DIP60: @nogc attribute

[via Digitalmars-d]

On Tuesday, 22 April 2014 at 19:42:20 UTC, Michel Fortin wrote:
> Objective-C isn't memory safe because it lets you play with raw 
> pointers too. If you limit yourself to ARC-managed pointers 
> (and avoid undefined behaviours inherited from C) everything is 
> perfectly memory safe.

I'm not convinced that it is safe in multi-threaded mode. How 
does ARC deal with parallell reads and writes from two different 
threads? IIRC the most common implementations deals with 
read/read and write/write, but read/write is too costly?