipper = boost::spirit::qi::char_class<boost::spirit::tag::char_code<boost::spirit::tag::space, boost::spirit::char_encoding::ascii> >]'
/usr/local/include/boost/spirit/home/qi/detail/pass_container.hpp:309:39:   required from 'bool boost::spirit::qi::detail::pass_container<F, Attr, Sequence>::dispatch_attribute(const Component&, mpl_::false_) const [with Component = boost::spirit::qi::reference<const boost::spirit::qi::rule<__gnu_cxx::__normal_iterator<const char*, std::__cxx11::basic_string<char> >, std::__cxx11::basic_string<char>, boost::proto::exprns_::expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::spirit::tag::char_code<boost::spirit::tag::space, boost::spirit::char_encoding::ascii> >, 0l>, boost::spirit::unused_type, boost::spirit::unused_type> >; F = boost::spirit::qi::detail::fail_function<__gnu_cxx::__normal_iterator<const char*, std::__cxx11::basic_string<char> >, boost::spirit::context<boost::fusion::cons<std::vector<std::__cxx11::basic_string<char> >&, boost::fusion::nil_>, boost::fusion::vector<> >, boost::spirit::qi::char_class<boost::spirit::tag::char_code<boost::spirit::tag::space, boost::spirit::char_encoding::ascii> > >; Attr = std::vector<std::__cxx11::basic_string<char> >; Sequence = mpl_::bool_<false>; mpl_::false_ = mpl_::bool_<false>]'
/usr/local/include/boost/spirit/home/qi/detail/pass_container.hpp:351:61:   required from 'bool boost::spirit::qi::detail::pass_container<F, Attr, Sequence>::operator()(const Component&) const [with Component = boost::spirit::qi::reference<const boost::spirit::qi::rule<__gnu_cxx::__normal_iterator<const char*, std::__cxx11::basic_string<char> >, std::__cxx11::basic_string<char>, boost::proto::exprns_::expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::spirit::tag::char_code<boost::spirit::tag::space, boost::spirit::char_encoding::ascii> >, 0l>, boost::spirit::unused_type, boost::spirit::unused_type> >; F = boost::spirit::qi::detail::fail_function<__gnu_cxx::__normal_iterator<const char*, std::__cxx11::basic_string<char> >, boost::spirit::context<boost::fusion::cons<std::vector<std::__cxx11::basic_string<char> >&, boost::fusion::nil_>, boost::fusion::vector<> >, boost::spirit::qi::char_class<boost::spirit::tag::char_code<boost::spirit::tag::space, boost::spirit::char_encoding::ascii> > >; Attr = std::vector<std::__cxx11::basic_string<char> >; Sequence = mpl_::bool_<false>]'
/usr/local/include/boost/spirit/home/qi/operator/kleene.hpp:65:23:   required from 'bool boost::spirit::qi::kleene<Subject>::parse_container(F) const [with F = boost::spirit::qi::detail::pass_container<boost::spirit::qi::detail::fail_function<__gnu_cxx::__normal_iterator<const char*, std::__cxx11::basic_string<char> >, boost::spirit::context<boost::fusion::cons<std::vector<std::__cxx11::basic_string<char> >&, boost::fusion::nil_>, boost::fusion::vector<> >, boost::spirit::qi::char_class<boost::spirit::tag::char_code<boost::spirit::tag::space, boost::spirit::char_encoding::ascii> > >, std::vector<std::__cxx11::basic_string<char> >, mpl_::bool_<false> >; Subject = boost::spirit::qi::reference<const boost::spirit::qi::rule<__gnu_cxx::__normal_iterator<const char*, std::__cxx11::basic_string<char> >, std::__cxx11::basic_string<char>, boost::proto::exprns_::expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::spirit::tag::char_code<boost::spirit::tag::space, boost::spirit::char_encoding::ascii> >, 0l>, boost::spirit::unused_type, boost::spirit::unused_type> >]'
/usr/local/include/boost/spirit/home/qi/operator/kleene.hpp:84:13:   [ skipping 6 instantiation contexts, use -ftemplate-backtrace-limit=0 to disable ]
