src/test/ui/union/union-trait-impl.rs

   1 // run-pass
   2
   3 use std::fmt;
   4
   5 union U {
   6     a: u8
   7 }
   8
   9 impl fmt::Display for U {
  10     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
  11         unsafe { write!(f, "Oh hai {}", self.a) }
  12     }
  13 }
  14
  15 fn main() {
  16     assert_eq!(U { a: 2 }.to_string(), "Oh hai 2");
  17 }