#[cfg(test)]
extern crate test;
-use std::any::{Any, AnyRefExt, AnyMutRefExt};
+use std::any::Any;
use std::intrinsics::TypeId;
use std::collections::HashMap;
use std::hash::{Hash, Hasher, Writer};
+use std::mem::{transmute, transmute_copy};
+use std::raw::TraitObject;
struct TypeIdHasher;
debug_assert!(bytes.len() == 8);
unsafe {
std::ptr::copy_nonoverlapping_memory(&mut self.value,
- std::mem::transmute(&bytes[0]),
+ transmute(&bytes[0]),
1)
}
}
}
}
+/// An extension of `AnyRefExt` allowing unchecked downcasting of trait objects to `&T`.
+trait UncheckedAnyRefExt<'a> {
+ /// Returns a reference to the boxed value, assuming that it is of type `T`. This should only be
+ /// called if you are ABSOLUTELY CERTAIN of `T` as you will get really wacky output if it’s not.
+ unsafe fn as_ref_unchecked<T: 'static>(self) -> &'a T;
+}
+
+impl<'a> UncheckedAnyRefExt<'a> for &'a Any {
+ #[inline]
+ unsafe fn as_ref_unchecked<T: 'static>(self) -> &'a T {
+ // Get the raw representation of the trait object
+ let to: TraitObject = transmute_copy(&self);
+
+ // Extract the data pointer
+ transmute(to.data)
+ }
+}
+
+/// An extension of `AnyMutRefExt` allowing unchecked downcasting of trait objects to `&mut T`.
+trait UncheckedAnyMutRefExt<'a> {
+ /// Returns a reference to the boxed value, assuming that it is of type `T`. This should only be
+ /// called if you are ABSOLUTELY CERTAIN of `T` as you will get really wacky output if it’s not.
+ unsafe fn as_mut_unchecked<T: 'static>(self) -> &'a mut T;
+}
+
+impl<'a> UncheckedAnyMutRefExt<'a> for &'a mut Any {
+ #[inline]
+ unsafe fn as_mut_unchecked<T: 'static>(self) -> &'a mut T {
+ // Get the raw representation of the trait object
+ let to: TraitObject = transmute_copy(&self);
+
+ // Extract the data pointer
+ transmute(to.data)
+ }
+}
+
/// A map containing zero or one values for any given type and allowing convenient,
/// type-safe access to those values.
///
impl AnyMap {
/// Retrieve the value stored in the map for the type `T`, if it exists.
pub fn find<'a, T: 'static>(&'a self) -> Option<&'a T> {
- self.data.find(&TypeId::of::<T>()).and_then(|any| any.as_ref::<T>())
+ self.data.find(&TypeId::of::<T>()).map(|any| unsafe { any.as_ref_unchecked::<T>() })
}
/// Retrieve a mutable reference to the value stored in the map for the type `T`, if it exists.
pub fn find_mut<'a, T: 'static>(&'a mut self) -> Option<&'a mut T> {
- self.data.find_mut(&TypeId::of::<T>()).and_then(|any| any.as_mut::<T>())
+ self.data.find_mut(&TypeId::of::<T>()).map(|any| unsafe { any.as_mut_unchecked::<T>() })
}
/// Set the value contained in the map for the type `T`.