| // Copyright 2018 The Rust Project Developers. See the COPYRIGHT |
| // file at the top-level directory of this distribution and at |
| // http://rust-lang.org/COPYRIGHT. |
| // |
| // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or |
| // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your |
| // option. This file may not be copied, modified, or distributed |
| // except according to those terms. |
| |
| union DummyUnion { |
| u8: u8, |
| bool: bool, |
| } |
| |
| #[repr(C)] |
| #[derive(Copy, Clone)] |
| enum Enum { |
| A, |
| B, |
| C, |
| } |
| |
| #[derive(Copy, Clone)] |
| union Foo { |
| a: bool, |
| b: Enum, |
| } |
| |
| union Bar { |
| foo: Foo, |
| u8: u8, |
| } |
| |
| // the value is not valid for bools |
| const BAD_BOOL: bool = unsafe { DummyUnion { u8: 42 }.bool}; |
| //~^ ERROR this constant likely exhibits undefined behavior |
| |
| // The value is not valid for any union variant, but that's fine |
| // unions are just a convenient way to transmute bits around |
| const BAD_UNION: Foo = unsafe { Bar { u8: 42 }.foo }; |
| |
| |
| fn main() { |
| } |
