DIP60: @nogc attribute

[via Digitalmars-d]

On Monday, 21 April 2014 at 20:29:46 UTC, Steven Schveighoffer 
wrote:
> It's pretty difficult to use manual RC and beat ARC. In fact in 
> some cases, ARC can beat manual, because the compiler has more 
> insight and knowledge of the rules being followed.

Are you sure? Have you tried to do it first with 
CFRelease/CFRetain, then with ARC?

I believe this is the real reason (but I could be wrong):

«You can’t implement custom retain or release methods.»

from

https://developer.apple.com/library/mac/releasenotes/ObjectiveC/RN-TransitioningToARC/Introduction/Introduction.html