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// Copyright 2019 The Fuchsia Authors
//
// Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0
// This file may not be copied, modified, or distributed except according to
// those terms.
#![allow(warnings)]
mod util;
use std::{marker::PhantomData, option::IntoIter};
use {static_assertions::assert_impl_all, zerocopy::Unaligned};
use crate::util::AU16;
// A struct 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)]
struct Foo {
a: u8,
}
assert_impl_all!(Foo: Unaligned);
#[derive(Unaligned)]
#[repr(transparent)]
struct Bar {
a: u8,
}
assert_impl_all!(Bar: Unaligned);
#[derive(Unaligned)]
#[repr(packed)]
struct Baz {
// NOTE: The `u16` type is not guaranteed to have alignment 2, although it
// does on many platforms. However, to fix this would require a custom type
// with a `#[repr(align(2))]` attribute, and `#[repr(packed)]` types are not
// allowed to transitively contain `#[repr(align(...))]` types. Thus, we
// have no choice but to use `u16` here. Luckily, these tests run in CI on
// platforms on which `u16` has alignment 2, so this isn't that big of a
// deal.
a: u16,
}
assert_impl_all!(Baz: Unaligned);
#[derive(Unaligned)]
#[repr(C, align(1))]
struct FooAlign {
a: u8,
}
assert_impl_all!(FooAlign: Unaligned);
#[derive(Unaligned)]
#[repr(transparent)]
struct Unsized {
a: [u8],
}
assert_impl_all!(Unsized: Unaligned);
#[derive(Unaligned)]
#[repr(C)]
struct TypeParams<'a, T: ?Sized, I: Iterator> {
a: I::Item,
b: u8,
c: PhantomData<&'a [u8]>,
d: PhantomData<&'static str>,
e: PhantomData<String>,
f: T,
}
assert_impl_all!(TypeParams<'static, (), IntoIter<()>>: Unaligned);
assert_impl_all!(TypeParams<'static, u8, IntoIter<()>>: Unaligned);
assert_impl_all!(TypeParams<'static, [u8], IntoIter<()>>: Unaligned);
// Deriving `Unaligned` should work if the struct has bounded parameters.
#[derive(Unaligned)]
#[repr(transparent)]
struct WithParams<'a: 'b, 'b: 'a, const N: usize, T: 'a + 'b + Unaligned>(
[T; N],
PhantomData<&'a &'b ()>,
)
where
'a: 'b,
'b: 'a,
T: 'a + 'b + Unaligned;
assert_impl_all!(WithParams<'static, 'static, 42, u8>: Unaligned);