error: `yield` can only be used in `#[coroutine]` closures, or `gen` blocks
  --> $DIR/yield-in-function.rs:3:13
   |
LL | fn main() { yield; }
   |             ^^^^^
   |
help: use `#[coroutine]` to make this closure a coroutine
   |
LL | #[coroutine] fn main() { yield; }
   | ++++++++++++

error[E0627]: yield expression outside of coroutine literal
  --> $DIR/yield-in-function.rs:3:13
   |
LL | fn main() { yield; }
   |             ^^^^^

error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0627`.