On Tue, Oct 14, 2008 at 8:17 PM, Oleg Krupnov <[EMAIL PROTECTED]> wrote: > You are right, casting from alloc worked, thank you. > > Is it the recommended practice to always cast after alloc? > > I still have a question in this regard. > > If the alloc returns id, then, from the compiler's perspective, there > can be two solutions: 1) assume that the id type can have each and any > method and let it be resolved at run time without any compiler warning > or
This won't work. The compiler emits different code depending upon the types involved. For example, there are differences depending on whether the return types are structures, floating point or integer values. > 2) assume that the id does not have any methods (except NSObject's) > and always issue a compiler warning when there is no explicit casting > to a type. Well that would be a pain. You'd get warnings everywhere. id, by definition, can be sent anything. > What compiler seems to be doing is rather strange: it looks > through the project, arbitrarily picks up a class with the matching > message name and issues a warning if the rest of the actual message > signature is not matching. How would you explain that? It comes down to the point I made above. It needs to know about the types. The proper way to solve this, in my opinion, is to allow a way of specifying that the return type varies depending on the class it's implemented on i.e. define the alloc method in such a way so that the compiler knows that -[<class> alloc] returns an object of type <class>. Something similar could be used for [NSString string] and [NSMutableString string] which have a similar problem (they return an id, rather than an NSString or NSMutableString). -- Chris _______________________________________________ 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: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [EMAIL PROTECTED]
