QException Class

Detailed Description

Qt Concurrent supports throwing and catching exceptions across thread boundaries, provided that the exception inherits from QException and implements two helper functions:

class MyException : public QException
{
public:
    void raise() const override { throw *this; }
    MyException *clone() const override { return new MyException(*this); }
};

QException subclasses must be thrown by value and caught by reference:

try  {
    QtConcurrent::blockingMap(list, throwFunction); // throwFunction throws MyException
} catch (MyException &e) {
    // handle exception
}

If you throw an exception that is not a subclass of QException, the Qt Concurrent functions will throw a QUnhandledException in the receiver thread.

When using QFuture, transferred exceptions will be thrown when calling the following functions:

• QFuture::waitForFinished()
• QFuture::result()
• QFuture::resultAt()
• QFuture::results()