error: expected 1 argument(s), found 0
 --> tests/compile-fail/surface_missing_args.rs:5:9
  |
5 |         source_iter() -> for_each();
  |         ^^^^^^^^^^^^^

error: expected 1 argument(s), found 0
 --> tests/compile-fail/surface_missing_args.rs:5:26
  |
5 |         source_iter() -> for_each();
  |                          ^^^^^^^^^^