Language Specification for Blocks 2008/2/25 — created 2008/7/28 — revised, __block syntax 2008/8/13 — revised, Block globals 2008/8/21 — revised, C++ elaboration 2008/11/1 — revised, __weak support 2009/1/12 — revised, explicit return types 2009/2/10 — revised, __block objects need retain Copyright 2008-2009 Apple, Inc. Permission is hereby granted, free of charge, to any person obtaining a copy o