Thread: exception from C function?

Hi CornedBee,


Why callback can not throw exception from general programming and design perspective? Does it anti some patterns?

Originally Posted by CornedBee

What crazy thing could the callback do that it would throw?

regards,
George

Sorry for the inconvenience because of my bad expression, Mats!


Well... Change my question in another way, do you think it is anti pattern to let callback function to throw exception? (it is a general question, not regarding to qsort)

Originally Posted by matsp

Like I said earlier, it's technically possible to construct such a thing. It is also technically possible to build a Television with all wires un-insulated, exposing tens of kilovolts to anyone getting near it. Neither is very desirable or necessary in any way.

If you want to continue discussing this matter, perhaps you can come up with a working example of using qsort() where the compare callback is actually doing something where it throws an exception for a valid reason.

--
Mats

regards,
George

Thanks Elysia!


"it catches the exception" -- I think you mean C++ callback to a C function. Not for a general case of C++ callback to a C++ function. Right?

Originally Posted by Elysia

No, not as long as it catches the exception. But the point was, for what reason would such a function throw an exception? There's very few feasible scenarios.

regards,
George

Thanks Elysia and Mats,


My question is answered.

Originally Posted by matsp

As discussed earlier, you should not call C++ code from C where the C++ code throws (and doesn't catch) - it is undefined behaviour - if it happens to work on one system, it's not guaranteed to happen in another system.

Is that clear enough?

--
Mats

regards,
George