On 26 Jun 2010, at 19:51, Quincey Morris wrote: > On Jun 26, 2010, at 10:52, Kyle Sluder wrote: > >> On Jun 26, 2010, at 9:45 AM, Jaime Magiera <[email protected]> wrote: >> >>> Hello, >>> >>> The list search keeps timing out for me, and web searches are not finding >>> anything. I can see how to tell if an NSNumber was initialized with an int >>> or boolean (NSCFNumber vs. NSCFBoolean). However, I can't figure out how to >>> determine if the NSNumber was initialized with an int or float. >> >> I hope you don't mind my asking why you need to do this? The existence of >> NSCFNumber and NSCFBoolean is an implementation detail upon which you can't >> rely (well, probably more like shouldn't). > > "Can't" is more correct than "shouldn't", in this context. The NSNumber > documentation for 'objCType' explicitly says: > >> Special Considerations >> The returned type does not necessarily match the method the receiver was >> created with. > > Incidentally, the OP is wrong in claiming that it's possible "to tell if an > NSNumber was initialized with an int or boolean (NSCFNumber vs. > NSCFBoolean)". This is triply wrong: > > 1. Unless this has changed recently, [NSNumber numberWithInt: 1] and > [NSNumber numberWithBool: YES] both return the same (singleton) object, as do > [NSNumber numberWithInt: 0] and [NSNumber numberWithBool: NO]. > > 2. Testing against NSCF classes is a mistake, because they're private and > undocumented, AFAIK. > > 3. As with 'objCType', the best you can determine is what type has been > chosen to *represent* the number, not what what type was passed when creating > the number. > > In other words, NSNumber is a wrapper of numeric values, not a wrapper of C > scalar types. > In light of the above a 10.5 + GC solution might be:
1. Define a category on NSNumber. 2. In the category file allocate a static map table myMap = [NSMapTable mapTableWithWeakToStrongObjects]; 3. Define counterparts to each factory method: eg: myNumberWithBool:(BOOL)theBool, etc 4. Each factory method allocates an instance and performs the equivalent of [myMap setObject:@"BOOL" forKey:[NSNumber numberWithBool:theBool]] 5. The initialisation type for any NSNumber instance can be obtained by querying the map table [myMap objectForKey:someNumber]; Regards Jonathan Mitchell Developer Mugginsoft LLP http://www.mugginsoft.com_______________________________________________ Cocoa-dev mailing list ([email protected]) 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: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [email protected]
