ARC专题：编写兼容ARC(自动引用计数) 和 non-ARC(非自动引用计数)的通用代码

下面这段宏可以解决这个问题，而不用同时编写2套代码

写法用传统的non-ARC写法

http://raptureinvenice.com/arc-support-without-branches/

// // ARCMacros.h // InnerBand // // For an explanation of why these work, see: // // http://raptureinvenice.com/arc-support-without-branches/ // // Created by John Blanco on 1/28/12. // Rapture In Venice releases all rights to this code. Feel free use and/or copy it openly and freely! // // NOTE: __bridge_tranfer is not included here because releasing would be inconsistent. // Avoid it unless you're using ARC exclusively or managing it with __has_feature(objc_arc). // #if !defined(__clang__) || __clang_major__ < 3 #ifndef __bridge #define __bridge #endif #ifndef __bridge_retain #define __bridge_retain #endif #ifndef __bridge_retained #define __bridge_retained #endif #ifndef __autoreleasing #define __autoreleasing #endif #ifndef __strong #define __strong #endif #ifndef __unsafe_unretained #define __unsafe_unretained #endif #ifndef __weak #define __weak #endif #endif #if __has_feature(objc_arc) #define SAFE_ARC_PROP_RETAIN strong #define SAFE_ARC_RETAIN(x) (x) #define SAFE_ARC_RELEASE(x) #define SAFE_ARC_AUTORELEASE(x) (x) #define SAFE_ARC_BLOCK_COPY(x) (x) #define SAFE_ARC_BLOCK_RELEASE(x) #define SAFE_ARC_SUPER_DEALLOC() #define SAFE_ARC_AUTORELEASE_POOL_START() @autoreleasepool { #define SAFE_ARC_AUTORELEASE_POOL_END() } #else #define SAFE_ARC_PROP_RETAIN retain #define SAFE_ARC_RETAIN(x) ([(x) retain]) #define SAFE_ARC_RELEASE(x) ([(x) release]) #define SAFE_ARC_AUTORELEASE(x) ([(x) autorelease]) #define SAFE_ARC_BLOCK_COPY(x) (Block_copy(x)) #define SAFE_ARC_BLOCK_RELEASE(x) (Block_release(x)) #define SAFE_ARC_SUPER_DEALLOC() ([super dealloc]) #define SAFE_ARC_AUTORELEASE_POOL_START() NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init]; #define SAFE_ARC_AUTORELEASE_POOL_END() [pool release]; #endif