> you can actually just duck type if you want (type as 'id') and the ARC compiler will do type inference behind your back to track memory so you still get all t

> you can actually just duck type if you want (type as 'id') and the ARC compiler will do type inference behind your back to track memory so you still get all the compile-time checks and other type inference advantages You lose compile-time type checking with id, so it's not at all like type inference. I'm not sure how ARC is relevant at all, as it changed nothing about how id works. Using id everywhere is pretty similar to using void * everywhere in C.