1/// Creates a new closure that returns an iterator where each iteration steps the given
2/// generator to the next `yield` statement.
3///
4/// Similar to [`iter::from_fn`], but allows arbitrary control flow.
5///
6/// [`iter::from_fn`]: crate::iter::from_fn
7///
8/// # Examples
9///
10/// ```
11/// #![feature(iter_macro, coroutines)]
12///
13/// let it = std::iter::iter!{|| {
14/// yield 1;
15/// yield 2;
16/// yield 3;
17/// } }();
18/// let v: Vec<_> = it.collect();
19/// assert_eq!(v, [1, 2, 3]);
20/// ```
21#[unstable(feature = "iter_macro", issue = "none", reason = "generators are unstable")]
22#[allow_internal_unstable(coroutines, iter_from_coroutine)]
23#[rustc_builtin_macro]
24pub macro iter($($t:tt)*) {
25 /* compiler-builtin */
26}
27