I've known of XOR tricks since the 80s, when you would "undraw" a graphic on the screen by redrawing it with XOR. But only recently I learned that the implement

I've known of XOR tricks since the 80s, when you would "undraw" a graphic on the screen by redrawing it with XOR. But only recently I learned that the implementation of multiport memory for CPU caches and the likes often uses a design based on multiple storage copies and XOR to get the last valid written result. Amazed that the CPU's cache is doing that kind of trick all the time just during regular code execution.