Function move_to_slice
pub(in ::collections::btree::node) fn move_to_slice<T>(src: &mut [MaybeUninit<T>], dst: &mut [MaybeUninit<T>])
Moves all values from a slice of initialized elements to a slice
of uninitialized elements, leaving behind src as all uninitialized.
Works like dst.copy_from_slice(src) but does not require T to be Copy.