Very clever, but that's the problem, clever is never the correct solution.
With a few bytes more more you can create an implementation that is a lot easier to understand. Bytes are cheap, developer time isn't.
With a few bytes more more you can create an implementation that is a lot easier to understand. Bytes are cheap, developer time isn't.
https://news.ycombinator.com/newsguidelines.html
I'd especially hammer the point in this case, because clever hacks are very much on topic for Hacker News. They are, in fact, what gave birth to the word hacker and the idea of hacking in the first place. Not only that but it was precisely the clever hacks with no particular utility that were prized most highly!
In Stockfish, there will only be one full-fledged board state in memory per search thread. So the size of the board state is pretty much irrelevant to performance. What's important is reducing the overhead of generating possible moves, applying those moves to the board state, and hashing the board state, which is what magic bitboards are for.