Discovery from class-dumping Yosemite system libraries.

[ChanMaxthon]

I class-dumped Apple's system libraries and discovered this:

NSObject is implemented in libobjc.dylib, despite header appeared in 
Foundation.framework

NSArray and friends, Objective-C classes that is toll-free bridged to 
CoreFoundation types, are implemented in CoreFoundation.framework, despite 
header appeared in Foundation.framework

CF types does have a one-to-one mapping to internal Objective-C classes, being 
subclasses of respective public umbrella classes or _NSCFType class for non-TFB 
types. This suggests that the polymorphic CoreFoundation functions maps to 
Objective-C methods on NSObject.

Apple did not make NSSet/CFBag and NS/CFRunLoop TFB but we can make that happen 
without breaking Apple's interface contracts.

Sent from my iPhone