error[E0133]: call to unsafe function is unsafe and requires unsafe function or block
 --> tests/ui/missing_unsafe.rs:4:12
  |
4 |         fn f(x: i32);
  |            ^        - items do not inherit unsafety from separate enclosing items
  |            |
  |            call to unsafe function
  |
  = note: consult the function's documentation for information on how to avoid undefined behavior