Enabling C++11 with clang causes constexpr errors

14:25:37: Running steps for project cxx11...
14:25:37: Configuration unchanged, skipping qmake step.
14:25:37: Starting: "/usr/bin/make" -w
make: Entering directory `/Users/stephenchu/Dropbox/cxx11'
/Qt/5.0/qtbase/bin/qmake -spec /Qt/5.0/qtbase/mkspecs/macx-clang CONFIG+=x86_64 -o Makefile cxx11.pro
make: Leaving directory `/Users/stephenchu/Dropbox/cxx11'
make: Entering directory `/Users/stephenchu/Dropbox/cxx11'
clang++ -c -pipe -mmacosx-version-min=10.6 -std=c++0x -stdlib=libc++ -g -gdwarf-2 -Wall -W -fPIE -DQT_GUI_LIB -DQT_CORE_LIB -DQT_SHARED -I/Qt/5.0/qtbase/mkspecs/macx-clang -I. -I/Qt/5.0/qtbase/include/QtCore -I/Qt/5.0/qtbase/include/QtGui -I/Qt/5.0/qtbase/include -I/System/Library/Frameworks/OpenGL.framework/Versions/A/Headers -I/System/Library/Frameworks/AGL.framework/Headers -I. -F/Qt/5.0/qtbase/lib -o main.o main.cpp
In file included from main.cpp:1:
In file included from /Qt/5.0/qtbase/include/QtCore/QtCore:4:
In file included from /Qt/5.0/qtbase/include/QtCore/qabstractanimation.h:1:
In file included from /Qt/5.0/qtbase/include/QtCore/../../src/corelib/animation/qabstractanimation.h:45:
In file included from /Qt/5.0/qtbase/include/QtCore/qobject.h:1:
In file included from /Qt/5.0/qtbase/include/QtCore/../../src/corelib/kernel/qobject.h:48:
In file included from /Qt/5.0/qtbase/include/QtCore/qstring.h:1:
In file included from /Qt/5.0/qtbase/include/QtCore/../../src/corelib/tools/qstring.h:46:
In file included from /Qt/5.0/qtbase/include/QtCore/qbytearray.h:1:
/Qt/5.0/qtbase/include/QtCore/../../src/corelib/tools/qbytearray.h:393:29: error: constexpr constructor never produces a constant expression [-Winvalid-constexpr]
    Q_DECL_CONSTEXPR inline QByteArray(QByteArrayDataPtr dd)
                            ^
/Qt/5.0/qtbase/include/QtCore/../../src/corelib/tools/qbytearray.h:394:13: note: reinterpret_cast is not allowed in a constant expression
        : d(reinterpret_cast<Data *>(dd.ptr))
            ^
In file included from main.cpp:1:
In file included from /Qt/5.0/qtbase/include/QtCore/QtCore:43:
In file included from /Qt/5.0/qtbase/include/QtCore/qurl.h:1:
/Qt/5.0/qtbase/include/QtCore/../../src/corelib/io/qurl.h:70:48: error: constexpr constructor's 1st parameter type 'QFlag' is not a literal type
    Q_DECL_CONSTEXPR inline QUrlTwoFlags(QFlag f) : i(f) {}
                                         ~~~~~~^
/Qt/5.0/qtbase/include/QtCore/../../src/corelib/global/qflags.h:51:7: note: 'QFlag' is not literal because it is not an aggregate and has no constexpr constructors other than copy or move constructors
class QFlag
      ^
main.cpp:121:40: warning: unused parameter 'v' [-Wunused-parameter]
        re.addRule(new RuleFunc([](QVariant & v) { return true; } ), {} );
                                              ^
1 warning and 2 errors generated.
make: *** [main.o] Error 1
make: Leaving directory `/Users/stephenchu/Dropbox/cxx11'
14:25:40: The process "/usr/bin/make" exited with code 2.
Error while building/deploying project cxx11 (target: Desktop)
When executing step 'Make'