Ok, i have something like this:
void EmailReceiverThread::foreachEmailAccount(ConfigEmailAccount account)
{
Email email;
EmailReader emailReader(account);
while (emailReader.pollEmail(email))
{
writeEmailToDatabase(email);
}
}
ForeachEmailAccount is a slot in EmailReceiverThread. It's called from the run() method:
GetConfigEmailDAO* accountReader = new GetConfigEmailDAO(type, m_channel);
connect(accountReader, SIGNAL(emailAccount(ConfigEmailAccount)),
this, SLOT(foreachEmailAccount(ConfigEmailAccount)), Qt::QueuedConnection);
DbThread::postAction(accountReader);
GetConfigEmailDAO does a query, fetch the email account and do the emit:
emit emailAccount(account);
This works so far. The problem is, i'm copying the class ConfigEmailAccount. I would like avoid that perfomance hit. So, my idea is emit the account using c++11 move semantics:
emit emailAccount(std::move(account));
I rewrited the slots and signals with the new syntax:
void foreachEmailAccount(ConfigEmailAccount&& account);
Unfortunaly, this doesn't work. I have the next compilation error:
moc_emailreceiverthread.cpp:88: error: cannot bind ‘ConfigEmailAccount’ lvalue to ‘ConfigEmailAccount&&’
case 1: _t->foreachEmailAccount((*reinterpret_cast< ConfigEmailAccount(*)>(_a[1]))); break;
What could i do?
Minimal verifiable example here:
#include <QCoreApplication>
#include <QObject>
class ConfigEmailAccount
{
QString some_data;
};
class GetConfigEmailDAO : public QObject
{
Q_OBJECT
public:
void execute();
signals:
void emailAccount(ConfigEmailAccount&& account);
};
void GetConfigEmailDAO::execute()
{
ConfigEmailAccount account;
emit emailAccount(std::move(account));
}
class EmailReceiverThread : public QObject
{
Q_OBJECT
public:
void execute();
public slots:
void foreachEmailAccount(ConfigEmailAccount&& account);
};
void EmailReceiverThread::execute()
{
GetConfigEmailDAO* accountReader = new GetConfigEmailDAO;
connect(accountReader, SIGNAL(emailAccount(ConfigEmailAccount)),
this, SLOT(foreachEmailAccount(ConfigEmailAccount)), Qt::QueuedConnection);
accountReader->execute();
}
void EmailReceiverThread::foreachEmailAccount(ConfigEmailAccount&& account)
{
}
int main(int argc, char *argv[])
{
QCoreApplication a(argc, argv);
qRegisterMetaType<ConfigEmailAccount>("ConfigEmailAccount");
EmailReceiverThread reader;
reader.execute();
return a.exec();
}
#include "main.moc"
