The hidden unsafety in the pr_ macros (here under the heading Bonus Point for no unsafe) was interesting. I wonder if there's anything the compiler could do to

The hidden unsafety in the pr_ macros (here under the heading Bonus Point for no unsafe) was interesting. I wonder if there's anything the compiler could do to detect this kind surprise-unsafety happening, for example a no-unsafe assertion in a source file. Also, why doesn't the compiler know by default that the stack allocated struct is "MaybeUninit"?