extern crate test;
use std::any::Any;
-use std::intrinsics::TypeId;
+use std::intrinsics::{forget, TypeId};
use std::collections::HashMap;
use std::hash::{Hash, Hasher, Writer};
use std::mem::{transmute, transmute_copy};
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;
+ unsafe fn downcast_ref_unchecked<T: 'static>(self) -> &'a T;
}
impl<'a> UncheckedAnyRefExt<'a> for &'a Any + 'a {
#[inline]
- unsafe fn as_ref_unchecked<T: 'static>(self) -> &'a T {
+ unsafe fn downcast_ref_unchecked<T: 'static>(self) -> &'a T {
// Get the raw representation of the trait object
let to: TraitObject = transmute_copy(&self);
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;
+ unsafe fn downcast_mut_unchecked<T: 'static>(self) -> &'a mut T;
}
impl<'a> UncheckedAnyMutRefExt<'a> for &'a mut Any + 'a {
#[inline]
- unsafe fn as_mut_unchecked<T: 'static>(self) -> &'a mut T {
+ unsafe fn downcast_mut_unchecked<T: 'static>(self) -> &'a mut T {
// Get the raw representation of the trait object
let to: TraitObject = transmute_copy(&self);
}
}
+/// An extension of `BoxAny` allowing unchecked downcasting of trait objects to `Box<T>`.
+trait UncheckedBoxAny {
+ /// Returns 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 downcast_unchecked<T: 'static>(self) -> Box<T>;
+}
+
+impl UncheckedBoxAny for Box<Any + 'static> {
+ #[inline]
+ unsafe fn downcast_unchecked<T: 'static>(self) -> Box<T> {
+ // Get the raw representation of the trait object
+ let to: TraitObject = *transmute::<&Box<Any>, &TraitObject>(&self);
+
+ // Prevent destructor on self being run
+ forget(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.
///
/// ```rust
/// # use anymap::AnyMap;
/// let mut data = AnyMap::new();
-/// assert_eq!(data.find(), None::<&int>);
+/// assert_eq!(data.get(), None::<&int>);
/// data.insert(42i);
-/// assert_eq!(data.find(), Some(&42i));
+/// assert_eq!(data.get(), Some(&42i));
/// data.remove::<int>();
-/// assert_eq!(data.find::<int>(), None);
+/// assert_eq!(data.get::<int>(), None);
///
/// #[deriving(PartialEq, Show)]
/// struct Foo {
/// str: String,
/// }
///
-/// assert_eq!(data.find::<Foo>(), None);
+/// assert_eq!(data.get::<Foo>(), None);
/// data.insert(Foo { str: "foo".to_string() });
-/// assert_eq!(data.find(), Some(&Foo { str: "foo".to_string() }));
-/// data.find_mut::<Foo>().map(|foo| foo.str.push('t'));
-/// assert_eq!(data.find::<Foo>().unwrap().str.as_slice(), "foot");
+/// assert_eq!(data.get(), Some(&Foo { str: "foo".to_string() }));
+/// data.get_mut::<Foo>().map(|foo| foo.str.push('t'));
+/// assert_eq!(data.get::<Foo>().unwrap().str.as_slice(), "foot");
/// ```
///
/// Values containing non-static references are not permitted.
}
impl AnyMap {
- /// Retrieve the value stored in the map for the type `T`, if it exists.
+ /// Deprecated: Renamed to `get`.
+ #[deprecated = "Renamed to `get`"]
pub fn find<T: Any + 'static>(&self) -> Option<&T> {
- self.data.find(&TypeId::of::<T>()).map(|any| unsafe { any.as_ref_unchecked::<T>() })
+ self.get::<T>()
}
- /// Retrieve a mutable reference to the value stored in the map for the type `T`, if it exists.
+ /// Deprecated: Renamed to `get_mut`.
+ #[deprecated = "Renamed to `get_mut`"]
pub fn find_mut<T: Any + 'static>(&mut self) -> Option<&mut T> {
- self.data.find_mut(&TypeId::of::<T>()).map(|any| unsafe { any.as_mut_unchecked::<T>() })
+ self.get_mut::<T>()
+ }
+
+ /// Retrieve the value stored in the map for the type `T`, if it exists.
+ pub fn get<T: Any + 'static>(&self) -> Option<&T> {
+ self.data.get(&TypeId::of::<T>())
+ .map(|any| unsafe { any.downcast_ref_unchecked::<T>() })
+ }
+
+ /// Retrieve a mutable reference to the value stored in the map for the type `T`, if it exists.
+ pub fn get_mut<T: Any + 'static>(&mut self) -> Option<&mut T> {
+ self.data.get_mut(&TypeId::of::<T>())
+ .map(|any| unsafe { any.downcast_mut_unchecked::<T>() })
}
/// Set the value contained in the map for the type `T`.
- /// This will override any previous value stored.
- pub fn insert<T: Any + 'static>(&mut self, value: T) {
- self.data.insert(TypeId::of::<T>(), box value as Box<Any>);
+ /// If there is a previous value stored, it will be returned.
+ pub fn insert<T: Any + 'static>(&mut self, value: T) -> Option<T> {
+ self.data.insert(TypeId::of::<T>(), box value as Box<Any>)
+ .map(|any| *unsafe { any.downcast_unchecked::<T>() })
}
- /// Remove the value for the type `T` if it existed.
- pub fn remove<T: Any + 'static>(&mut self) {
- self.data.remove(&TypeId::of::<T>());
+ /// Remove and return the value for the type `T` if it existed.
+ pub fn remove<T: Any + 'static>(&mut self) -> Option<T> {
+ self.data.remove(&TypeId::of::<T>())
+ .map(|any| *unsafe { any.downcast_unchecked::<T>() })
}
/// Does a value of type `T` exist?
b.iter(|| {
let mut data = AnyMap::new();
for _ in range(0u, 100) {
- data.insert(42i);
+ let _ = data.insert(42i);
}
})
}
#[bench]
-fn bench_find_missing(b: &mut ::test::Bencher) {
+fn bench_get_missing(b: &mut ::test::Bencher) {
b.iter(|| {
let data = AnyMap::new();
for _ in range(0u, 100) {
- assert_eq!(data.find(), None::<&int>);
+ assert_eq!(data.get(), None::<&int>);
}
})
}
#[bench]
-fn bench_find_present(b: &mut ::test::Bencher) {
+fn bench_get_present(b: &mut ::test::Bencher) {
b.iter(|| {
let mut data = AnyMap::new();
- data.insert(42i);
+ let _ = data.insert(42i);
// These inner loops are a feeble attempt to drown the other factors.
for _ in range(0u, 100) {
- assert_eq!(data.find(), Some(&42i));
+ assert_eq!(data.get(), Some(&42i));
}
})
}