> Yes. An analog would be uninitialized memory. The compiler is free to make optimizations that assume that uninitialized memory holds every value and no value simultaneously (because it is undefined behavior to ever read it).
Even casting a MaybeUninit<i32>::uninit() to i32 is UB, even though every bit pattern in that memory space is a valid i32.
What's interesting is your code example is solved in Rust. By preventing a reference and a mutable reference all of the sudden the code becomes easier to reason about. No need for special attributes: https://www.lysator.liu.se/c/restrict.html#comparison-with-n...
Even casting a MaybeUninit<i32>::uninit() to i32 is UB, even though every bit pattern in that memory space is a valid i32.
What's interesting is your code example is solved in Rust. By preventing a reference and a mutable reference all of the sudden the code becomes easier to reason about. No need for special attributes: https://www.lysator.liu.se/c/restrict.html#comparison-with-n...