Mac Apps That Use Garbage Collection Must Move to ARC

[Benjamin Thaut via Digitalmars-d]

Am 26.02.2015 um 05:08 schrieb Walter Bright:
> On 2/25/2015 7:27 PM, deadalnix wrote:
>> On Thursday, 26 February 2015 at 02:48:15 UTC, Walter Bright wrote:
>>> Writing a generational collector for D is possible right now with no
>>> language
>>> changes, it's just that nobody has bothered to do it. Don't need write
>>> barriers for it, either.
>> How are you planning to track assignment a pointer to the young
>> generation in
>> the old generation ? Because if you plan to rescan the whole old
>> generation,
>> this is not exactly a generational GC.
>
> A lot of benefit simply came from compacting all the remaining used
> allocations together, essentially defragging the memory.

What you are describing is a compacting GC and not a generational GC. 
Please just describe in words how you would do a generational GC without 
write barriers. Because just as deadalnix wrote, the problem is tracking 
pointers within the old generation that point to the new generation.