| // Copyright 2019 The Fuchsia Authors |
| // |
| // Licensed under a BSD-style license <LICENSE-BSD>, Apache License, Version 2.0 |
| // <LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0>, or the MIT |
| // license <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your option. |
| // 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); |