What are the worst parts of D?

[Dicebot via Digitalmars-d]

On Thursday, 9 October 2014 at 16:22:52 UTC, Andrei Alexandrescu 
wrote:
>>> To clarify: calling GC.free does remove the root, correct?
>>
>> Not before it creates one. When I mean "avoid creating new GC 
>> roots" I
>> mean "no GC activity at all other than extending existing 
>> chunks"
>
> That's interesting. So GC.malloc followed by GC.free does 
> actually affect things negatively?

Yes and quite notably so as GC.malloc can potentially trigger 
collection. With concurrent GC collection is not a disaster but 
it still affects the latency and should be avoided.

> Also let's note that extending existing chunks may result in 
> new allocations.

Yes. But as those chunks never get free'd it comes to O(1) 
allocation count over process lifetime with most allocations 
happening during program startup / warmup.

Don has mentioned this as one of important points during his 
DConf 2014 talk but it probably didn't catch as much attention as 
it should.