Re: Domain name parser not working

Michael Powell <[email protected]>
Newsgroups gmane.comp.parsers.spirit.general
Message-ID <CAMEoF_G6con+_nL+Gcia+=9ew6r3UzfsD6xai89PoSdpBqeszg@mail.gmail.com> 
Now after providing additional follow up, live examples, etc, any
feedback on this at all?

This cannot be that difficult, however any of the documentation, etc,
I am scanning does not seem to work or are incomplete at best, which
isn't helping the case.

Thanks!

Cheers,

Michael Powell

On Mon, Jan 1, 2018 at 9:30 PM, Michael Powell <[email protected]> wrote:
> On Mon, Jan 1, 2018 at 9:20 PM, Michael Powell <[email protected]> wrote:
>> On Mon, Jan 1, 2018 at 8:59 PM, Michael Powell <[email protected]> wrote:
>>> On Mon, Jan 1, 2018 at 7:32 PM, Michael Powell <[email protected]> wrote:
>>>> On Mon, Jan 1, 2018 at 7:11 PM, Michael Powell <[email protected]> wrote:
>>>>> On Mon, Jan 1, 2018 at 6:49 PM, Michael Powell <[email protected]> wrote:
>>>>>> Hello,
>>>>>>
>>>>>> // Where Let is char_(/*upper/lower-case chars*/), Dig is
>>>>>> char_("0123456789"), Hyp is char_('.'), and dot_ is '.'.
>>>>>>
>>>>>> template<typename It>
>>>>>> struct DomainNameParser : boost::spirit::qi::grammar<It, Ast::Address()> {
>>>>>>
>>>>>>   DomainNameParser() {
>>>>>>
>>>>>>     _hyp = char_('-');
>>>>>>     _dig = char_(DOMAIN_NAME_PARSER_DIGITS);
>>>>>>     _let = char_(DOMAIN_NAME_PARSER_LOWERCASE DOMAIN_NAME_PARSER_UPPERCASE);
>>>>>>
>>>>>>     // A straight interpretation of the Domain Name grammar leads me to this:
>>>>>>     /*qi::rule<It, std::string()>*/ _label = raw[_let >> -(*(_let |
>>>>>> _dig | _hyp) >> (_let | _dig))];
>>>>>>     /*qi::rule<It, Ast::Address()>*/ _start = (_label % dot_) >> eoi;
>>>>>>     // ...
>>>>>>
>>>>>>  }
>>>>>> };
>>>>>>
>>>>>> Assuming,
>>>>>>
>>>>>> struct Address {
>>>>>>   std::vector<std::string> _labels;
>>>>>> };
>>>>>>
>>>>>> BOOST_FUSION_ADAPT_STRUCT(Ast::Address,
>>>>>>     (std::vector<std::string>, _labels)
>>>>>> )
>>>>>>
>>>>>> However, this is failing to match: "E-PHUMZ8G8j1KEZG26C" in spite of
>>>>>> the fact this matches the expected pattern. No skippers involved, just
>>>>>> the iterator (std::string::const_iterator), and the AST, of course.
>>>>>>
>>>>>> For now, dropping the semantic action until I can get the parser to
>>>>>> work properly. However, eventually I want to incorporate the
>>>>>> validation rule:
>>>>>>
>>>>>> struct label_validation {
>>>>>>     // Notwithstanding Qi/Fusion bits that glue it together.
>>>>>>     bool operator()(std::string const& l) const {
>>>>>>         return l.length() <= 63;
>>>>>>     }
>>>>>> };
>>>>>>
>>>>>> Once again I am suspicious whether Optional is working properly, never
>>>>>> minding Kleene Star productions. I ended up needing to separate out
>>>>>> Alternative phrases instead of the Optional before in order to make it
>>>>>> work properly.
>>>>>>
>>>>>> Perhaps I need to capture each phrase in a rule of its own focused
>>>>>> solely on std::string or char, respectively, as contrasted with the
>>>>>> entire std::string?
>>>>>
>>>>> Here's an MRP:
>>>>>
>>>>> https://wandbox.org/permlink/cbpUPMnQ4APZeDdw
>>>>
>>>> I tried a little bit different version, IMO a little closer to the RFC
>>>> if not exactly:
>>>>
>>>> https://wandbox.org/permlink/1sDTqnFphTA2egDu
>>>>
>>>> Notwithstanding the roll up in to std::vector of std::string, and
>>>> ultimately ast::address.
