[Interest] Signal and Slot mechansim in Qt4.8.x

Till Oliver Knoll till.oliver.knoll at gmail.com
Fri Aug 8 14:03:22 CEST 2014

Am 08.08.2014 um 12:15 schrieb Giuseppe D'Angelo <giuseppe.dangelo at kdab.com>:

> Il 08/08/2014 10:51, Bo Thorsen ha scritto:
>> The order of the slots execution is undefined. You can not rely on it.
> Generally speaking it *is* defined: slot activation follows the order of the connect() statements (*).

But, but...!

> ...
> (*) It has been finalized, by documenting it, around Qt 4.6. I guess simply too many people were relying on that behaviour 

I was just about to complain ;) Didn't realise that this behaviour has been made "official" now :)

It might be okay if you have a /single/ class connecting to a given signal "in a well-defined order". But as soon as slots of multiple classes are to be connected to a given signal "in a well-defined order" such a design would probably be doomed to fail rather sooner than later, IMHO.

So I'm a bit surprised that people started to rely on the "connection order" (I remember faintly that some Qt docs even stated clearly that the "order was undefined").

But then again, nothing should surprise me anymore in software engineering (just frighten) ;)


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