1 #![feature(existential_type)]
4 type BitsIter: Iterator<Item = u8>;
5 fn iter_bits(self, n: u8) -> Self::BitsIter;
8 existential type IterBitsIter<T, E, I>: std::iter::Iterator<Item = I>;
9 //~^ ERROR could not find defining uses
11 impl<T, E> IterBits for T
13 T: std::ops::Shr<Output = T>
14 + std::ops::BitAnd<T, Output = T>
15 + std::convert::From<u8>
16 + std::convert::TryInto<u8, Error = E>,
19 type BitsIter = IterBitsIter<T, E, u8>;
20 fn iter_bits(self, n: u8) -> Self::BitsIter {
21 //~^ ERROR type parameter `E` is part of concrete type but not used
24 .map(move |shift| ((self >> T::from(shift)) & T::from(1)).try_into().unwrap())