error: implementation of `FnMut` is not general enough
  --> $DIR/higher-ranked-lifetime-error.rs:12:5
   |
LL |     assert_all::<_, &String>(id);
   |     ^^^^^^^^^^^^^^^^^^^^^^^^ implementation of `FnMut` is not general enough
   |
   = note: `for<'a> fn(&'a String) -> &'a String {id}` must implement `FnMut<(&String,)>`
   = note: ...but it actually implements `FnMut<(&'0 String,)>`, for some specific lifetime `'0`

error: aborting due to 1 previous error