1error[E0038]: the trait `StreamingIterator` cannot be made into an object
2  --> $DIR/trait-objects.rs:10:21
3   |
4LL | fn min_size(x: &mut dyn for<'a> StreamingIterator<Item<'a> = &'a i32>) -> usize {
5   |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `StreamingIterator` cannot be made into an object
6   |
7note: for a trait to be "object safe" it needs to allow building a vtable to allow the call to be resolvable dynamically; for more information visit <https://doc.rust-lang.org/reference/items/traits.html#object-safety>
8  --> $DIR/trait-objects.rs:4:10
9   |
10LL | trait StreamingIterator {
11   |       ----------------- this trait cannot be made into an object...
12LL |     type Item<'a> where Self: 'a;
13   |          ^^^^ ...because it contains the generic associated type `Item`
14   = help: consider moving `Item` to another trait
15
16error: aborting due to previous error
17
18For more information about this error, try `rustc --explain E0038`.
19