Why exceptions for error handling is so important

[via Digitalmars-d]

On Tuesday, 13 January 2015 at 23:40:41 UTC, deadalnix wrote:
>> 1. Restricting the exception object to 512 bytes, preallocated 
>> in TLS.
>>
>
> Exception can bubble from one thread to another.

How? If you are thinking coroutines, then the exception can be 
moved with it.

>> 2. Only have one exception in flight per thread
>>
>
> I don't see how you could have more.

In a catch you can throw a new one and initialize with the old, 
but if they are both in the same memory space it will go wrong.

>
>> 3. Require that the first 8 bytes of the exception buffer are 
>> 0 when no exception is in flight, and use them for encoding 
>> exception type when one is in flight.
>>
>
> The first 8 bytes are already what is used to do matching. But, 
> because of inheritance, it is not as simple as you think it is. 
> Also, who the fuck care what is in the buffer when no exception 
> are in flight ?

1. So that you can mark a non-D function with @checkexception and 
allow it to both cast D-exceptions and propagate D-exceptions.

> Skipping 4 and 5, you obviously didn't though that through.

?