123456789101112131415161718192021222324252627282930
// 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) } } }