Why is rehash not @safe?

["Nordlöw" via Digitalmars-d-learn]

On Saturday, 30 August 2014 at 17:31:54 UTC, monarch_dodra wrote:
> Really, it's lose-lose. The only (AFAIK) solution is to migrate 
> AA's to a template-library that individually infers the correct 
> safety for every types.

Isn't there anyway to say that rehash() should infer safeness 
from typeinfo(T).hash() provided that its safeness is visible in 
the call context?