| /// Creates a new closure that returns an iterator where each iteration steps the given |
| /// generator to the next `yield` statement. |
| /// |
| /// Similar to [`iter::from_fn`], but allows arbitrary control flow. |
| /// |
| /// [`iter::from_fn`]: crate::iter::from_fn |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// #![feature(iter_macro, coroutines)] |
| /// |
| /// let it = std::iter::iter!{|| { |
| /// yield 1; |
| /// yield 2; |
| /// yield 3; |
| /// } }(); |
| /// let v: Vec<_> = it.collect(); |
| /// assert_eq!(v, [1, 2, 3]); |
| /// ``` |
| #[unstable(feature = "iter_macro", issue = "142269", reason = "generators are unstable")] |
| #[allow_internal_unstable(coroutines, iter_from_coroutine)] |
| #[rustc_builtin_macro] |
| pub macro iter($($t:tt)*) { |
| /* compiler-builtin */ |
| } |