>>>>
>>>>> More or less based on RFC 1034: https://tools.ietf.org/html/rfc1034#section-3.5
>>>>>
>>>>> Thoughts?
>>>
>>> I decided to "simplify" in terms of the grammar rules themselves just a bit:
>>>
>>> https://wandbox.org/permlink/I6qWWxp3urd1Q9wD
>>>
>>> I figure the specifics of a grammatically correct label can be validated for:
>>>
>>> 1) specific content (first letter, last character, everything in between)
>>> 2) length of content
>>>
>>> With that in mind, it is possible to introduce semantic actions
>>> performing this label verification? Either two, or a single one
>>> performing both, if necessary.
>>>
>>> The Fusion functional strategy seems appealing, but I was unable to
>>> get that to work quite right at compile time. Willing consider other
>>> approaches to the same.
>>
>> Which, as soon as I approach a semantic action for purposes of
>> "simple" label length validation, in this case absurdly limited for
>> test purposes, I get the compiler errors.
>>
>> https://wandbox.org/permlink/CLCRxpWVFNMmS1Fk
>>
>> void validate_label(std::string const& l, boost::fusion::unused_type
>> const&, bool& pass) {
>>   pass = l.length() < 4;
>> }
>>
>> // ...
>>
>> _label = (raw[_let >> -(*(_let | _dig | _hyp) >> (_let |
>> _dig))])[validate_label];
>
> Even a function object does not work, modeled after the Qi
> documentation. I get similar errors.
>
> https://wandbox.org/permlink/XwkMAFESBdKQEhFE
> http://www.boost.org/doc/libs/1_66_0/libs/spirit/doc/html/spirit/qi/tutorials/semantic_actions.html
>
> struct label_validation {
>   void operator()(std::string const& l, boost::fusion::unused_type
> const&, bool& pass) {
>     pass = l.length() < 4;
>   }
> };
>
> Which only difference in usage, as far as I can tell, should be this:
>
> _label = (raw[_let >> -(*(_let | _dig | _hyp) >> (_let |
> _dig))])[label_validation()];
>
>> The errors:
>>
>> In file included from
>> /opt/wandbox/boost-1.65.1/gcc-head/include/boost/spirit/home/qi/action/action.hpp:21,
>>                  from
>> /opt/wandbox/boost-1.65.1/gcc-head/include/boost/spirit/home/qi/action.hpp:14,
>>                  from
>> /opt/wandbox/boost-1.65.1/gcc-head/include/boost/spirit/home/qi.hpp:14,
>>                  from prog.cc:3:
>> /opt/wandbox/boost-1.65.1/gcc-head/include/boost/spirit/home/support/action_dispatch.hpp:
>> In instantiation of 'bool
>> boost::spirit::traits::action_dispatch<Component>::operator()(RT
>> (*)(A0, A1, A2), Attribute&, Context&) [with RT = void; A0 = const
>> std::__cxx11::basic_string<char>&; A1 = const
>> boost::fusion::unused_type&; A2 = bool&; Attribute =
>> boost::iterator_range<__gnu_cxx::__normal_iterator<const char*,
>> std::__cxx11::basic_string<char> > >; Context =
>> boost::spirit::context<boost::fusion::cons<std::__cxx11::basic_string<char>&,
>> boost::fusion::nil_>, boost::fusion::vector<> >; Component =
>> boost::spirit::qi::raw_directive<boost::spirit::qi::sequence<boost::fusion::cons<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::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type> >,
>> boost::fusion::cons<boost::spirit::qi::optional<boost::spirit::qi::sequence<boost::fusion::cons<boost::spirit::qi::kleene<boost::spirit::qi::alternative<boost::fusion::cons<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::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type> >,
>> boost::fusion::cons<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::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type> >,
>> boost::fusion::cons<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::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type> >,
>> boost::fusion::nil_> > > > >,
>> boost::fusion::cons<boost::spirit::qi::alternative<boost::fusion::cons<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::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type> >,
>> boost::fusion::cons<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::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type> >,
>> boost::fusion::nil_> > >, boost::fusion::nil_> > > >,
>> boost::fusion::nil_> > > >]':
>> /opt/wandbox/boost-1.65.1/gcc-head/include/boost/spirit/home/qi/action/action.hpp:69:55:
>>   required from 'bool boost::spirit::qi::action<Subject,
>> Action>::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::__cxx11::basic_string<char>&,
>> boost::fusion::nil_>, boost::fusion::vector<> >; Skipper =
>> boost::spirit::unused_type; Attribute = const
>> boost::spirit::unused_type; Subject =
