X-Git-Url: https://git.chrismorgan.info/anymap/blobdiff_plain/6bd64ec0703e63441de187902de9f272c59f47cc..7dc36adf24d48394bcb9d0aa802746e3d4a1f564:/src/lib.rs

diff --git a/src/lib.rs b/src/lib.rs
index 2d03c56..0c71e36 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,20 +1,21 @@
 //! This crate provides the `AnyMap` type, a safe and convenient store for one value of each type.
 
-#![crate_id = "anymap#0.9"]
-#![crate_type = "rlib"]
-#![crate_type = "dylib"]
+#![crate_name = "anymap"]
+#![crate_type = "lib"]
 #![feature(default_type_params)]
 #![warn(unnecessary_qualification, non_uppercase_statics,
         variant_size_difference, managed_heap_memory, unnecessary_typecast,
-        missing_doc, unused_result, deprecated_owned_vector)]
+        missing_doc, unused_result)]
 
 #[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::collections::{Collection, HashMap, Mutable};
 use std::hash::{Hash, Hasher, Writer};
+use std::mem::{transmute, transmute_copy};
+use std::raw::TraitObject;
 
 struct TypeIdHasher;
 
@@ -29,7 +30,7 @@ impl Writer for TypeIdState {
         debug_assert!(bytes.len() == 8);
         unsafe {
             std::ptr::copy_nonoverlapping_memory(&mut self.value,
-                                                 std::mem::transmute(&bytes[0]),
+                                                 transmute(&bytes[0]),
                                                  1)
         }
     }
@@ -45,6 +46,42 @@ impl Hasher<TypeIdState> for TypeIdHasher {
     }
 }
 
+/// 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.
 ///
@@ -71,7 +108,7 @@ impl Hasher<TypeIdState> for TypeIdHasher {
 ///
 /// Values containing non-static references are not permitted.
 pub struct AnyMap {
-    data: HashMap<TypeId, Box<Any>:'static, TypeIdHasher>,
+    data: HashMap<TypeId, Box<Any>, TypeIdHasher>,
 }
 
 impl AnyMap {
@@ -86,31 +123,54 @@ impl AnyMap {
 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`.
     /// This will override any previous value stored.
     pub fn insert<T: 'static>(&mut self, value: T) {
-        self.data.insert(TypeId::of::<T>(), box value as Box<Any>:'static);
+        self.data.insert(TypeId::of::<T>(), box value as Box<Any>);
     }
 
     /// Remove the value for the type `T` if it existed.
     pub fn remove<T: 'static>(&mut self) {
         self.data.remove(&TypeId::of::<T>());
     }
+
+    /// Does a value of type `T` exist?
+    pub fn contains<T: 'static>(&self) -> bool {
+        self.data.contains_key(&TypeId::of::<T>())
+    }
+}
+
+impl Collection for AnyMap {
+    fn len(&self) -> uint {
+        self.data.len()
+    }
+
+    fn is_empty(&self) -> bool {
+        self.data.is_empty()
+    }
+}
+
+impl Mutable for AnyMap {
+    fn clear(&mut self) {
+        self.data.clear();
+    }
 }
 
 #[bench]
 fn bench_insertion(b: &mut ::test::Bencher) {
     b.iter(|| {
         let mut data = AnyMap::new();
-        data.insert(42i);
+        for _ in range(0u, 100) {
+            data.insert(42i);
+        }
     })
 }
 
@@ -118,7 +178,9 @@ fn bench_insertion(b: &mut ::test::Bencher) {
 fn bench_find_missing(b: &mut ::test::Bencher) {
     b.iter(|| {
         let data = AnyMap::new();
-        assert_eq!(data.find(), None::<&int>);
+        for _ in range(0u, 100) {
+            assert_eq!(data.find(), None::<&int>);
+        }
     })
 }
 
@@ -127,6 +189,9 @@ fn bench_find_present(b: &mut ::test::Bencher) {
     b.iter(|| {
         let mut data = AnyMap::new();
         data.insert(42i);
-        assert_eq!(data.find(), Some(&42i));
+        // These inner loops are a feeble attempt to drown the other factors.
+        for _ in range(0u, 100) {
+            assert_eq!(data.find(), Some(&42i));
+        }
     })
 }