Exception Hierarchy [WAS: Re: Top 5]

[downs]

Sean Kelly wrote:
> Andrei Alexandrescu wrote:
>> downs wrote:
>>
>>> 3) the Exception/Error problem (they're different things, they
>>> shouldn't inherit!)
>>
>> I think Exception should inherit Error.
> 
> I personally dislike the use of "Error" to denote exceptions of any
> sort.  To me, errors are what /cause/ exceptions to be thrown.  For this
> reason, in Tango and druntime, "Exception" is defined as the top-level
> class from which all exceptions should derive (imagine that), making it
> equivalent to your "Error" object.
> 

Errors are useful. There is a class of problems that should not be trivially recoverable, i.e. not if you don't know what you're doing.

It's the class of problems that would not be caught in release mode.

Why? Because if such problems are caught thoughtlessly, then the program behavior changes in release mode .. which is a big, BIG no-no.

So ArrayBoundsError, AssertFailedError, and InvariantError are all valid, and should NOT be derived from Exceptions.

 --downs