“Multiple Inheritance (object-oriented programming) was widely supposed to be very difficult to implement efficiently. For example, in a summary of C++ in his book on objective C Brd.Cox actually claimed that adding Multiple inheritance to C++ was impossible. Thus, multiple inheritance seemed more of a challenge. Since I had considered multiple inheritance as early as 1982 and found a simple and efficient implementation technique in 1984. I couldn’t resist the challenge. I suspect this to be the only case in which fashion affected the sequence of events.” —  Bjarne Stroustrup