C++ teachers like Herb Sutter like to jump in here and make a correction: A moved-from object is in a valid state, you just might not know which state. You can

C++ teachers like Herb Sutter like to jump in here and make a correction: A moved-from object is in a valid state, you just might not know which state. You can still call methods on it that are valid in any state. ("What is your length?") But you shouldn't fall methods that are only valid in some states. ("Give me your first element.")