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// Copyright 2017 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.
// To work around #46855
// compile-flags: -Z mir-opt-level=0
// Regression test for the inhabitedness of unions with uninhabited variants, issue #46845
use std::mem;
#[derive(Copy, Clone)]
enum Never { }
// A single uninhabited variant shouldn't make the whole union uninhabited.
union Foo {
a: u64,
_b: Never
}
// If all the variants are uninhabited, however, the union should be uninhabited.
union Bar {
_a: (Never, u64),
_b: (u64, Never)
}
fn main() {
assert_eq!(mem::size_of::<Foo>(), 8);
assert_eq!(mem::size_of::<Bar>(), 0);
let f = [Foo { a: 42 }, Foo { a: 10 }];
println!("{}", unsafe { f[0].a });
assert_eq!(unsafe { f[1].a }, 10);
}
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