Pure, Nothrow in Generic Programming

[Walter Bright]

Andrei Alexandrescu wrote:
> Let's not confuse undefined with implementation-defined. I am firmly 
> convinced that memcmp never falls in the undefined behavior realm. The 
> behavior is always defined.

Makes sense. But I'd still want to make it not @safe, by using a more 
expansive definition of @safe to include some implementation defined 
behaviors.