diff options
Diffstat (limited to 'tests/ui/transmutability/visibility/should_reject_if_dst_has_unreachable_field.rs')
-rw-r--r-- | tests/ui/transmutability/visibility/should_reject_if_dst_has_unreachable_field.rs | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/tests/ui/transmutability/visibility/should_reject_if_dst_has_unreachable_field.rs b/tests/ui/transmutability/visibility/should_reject_if_dst_has_unreachable_field.rs new file mode 100644 index 000000000..d7e21676f --- /dev/null +++ b/tests/ui/transmutability/visibility/should_reject_if_dst_has_unreachable_field.rs @@ -0,0 +1,38 @@ +//! Unless visibility is assumed, a transmutation should be rejected if the +//! destination type contains an unreachable field (e.g., a public field with a +//! private type). (This rule is distinct from type privacy, which still may +//! forbid naming such types.) + +#![crate_type = "lib"] +#![feature(transmutability)] +#![allow(dead_code)] + +mod assert { + use std::mem::BikeshedIntrinsicFrom; + + pub fn is_transmutable<Src, Dst, Context>() + where + Dst: BikeshedIntrinsicFrom<Src, Context> // safety is NOT assumed + {} +} + +mod src { + #[repr(C)] pub(in super) struct Zst; + + #[repr(C)] pub(in super) struct Src { + pub(in super) field: Zst, + } +} + +mod dst { + #[repr(C)] pub(self) struct Zst; // <- unreachable type + + #[repr(C)] pub(in super) struct Dst { + pub(in super) field: Zst, + } +} + +fn test() { + struct Context; + assert::is_transmutable::<src::Src, dst::Dst, Context>(); //~ ERROR cannot be safely transmuted +} |