diff options
| -rw-r--r-- | src/liballoc/boxed.rs | 27 | ||||
| -rw-r--r-- | src/librustc_typeck/coherence/orphan.rs | 5 |
2 files changed, 29 insertions, 3 deletions
diff --git a/src/liballoc/boxed.rs b/src/liballoc/boxed.rs index 74f0599e486..41541619945 100644 --- a/src/liballoc/boxed.rs +++ b/src/liballoc/boxed.rs @@ -10,6 +10,8 @@ //! A unique pointer type. +#![stable] + use core::any::{Any, AnyRefExt}; use core::clone::Clone; use core::cmp::{PartialEq, PartialOrd, Eq, Ord, Ordering}; @@ -44,7 +46,7 @@ pub static HEAP: () = (); /// A type that represents a uniquely-owned value. #[lang = "owned_box"] -#[unstable = "custom allocators will add an additional type parameter (with default)"] +#[stable] pub struct Box<T>(Unique<T>); #[stable] @@ -111,18 +113,37 @@ impl<S: hash::Writer, Sized? T: Hash<S>> Hash<S> for Box<T> { } } +#[cfg(not(stage0))] +impl Box<Any> { + pub fn downcast<T: 'static>(self) -> Result<Box<T>, Box<Any>> { + if self.is::<T>() { + unsafe { + // Get the raw representation of the trait object + let to: TraitObject = + mem::transmute::<Box<Any>, TraitObject>(self); + + // Extract the data pointer + Ok(mem::transmute(to.data)) + } + } else { + Err(self) + } + } +} /// Extension methods for an owning `Any` trait object. #[unstable = "post-DST and coherence changes, this will not be a trait but \ rather a direct `impl` on `Box<Any>`"] +#[cfg(stage0)] pub trait BoxAny { /// Returns the boxed value if it is of type `T`, or /// `Err(Self)` if it isn't. - #[unstable = "naming conventions around accessing innards may change"] + #[stable] fn downcast<T: 'static>(self) -> Result<Box<T>, Self>; } #[stable] +#[cfg(stage0)] impl BoxAny for Box<Any> { #[inline] fn downcast<T: 'static>(self) -> Result<Box<T>, Box<Any>> { @@ -147,7 +168,7 @@ impl<Sized? T: fmt::Show> fmt::Show for Box<T> { } } -impl fmt::Show for Box<Any+'static> { +impl fmt::Show for Box<Any> { fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { f.pad("Box<Any>") } diff --git a/src/librustc_typeck/coherence/orphan.rs b/src/librustc_typeck/coherence/orphan.rs index 79443200ddf..49f150cf027 100644 --- a/src/librustc_typeck/coherence/orphan.rs +++ b/src/librustc_typeck/coherence/orphan.rs @@ -57,6 +57,11 @@ impl<'cx, 'tcx,'v> visit::Visitor<'v> for OrphanChecker<'cx, 'tcx> { ty::ty_trait(ref data) => { self.check_def_id(item.span, data.principal_def_id()); } + ty::ty_uniq(..) => { + self.check_def_id(item.span, + self.tcx.lang_items.owned_box() + .unwrap()); + } _ => { span_err!(self.tcx.sess, item.span, E0118, "no base type found for inherent implementation; \ |