error[E0310]: the parameter type `T` may not live long enough
  --> $DIR/projection-implied-bounds.rs:30:18
   |
LL | fn generic2<T: Iterator>(value: T) {
   |             -- help: consider adding an explicit lifetime bound...: `T: 'static +`
LL |     twice(value, |value_ref, item| invoke2(value_ref, item));
   |                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ...so that the type `T` will meet its required lifetime bounds

error: aborting due to previous error

For more information about this error, try `rustc --explain E0310`.