Ready... cancel... wait for it! (part 1)

One of the cardinal rules of the OVERLAPPED structure is the OVERLAPPED structure must remain valid until the I/O completes. The reason is that the OVERLAPPED structure is manipulated by address rather than by value. The word complete here has a specific technical meaning. It doesn't mean "must remain valid until you are no longer interested in the result of the I/O." It means that the structure