I shudder to think about a teacher or interviewer who wishes to check if the student or interviewee knows about such *forbidden* knowledge as prototypes. Personally I will give better marks to someone who says it needs to be done with references than to someone who immediately thinks about prototypes and still calls subroutines the "ampersand" way, thus utterly defeating the use of prototypes. Those are not the people you want to tinker with the control program of your nuclear reactor.
CountZero
A program should be light and agile, its subroutines connected like a string of pearls. The spirit and intent of the program should be retained throughout. There should be neither too little or too much, neither needless loops nor useless variables, neither lack of structure nor overwhelming rigidity." - The Tao of Programming, 4.1 - Geoffrey James