See https://stroustrup.com/classes_1982.pdf from 1981, page 4: "This defines a destructive read for objects of class x, as opposed to the copy operation as implied by the standard semantics."
Then "C with classes" turned into C++ which lacked this important feature for about 30 years until it came back with C++ 11's move assignment operators. Amazing, I wonder what took them this long. :-)