Astra Kernel 
#RustQuiz: what will be the output?
A. false
B. true
C. Compilation error
D. unsafe block is missing
Andreas Grois@AstraKernel Ohhh, that's a tricky one. I honestly have no clue. I am even unsure if debug and release will yield the same result here.
@AstraKernel That said: I think the result is true. I don't know the actual reasoning behind this, but if I remember correctly, Rust does not create an actual in-memory representation of instances of types with cardinality 1, as those would all be identical anyhow...
One consequence - again iirc - is that all instances of a type with cardinality 1 have the same address.
One consequence - again iirc - is that all instances of a type with cardinality 1 have the same address.
HJVT@soulsource @AstraKernel
I'm a little unsure if there's actually a guarantee that taking two references to the same ZST will return the same pointer.
I'm a little unsure if there's actually a guarantee that taking two references to the same ZST will return the same pointer.
@hjvt @AstraKernel Interesting. I had it somehow stuck in my mind that this is defined, and getting the address always yields the same value (at least for the same type).
However, doing a quick web search yields no mention of this, so I probably misremembered.
Corax@hjvt @soulsource @AstraKernel But what of two ZSTs composed together in another ZST?
The array here is itself zero-sized; is there no guarantee that a pointer to an array element must be pointing to an address inside the array? Which would necessitate that the array and the two elements all have the same address?
I am unreasonably fascinated by this problem ^_^
check this out:
(in release mode, all will have same address)