Caching with GCD

gistfile1.txt

// as seen in http://www.cocoanetics.com/2012/02/caching-caches/
// benefits: thread-safe

- (id) cachedObject
{
  static dispatch_once_t onceToken;
  static id objectToCache;

  dispatch_once(&onceToken,^{
    objectToCache = ...; // create the object
  });

  return objectToCache
}