You could also just isoheap according to type, where the type is whatever you come up with to make C++ casts sound. It could literally be C++ types or something

You could also just isoheap according to type, where the type is whatever you come up with to make C++ casts sound. It could literally be C++ types or something looser (like if you want to say that bitcasting a int ptr to a float ptr is ok). Then you don’t need any language changes to make UAF type safe.