Transitioning to a type aware Garbage Collector

[Frits van Bommel]

Walter Bright wrote:
> Paul Findlay wrote:
>> Walter Bright wrote:
>>> To improve GC performance, we need to transition to a GC that is 
>>> aware of the types of what it is allocating.
>> Does this mean the D garbage collector will be an exact (or precise) 
>> garbage collector?
> 
> No.

So what exactly *does* it mean?
Is it, as Pragma put it, a "bool containsPointers" per block?
Or is it mostly-precise?

"Not exact/precise" still leaves a pretty big range...


And if it's just a bool, what was the reasoning behind this decision?
Ease of implementation? The overhead of the metadata needed to get to 
mostly-precise? All of the above?