[Boost-users] [phoenix] [clang] error assigning function object

Subject: [Boost-users] [phoenix] [clang] error assigning function object
From: Nathan Ridge (zeratul976_at_[hidden])
Date: 2016-01-07 20:29:54

Hi there,

I'm experiencing a compiler error in code that tries to assign a Boost.Phoenix function object returned by invoking a phoenix::function with a std::string as one of the bound parameters.

I've reduced my error to the following minimal code:

#include <string>
#include <boost/phoenix/core/argument.hpp>
#include <boost/phoenix/function.hpp>

struct S {
    void operator()(std::string, int) const;
};

boost::phoenix::function<S> lazy;

auto func1 = lazy(std::string(), boost::phoenix::placeholders::_1);
auto func2 = func1;

void foo() {
    func2 = func1;
}

My compiler version is clang 3.7; the error does not occur with gcc 5.1.

The error also goes away if I change the type of the first argument from std::string to a different type (like int).

The compiler error is shown below. Any ideas as to what is going on? Am I doing something wrong, or did I run into a bug in Phoenix?

Thanks,
Nate

In file included from test.cpp:81:
In file included from /home/nr/dev/dist/boost/include/boost/phoenix/core/argument.hpp:13:
In file included from /home/nr/dev/dist/boost/include/boost/phoenix/core/actor.hpp:25:
In file included from /home/nr/dev/dist/boost/include/boost/proto/make_expr.hpp:100:
In file included from /home/nr/dev/dist/boost/include/boost/proto/detail/make_expr_.hpp:3:
/home/nr/dev/dist/boost/include/boost/proto/detail/preprocessed/make_expr_.hpp:73:88: error: no type named 'type' in
      'boost::proto::transform<boost::proto::switch_<boost::phoenix::phoenix_generator, boost::proto::tag_of<boost::proto::_> ()>, void>::result<boost::phoenix::phoenix_generator
      (boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::assign, boost::proto::argsns_::list2<boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval,
      boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>,
      boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>,
      boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>,
      boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval,
      boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>,
      boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>,
      boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>>>, 2>)>'
        typedef typename proto_generator::template result<proto_generator(expr_type)>::type result_type;
                ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~
/home/nr/dev/dist/boost/include/boost/proto/make_expr.hpp:180:34: note: in instantiation of template class 'boost::proto::detail::make_expr_<boost::proto::tagns_::tag::assign,
      boost::phoenix::phoenix_domain, boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval,
      boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>,
      boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>,
      boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>, const
      boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval,
      boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>,
      boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>,
      boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>>, void, void, void,
      void, void, void, void, void, void>' requested here
                typename detail::make_expr_<
                                 ^
/home/nr/dev/dist/boost/include/boost/phoenix/core/actor.hpp:225:36: note: in instantiation of template class 'boost::proto::result_of::make_expr<boost::proto::tagns_::tag::assign,
      boost::phoenix::phoenix_domain, boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval,
      boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>,
      boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>,
      boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>, const
      boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval,
      boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>,
      boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>,
      boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>>, void, void, void,
      void, void, void, void, void, void>' requested here
        typename proto::result_of::make_expr<
                                   ^
/home/nr/dev/dist/boost/include/boost/phoenix/core/actor.hpp:185:12: note: while substituting deduced template arguments into function template 'operator=' [with A0 = const
      boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval,
      boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>,
      boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>,
      boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>>]
    struct actor
           ^
/home/nr/dev/dist/boost/include/boost/proto/matches.hpp:830:44: note: in instantiation of template class 'boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::assign,
      boost::proto::argsns_::list2<boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval,
      boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>,
      boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>,
      boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>,
      boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval,
      boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>,
      boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>,
      boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>>>, 2>' requested
      here
          : Cases::template case_<typename Expr::proto_tag>::template impl<Expr, State, Data>
                                           ^
/home/nr/dev/dist/boost/include/boost/proto/transform/impl.hpp:238:13: note: in instantiation of template class 'boost::proto::switch_<boost::phoenix::phoenix_generator,
      boost::proto::tag_of<boost::proto::_> ()>::impl<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::assign,
      boost::proto::argsns_::list2<boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval,
      boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>,
      boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>,
      boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>,
      boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval,
      boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>,
      boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>,
      boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>>>, 2>, int,
      boost::proto::envns_::empty_env>' requested here
          : PrimitiveTransform::template impl<Expr, empty_state, empty_env>
            ^
/home/nr/dev/dist/boost/include/boost/proto/transform/impl.hpp:255:9: note: in instantiation of template class 'boost::proto::detail::apply_transform<boost::phoenix::phoenix_generator
      (boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::assign, boost::proto::argsns_::list2<boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval,
      boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>,
      boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>,
      boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>,
      boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval,
      boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>,
      boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>,
      boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>>>, 2>)>' requested
      here
        BOOST_PROTO_TRANSFORM_(PrimitiveTransform, X)
        ^
/home/nr/dev/dist/boost/include/boost/proto/transform/impl.hpp:194:48: note: expanded from macro 'BOOST_PROTO_TRANSFORM_'
        typedef typename boost::proto::detail::apply_transform<Sig>::result_type type;                          \
                                               ^
/home/nr/dev/dist/boost/include/boost/proto/detail/preprocessed/make_expr_.hpp:73:43: note: in instantiation of template class
      'boost::proto::transform<boost::proto::switch_<boost::phoenix::phoenix_generator, boost::proto::tag_of<boost::proto::_> ()>, void>::result<boost::phoenix::phoenix_generator
      (boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::assign, boost::proto::argsns_::list2<boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval,
      boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>,
      boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>,
      boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>,
      boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval,
      boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>,
      boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>,
      boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>>>, 2>)>' requested
      here
        typedef typename proto_generator::template result<proto_generator(expr_type)>::type result_type;
                                          ^
/home/nr/dev/dist/boost/include/boost/proto/make_expr.hpp:180:34: note: in instantiation of template class 'boost::proto::detail::make_expr_<boost::proto::tagns_::tag::assign,
      boost::phoenix::phoenix_domain, boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval,
      boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>,
      boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>,
      boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>,
      boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval,
      boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>,
      boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>,
      boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>>, void, void, void,
      void, void, void, void, void, void>' requested here
                typename detail::make_expr_<
                                 ^
/home/nr/dev/dist/boost/include/boost/phoenix/core/actor.hpp:213:36: note: in instantiation of template class 'boost::proto::result_of::make_expr<boost::proto::tagns_::tag::assign,
      boost::phoenix::phoenix_domain, boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval,
      boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>,
      boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>,
      boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>,
      boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval,
      boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>,
      boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>,
      boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>>, void, void, void,
      void, void, void, void, void, void>' requested here
        typename proto::result_of::make_expr<
                                   ^
test.cpp:96:8: note: while substituting deduced template arguments into function template 'operator=' [with A0 =
      boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::phoenix::detail::tag::function_eval,
      boost::proto::argsns_::list3<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<S>, 0>,
      boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<std::basic_string<char>>, 0>,
      boost::phoenix::actor<boost::proto::exprns_::basic_expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::phoenix::argument<1>>, 0>>>, 3>>]
        func2 = func1;
              ^
1 error generated.