Why does QT use so few exceptions?

DenisKormalev

Tobias, does it mean that some day (version of Qt like 6.10) we will have exception-style error handling in Qt, not error()-methods?

tobias.hunger

Denis: For consistency we should not mix error handling styles in modules, so I can not see this happen without causing a mayor version number change (since the non-exception style would need to get removed which will break source compatibility).

But this is just my opinion: I am not aware of any plans for Qt 5 or later.

danilocesar

[quote author="Tobias Hunger" date="1286374926"]
But this is just my opinion: I am not aware of any plans for Qt 5 or later.[/quote]

NOOOOOOO!!! =P

tobias.hunger

danilocesar: What was that NOOOOO about?

danilocesar

It's a good place to change major architecture decisions without harm current devs.
From a simplistic point of view (without thinking about continuous improvement of current apps, kde, nokia, market, etc), who doesn't want Qt 5? :)

MTK358

[quote author="Tobias Hunger" date="1286394948"]danilocesar: What was that NOOOOO about?[/quote]

Just read this sentence and forget about the context of this thread:

"I am not aware of any plans for Qt 5 or later."

tobias.hunger

MTK358: I do not know of any plans, that does not mean that nobody else is doing planning;-)

s.frings

To come back to the original question: Is there a technical reason, not to use exception to handle errors? I understood, that the reason was historically, so it's basically a good idea to use exceptions in my own programs.

Franzk

I don't think there would be a lot of places where Qt would really benefit from exceptions, but hey, I might be missing something :).

tobias.hunger

s.frings: Yes, there is no reason not to use exceptions in your own programs. I do not know whether it is a good idea for consistency reasons: I prefer not having to switch between exception/non-exception code, but that is just a matter of taste.

ivan.todorovich

What about QSqlError ?
I find it annoying calling lastError() every time I execute a SQL query. I can't think of a better place to use exceptions instead of error codes. Not to mention that exceptions are thread-safe.

szh1

What are the advantages of Exceptions?

goetz

Some of them are explained "here":http://www.parashift.com/c++-faq-lite/exceptions.html

And keep in mind:
there is NO one size fits all! Exceptions might work wel for one case, but not for the other.

szh1

I hope Qt starts to use exceptions soon!

goetz

You'll have to wait at least until Qt 5 comes around.

All releases of the Qt 4 series will stay source and binary compatible. Switching to using exceptions is a far too big change. Maybe it will come sometimes, but don't expect anything. There aren't even rumors about a timeline of Qt 5, even less abut exceptions...