A LIFO (last in, first out) Objective-C implementation of Apple's NSOperationQueue.
CBOperationStack has the same interface as NSOperationQueue with the difference that operations are (roughly) run in a last in, first out order as opposed to NSOperationQueue's first in, first out order.
The other difference from NSOperationQueue is the addition of one method:
- (void)addOperationAtBottomOfStack:(NSOperation *)op;
which effectively allows you to use CBOperationStack as a queue as well.
CBOperationStack does not implement either the + (id)currentQueue or + (id)mainQueue methods yet.