/usr/local/include/boost/function/function_template.hpp:1072:16:   required from 'boost::function<R(T0, T1, T2, T3)>::function(Functor, typename boost::enable_if_c<(! boost::is_integral<Functor>::value), int>::type) [with Functor = boost::spirit::qi::detail::parser_binder<boost::spirit::qi::kleene<boost::spirit::qi::reference<const boost::spirit::qi::rule<__gnu_cxx::__normal_iterator<const char*, std::__cxx11::basic_string<char> >, std::__cxx11::basic_string<char>, boost::proto::exprns_::expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::spirit::tag::char_code<boost::spirit::tag::space, boost::spirit::char_encoding::ascii> >, 0l>, boost::spirit::unused_type, boost::spirit::unused_type> > >, mpl_::bool_<false> >; R = bool; T0 = __gnu_cxx::__normal_iterator<const char*, std::__cxx11::basic_string<char> >&; T1 = const __gnu_cxx::__normal_iterator<const char*, std::__cxx11::basic_string<char> >&; T2 = boost::spirit::context<boost::fusion::cons<std::vector<std::__cxx11::basic_string<char> >&, boost::fusion::nil_>, boost::fusion::vector<> >&; T3 = const boost::spirit::qi::char_class<boost::spirit::tag::char_code<boost::spirit::tag::space, boost::spirit::char_encoding::ascii> >&; typename boost::enable_if_c<(! boost::is_integral<Functor>::value), int>::type = int]'
/usr/local/include/boost/function/function_template.hpp:1125:5:   required from 'typename boost::enable_if_c<(! boost::is_integral<Functor>::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::kleene<boost::spirit::qi::reference<const boost::spirit::qi::rule<__gnu_cxx::__normal_iterator<const char*, std::__cxx11::basic_string<char> >, std::__cxx11::basic_string<char>, boost::proto::exprns_::expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::spirit::tag::char_code<boost::spirit::tag::space, boost::spirit::char_encoding::ascii> >, 0l>, boost::spirit::unused_type, boost::spirit::unused_type> > >, mpl_::bool_<false> >; R = bool; T0 = __gnu_cxx::__normal_iterator<const char*, std::__cxx11::basic_string<char> >&; T1 = const __gnu_cxx::__normal_iterator<const char*, std::__cxx11::basic_string<char> >&; T2 = boost::spirit::context<boost::fusion::cons<std::vector<std::__cxx11::basic_string<char> >&, boost::fusion::nil_>, boost::fusion::vector<> >&; T3 = const boost::spirit::qi::char_class<boost::spirit::tag::char_code<boost::spirit::tag::space, boost::spirit::char_encoding::ascii> >&; typename boost::enable_if_c<(! boost::is_integral<Functor>::value), boost::function<R(T0, T1, T2, T3)>&>::type = boost::function<bool(__gnu_cxx::__normal_iterator<const char*, std::__cxx11::basic_string<char> >&, const __gnu_cxx::__normal_iterator<const char*, std::__cxx11::basic_string<char> >&, boost::spirit::context<boost::fusion::cons<std::vector<std::__cxx11::basic_string<char> >&, boost::fusion::nil_>, boost::fusion::vector<> >&, const boost::spirit::qi::char_class<boost::spirit::tag::char_code<boost::spirit::tag::space, boost::spirit::char_encoding::ascii> >&)>&]'
/usr/local/include/boost/spirit/home/qi/nonterminal/rule.hpp:183:19:   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::dereference, boost::proto::argsns_::list1<boost::spirit::qi::rule<__gnu_cxx::__normal_iterator<const char*, std::__cxx11::basic_string<char> >, std::__cxx11::basic_string<char>, boost::proto::exprns_::expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::spirit::tag::char_code<boost::spirit::tag::space, boost::spirit::char_encoding::ascii> >, 0l>, boost::spirit::unused_type, boost::spirit::unused_type>&>, 1l>; Iterator = __gnu_cxx::__normal_iterator<const char*, std::__cxx11::basic_string<char> >; T1 = std::vector<std::__cxx11::basic_string<char> >; T2 = boost::proto::exprns_::expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::spirit::tag::char_code<boost::spirit::tag::space, boost::spirit::char_encoding::ascii> >, 0l>; T3 = boost::spirit::unused_type; T4 = boost::spirit::unused_type; mpl_::true_ = mpl_::bool_<true>]'
