Incompatible pointer types sending 'Class' to parameter of type 'id'

Question

I have updated xcode and now I get the error message Incompatible pointer types sending 'Class' to parameter of type 'id'


- (void)mapObjectClass:(Class)objectClass toCellClass:(Class)cellClass {
  [self.objectToCellMap setObject:cellClass forKey:objectClass];
}

I would really appreciate it if someone can shed some light on this issue im having and how I can resolve it.

from my understanding, id is the equivalent to a void *. Class isn't a pointer, therefore, not compatible with id. Feel free to correct me if I'm wrong. :) — Simon Germain, Oct 19 '12 at 23:57
Hi Simon, thank you for your prompt response, so what do you suggest I change it to? — Armin Nehzat, Oct 19 '12 at 23:59
@SimonGermain is not quite correct. id is a generic type meaning an Objective-C object of any class. Class objects are indeed objects and can be sent to methods expecting id arguments. The problem is rmaddy describes in his answer. — Andrew Madsen, Oct 20 '12 at 00:03
thank you Simon and Andrew, changing id to Class solved the issue :) — Armin Nehzat, Oct 20 '12 at 03:14

score 5 · Accepted Answer · answered Oct 19 '12 at 23:59

Keys for an NSDictionary must be objects that adhere to the NSCopying protocol. Class doesn't qualify.

The first question is why are your method parameters of type Class and not something more typical such as a specific class type (object pointer) or id?

Incompatible pointer types sending 'Class' to parameter of type 'id'

1 Answers1