| #![feature(type_alias_impl_trait)] |
| |
| trait IterBits { |
| type BitsIter: Iterator<Item = u8>; |
| fn iter_bits(self, n: u8) -> Self::BitsIter; |
| } |
| |
| type IterBitsIter<T, E, I> = impl std::iter::Iterator<Item = I>; |
| |
| impl<T: Copy, E> IterBits for T |
| where |
| T: std::ops::Shr<Output = T> |
| + std::ops::BitAnd<T, Output = T> |
| + std::convert::From<u8> |
| + std::convert::TryInto<u8, Error = E>, |
| E: std::fmt::Debug, |
| { |
| type BitsIter = IterBitsIter<T, E, u8>; |
| fn iter_bits(self, n: u8) -> Self::BitsIter { |
| //~^ ERROR non-defining opaque type use in defining scope |
| (0u8..n).rev().map(move |shift| ((self >> T::from(shift)) & T::from(1)).try_into().unwrap()) |
| } |
| } |
| |
| fn main() {} |