Thanks Steve! It turns out I had misremembered; the cast I was thinking of is https://github.com/oxidecomputer/hubris/blob/master/sys/kern/src/startup.rs#L131

Thanks Steve! It turns out I had misremembered; the cast I was thinking of is https://github.com/oxidecomputer/hubris/blob/master/sys/kern/src/startup.rs#L131-L134 https://github.com/oxidecomputer/hubris/blob/master/sys/kern... from &mut MaybeUninit<[T]> to &mut [MaybeUninit<T>], which doesn't construct a reference to something uninitialized.