>> boost::spirit::qi::raw_directive<boost::spirit::qi::sequence<boost::fusion::cons<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::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type> >,
>> boost::fusion::cons<boost::spirit::qi::optional<boost::spirit::qi::sequence<boost::fusion::cons<boost::spirit::qi::kleene<boost::spirit::qi::alternative<boost::fusion::cons<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::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type> >,
>> boost::fusion::cons<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::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type> >,
>> boost::fusion::cons<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::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type> >,
>> boost::fusion::nil_> > > > >,
>> boost::fusion::cons<boost::spirit::qi::alternative<boost::fusion::cons<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::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type> >,
>> boost::fusion::cons<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::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type> >,
>> boost::fusion::nil_> > >, boost::fusion::nil_> > > >,
>> boost::fusion::nil_> > > >; Action = void (&)(const
>> std::__cxx11::basic_string<char>&, const boost::fusion::unused_type&,
>> bool&)]'
>> /opt/wandbox/boost-1.65.1/gcc-head/include/boost/spirit/home/qi/nonterminal/detail/parser_binder.hpp:33:65:
>>   required from 'bool boost::spirit::qi::detail::parser_binder<Parser,
>> Auto>::call(Iterator&, const Iterator&, Context&, const Skipper&,
>> mpl_::true_) const [with Iterator = __gnu_cxx::__normal_iterator<const
>> char*, std::__cxx11::basic_string<char> >; Skipper =
>> boost::spirit::unused_type; Context =
>> boost::spirit::context<boost::fusion::cons<std::__cxx11::basic_string<char>&,
>> boost::fusion::nil_>, boost::fusion::vector<> >; Parser =
>> boost::spirit::qi::action<boost::spirit::qi::raw_directive<boost::spirit::qi::sequence<boost::fusion::cons<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::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type> >,
>> boost::fusion::cons<boost::spirit::qi::optional<boost::spirit::qi::sequence<boost::fusion::cons<boost::spirit::qi::kleene<boost::spirit::qi::alternative<boost::fusion::cons<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::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type> >,
>> boost::fusion::cons<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::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type> >,
>> boost::fusion::cons<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::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type> >,
>> boost::fusion::nil_> > > > >,
>> boost::fusion::cons<boost::spirit::qi::alternative<boost::fusion::cons<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::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type> >,
>> boost::fusion::cons<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::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type> >,
>> boost::fusion::nil_> > >, boost::fusion::nil_> > > >,
>> boost::fusion::nil_> > > >, void (&)(const
>> std::__cxx11::basic_string<char>&, const boost::fusion::unused_type&,
>> bool&)>; Auto = mpl_::bool_<false>; mpl_::true_ = mpl_::bool_<true>]'
>> /opt/wandbox/boost-1.65.1/gcc-head/include/boost/spirit/home/qi/nonterminal/detail/parser_binder.hpp:53:67:
>>   required from 'bool boost::spirit::qi::detail::parser_binder<Parser,
>> Auto>::operator()(Iterator&, const Iterator&, Context&, const
>> Skipper&) const [with Iterator = __gnu_cxx::__normal_iterator<const
>> char*, std::__cxx11::basic_string<char> >; Skipper =
>> boost::spirit::unused_type; Context =
>> boost::spirit::context<boost::fusion::cons<std::__cxx11::basic_string<char>&,
>> boost::fusion::nil_>, boost::fusion::vector<> >; Parser =
>> boost::spirit::qi::action<boost::spirit::qi::raw_directive<boost::spirit::qi::sequence<boost::fusion::cons<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::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type> >,
>> boost::fusion::cons<boost::spirit::qi::optional<boost::spirit::qi::sequence<boost::fusion::cons<boost::spirit::qi::kleene<boost::spirit::qi::alternative<boost::fusion::cons<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::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type> >,
>> boost::fusion::cons<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::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type> >,
