1 error[E0271]: type mismatch resolving `<Adapter<I> as Iterator>::Item == Option<T>`
2 --> $DIR/associated-types-issue-20346.rs:34:5
4 LL | fn is_iterator_of<A, I: Iterator<Item=A>>(_: &I) {}
5 | ------ required by this bound in `is_iterator_of`
7 LL | fn test_adapter<T, I: Iterator<Item=Option<T>>>(it: I) {
8 | - this type parameter
10 LL | is_iterator_of::<Option<T>, _>(&adapter);
11 | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected enum `Option`, found type parameter `T`
13 = note: expected enum `Option<T>`
16 error: aborting due to previous error
18 For more information about this error, try `rustc --explain E0271`.