LRU cache for ~=

[Sean Kelly]

Andrei Alexandrescu Wrote:
>
> 
> What I'm saying is that with the cache in place we'll have slices that 
> are safe and efficient. Right now they are not safe and not efficient. I 
> can hardly find reasons to characterize the new state of affairs as kludgey.

I'm not sure I agree that they'd be safe.  Given only a pointer to the head of a block there's no way to know whether it represents the array or a slice of the array from [0..n].