>> boost::fusion::cons<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::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type> >,
>> boost::fusion::nil_> > > > >,
>> boost::fusion::cons<boost::spirit::qi::alternative<boost::fusion::cons<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::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type> >,
>> boost::fusion::cons<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::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type> >,
>> boost::fusion::nil_> > >, boost::fusion::nil_> > > >,
>> boost::fusion::nil_> > > >, void (&)(const
>> std::__cxx11::basic_string<char>&, const boost::fusion::unused_type&,
>> bool&)>; Auto = mpl_::bool_<false>]'
>> /opt/wandbox/boost-1.65.1/gcc-head/include/boost/function/function_template.hpp:138:22:
>>   required from 'static R
>> boost::detail::function::function_obj_invoker4<FunctionObj, R, T0, T1,
>> T2, T3>::invoke(boost::detail::function::function_buffer&, T0, T1, T2,
>> T3) [with FunctionObj =
>> boost::spirit::qi::detail::parser_binder<boost::spirit::qi::action<boost::spirit::qi::raw_directive<boost::spirit::qi::sequence<boost::fusion::cons<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::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type> >,
>> boost::fusion::cons<boost::spirit::qi::optional<boost::spirit::qi::sequence<boost::fusion::cons<boost::spirit::qi::kleene<boost::spirit::qi::alternative<boost::fusion::cons<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::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type> >,
>> boost::fusion::cons<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::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type> >,
>> boost::fusion::cons<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::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type> >,
>> boost::fusion::nil_> > > > >,
>> boost::fusion::cons<boost::spirit::qi::alternative<boost::fusion::cons<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::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type> >,
>> boost::fusion::cons<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::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type> >,
>> boost::fusion::nil_> > >, boost::fusion::nil_> > > >,
>> boost::fusion::nil_> > > >, void (&)(const
>> std::__cxx11::basic_string<char>&, const boost::fusion::unused_type&,
>> bool&)>, 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::__cxx11::basic_string<char>&,
>> boost::fusion::nil_>, boost::fusion::vector<> >&; T3 = const
>> boost::spirit::unused_type&]'
>> /opt/wandbox/boost-1.65.1/gcc-head/include/boost/function/function_template.hpp:925:38:
>>   [ skipping 2 instantiation contexts, use
>> -ftemplate-backtrace-limit=0 to disable ]
>> /opt/wandbox/boost-1.65.1/gcc-head/include/boost/function/function_template.hpp:1061:16:
>>   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::action<boost::spirit::qi::raw_directive<boost::spirit::qi::sequence<boost::fusion::cons<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::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type> >,
>> boost::fusion::cons<boost::spirit::qi::optional<boost::spirit::qi::sequence<boost::fusion::cons<boost::spirit::qi::kleene<boost::spirit::qi::alternative<boost::fusion::cons<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::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type> >,
>> boost::fusion::cons<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::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type> >,
>> boost::fusion::cons<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::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type> >,
>> boost::fusion::nil_> > > > >,
>> boost::fusion::cons<boost::spirit::qi::alternative<boost::fusion::cons<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::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type> >,
>> boost::fusion::cons<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::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type> >,
>> boost::fusion::nil_> > >, boost::fusion::nil_> > > >,
>> boost::fusion::nil_> > > >, void (&)(const
>> std::__cxx11::basic_string<char>&, const boost::fusion::unused_type&,
>> bool&)>, 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::__cxx11::basic_string<char>&,
>> boost::fusion::nil_>, boost::fusion::vector<> >&; T3 = const
>> boost::spirit::unused_type&; typename boost::enable_if_c<(!
