• terranium <spam here.lot> May 08 2008
• "Simen Kjaeraas" <simen.kjaras gmail.com> May 08 2008

BCS Wrote:

I perform downcasts extremely rarely.


 That's *exactly* why you need safe cast.
 


 How does that follow? I don't see the connection.


When you do some unusual thing, the probability of mistake increases.

 And this will result in a Seg-V. The program will stop in a predictable 
 manner. IMHO (and it seems others opinions) that is what matters.


The program will not stop in a predictable manner since a third party library
can silently handle nulls, e.g. XML serialization. And if it stops in an AV
this happens in an unpredictable location - miles away from the place where the
bug was triggered. What matters is a presence of bugs, to solve this you must
eliminate them, to eliminate them you should know, where the bug was triggered
(and of course you need to know that there is a bug), to help locating bug an
exception should be thrown as soon as possible after the bug was triggered,
ideally exception should be thrown in the same location, where the bug was
triggered.

terranium <spam here.lot> wrote:
 BCS Wrote:
 And this will result in a Seg-V. The program will stop in a predictable
 manner. IMHO (and it seems others opinions) that is what matters.


 The program will not stop in a predictable manner since a third party  
 library can silently handle nulls, e.g. XML serialization.


So, don't send any unsanitized data to a third-party library? A third-party
library might also catch and ignore exceptions, if the language  
automatically
threw one when seeing an invalid cast.

-- Simen