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// Copyright 2022 Google LLC
// Licensed under the 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.
// Copied from https://github.com/rust-lang/rust/pull/97629
#[derive(Default)]
#[repr(transparent)]
pub struct Exclusive<T> {
inner: T,
}
// Safety: 'inner' is inaccessible from a shared ref
unsafe impl<T> Sync for Exclusive<T> {}
impl<T> std::panic::UnwindSafe for Exclusive<T> {}
impl<T> std::panic::RefUnwindSafe for Exclusive<T> {}
impl<T> std::fmt::Debug for Exclusive<T> {
fn fmt(
&self, f: &mut std::fmt::Formatter<'_>,
) -> Result<(), std::fmt::Error> {
f.debug_struct("Exclusive").finish_non_exhaustive()
}
}
impl<T> Exclusive<T> {
/// Wrap a value in an `Exclusive`
#[must_use]
pub const fn new(t: T) -> Self {
Self { inner: t }
}
/// Get exclusive access to the underlying value.
#[must_use]
pub fn get_mut(&mut self) -> &mut T {
&mut self.inner
}
}