Le 25 nov. 2013 à 10:23, Gerriet M. Denkmann <gerr...@mdenkmann.de> a écrit :
> The documentation states: "CFArray is “toll-free bridged” with its Cocoa > Foundation counterpart, NSArray. This means that the Core Foundation type is > interchangeable in function or method calls with the bridged Foundation > object. Therefore, in a method where you see an NSArray * parameter, you can > pass in a CFArrayRef" > > Does this also mean: "any message you can send to an NSArray, you can send > also to an CFArrayRef"? > > NSFont *fo = [ NSFont fontWithName: @"Thonburi" size: 0 ]; > CTFontRef font = (__bridge CTFontRef)fo; > CFArrayRef tags = CTFontCopyAvailableTables ( font, 0 ); > NSArray *tagsArray = CFBridgingRelease(tags); > // next line prints: class __NSCFArray count: 18 > NSLog(@"%s class %@ count: %lu",__FUNCTION__, [tagsArray class], > [tagsArray count]); > > So sending messages to an CFArrayRef seems to be ok. Or not? > > But then this line crashes: > > NSString *tagDescription = [ tagsArray description ]; > > My mistake? My false assumption? You just hit a corner case. Toll free bridging is supported only for collections of objects compatible with id. CTFontCopyAvailableTables() is one of the very few API that returns a CFArrayRef that contains plain int value, and so cannot be safely converted to NSArray. An other well known corner case is when you try to cast a CFMutableDictionary into a NSMutableDictionary. The later requires that key are copyable objects while the former support other types of keys. Except such cases, you should be able to call any NSArray method on a CFArrayRef. -- Jean-Daniel _______________________________________________ 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
