error: generic parameters on `where` clauses are reserved for future use
  --> $DIR/where_with_bound.rs:1:19
   |
LL | fn foo<T>() where <T>::Item: ToString, T: Iterator { }
   |                   ^^^ currently unsupported

error[E0412]: cannot find type `Item` in the crate root
  --> $DIR/where_with_bound.rs:1:24
   |
LL | fn foo<T>() where <T>::Item: ToString, T: Iterator { }
   |                        ^^^^ not found in the crate root

error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0412`.