title: Get pointer to class of instance variable in Objective-C
body: <p>I have an object that has several properties.  If I have a pointer to one of those properties, is it possible to get a pointer to the class instance to which that ivar belongs?</p>
  <p>for example:  foo.bar, where I know the address of bar, can the address of foo be found?</p>
  <p>This seems related to: <a href="http://developer.apple.com/documentation/Cocoa/Reference/ObjCRuntimeRef/Reference/reference.html#//apple_ref/c/func/ivar_getOffset" rel="nofollow noreferrer">run time references</a> but I didn't see any references that were quite what I'm looking for.</p>
  <p>Thanks for your help!</p>