NSValueTransformer for C structs in Core Data

Question

How do I create a NSValueTransformer for a C struct, such as a CGRect in Core Data?

Apparently transformedValue & reverseTransformedValue require and id. Is there a way to pass a void*, or a better way to do this?

Answer 1

Use NSValue to wrap C pointers.

[NSValue valueWithPointer:&struct]

Specifically for CGRect, you can use

[NSValue valueWithCGRect:rect]

which is declared in UIKit/UIGeometry.h