| //! 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 fn is_maybe_transmutable<Src, Dst>() |
| where |
| Dst: BikeshedIntrinsicFrom<Src, { |
| 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>(); |
| } |
| } |