src/test/ui/transmutability/visibility/should_accept_if_src_has_private_variant.rs

   1 // check-pass
   2 //! The presence of a private variant in the source type does not affect
   3 //! transmutability.
   4
   5 #![crate_type = "lib"]
   6 #![feature(transmutability)]
   7 #![allow(dead_code)]
   8
   9 mod assert {
  10     use std::mem::BikeshedIntrinsicFrom;
  11
  12     pub fn is_transmutable<Src, Dst, Context>()
  13     where
  14         Dst: BikeshedIntrinsicFrom<Src, Context> // safety is NOT assumed
  15     {}
  16 }
  17
  18 mod src {
  19     #[derive(Copy, Clone)]
  20     #[repr(C)] pub(in super) struct Zst;
  21
  22     #[repr(C)] pub(in super) union Src {
  23         pub(self) field: Zst, // <- private variant
  24     }
  25 }
  26
  27 mod dst {
  28     #[repr(C)] pub(in super) struct Zst;
  29
  30     #[repr(C)] pub(in super) struct Dst {
  31         pub(in super) field: Zst,
  32     }
  33 }
  34
  35 fn test() {
  36     struct Context;
  37     assert::is_transmutable::<src::Src, dst::Dst, Context>();
  38 }