>> boost::is_integral<Functor>::value), int>::type = int]'
>> /opt/wandbox/boost-1.65.1/gcc-head/include/boost/function/function_template.hpp:1114:5:
>>   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::action<boost::spirit::qi::raw_directive<boost::spirit::qi::sequence<boost::fusion::cons<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::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type> >,
>> boost::fusion::cons<boost::spirit::qi::optional<boost::spirit::qi::sequence<boost::fusion::cons<boost::spirit::qi::kleene<boost::spirit::qi::alternative<boost::fusion::cons<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::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type> >,
>> boost::fusion::cons<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::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type> >,
>> boost::fusion::cons<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::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type> >,
>> boost::fusion::nil_> > > > >,
>> boost::fusion::cons<boost::spirit::qi::alternative<boost::fusion::cons<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::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type> >,
>> boost::fusion::cons<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::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type> >,
>> boost::fusion::nil_> > >, boost::fusion::nil_> > > >,
>> boost::fusion::nil_> > > >, void (&)(const
>> std::__cxx11::basic_string<char>&, const boost::fusion::unused_type&,
>> bool&)>, 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::__cxx11::basic_string<char>&,
>> boost::fusion::nil_>, boost::fusion::vector<> >&; T3 = const
>> boost::spirit::unused_type&; 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::__cxx11::basic_string<char>&,
>> boost::fusion::nil_>, boost::fusion::vector<> >&, const
>> boost::spirit::unused_type&)>&]'
>> /opt/wandbox/boost-1.65.1/gcc-head/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::subscript,
>> boost::proto::argsns_::list2<const
>> boost::proto::exprns_::expr<boost::proto::tagns_::tag::subscript,
>> boost::proto::argsns_::list2<const
>> boost::proto::exprns_::expr<boost::proto::tagns_::tag::terminal,
>> boost::proto::argsns_::term<boost::spirit::tag::raw>, 0>&, const
>> boost::proto::exprns_::expr<boost::proto::tagns_::tag::shift_right,
>> boost::proto::argsns_::list2<boost::spirit::qi::rule<__gnu_cxx::__normal_iterator<const
>> char*, std::__cxx11::basic_string<char> >,
>> std::__cxx11::basic_string<char>(), boost::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type>&, const
>> boost::proto::exprns_::expr<boost::proto::tagns_::tag::negate,
>> boost::proto::argsns_::list1<const
>> boost::proto::exprns_::expr<boost::proto::tagns_::tag::shift_right,
>> boost::proto::argsns_::list2<const
>> boost::proto::exprns_::expr<boost::proto::tagns_::tag::dereference,
>> boost::proto::argsns_::list1<const
>> boost::proto::exprns_::expr<boost::proto::tagns_::tag::bitwise_or,
>> boost::proto::argsns_::list2<const
>> boost::proto::exprns_::expr<boost::proto::tagns_::tag::bitwise_or,
>> boost::proto::argsns_::list2<boost::spirit::qi::rule<__gnu_cxx::__normal_iterator<const
>> char*, std::__cxx11::basic_string<char> >,
>> std::__cxx11::basic_string<char>(), boost::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type>&,
>> boost::spirit::qi::rule<__gnu_cxx::__normal_iterator<const char*,
>> std::__cxx11::basic_string<char> >,
>> std::__cxx11::basic_string<char>(), boost::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type>&>, 2>&,
>> boost::spirit::qi::rule<__gnu_cxx::__normal_iterator<const char*,
>> std::__cxx11::basic_string<char> >,
>> std::__cxx11::basic_string<char>(), boost::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type>&>, 2>&>, 1>&,
>> const boost::proto::exprns_::expr<boost::proto::tagns_::tag::bitwise_or,
>> boost::proto::argsns_::list2<boost::spirit::qi::rule<__gnu_cxx::__normal_iterator<const
>> char*, std::__cxx11::basic_string<char> >,
>> std::__cxx11::basic_string<char>(), boost::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type>&,
>> boost::spirit::qi::rule<__gnu_cxx::__normal_iterator<const char*,
>> std::__cxx11::basic_string<char> >,
