Re: [Obj-C Compiler Bug?] Two different classes declaring a message with the same name - compiler warning

FROM : Chris Suter
DATE : Tue Oct 14 11:00:05 2008

On Tue, Oct 14, 2008 at 7:43 PM, Oleg Krupnov <oleg.<email_removed>> wrote:
> In my project I have two different, totally unrelated classes.
>
> @interface ClassA : NSObject{}
>
> -(id)initWithContext:(ContextA*)context;
>
> @end
>
>
> @interface ClassB : NSObject{}
>
> -(id)initWithContext:(ContextB*)context;
>
> @end
>
> The problem is that when I call
>
> ContextA* context = ...;
> [[ClassA alloc] initWithContext:context];
>
> Not in all cases, but in some I get the warning that the var "context"
> is of different type (ContextA) than expected (ContextB). It seems
> like the compiler erroneously resolves this call to ClassB instead of
> ClassA, I guess because the two methods have the same name. This
> problem disappears if I rename one of the methods to
> "initWithContext2".
>
> I'd like to keep the same name and I hate the compiler warning. Is
> there any resolution? Is it really a bug of the Obj-C compiler?


No, it's not a bug.

The problem is that the compiler doesn't know which method you mean
because the "alloc" call returns an id. Either change the names of
your methods (which might make sense given that "context" doesn't tell
you much) or cast the return from alloc to the appropriate type. You
could use a macro to make it slightly more readable.

-- Chris