Why does scope(success) have to use exceptions?

[Maxim Fomin]

On Thursday, 17 January 2013 at 15:16:07 UTC, Johannes Pfau wrote:
> Am Thu, 17 Jan 2013 13:15:06 +0100
> schrieb "Maxim Fomin" <maxim at maxim-fomin.ru>:
>
>> On linux, segfaults can be translated into exceptions using 
>> this module 
>> (https://github.com/D-Programming-Language/druntime/blob/master/src/etc/linux/memoryerror.d) 
>> however I do not know how to use it - I get linker errors.
>> 
>> On windows null pointer errors are translated into 
>> Object.Error (Access Violation) - I do not remember exactly.
>> 
>> In any case, your void callScope(ref int x) can be blown up by:
>> int* ptr; callScope(*ptr); so, exceptions may come when they 
>> are not expected.
>
> Uh, does that meany that a D compiler can never optimize by 
> removing
> exception handling, even if it can prove that all involved 
> methods are
> nothrow and don't throw errors as well?

DMD should optimize, but I was arguing that in this situation it 
should not do this.