Why is rehash not @safe?

[Orvid King via Digitalmars-d-learn]

On 8/30/2014 9:27 AM, "Nordlöw" wrote:
> I just noticed that AA rehash is @system. Is there a reason for this? Is
> it system because bad things can happen or simply because it's a low
> level function? Should I always tag functions calling rehash as @trusted?

Rehash itself would have to be marked @trusted rather than @safe if 
anything.