1error[E0631]: type mismatch in closure arguments
2  --> $DIR/issue-36053-2.rs:7:32
3   |
4LL |     once::<&str>("str").fuse().filter(|a: &str| true).count();
5   |                                ^^^^^^ -------------- found signature of `for<'r> fn(&'r str) -> _`
6   |                                |
7   |                                expected signature of `for<'r> fn(&'r &str) -> _`
8   |
9note: required by a bound in `filter`
10  --> $SRC_DIR/core/src/iter/traits/iterator.rs:LL:COL
11   |
12LL |         P: FnMut(&Self::Item) -> bool,
13   |            ^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `filter`
14
15error[E0599]: the method `count` exists for struct `Filter<Fuse<std::iter::Once<&str>>, [closure@$DIR/issue-36053-2.rs:7:39: 7:53]>`, but its trait bounds were not satisfied
16  --> $DIR/issue-36053-2.rs:7:55
17   |
18LL |     once::<&str>("str").fuse().filter(|a: &str| true).count();
19   |                                       --------------  ^^^^^ method cannot be called on `Filter<Fuse<std::iter::Once<&str>>, [closure@$DIR/issue-36053-2.rs:7:39: 7:53]>` due to unsatisfied trait bounds
20   |                                       |
21   |                                       doesn't satisfy `<_ as FnOnce<(&&str,)>>::Output = bool`
22   |                                       doesn't satisfy `_: FnMut<(&&str,)>`
23   |
24  ::: $SRC_DIR/core/src/iter/adapters/filter.rs:LL:COL
25   |
26LL | pub struct Filter<I, P> {
27   | ----------------------- doesn't satisfy `_: Iterator`
28   |
29   = note: the following trait bounds were not satisfied:
30           `<[closure@$DIR/issue-36053-2.rs:7:39: 7:53] as FnOnce<(&&str,)>>::Output = bool`
31           which is required by `Filter<Fuse<std::iter::Once<&str>>, [closure@$DIR/issue-36053-2.rs:7:39: 7:53]>: Iterator`
32           `[closure@$DIR/issue-36053-2.rs:7:39: 7:53]: FnMut<(&&str,)>`
33           which is required by `Filter<Fuse<std::iter::Once<&str>>, [closure@$DIR/issue-36053-2.rs:7:39: 7:53]>: Iterator`
34           `Filter<Fuse<std::iter::Once<&str>>, [closure@$DIR/issue-36053-2.rs:7:39: 7:53]>: Iterator`
35           which is required by `&mut Filter<Fuse<std::iter::Once<&str>>, [closure@$DIR/issue-36053-2.rs:7:39: 7:53]>: Iterator`
36
37error: aborting due to 2 previous errors
38
39Some errors have detailed explanations: E0599, E0631.
40For more information about an error, try `rustc --explain E0599`.
41