>> std::__cxx11::basic_string<char>(), boost::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type>&>, 2>&>, 2>&>,
>> 1>&>, 2>&>, 2>&,
>> boost::proto::exprns_::expr<boost::proto::tagns_::tag::terminal,
>> boost::proto::argsns_::term<void (&)(const
>> std::__cxx11::basic_string<char>&, const boost::fusion::unused_type&,
>> bool&)>, 0> >, 2>; Iterator = __gnu_cxx::__normal_iterator<const
>> char*, std::__cxx11::basic_string<char> >; T1 =
>> std::__cxx11::basic_string<char>(); T2 = boost::spirit::unused_type;
>> T3 = boost::spirit::unused_type; T4 = boost::spirit::unused_type;
>> mpl_::true_ = mpl_::bool_<true>]'
>> /opt/wandbox/boost-1.65.1/gcc-head/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::subscript,
>> boost::proto::argsns_::list2<const
>> boost::proto::exprns_::expr<boost::proto::tagns_::tag::subscript,
>> boost::proto::argsns_::list2<const
>> boost::proto::exprns_::expr<boost::proto::tagns_::tag::terminal,
>> boost::proto::argsns_::term<boost::spirit::tag::raw>, 0>&, const
>> boost::proto::exprns_::expr<boost::proto::tagns_::tag::shift_right,
>> boost::proto::argsns_::list2<boost::spirit::qi::rule<__gnu_cxx::__normal_iterator<const
>> char*, std::__cxx11::basic_string<char> >,
>> std::__cxx11::basic_string<char>(), boost::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type>&, const
>> boost::proto::exprns_::expr<boost::proto::tagns_::tag::negate,
>> boost::proto::argsns_::list1<const
>> boost::proto::exprns_::expr<boost::proto::tagns_::tag::shift_right,
>> boost::proto::argsns_::list2<const
>> boost::proto::exprns_::expr<boost::proto::tagns_::tag::dereference,
>> boost::proto::argsns_::list1<const
>> boost::proto::exprns_::expr<boost::proto::tagns_::tag::bitwise_or,
>> boost::proto::argsns_::list2<const
>> boost::proto::exprns_::expr<boost::proto::tagns_::tag::bitwise_or,
>> boost::proto::argsns_::list2<boost::spirit::qi::rule<__gnu_cxx::__normal_iterator<const
>> char*, std::__cxx11::basic_string<char> >,
>> std::__cxx11::basic_string<char>(), boost::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type>&,
>> boost::spirit::qi::rule<__gnu_cxx::__normal_iterator<const char*,
>> std::__cxx11::basic_string<char> >,
>> std::__cxx11::basic_string<char>(), boost::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type>&>, 2>&,
>> boost::spirit::qi::rule<__gnu_cxx::__normal_iterator<const char*,
>> std::__cxx11::basic_string<char> >,
>> std::__cxx11::basic_string<char>(), boost::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type>&>, 2>&>, 1>&,
>> const boost::proto::exprns_::expr<boost::proto::tagns_::tag::bitwise_or,
>> boost::proto::argsns_::list2<boost::spirit::qi::rule<__gnu_cxx::__normal_iterator<const
>> char*, std::__cxx11::basic_string<char> >,
>> std::__cxx11::basic_string<char>(), boost::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type>&,
>> boost::spirit::qi::rule<__gnu_cxx::__normal_iterator<const char*,
>> std::__cxx11::basic_string<char> >,
>> std::__cxx11::basic_string<char>(), boost::spirit::unused_type,
>> boost::spirit::unused_type, boost::spirit::unused_type>&>, 2>&>, 2>&>,
>> 1>&>, 2>&>, 2>&,
>> boost::proto::exprns_::expr<boost::proto::tagns_::tag::terminal,
>> boost::proto::argsns_::term<void (&)(const
>> std::__cxx11::basic_string<char>&, const boost::fusion::unused_type&,
>> bool&)>, 0> >, 2>; Iterator = __gnu_cxx::__normal_iterator<const
>> char*, std::__cxx11::basic_string<char> >; T1 =
>> std::__cxx11::basic_string<char>(); T2 = boost::spirit::unused_type;
>> T3 = boost::spirit::unused_type; T4 = boost::spirit::unused_type]'
>> prog.cc:71:20:   required from
>> 'client::my_grammar<Iterator>::my_grammar() [with Iterator =
>> __gnu_cxx::__normal_iterator<const char*,
>> std::__cxx11::basic_string<char> >]'
>> prog.cc:117:20:   required from here
>> /opt/wandbox/boost-1.65.1/gcc-head/include/boost/spirit/home/support/action_dispatch.hpp:189:14:
>> error: invalid initialization of reference of type 'const
>> std::__cxx11::basic_string<char>&' from expression of type
>> 'boost::iterator_range<__gnu_cxx::__normal_iterator<const char*,
>> std::__cxx11::basic_string<char> > >'
>>              f(attr, context, pass);
>>              ~^~~~~~~~~~~~~~~~~~~~~
>>
>>
>>>>> Cheers,
>>>>>
>>>>> Michael
>>>>>
>>>>>> Cheers,
>>>>>>
>>>>>> Michael Powell

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