diff options
Diffstat (limited to 'src/test/ui/transmutability/unions/should_reject_intersecting.rs')
-rw-r--r-- | src/test/ui/transmutability/unions/should_reject_intersecting.rs | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/src/test/ui/transmutability/unions/should_reject_intersecting.rs b/src/test/ui/transmutability/unions/should_reject_intersecting.rs new file mode 100644 index 000000000..58e399fb9 --- /dev/null +++ b/src/test/ui/transmutability/unions/should_reject_intersecting.rs @@ -0,0 +1,38 @@ +//! ALL valid bit patterns of the source must be valid bit patterns of the +//! destination type, unless validity is assumed. + +#![crate_type = "lib"] +#![feature(transmutability)] +#![allow(dead_code, incomplete_features, non_camel_case_types)] + +mod assert { + use std::mem::BikeshedIntrinsicFrom; + pub struct Context; + + pub fn is_transmutable<Src, Dst>() + where + Dst: BikeshedIntrinsicFrom<Src, Context, false, false, false, true> + // validity is NOT assumed ----------------------------^^^^^ + {} +} + +#[derive(Clone, Copy)] #[repr(u8)] enum Ox00 { V = 0x00 } +#[derive(Clone, Copy)] #[repr(u8)] enum Ox7F { V = 0x7F } +#[derive(Clone, Copy)] #[repr(u8)] enum OxFF { V = 0xFF } + +fn test() { + #[repr(C)] + union A { + a: Ox00, + b: Ox7F, + } + + #[repr(C)] + union B { + a: Ox7F, + b: OxFF, + } + + assert::is_transmutable::<A, B>(); //~ ERROR cannot be safely transmuted + assert::is_transmutable::<B, A>(); //~ ERROR cannot be safely transmuted +} |