//@ build-fail // Cyclic assoc. const defaults don't error unless *used* trait Tr { const A: u8 = Self::B; //~^ cycle detected const B: u8 = Self::A; } // This impl is *allowed* unless its assoc. consts are used impl Tr for () {} fn main() { // This triggers the cycle error assert_eq!(<() as Tr>::A, 0); }