This strikes me as being interesting primarily for the potential impact it has on interface design. There are applications of (this sort of) virtual memory mani

This strikes me as being interesting primarily for the potential impact it has on interface design. There are applications of (this sort of) virtual memory manipulation beyond circular buffers. Performance is one consideration, but not the only one. Also, this is a demonstration - of course it lacks synchronization mechanisms for multithreading! Any particular application of the principle would be adapted for the context in which it occurred (and hopefully be justified thereby). (As an aside, that caveat only applies if you begin with a poll function that performs the copy itself. That implementation isn't the only obvious one, especially given a large buffer - though I suppose there's room for disagreement on that.)