What’s not possible in C++ is the actual prevention of the moved-from value from being used after the move. Entire API’s are designed around this: my type that

What’s not possible in C++ is the actual prevention of the moved-from value from being used after the move. Entire API’s are designed around this: my type that tracks a background task can have a shutdown() method that moves self, so that if you call foo.shutdown(), you can’t use foo any more. This is more than just preventing a value from being used, it also facilitates making a rule that “moves are only just memcpy()”, and it can actually be enforced: C++ move semantics require you to write arbitrary code that pillages the moved-from value (like setting the heap pointer of a moved-from value to nullptr) to ensure the old value is safe: rust just says “nope, there’s no constructor, moves are just a memcpy. We will keep it safe by simply not letting code use the old value.” C++ can never have this unless they offered yet another mutually incompatible form of move semantics (lol, what would the sigil be? &*&?)