/usr/local/include/boost/spirit/home/qi/nonterminal/rule.hpp:221:32:   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::dereference, boost::proto::argsns_::list1<boost::spirit::qi::rule<__gnu_cxx::__normal_iterator<const char*, std::__cxx11::basic_string<char> >, std::__cxx11::basic_string<char>, boost::proto::exprns_::expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::spirit::tag::char_code<boost::spirit::tag::space, boost::spirit::char_encoding::ascii> >, 0l>, boost::spirit::unused_type, boost::spirit::unused_type>&>, 1l>; Iterator = __gnu_cxx::__normal_iterator<const char*, std::__cxx11::basic_string<char> >; T1 = std::vector<std::__cxx11::basic_string<char> >; T2 = boost::proto::exprns_::expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::spirit::tag::char_code<boost::spirit::tag::space, boost::spirit::char_encoding::ascii> >, 0l>; T3 = boost::spirit::unused_type; T4 = boost::spirit::unused_type]'
main.cpp:12:20:   required from 'Grammar<Iterator>::Grammar() [with Iterator = __gnu_cxx::__normal_iterator<const char*, std::__cxx11::basic_string<char> >]'
main.cpp:21:42:   required from here
/usr/local/include/boost/spirit/home/qi/nonterminal/rule.hpp:304:17: error: no match for call to '(const function_type {aka const boost::function<bool(__gnu_cxx::__normal_iterator<const char*, std::__cxx11::basic_string<char> >&, const __gnu_cxx::__normal_iterator<const char*, std::__cxx11::basic_string<char> >&, boost::spirit::context<boost::fusion::cons<boost::spirit::unused_type&, boost::fusion::nil_>, boost::fusion::vector<> >&, const boost::spirit::qi::literal_string<const std::__cxx11::basic_string<char>, true>&)>}) (__gnu_cxx::__normal_iterator<const char*, std::__cxx11::basic_string<char> >&, const __gnu_cxx::__normal_iterator<const char*, std::__cxx11::basic_string<char> >&, boost::spirit::qi::rule<__gnu_cxx::__normal_iterator<const char*, std::__cxx11::basic_string<char> >, std::__cxx11::basic_string<char>, boost::proto::exprns_::expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::spirit::tag::char_code<boost::spirit::tag::space, boost::spirit::char_encoding::ascii> >, 0l>, boost::spirit::unused_type, boost::spirit::unused_type>::context_type&, const boost::spirit::qi::char_class<boost::spirit::tag::char_code<boost::spirit::tag::space, boost::spirit::char_encoding::ascii> >&)'
                 if (f(first, last, context, skipper))
                 ^~
In file included from /usr/local/include/boost/function/detail/maybe_include.hpp:33:0,
                 from /usr/local/include/boost/function/detail/function_iterate.hpp:14,
                 from /usr/local/include/boost/preprocessor/iteration/detail/iter/forward1.hpp:67,
                 from /usr/local/include/boost/function.hpp:64,
                 from /usr/local/include/boost/spirit/home/qi/nonterminal/rule.hpp:16,
                 from /usr/local/include/boost/spirit/home/qi/nonterminal.hpp:14,
                 from /usr/local/include/boost/spirit/home/qi.hpp:21,
                 from /usr/local/include/boost/spirit/include/qi.hpp:16,
                 from main.cpp:1:
/usr/local/include/boost/function/function_template.hpp:765:17: note: candidate: boost::function4<R, T1, T2, T3, T4>::result_type boost::function4<R, T1, T2, T3, T4>::operator()(T0, T1, T2, T3) const [with R = bool; T0 = __gnu_cxx::__normal_iterator<const char*, std::__cxx11::basic_string<char> >&; T1 = const __gnu_cxx::__normal_iterator<const char*, std::__cxx11::basic_string<char> >&; T2 = boost::spirit::context<boost::fusion::cons<boost::spirit::unused_type&, boost::fusion::nil_>, boost::fusion::vector<> >&; T3 = const boost::spirit::qi::literal_string<const std::__cxx11::basic_string<char>, true>&; boost::function4<R, T1, T2, T3, T4>::result_type = bool]
     result_type operator()(BOOST_FUNCTION_PARMS) const
                 ^~~~~~~~
/usr/local/include/boost/function/function_template.hpp:765:17: note:   no known conversion for argument 4 from 'const boost::spirit::qi::char_class<boost::spirit::tag::char_code<boost::spirit::tag::space, boost::spirit::char_encoding::ascii> >' to 'const boost::spirit::qi::literal_string<const std::__cxx11::basic_string<char>, true>&'

