Sorry, I wasn't clear enough that my code was intended as sarcastic. It's obviously silly to zero variables because the compiler is free to ignore you. The point is, the underlying machine is going to do the same.

There are many ways to dig out stale memory if you're running at sufficient privilege, for example. Direct cache introspection, for example, or bypass. Zero-izing alone is not sufficiently strong to mitigate the threats people imagine it works against.