null dereference exception vs. segfault?

[Ryan W Sims]

On 8/2/10 10:33 AM, bearophile wrote:
> Mafi:
>> If you want a NullPointerException as part of your program flow, you can
>> use enforce() (in std.contracts I think). I don't think catching a
>> NullPointerException in a big code block where you don't know which
>> dereferencing should fail is good style.
>
> enforce() is not a panacea (panchrest); as far as I know DMD doesn't inline any function that contains enforce(). So sometimes an assert() is better, especially if it's inside a contract (precondition, etc). DesignByConstrac-style programming is not something that just happens, you have to train yourself for some time for it.
>
> Bye,
> bearophile

The problem isn't how to check it on a case-by-case basis, there are 
plenty of ways to check that a given pointer is non-null. The problem is 
debugging _unexpected_ null dereferences, for which a NPE or its 
equivalent is very helpful, a segfault is _not_.

Sorry, didn't mean to reopen a can of worms, just wanted to be clear.

--
rwsims