Question

I’ve got an id* type and would like to cast it to an NSString * – with ARC enabled. How do I achieve this?

EDIT:
This doesn’t work… how should I adapt this to make it work?

id *idStar = ...;
NSString **string2Star = (NSString **) idStar;
NSLog(@"%@", *string2Star);

Answer 1

id * can’t be cast to NSString * under any circumstances.

Keep in mind that id is already a pointer type; making it equivalent not to NSString, but to NSString *.

In order to cast, you’d have to cast it to NSString **.

Edit:

In the case you are presenting, the cast is completely unnecessary.

NSString *string2Star = *idStar;

should do nicely; and even that’s moderately unnecessary.

Keep in mind that the variable type in Objective-C basically is nothing more than a hint to the compiler to let it know what methods you are planning to call; and warn you if you call different ones.

The actual method call mapping all happens at runtime; meaning that casts are fairly meaningless.