Prime sieve language race

[Bastiaan Veelo]

On Tuesday, 13 July 2021 at 19:45:48 UTC, ag0aep6g wrote:
> On Tuesday, 13 July 2021 at 19:06:12 UTC, Bastiaan Veelo wrote:
>>     // If not called from multiple threads, this can be 
>> trusted.
>
> I.e., it can't be trusted. When a function needs a comment that 
> explains how to call it safely, then it's an @system function.

Then `printResults` can't be trusted either. Or change the 
comment s/If/Since/?