src/test/ui/pattern/usefulness/refutable-pattern-in-fn-arg.stderr

   1 error[E0005]: refutable pattern in function argument: `_` not covered
   2   --> $DIR/refutable-pattern-in-fn-arg.rs:2:14
   3    |
   4 LL |     let f = |3: isize| println!("hello");
   5    |              ^ pattern `_` not covered
   6    |
   7    = note: the matched value is of type `isize`
   8
   9 error: aborting due to previous error
  10
  11 For more information about this error, try `rustc --explain E0005`.