[Qt-interest] can not copy QString and other non understood other c++ error

[Matthias Pospiech]

This code does not compile:


class TaskPrivate
{
public:
    TaskPrivate(Task * parent)
        : taskHandle(0)
        , aiChannels(AIChannels(parent))
    {}

    AIChannels aiChannels;
    TaskHandle taskHandle;
    QString taskName;
};


Task::Task(QObject *parent, QString taskName /* = "" */)
    :   QObject(parent)    
    ,   d(new TaskPrivate(this))
{
    d->taskName = taskName;
    TaskHandle & taskHandle = d->taskHandle;
    int error = DAQmxCreateTask (taskName.toLatin1(), &taskHandle);
}

with these errors:

src\task.cpp: In constructor 
'TaskPrivate::TaskPrivate(NationalInstruments::DAQ::Task*)':

src\task.cpp:21: warning: 'TaskPrivate::taskHandle' will be initialized 
after

src\task.cpp:17: warning: 'NationalInstruments::DAQ::AIChannels 
TaskPrivate::aiChannels'

src\task.cpp:9: warning: when initialized here

src\task.cpp: In constructor 
'NationalInstruments::DAQ::Task::Task(QObject*, QString)':

src\task.cpp:31: error: passing 'const QString' as 'this' argument of 
'QString& QString::operator=(const QString&)' discards qualifiers

src\task.cpp:32: error: invalid initialization of reference of type 
'void*&' from expression of type 'void* const'

src\task.cpp:33: warning: unused variable 'error'


and I have no idea why. Can anybody help me out?

Matthias