This just doesn't scale and it would have been a non starter because it would break so much exiting code. Mem swap is just one of the ways to move via mutable r

This just doesn't scale and it would have been a non starter because it would break so much exiting code. Mem swap is just one of the ways to move via mutable references, there are many many others. Option::take is one that I use quite often and it would be super weird if that was unsafe.