diff options
Diffstat (limited to 'tests/ui/transmutability/arrays/should_require_well_defined_layout.rs')
-rw-r--r-- | tests/ui/transmutability/arrays/should_require_well_defined_layout.rs | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/tests/ui/transmutability/arrays/should_require_well_defined_layout.rs b/tests/ui/transmutability/arrays/should_require_well_defined_layout.rs new file mode 100644 index 000000000..853bd9cbc --- /dev/null +++ b/tests/ui/transmutability/arrays/should_require_well_defined_layout.rs @@ -0,0 +1,66 @@ +//! An array must have a well-defined layout to participate in a transmutation. + +#![crate_type = "lib"] +#![feature(transmutability)] +#![allow(dead_code, incomplete_features, non_camel_case_types)] + +mod assert { + use std::mem::{Assume, BikeshedIntrinsicFrom}; + pub struct Context; + + pub fn is_maybe_transmutable<Src, Dst>() + where + Dst: BikeshedIntrinsicFrom<Src, Context, { + Assume::ALIGNMENT + .and(Assume::LIFETIMES) + .and(Assume::SAFETY) + .and(Assume::VALIDITY) + }> + {} +} + +fn should_reject_repr_rust() +{ + fn unit() { + type repr_rust = [String; 0]; + assert::is_maybe_transmutable::<repr_rust, ()>(); //~ ERROR cannot be safely transmuted + assert::is_maybe_transmutable::<u128, repr_rust>(); //~ ERROR cannot be safely transmuted + } + + fn singleton() { + type repr_rust = [String; 1]; + assert::is_maybe_transmutable::<repr_rust, ()>(); //~ ERROR cannot be safely transmuted + assert::is_maybe_transmutable::<u128, repr_rust>(); //~ ERROR cannot be safely transmuted + } + + fn duplex() { + type repr_rust = [String; 2]; + assert::is_maybe_transmutable::<repr_rust, ()>(); //~ ERROR cannot be safely transmuted + assert::is_maybe_transmutable::<u128, repr_rust>(); //~ ERROR cannot be safely transmuted + } +} + +fn should_accept_repr_C() +{ + fn unit() { + #[repr(C)] struct repr_c(u8, u16, u8); + type array = [repr_c; 0]; + assert::is_maybe_transmutable::<array, ()>(); + assert::is_maybe_transmutable::<i128, array>(); + } + + fn singleton() { + #[repr(C)] struct repr_c(u8, u16, u8); + type array = [repr_c; 1]; + assert::is_maybe_transmutable::<array, repr_c>(); + assert::is_maybe_transmutable::<repr_c, array>(); + } + + fn duplex() { + #[repr(C)] struct repr_c(u8, u16, u8); + #[repr(C)] struct duplex(repr_c, repr_c); + type array = [repr_c; 2]; + assert::is_maybe_transmutable::<array, duplex>(); + assert::is_maybe_transmutable::<duplex, array>(); + } +} |