GC in D and synadard library.

[Dan Partelly]

I started to look into D very recently. I would like to know the 
following, if you guys are so nice to help me:

1. What is the performance of D's GC, what trade-offs where done 
in design , and if a in-deep primer on efficient usage and 
gotchas of the current implementation exists.

2. GC is never good enough. What are the current plans in this 
area for D. In general, please point me to the place where 
current work on D is done.

3. I need to be able to run with GC totally disabled sometimes. 
In the light of this:
    - are there any features of core language which depend on 
garbage collection ? (i.e unbound arrays, strings ..)
    - are there any features from standard library which depend on 
active garbage collection?
    - Please point me to a list where there is an exhaustive 
enumeration of which language features *and* library features 
requires GC active. Looking at standard library docs I did not 
seen markings which identify clearly and unequivocally what 
requires GC active and what not.

4. Is Andrei Alexandrescu's book from 2009 on D still actual, or 
the language evolution made it obsolete ?

With thanks.