src/test/ui/union/union-copy.rs

   1 #[derive(Clone)]
   2 union U {
   3     a: u8
   4 }
   5
   6 #[derive(Clone)]
   7 union W {
   8     a: std::mem::ManuallyDrop<String>
   9 }
  10
  11 impl Copy for U {} // OK
  12 impl Copy for W {} //~ ERROR the trait `Copy` may not be implemented for this type
  13
  14 fn main() {}