Dave Thomas wrote:
> I don't think the cost of a hash is going to be significant--if it is, 
> then I'd hope that implementors find a way of optimizing these styles of 
> keyword hashes, because they're used more and more (*cough*Rails*cough*).

Hard to do, since it has to be a hash on the callee side. Constructing 
the hash could perhaps be delayed, in case the callee was a C function, 
but it still has to be something. In comparison, new(1000) is almost free.