opDispatch, duck typing, and error messages

[Jonathan M Davis]

> Jonathan M Davis wrote:
> > I just checked. Exception _does_ take a default file and line number.
> 
> Huh, maybe my dmd is getting old.
> 
> Maybe we should revisit this after the next dmd release. Sounds like
> one is coming pretty soon with a lot of yummy goodness in it. All
> of this Exception stuff may be moot.

It was in dmd 2.052. I don't know when the change was made though. I might 
have been the one to change it too. I made several changes a while back to 
make it so that Exception and Error types had default file and line numbers 
(and I actually had to remove several on various Errors, because the way that 
they're actually created makes them not work with default arguments).

- Jonathan M Davis