| fn iterate<T, F>(initial: T, f: F) -> Iterate<T, F> { | |
| Iterate { | |
| state: initial, | |
| f: f, | |
| } | |
| } | |
| pub struct Iterate<T, F> { | |
| state: T, | |
| f: F | |
| } | |
| impl<T: Clone, F> Iterator for Iterate<T, F> where F: Fn(&T) -> T { | |
| type Item = T; | |
| #[inline] | |
| fn next(&mut self) -> Option<Self::Item> { | |
| self.state = (self.f)(&self.state); | |
| Some(self.state.clone()) | |
| } | |
| #[inline] | |
| fn size_hint(&self) -> (usize, Option<usize>) { (usize::MAX, None) } | |
| } | |
| fn main() { | |
| let a = iterate(0, |x| x+1); | |
| println!("{:?}", a.iter().take(10).collect::<Vec<usize>>()); | |
| //~^ ERROR no method named `iter` found | |
| } |