error[E0747]: constant provided when a type was expected
  --> $DIR/generic-function-item-where-type.rs:4:11
   |
LL |     foo::<main>()
   |           ^^^^
   |
   = help: `main` is a function item, not a type
   = help: function item types cannot be named directly

error: aborting due to previous error

For more information about this error, try `rustc --explain E0747`.