Re: Multiple declarations and the ID type
Re: Multiple declarations and the ID type
- Subject: Re: Multiple declarations and the ID type
- From: Jamie <email@hidden>
- Date: Mon, 21 Jun 2004 19:02:14 +0100
Cool
Cast to the protocol? I didn't know you could do that. Is that really
the only way this can be solved?
Jamie
On 21 Jun 2004, at 18:24, Alberto Ricart wrote:
Create a formal protocol and type your objects to conform to the
protocol, and cast to that prior to calling the method. Essentially
you never message to any method not in a protocol or type - this is
kind of extra work, but will silence the compiler.
/a
On Jun 21, 2004, at 11:31 AM, Jamie wrote:
I am having an annoying problem with warnings being issued from the
compiler when I am building my app.
I have an instance variable of type ID, that gets assigned different
object types that it has to deal with. Each of these objects has a
method
- (void) setName: (NSString *) theName;
The problem is that because I am dynamically typing, the compiler
doesn't know whether to use that definition or one of another two it
finds in the other headers that are included in my project, and I get
a multiple declarations error.
I have trawled the archives but have found no viable solution to this
issue for my case. The only fix I can think of at the moment is to
change the variable and method names to something unique, but that
seems like a copout. The two suggestions I have read are - to cast
the variable as you send the message, but that is not possible since
it could be one of three different classes, and the other is to
statically type it - also not possible.
I tried creating a parent class so that it would just contain that
method, and maybe a few other common ones, so that I could statically
type the variable, but then i got the inverse of the problem:
because not all subclasses responded to the same methods, I get
"object may not respond to -selector". Basically it seems like catch
22. How can get rid of this error?
PS - I do understand why I get the mesages, i just don't see a way
round it in my case. I thought the idea of dynamic typing was for
situations such as this where you don't know what type your object
will be - great, but not if it leaves you with loads of warnings and
badly compiled code.
--
jkp
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