custom exception type

[Trass3r]

> E.this performs nothing new. But without it, I get a compiler error:
>     trial.d(7): Error: constructor trial.E.this no match for implicit  
> super() call in constructor
> Isn't the constructor inherited like other attributes?

I think if you don't provide a constructor a default one is created:  
this(){}
Then an implicit call to super() is inserted cause there's no explicit one.
But there is no this() without parameters in the Exception class if I'm  
not mistaken. You can look it up in _object.d in the druntime source.