Discussion Thread: DIP 1035-- at system Variables--Community Review Round 1

[ag0aep6g]

On 17.06.20 16:27, Andrei Alexandrescu wrote:
> Not even close. The crux of the matter is that forgetting to add @system 
> to that variable makes @safe code do unsafe things with no diagnostic 
> for the compiler. That's a problem with the safety system, regardless of 
> the adoption of this DIP. We can't say "@safe D code is safe, except of 
> course if you forget to insert @system on key variables, in which case 
> it won't be with no warning."

If you forget @system on a safety-critical variable, then an @trusted 
function that relies on it does not have a safe interface and is invalid.

We're saying "@safe D code is safe, except when you make a mistake in 
@trusted code". Relying on a non- at system variable is such a mistake.