Robert Jacques wrote:
Yes, although classes have hidden vars, which are runtime dependent, changing the offset. Structs may be embedded in other things (therefore offset). And then there's the whole slicing from an array issue.
Um, no. Field accesses for class variables are (pointer + offset). Successive subclasses append their fields to the object, so if you sliced an object and changed its vtbl pointer, you could get a valid instance of its superclass.
If the class layout weren't determined at compile time, field accesses would be as slow as virtual function calls.
