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// Copyright 2019 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#![allow(warnings)]
use std::{marker::PhantomData, option::IntoIter};
use zerocopy::Unaligned;
struct IsUnaligned<T: Unaligned>(T);
// Fail compilation if `$ty: !Unaligned`.
macro_rules! is_unaligned {
($ty:ty) => {
const _: () = {
let _: IsUnaligned<$ty>;
};
};
}
// A union is `Unaligned` if:
// - `repr(align)` is no more than 1 and either
// - `repr(C)` or `repr(transparent)` and
// - all fields `Unaligned`
// - `repr(packed)`
#[derive(Unaligned)]
#[repr(C)]
union Foo {
a: u8,
}
is_unaligned!(Foo);
// Transparent unions are unstable; see issue #60405
// <https://github.com/rust-lang/rust/issues/60405> for more information.
// #[derive(Unaligned)]
// #[repr(transparent)]
// union Bar {
// a: u8,
// }
// is_unaligned!(Bar);
#[derive(Unaligned)]
#[repr(packed)]
union Baz {
a: u16,
}
is_unaligned!(Baz);
#[derive(Unaligned)]
#[repr(C, align(1))]
union FooAlign {
a: u8,
}
is_unaligned!(FooAlign);
#[derive(Unaligned)]
#[repr(C)]
union TypeParams<'a, T: Copy, I: Iterator>
where
I::Item: Copy,
{
a: T,
c: I::Item,
d: u8,
e: PhantomData<&'a [u8]>,
f: PhantomData<&'static str>,
g: PhantomData<String>,
}
is_unaligned!(TypeParams<'static, (), IntoIter<()>>);
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