Clang's ARC support and cycles

Clang has new feature called ARC. Concep开发者_开发问答t looks cool. Is this feature support detecting cycles?

ARC has support for weak references. If one of the references in a cycle is a weak reference, this will allow the cycle to be properly released. See this post by Chris Lattner from Apple:

[ARC introduces] zeroing weak references, which are like assign properties in their cycle breaking ability but a lot safer since they can't dangle.

Nope... ARC is only for automating retain and release - nothing else... I'm pretty sure Instruments has a tool for this - at least in 4.1/4.2