Isn't this char_class convertible to this literal_string? The error only occured when I introduced an intermediate rule (here "ident"), if I define:

ident_list = *qi::lexeme[*qi::alnum]

it compiles just fine.

score 2 · Accepted Answer · edited May 23 '17 at 11:53

The signatures on the rules are slightly misspelt:

qi::rule<Iterator, std::vector<std::string>, ascii::space_type> ident_list;                                                                                                                                       
qi::rule<Iterator, std::string, ascii::space_type> ident;

Should probably be

qi::rule<Iterator, std::vector<std::string>(), ascii::space_type> ident_list;                                                                                                                                       
qi::rule<Iterator, std::string(), ascii::space_type> ident;

// and also
struct Grammar: qi::grammar<Iterator, std::vector<std::string>(), ascii::space_type>

Now it compiles.

More notes: as long as ident is a lexeme, you can simply drop the skipper from it (see Boost spirit skipper issues).

There's another bug in that it matches *qi::alnum which means that 0 chars is a match. You will want to use at least 1 char: +qi::alnum.

Here's a working sample (which also shows my preferred method of coding the skipper into the grammar since it's usually part of the grammar anyways):

Live On Coliru

#include <boost/spirit/include/qi.hpp>

namespace qi = boost::spirit::qi;

template <typename Iterator> struct Grammar : qi::grammar<Iterator, std::vector<std::string>()> {
    Grammar() : Grammar::base_type(start) {
        using namespace qi;
        ident      = +alnum;
        ident_list = *ident;
        start      = skip(ascii::space) [ident_list];
    }
  private:
    qi::rule<Iterator, std::vector<std::string>()> start;
    qi::rule<Iterator, std::vector<std::string>(), qi::ascii::space_type> ident_list;
    qi::rule<Iterator, std::string()> ident;
};

int main() {
    Grammar<std::string::const_iterator> grammar;
    std::vector<std::string> result;

    std::string const input = "My list of ident";

    auto start = input.begin(), end = input.end();
    if (parse(start, end, grammar, result))
        std::cout << "Parsed " << result.size() << " tokens\n";
    else
        std::cout << "Parsing failed\n";

    if (start != end)
        std::cout << "Remaining unparsed input: '" << std::string(start,end) << "'\n";
}

Prints

Parsed 4 tokens

BONUS

In the case of such a simple grammar, consider just inlining it:

Live On Coliru

#include <boost/spirit/include/qi.hpp>
namespace qi = boost::spirit::qi;

int main() {
    for (std::string const input : { "My list of ident", " My list of ident " }) {
        auto f = input.begin(), l = input.end();

        std::list<std::string> result;
        if (qi::phrase_parse(f, l, *qi::lexeme[+qi::graph], qi::space, result))
            std::cout << "Parsed " << result.size() << " tokens\n";
        else
            std::cout << "Parsing failed\n";

        if (f != l)
            std::cout << "Remaining unparsed input: '" << std::string(f,l) << "'\n";
    }
}

Added a bonus [simplified version](http://coliru.stacked-crooked.com/a/7460ae5c45086326) — sehe, Dec 15 '16 at 22:52
I'm not sure, but it seems that Spirit machinery uses whether a type is part of the qi::domain as a basis to distinguish between skippers and attributes, and `std::string` is in fact part of that domain (a string by itself can be used as `lit(string)`) and so it is considered as a skipper. — llonesmiz, Dec 16 '16 at 05:31
Thank you very much, I'm a bit surprised that we need to add `std::string()` in the template parameter instead of `std::string`, but as long as it works that's perfect :) I agree that for a simple grammar like this it could be inlined, but basically this was just incremental testing before building my whole grammar and I couldn't get this step correctly. — Antoine HOM, Dec 16 '16 at 10:09
You shouldn't be too surprised, as this has been documented all along: http://www.boost.org/doc/libs/1_62_0/libs/spirit/doc/html/spirit/qi/reference/parser_concepts/nonterminal.html#spirit.qi.reference.parser_concepts.nonterminal.signature — sehe, Dec 16 '16 at 10:10
@jv_ Yeah. I know this "lenience" was added ~2 releases ago as a kind of gimmick, but I think it's a misfeature. I don't like the mindset that says "Okay we'll just try to guess what the developer really meant and soldier on" — sehe, Dec 16 '16 at 10:16

boost spirit compilation error

1 Answers1

BONUS