Michael Rynn, I don't agree. In my opinion it's better to keep the built-in AAs very flexible and very easy to use. I prefer them to have methods/attributes to make them more handy to use in real situations (time ago I have listed here time several missing things, like clear and copy methods, while I have said that the rehash can be removed), while the performance tweak parameters can be added to a associative array in Phobos, that can be used for more specialized purposes.
Bye, bearophile