diff options
Diffstat (limited to 'src/test/ui/transmutability/enums/should_respect_endianness.rs')
-rw-r--r-- | src/test/ui/transmutability/enums/should_respect_endianness.rs | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/src/test/ui/transmutability/enums/should_respect_endianness.rs b/src/test/ui/transmutability/enums/should_respect_endianness.rs new file mode 100644 index 000000000..67a3c4e94 --- /dev/null +++ b/src/test/ui/transmutability/enums/should_respect_endianness.rs @@ -0,0 +1,33 @@ +//! The target endianness should be a consideration in computing the layout of +//! an enum with a multi-byte tag. + +#![crate_type = "lib"] +#![feature(arbitrary_enum_discriminant)] +#![feature(transmutability)] +#![allow(dead_code)] + +mod assert { + use std::mem::BikeshedIntrinsicFrom; + pub struct Context; + + pub fn is_transmutable<Src, Dst>() + where + Dst: BikeshedIntrinsicFrom<Src, Context, true, true, true, true> + {} +} + +#[repr(u16)] enum Src { V = 0xCAFE } + +#[repr(u8)] enum OxCA { V = 0xCA } +#[repr(u8)] enum OxFE { V = 0xFE } + +#[cfg(target_endian = "big")] #[repr(C)] struct Expected(OxCA, OxFE); +#[cfg(target_endian = "big")] #[repr(C)] struct Unexpected(OxFE, OxCA); + +#[cfg(target_endian = "little")] #[repr(C)] struct Expected(OxFE, OxCA); +#[cfg(target_endian = "little")] #[repr(C)] struct Unexpected(OxCA, OxFE); + +fn should_respect_endianness() { + assert::is_transmutable::<Src, Expected>(); + assert::is_transmutable::<Src, Unexpected>(); //~ ERROR cannot be safely transmuted +} |