Let's improve D's exceptions

[Jacob Carlborg via Digitalmars-d]

On 2015-05-13 17:08, Adam D. Ruppe wrote:
> Have you ever done:
>
> if(something) {
>     import std.conv;
>     throw new Exception("some error " ~ to!string(some_value));
> }
>
> Don't you hate it?
>
> * having to import std.conv to see data from your exception is a pain
> * it allocates eagerly and thus isn't suitable for a lot of places
> * inspecting the data can be a pain as the string is unstructured
>
> This assumes the data is even bothered to be added. Anyone who has
> gotten a RangeError in D knows important information is often just dropped!
>
> A good solution is to make a new exception subclass for each error type,
> storing details as data members. However, that's a bit of a pain in D
> because of all the work you have to do to make a complete subclass:

Yeah, I really hate that people are using plain Exception instead of 
creating a subclass. I'm trying to point this out in pull requests and 
similar but it's hard to get people to listen.

One thing that is _not_ making things better is "enforce" which, if I 
recall correctly, throws Exception by default.

I think this is related: http://wiki.dlang.org/DIP33

-- 
/Jacob Carlborg