> "valid but unspecified state", not in an invalid state That's mostly a detail because you can't rely on that to do anything interesting. Basically you can as

> "valid but unspecified state", not in an invalid state That's mostly a detail because you can't rely on that to do anything interesting. Basically you can assign a new value to the object, or just destruct it. Having a "valid" but unknown value is completely useless. What is sad is that the same mechanism has been overloaded for at least 2 different things: simple perf optim (when you fall into this situation of no guarantee), and movable unique ownership (like unique_ptr) where you actually can read the resulting object after the move an expect a predictable (in a portable and standardized way ) outcome.