Build failure of msgpack_cpp11.cpp on g++6

[jamessan]

g++ -DHAVE_CONFIG_H -I. -I..  -I../include -pthread -DMSGPACK_DISABLE_LEGACY_NIL -DMSGPACK_DISABLE_LEGACY_CONVERT -Wdate-time -D_FORTIFY_SOURCE=2  -O3 -Wall -Wextra -Wno-mismatched-tags -Werror -g -O2 -Wformat -Werror=format-security -std=c++11 -g -c -o msgpack_cpp11.o msgpack_cpp11.cpp
In file included from ../include/msgpack/adaptor/msgpack_tuple.hpp:18:0,
                 from ../include/msgpack/type.hpp:22,
                 from ../include/msgpack/object.hpp:839,
                 from ../include/msgpack.hpp:10,
                 from msgpack_cpp11.cpp:1:
../include/msgpack/adaptor/detail/cpp11_msgpack_tuple.hpp: In instantiation of 'static msgpack::v1::type::tuple<T, Args ...> msgpack::v1::MsgpackTupleAsImpl<T, Args>::as(const msgpack::v1::object&) [with T = no_def_con_composite; Args = {}]':
../include/msgpack/adaptor/detail/cpp11_msgpack_tuple.hpp:161:47:   required from 'static msgpack::v1::type::tuple<Args ...> msgpack::v1::MsgpackTupleAs<Args>::as(const msgpack::v1::object&) [with Args = {no_def_con_composite}]'
../include/msgpack/adaptor/detail/cpp11_msgpack_tuple.hpp:154:40:   required from 'static msgpack::v1::type::tuple<T, Args ...> msgpack::v1::MsgpackTupleAsImpl<T, Args>::as(const msgpack::v1::object&) [with T = no_def_con; Args = {no_def_con_composite}]'
../include/msgpack/adaptor/detail/cpp11_msgpack_tuple.hpp:161:47:   required from 'static msgpack::v1::type::tuple<Args ...> msgpack::v1::MsgpackTupleAs<Args>::as(const msgpack::v1::object&) [with Args = {no_def_con, no_def_con_composite}]'
../include/msgpack/adaptor/detail/cpp11_msgpack_tuple.hpp:154:40:   required from 'static msgpack::v1::type::tuple<T, Args ...> msgpack::v1::MsgpackTupleAsImpl<T, Args>::as(const msgpack::v1::object&) [with T = no_def_con; Args = {no_def_con, no_def_con_composite}]'
../include/msgpack/adaptor/detail/cpp11_msgpack_tuple.hpp:161:47:   required from 'static msgpack::v1::type::tuple<Args ...> msgpack::v1::MsgpackTupleAs<Args>::as(const msgpack::v1::object&) [with Args = {no_def_con, no_def_con, no_def_con_composite}]'
../include/msgpack/adaptor/detail/cpp11_msgpack_tuple.hpp:207:43:   required from 'msgpack::v1::type::tuple<Args ...> msgpack::v1::adaptor::as<msgpack::v1::type::tuple<Args ...>, typename std::enable_if<msgpack::v1::detail::all_of_imp<msgpack::v1::has_as<Args>::value ...>::value>::type>::operator()(const msgpack::v1::object&) const [with Args = {no_def_con, no_def_con, no_def_con_composite}; typename std::enable_if<msgpack::v1::detail::all_of_imp<msgpack::v1::has_as<Args>::value ...>::value>::type = void]'
../include/msgpack/object.hpp:559:37:   required from 'typename std::enable_if<msgpack::v1::has_as<T>::value, T>::type msgpack::v1::object::as() const [with T = msgpack::v1::type::tuple<no_def_con, no_def_con, no_def_con_composite>; typename std::enable_if<msgpack::v1::has_as<T>::value, T>::type = msgpack::v1::type::tuple<no_def_con, no_def_con, no_def_con_composite>]'
msgpack_cpp11.cpp:504:92:   required from here
../include/msgpack/adaptor/detail/cpp11_msgpack_tuple.hpp:154:43: error: could not convert 'msgpack::v1::type::tuple_cat(Tuples&& ...) [with Tuples = {msgpack::v1::type::tuple<no_def_con_composite>, msgpack::v1::type::tuple<>}; decltype (std::tuple_cat((forward<typename std::remove_reference<Tuples>::type::base>)(msgpack::v1::type::tuple_cat::args)...)) = std::tuple<no_def_con_composite>; typename std::remove_reference<Tuples>::type::base = <type error>](msgpack::v1::MsgpackTupleAs<>::as((* & o)))' from 'std::__tuple_cat_result<std::tuple<no_def_con_composite>, std::tuple<> >::__type {aka std::tuple<no_def_con_composite>}' to 'msgpack::v1::type::tuple<no_def_con_composite>'
             MsgpackTupleAs<Args...>::as(o));
                                           ^

