What are the digits in an ObjC method type encoding string?
method-signature, objective-c, objective-c-runtime
Solution
This looks like an encoding of a setter method like this:
- (void) setSomething:(id) anObject
To break it down:
- `v` means void return type
- `12` means the size of the argument frame (12 bytes)
- `@0` means that there is an Objective-C object type at byte offset 0 of the argument frame (this is the implicit `self` object in each Objective-C method)
- `:4` means that there is a selector at byte offset 4 (this is the implicit `_cmd` in every method, which is the selector that was used to invoke the method).
- `@8` means that there is another Objective-C object type at byte offset 8.
Problem
I'm reading Apple's article about Objective-C runtime type encoding strings and some methods have numbers in their type strings. What do the numbers in `v12@0:4@8` mean?