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Use raw pointers for downcasting, not TraitObject

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This mirrors a change in mopa.
This commit is contained in:
Chris Morgan 2016-06-11 10:46:30 +10:00
parent 0c3026f7de
commit c52281b376
1 changed files with 3 additions and 15 deletions
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18
src/any.rs
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@ -3,7 +3,6 @@
//! This stuff is all based on `std::any`, but goes a little further, with `CloneAny` being a //! This stuff is all based on `std::any`, but goes a little further, with `CloneAny` being a
//! cloneable `Any` and with the `Send` and `Sync` bounds possible on both `Any` and `CloneAny`. //! cloneable `Any` and with the `Send` and `Sync` bounds possible on both `Any` and `CloneAny`.
use std::mem;
use std::fmt; use std::fmt;
use std::any::Any as StdAny; use std::any::Any as StdAny;
@ -88,17 +87,6 @@ macro_rules! impl_clone {
} }
} }
#[cfg(feature = "unstable")]
use std::raw::TraitObject;
#[cfg(not(feature = "unstable"))]
#[repr(C)]
#[derive(Copy, Clone)]
struct TraitObject {
pub data: *mut (),
pub vtable: *mut (),
}
#[allow(missing_docs)] // Bogus warning (it’s not public outside the crate), ☹ #[allow(missing_docs)] // Bogus warning (it’s not public outside the crate), ☹
pub trait UncheckedAnyExt: Any { pub trait UncheckedAnyExt: Any {
unsafe fn downcast_ref_unchecked<T: Any>(&self) -> &T; unsafe fn downcast_ref_unchecked<T: Any>(&self) -> &T;
@ -123,15 +111,15 @@ macro_rules! implement {
impl UncheckedAnyExt for $base $(+ $bounds)* { impl UncheckedAnyExt for $base $(+ $bounds)* {
unsafe fn downcast_ref_unchecked<T: 'static>(&self) -> &T { unsafe fn downcast_ref_unchecked<T: 'static>(&self) -> &T {
mem::transmute(mem::transmute::<_, TraitObject>(self).data) &*(self as *const Self as *const T)
} }
unsafe fn downcast_mut_unchecked<T: 'static>(&mut self) -> &mut T { unsafe fn downcast_mut_unchecked<T: 'static>(&mut self) -> &mut T {
mem::transmute(mem::transmute::<_, TraitObject>(self).data) &mut *(self as *mut Self as *mut T)
} }
unsafe fn downcast_unchecked<T: 'static>(self: Box<Self>) -> Box<T> { unsafe fn downcast_unchecked<T: 'static>(self: Box<Self>) -> Box<T> {
mem::transmute(mem::transmute::<_, TraitObject>(self).data) Box::from_raw(Box::into_raw(self) as *mut T)
} }
} }