D array expansion and non-deterministic re-allocation

[Walter Bright]

Bartosz Milewski wrote:
> I read Andrei's chapter on arrays and there's one thing that concerns
> me. When a slice is extended, the decision to re-allocate, and
> therefore to cut its connection to other slices, is
> non-deterministic.

It is not non-deterministic. Try it - you'll get the same results every 
time. It is implementation-defined behavior.


> How does that influence program testing and can it
> be exploited to attack a buggy system?

Exploitations rely on undefined-behavior, such as buffer overflows, not 
implementation-defined behavior. This issue is no more conducive to an 
"exploit" than any other garden variety programming issue. It's entirely 
different than a buffer overflow attack.