Apple's CFArray does some of this. It can have different implementations depending on the number of elements in it.[1] I don't think it observes the usage patte

Apple's CFArray does some of this. It can have different implementations depending on the number of elements in it.[1] I don't think it observes the usage pattern yet. [1]: http://ridiculousfish.com/blog/archives/2005/12/23/array/ http://ridiculousfish.com/blog/archives/2005/12/23/array/