[redboltz]

Could you tell me g++ version and libstdc++ version?

[jamessan]

Toolchain package versions: binutils_2.26-4 dpkg-dev_1.18.4 g++-6_6-20160109-1 gcc-6_6-20160109-1 libc6-dev_2.22-0experimental0 libstdc++-5-dev_5.3.1-8 libstdc++-6-dev_6-20160109-1 libstdc++6_6-20160109-1 linux-libc-dev_4.4.1-1~exp1

Here's the full build log.

[jamessan]

g++6 defaults to -std=gnu++14 instead of -std=gnu++98, so that may help determine why the compile errors are happening.

[redboltz]

Thank you for the information. I've just set up g++6 environment on my Linux 4.3.3-2-ARCH #1 SMP PREEMPT Wed Dec 23 20:09:18 CET 2015 x86_64 GNU/Linux.

I reproduced the same compile error on the environment. I set -std=c++11 explicitly and got the same error.

I will start debugging on the environment.

[redboltz]

It seems that the compile error in not related to hppa and related to g++6. I updated the title of the issue.
See #425.

[redboltz]

Here is a simple code that reproduces the error:

#include <msgpack.hpp>

struct foo {
    int i;
    MSGPACK_DEFINE(i);
};

// `as` specialization for `foo`
namespace msgpack {
MSGPACK_API_VERSION_NAMESPACE(MSGPACK_DEFAULT_API_NS) {
    namespace adaptor {
    template <>
    struct as<foo> {
        foo operator()(msgpack::object const& o) const {
            if (o.type != msgpack::type::ARRAY) throw msgpack::type_error();
            if (o.via.array.size != 1) throw msgpack::type_error();
            return foo {o.via.array.ptr[0].as<int>()};
        }
    };
    } // adaptor
} // MSGPACK_API_VERSION_NAMESPACE(MSGPACK_DEFAULT_API_NS)
} // msgpack

int main() {
    msgpack::object o;
    auto val1 = o.as<std::tuple<foo>>(); // OK
    auto val2 = o.as<msgpack::type::tuple<foo>>(); // ERROR
}

[redboltz]

The following code cannot compile on g++6. It seems that the cause of the issue.

#include <tuple>

template <typename... Types>
struct my_tuple : std::tuple<Types...> {
    // inheriting constructor
    using std::tuple<Types...>::tuple;
};

int main() {
    std::tuple<int> st;
    my_tuple<int> mt(st);
}

[redboltz]

I reported the issue. https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69853

[redboltz]

The issue I reported to gcc bugzilla is suspended. See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69853#c2
I understand the situation and started looking for a workaround. I implemented #426. It works on my g++6 environment. @jamessan and @ueno, could you test #426?

[ueno]

Thanks, #426 compiles fine with the mock command on Fedora:

$ mock -r fedora-rawhide-x86_64 --install git
$ mock -r fedora-rawhide-x86_64 --shell
# gcc --version
gcc (GCC) 6.0.0 20160212 (Red Hat 6.0.0-0.11)
...
# git clone -b fix_422 git://github.com/redboltz/msgpack-c.git
# cd msgpack-c
# ./bootstrap && ./configure && make && make check

though the patch doesn't cleanly apply to the 1.4.0 release. Do you have any plan on the new release with it?