error[E0283]: type annotations needed
  --> $DIR/leak-check-in-selection-2.rs:17:5
   |
LL |     impls_trait::<(), _>();
   |     ^^^^^^^^^^^^^^^^^^^^ cannot infer type of the type parameter `U` declared on the function `impls_trait`
   |
note: multiple `impl`s satisfying `for<'a> (): Trait<&'a str, _>` found
  --> $DIR/leak-check-in-selection-2.rs:10:1
   |
LL | impl<'a> Trait<&'a str, &'a str> for () {}
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
LL |
LL | impl<'a> Trait<&'a str, String> for () {}
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
note: required by a bound in `impls_trait`
  --> $DIR/leak-check-in-selection-2.rs:14:19
   |
LL | fn impls_trait<T: for<'a> Trait<&'a str, U>, U>() {}
   |                   ^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `impls_trait`

error: aborting due to 1 previous error

For more information about this error, try `rustc --explain E0283`.