Including QAxFactory causes compilation error when QT_NO_CAST_FROM_ASCII is defined

c:\buildslave-transmission\local-x64-msvc14\include\activeqt\qaxfactory.h(192): error C2248: 'QString::QString': cannot access private member declared in class 'QString'
C:\buildslave-transmission\local-x64-msvc14\include\QtCore/qstring.h(771): note: see declaration of 'QString::QString'
c:\buildslave-transmission\windows-x64\src\qt\ComInteropHelper.h(17): note: see declaration of 'QString'
c:\buildslave-transmission\local-x64-msvc14\include\activeqt\qaxfactory.h(192): note: while compiling class template member function 'QStringList QAxClass<InteropObject>::featureList(void) const'
C:\buildslave-transmission\windows-x64\src\qt\ComInteropHelper.cc(22): note: see reference to class template instantiation 'QAxClass<InteropObject>' being compiled

--- a/qaxfactory.h
+++ b/qaxfactory.h
@@ -189,7 +189,7 @@
     {}
 
     const QMetaObject *metaObject(const QString &) const { return &T::staticMetaObject; }
-    QStringList featureList() const { return QStringList(QString(T::staticMetaObject.className())); }
+    QStringList featureList() const { return QStringList(QLatin1String(T::staticMetaObject.className())); }
     QObject *createObject(const QString &key)
     {
         const QMetaObject &mo = T::staticMetaObject;