Mac OS X 10.5 added many convenient methods to existing Cocoa framework. However, whenever you want to write codes which should be also targeted to pre-OS X 10.5, you cannot but write your own version of the methods provided by 10.5.
Recently I had to use componentsSeparatedByCharactersInSet, and compiler complaint that NSString may not have the method. Umm.. I looked up the document, and Ah!!! it is only supported from 10.5!
So, I had to write the method for pre-10.5 OS X. However, fortunately I found existing implementation from a project hosted at Google. ( Thanks, Google code!!! )
It saved a handful of minutes!!