tests/ui/coroutine/gen_fn.none.stderr

error: expected one of `#`, `async`, `const`, `default`, `extern`, `fn`, `pub`, `unsafe`, or `use`, found `gen`
  --> $DIR/gen_fn.rs:4:1
   |
LL | gen fn foo() {}
   | ^^^ expected one of 9 possible tokens

error: aborting due to previous error