10.0BETA and 11.0 CURRENT: devel/kdesdk: error: union member '__lx' has a non-trivial constructor value_type __lx; ^ /usr/include/c++/v1/string:1140:9

On freeBSD > 10.0-BETA it is impossible to compile/install port
devel/kdesdk which is crucial for devel/kdevelop-kde4.

The error occured is shown below.

I already have tried rebuilding devel/kdevelop with

portmaster -f devel/kdevelop-kde4 to ensure that all requisite ports
are up and not compiled with compiler option -std=c++11 (defined in
my /etc/src.conf, but some ports violently incorporate this file, too,
like port  graphics/libfpx.

This problem is sticky since gcc has gone from FBSD 10.0-CURRENT and it
is a pain in the ass if someone relies on a CDE like kdevelop which now
is considered broken.

Does anyone have a glue what to look for to solve the problem?

Thanks in advance,

Oliver


[...]
In file included
from /usr/ports/devel/kdesdk4/work/kdesdk-4.10.5/umbrello/umbrello/codeimport/kdevcppparser/ast.cpp:20:
In file included
from /usr/ports/devel/kdesdk4/work/kdesdk-4.10.5/umbrello/umbrello/codeimport/kdevcppparser/ast.h:23:
In file included
from /usr/ports/devel/kdesdk4/work/kdesdk-4.10.5/umbrello/umbrello/codeimport/kdevcppparser/position.h:41:
In file included
from /usr/local/include/boost/spirit/include/classic.hpp:11: In file
included from /usr/local/include/boost/spirit/home/classic.hpp:24: In
file included
from /usr/local/include/boost/spirit/home/classic/core.hpp:32: In file
included
from /usr/local/include/boost/spirit/home/classic/core/primitives/primitives.hpp:16:
In file included
from /usr/local/include/boost/spirit/home/classic/core/composite/impl/directives.ipp:16:
In file included
from /usr/local/include/boost/spirit/home/classic/core/scanner/skipper.hpp:16:
In file included
from /usr/local/include/boost/spirit/home/classic/core/primitives/impl/primitives.ipp:26: /usr/include/c++/v1/string:1143:24:
error: union member '__lx' has a non-trivial constructor value_type
__lx; ^ /usr/include/c++/v1/string:1140:9: note: in instantiation of
member class 'std::__1::basic_string<QChar,
std::__1::char_traits<QChar>, std::__1::allocator<QChar>
>::__short::<anonymous union at /usr/include/c++/v1/string:1140:9>'
>requested here union ^ /usr/include/c++/v1/string:1150:37: note: in
>instantiation of member class 'std::__1::basic_string<QChar,
>std::__1::char_traits<QChar>, std::__1::allocator<QChar> >::__short'
>requested here union __lx{__long __lx; __short __lxx;};
>^ /usr/include/c++/v1/string:1152:23: note: in instantiation of member
>class 'std::__1::basic_string<QChar, std::__1::char_traits<QChar>,
>std::__1::allocator<QChar> >::__lx' requested here enum {__n_words =
>sizeof(__lx) / sizeof(size_type)};
                      ^
/usr/ports/devel/kdesdk4/work/kdesdk-4.10.5/umbrello/umbrello/codeimport/kdevcppparser/position.h:48:33:
note: in instantiation of template class 'std::__1::basic_string<QChar,
std::__1::char_traits<QChar>, std::__1::allocator<QChar> >' requested
here class PositionFilename : public PositionFilenameType ^
/usr/local/include/qt4/QtCore/qchar.h:74:5: note: because type 'QChar'
has a user-provided default constructor QChar();
    ^
In file included
from /usr/ports/devel/kdesdk4/work/kdesdk-4.10.5/umbrello/umbrello/codeimport/kdevcppparser/ast.cpp:20:
In file included
from /usr/ports/devel/kdesdk4/work/kdesdk-4.10.5/umbrello/umbrello/codeimport/kdevcppparser/ast.h:23:
In file included
from /usr/ports/devel/kdesdk4/work/kdesdk-4.10.5/umbrello/umbrello/codeimport/kdevcppparser/position.h:41:
In file included
from /usr/local/include/boost/spirit/include/classic.hpp:11: In file
included from /usr/local/include/boost/spirit/home/classic.hpp:24: In
file included
from /usr/local/include/boost/spirit/home/classic/core.hpp:28: In file
included
from /usr/local/include/boost/spirit/home/classic/core/match.hpp:15: In
file included from /usr/local/include/boost/optional.hpp:15: In file
included from /usr/local/include/boost/optional/optional.hpp:19: In
file included
from /usr/include/c++/v1/algorithm:627: /usr/include/c++/v1/memory:1951:55:
error: no member named 'value' in
'std::__1::is_empty<std::__1::basic_string<QChar,
std::__1::char_traits<QChar>, std::__1::allocator<QChar> >::__rep>'
bool = is_empty<_T1>::value