trait Set { fn contains(&self, _: T) -> bool; fn set(&mut self, _: T); } impl<'a, T, S> Set<&'a [T]> for S where T: Copy, S: Set, { fn contains(&self, bits: &[T]) -> bool { bits.iter().all(|&bit| self.contains(bit)) } fn set(&mut self, bits: &[T]) { for &bit in bits { self.set(bit) } } } fn main() { let bits: &[_] = &[0, 1]; 0.contains(bits); //~^ ERROR overflow }