src/test/ui/typeck/issue-89856.rs

   1 fn take_str_maybe(x: Option<&str>) -> Option<&str> { None }
   2
   3 fn main() {
   4     let string = String::from("Hello, world");
   5     let option = Some(&string);
   6     take_str_maybe(option);
   7     //~^ ERROR: mismatched types [E0308]
   8 }