src/test/ui/consts/control-flow/try.rs

   1 // The `?` operator is still not const-evaluatable because it calls `From::from` on the error
   2 // variant.
   3
   4 const fn opt() -> Option<i32> {
   5     let x = Some(2);
   6     x?; //~ ERROR `?` is not allowed in a `const fn`
   7     None
   8 }
   9
  10 fn main() {}