On Sep 22, 2012, at 4:46 PM, Boris Dobroslav <[email protected]> wrote:
> I'm perplexed by one line that appears in the file AVSPDocument.h from the 
> apple example code project AVSimplePlayer:
> 
> staticvoid *AVSPPlayerItemStatusContext = &AVSPPlayerItemStatusContext;
> 
> This definition appears outside of Objective-C @interface or @implementation, 
> so it must be pure C. But isn't it self-referential? Is it a C idiom? Any 
> pointers would be appreciated.

The intent is to get a unique pointer that differs from every other pointer 
value. The code can then use that address as a unique key or sentinel. 

The fact that this line takes the address of a global variable and stores that 
address in the same global variable is just a clever trick that is legal in C.


-- 
Greg Parker     [email protected]     Runtime Wrangler



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