On Aug 20, 2012, at 12:52 PM, I wrote: > My first thought was to declare some categories on NSArray and NSDictionary > to define those methods, but that's likely to cause issues when iOS 6 comes > out and already includes those methods — I'll get compile errors (which I can > work around with #ifdefs) but also a warning at launch time because the > methods are declared in two places.
As an experiment I added the category @interface for these methods, but not the @implementation — the app still ran fine (at least in the 5.1 simulator; don't have an iOS 5 device to try it on right now.) My guess is that the compiler is smart enough to emit calls to e.g. objectForKey: instead of objectForKeyedSubscript: when it sees that the receiver is an instance of NSDictionary. But I haven't yet disassembled the code to verify this. Here's the declaration I use: // Compatibility declarations to allow NSArray/NSDictionary subscripting in iOS with Xcode 4.4. // The compiler needs to see declarations of these methods to make the class subscriptable, but // the iOS 5.1 SDK doesn't contain them on NSArray/NSDictionary. It appears it isn't necessary // to actually implement these methods, though... #if (defined(__IPHONE_OS_VERSION_MAX_ALLOWED) && __IPHONE_OS_VERSION_MAX_ALLOWED < 60000) @interface NSArray (PreiOS6) - (id)objectAtIndexedSubscript:(NSUInteger)index; @end @interface NSMutableArray (PreiOS6) - (void)setObject: (id)object atIndexedSubscript:(NSUInteger)index; @end @interface NSDictionary (PreiOS6) - (id)objectForKeyedSubscript:(id)key; @end @interface NSMutableDictionary (PreiOS6) - (void)setObject: (id)object forKeyedSubscript:(id)key; @end #endif —Jens _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
