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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)]
#[macro_use]
mod util;
use std::{marker::PhantomData, option::IntoIter};
use {static_assertions::assert_impl_all, zerocopy::FromZeroes};
// A union is `FromZeroes` if:
// - all fields are `FromZeroes`
#[derive(Clone, Copy, FromZeroes)]
union Zst {
a: (),
}
assert_impl_all!(Zst: FromZeroes);
#[derive(FromZeroes)]
union One {
a: bool,
}
assert_impl_all!(One: FromZeroes);
#[derive(FromZeroes)]
union Two {
a: bool,
b: Zst,
}
assert_impl_all!(Two: FromZeroes);
#[derive(FromZeroes)]
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>,
}
assert_impl_all!(TypeParams<'static, (), IntoIter<()>>: FromZeroes);
// Deriving `FromZeroes` should work if the union has bounded parameters.
#[derive(FromZeroes)]
#[repr(C)]
union WithParams<'a: 'b, 'b: 'a, const N: usize, T: 'a + 'b + FromZeroes>
where
'a: 'b,
'b: 'a,
T: 'a + 'b + Copy + FromZeroes,
{
a: [T; N],
b: PhantomData<&'a &'b ()>,
}
assert_impl_all!(WithParams<'static, 'static, 42, u8>: FromZeroes);