[Interest] Are slots even needed these days?

[d3fault]

On Sat, May 7, 2016 at 2:29 AM, Nye <kshegunov at gmail.com> wrote:

> I don't see any multiple inheritance that forms a diamond. And although I
> like the older syntax better, I don't see what's the problem with the new
> syntax here. This:
>

You're right, my example didn't suffer from the diamond inheritance
problem. But suppose you want to inherit from a QWidget derived class (or
any of the QObject derived classes in Qt xD) in addition to the
signals/slots interface: if the interface itself derives from QObject,
you'd have diamond inheritance.


> QObject * a = new A;
> QObject * b = new B;
> QObject::connect(a, A::someSignal, b, B::someSlot);
>
> should be working just fine.
>

Yes it works, but you're no longer using an interface when you mention A or
B [in the connect statement].


> Plus I don't see a reason for the asQObject() method, qobject_cast or
> dynamic_cast would be much simpler and cleaner.
>

Interface doesn't inherit from QObject, so qobject_cast doesn't work. I
don't compile with RTTI, so dynamic_cast is out.

PS.
>
I just realized you're worried that the functions are virtual. Well this is
> of no consequence, the vtable is respected (if I remember correctly that's
> specified in the standard). So the following should also be working without
> any problem:
>
> QObject::connect(a, Interface::someSignal, b, Interface::someSlot);
>

That does not compile. (even with the missing ampersands added it still
doesn't :-P)


d3fault
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