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// SPDX-License-Identifier: Apache-2.0 OR MIT
//! Rust standard library vendored code.
//!
//! The contents of this file come from the Rust standard library, hosted in
//! the <https://github.com/rust-lang/rust> repository, licensed under
//! "Apache-2.0 OR MIT" and adapted for kernel use. For copyright details,
//! see <https://github.com/rust-lang/rust/blob/master/COPYRIGHT>.
use crate::sync::{arc::ArcInner, Arc};
use core::any::Any;
impl Arc<dyn Any + Send + Sync> {
/// Attempt to downcast the `Arc<dyn Any + Send + Sync>` to a concrete type.
pub fn downcast<T>(self) -> core::result::Result<Arc<T>, Self>
where
T: Any + Send + Sync,
{
if (*self).is::<T>() {
// SAFETY: We have just checked that the type is correct, so we can cast the pointer.
unsafe {
let ptr = self.ptr.cast::<ArcInner<T>>();
core::mem::forget(self);
Ok(Arc::from_inner(ptr))
}
} else {
Err(self)
}
}
}
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