//! This crate provides the `AnyMap` type, a safe and convenient store for one value of each type.
-#![feature(core, std_misc, hash)]
+#![feature(core, std_misc)]
#![cfg_attr(test, feature(test))]
-#![warn(unused_qualifications, non_upper_case_globals,
- variant_size_differences, unused_typecasts,
- missing_docs, unused_results)]
+#![warn(missing_docs, unused_results)]
#[cfg(test)]
extern crate test;
use std::any::{Any, TypeId};
-use std::mem::forget;
-use std::collections::HashMap;
-use std::collections::hash_map;
-use std::hash::{Hasher, Writer};
-use std::collections::hash_state::HashState;
-use std::mem::transmute;
-use std::raw::TraitObject;
-
-struct TypeIdHasher {
- value: u64,
-}
-
-struct TypeIdState;
-
-impl HashState for TypeIdState {
- type Hasher = TypeIdHasher;
-
- fn hasher(&self) -> TypeIdHasher {
- TypeIdHasher { value: 0 }
- }
-}
-
-impl Writer for TypeIdHasher {
- #[inline(always)]
- fn write(&mut self, bytes: &[u8]) {
- // This expects to receive one and exactly one 64-bit value
- debug_assert!(bytes.len() == 8);
- unsafe {
- std::ptr::copy_nonoverlapping_memory(&mut self.value,
- transmute(&bytes[0]),
- 1)
+use std::marker::PhantomData;
+
+use raw::RawAnyMap;
+use unchecked_any::UncheckedAnyExt;
+
+macro_rules! impl_common_methods {
+ (
+ field: $t:ident.$field:ident;
+ new() => $new:expr;
+ with_capacity($with_capacity_arg:ident) => $with_capacity:expr;
+ ) => {
+ impl $t {
+ /// Create an empty collection.
+ #[inline]
+ pub fn new() -> $t {
+ $t {
+ $field: $new,
+ }
+ }
+
+ /// Creates an empty collection with the given initial capacity.
+ #[inline]
+ pub fn with_capacity($with_capacity_arg: usize) -> $t {
+ $t {
+ $field: $with_capacity,
+ }
+ }
+
+ /// Returns the number of elements the collection can hold without reallocating.
+ #[inline]
+ pub fn capacity(&self) -> usize {
+ self.$field.capacity()
+ }
+
+ /// Reserves capacity for at least `additional` more elements to be inserted
+ /// in the collection. The collection may reserve more space to avoid
+ /// frequent reallocations.
+ ///
+ /// # Panics
+ ///
+ /// Panics if the new allocation size overflows `usize`.
+ #[inline]
+ pub fn reserve(&mut self, additional: usize) {
+ self.$field.reserve(additional)
+ }
+
+ /// Shrinks the capacity of the collection as much as possible. It will drop
+ /// down as much as possible while maintaining the internal rules
+ /// and possibly leaving some space in accordance with the resize policy.
+ #[inline]
+ pub fn shrink_to_fit(&mut self) {
+ self.$field.shrink_to_fit()
+ }
+
+ /// Returns the number of items in the collection.
+ #[inline]
+ pub fn len(&self) -> usize {
+ self.$field.len()
+ }
+
+ /// Returns true if there are no items in the collection.
+ #[inline]
+ pub fn is_empty(&self) -> bool {
+ self.$field.is_empty()
+ }
+
+ /// Removes all items from the collection. Keeps the allocated memory for reuse.
+ #[inline]
+ pub fn clear(&mut self) {
+ self.$field.clear()
+ }
}
}
}
-impl Hasher for TypeIdHasher {
- type Output = u64;
-
- fn reset(&mut self) { }
-
- fn finish(&self) -> u64 { self.value }
-}
-
-/// 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 downcast_ref_unchecked<T: 'static>(self) -> &'a T;
-}
-
-impl<'a> UncheckedAnyRefExt<'a> for &'a Any {
- #[inline]
- unsafe fn downcast_ref_unchecked<T: 'static>(self) -> &'a T {
- // Get the raw representation of the trait object
- let to: TraitObject = transmute(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 downcast_mut_unchecked<T: 'static>(self) -> &'a mut T;
-}
-
-impl<'a> UncheckedAnyMutRefExt<'a> for &'a mut Any {
- #[inline]
- unsafe fn downcast_mut_unchecked<T: 'static>(self) -> &'a mut T {
- // Get the raw representation of the trait object
- let to: TraitObject = transmute(self);
-
- // Extract the data pointer
- transmute(to.data)
- }
-}
-
-/// 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)
- }
-}
+mod unchecked_any;
+pub mod raw;
/// A collection containing zero or one values for any given type and allowing convenient,
/// type-safe access to those values.
/// ```
///
/// Values containing non-static references are not permitted.
-#[stable]
+#[derive(Debug)]
pub struct AnyMap {
- data: HashMap<TypeId, Box<Any + 'static>, TypeIdState>,
+ raw: RawAnyMap,
}
-impl AnyMap {
- /// Construct a new `AnyMap`.
- #[inline]
- #[stable]
- pub fn new() -> AnyMap {
- AnyMap {
- data: HashMap::with_hash_state(TypeIdState),
- }
- }
-
- /// Creates an empty AnyMap with the given initial capacity.
- #[inline]
- #[stable]
- pub fn with_capcity(capacity: usize) -> AnyMap {
- AnyMap {
- data: HashMap::with_capacity_and_hash_state(capacity, TypeIdState),
- }
- }
-
- /// Returns the number of elements the collection can hold without reallocating.
- #[inline]
- #[stable]
- pub fn capacity(&self) -> usize {
- self.data.capacity()
- }
-
- /// Reserves capacity for at least `additional` more elements to be inserted
- /// in the `AnyMap`. The collection may reserve more space to avoid
- /// frequent reallocations.
- ///
- /// # Panics
- ///
- /// Panics if the new allocation size overflows `usize`.
- #[inline]
- #[stable]
- pub fn reserve(&mut self, additional: usize) {
- self.data.reserve(additional)
- }
-
- /// Shrinks the capacity of the collection as much as possible. It will drop
- /// down as much as possible while maintaining the internal rules
- /// and possibly leaving some space in accordance with the resize policy.
- #[inline]
- #[stable]
- pub fn shrink_to_fit(&mut self) {
- self.data.shrink_to_fit()
- }
-
- /// An iterator visiting all items in the collection in arbitrary order.
- /// Iterator element type is `&Any`.
- ///
- /// This is probably not a great deal of use.
- #[inline]
- #[stable]
- pub fn iter(&self) -> Iter {
- Iter {
- inner: self.data.iter(),
- }
- }
-
- /// An iterator visiting all items in the collection in arbitrary order.
- /// Iterator element type is `&mut Any`.
- ///
- /// This is probably not a great deal of use.
- #[inline]
- #[stable]
- pub fn iter_mut(&mut self) -> IterMut {
- IterMut {
- inner: self.data.iter_mut(),
- }
- }
-
- /// An iterator visiting all items in the collection in arbitrary order.
- /// Creates a consuming iterator, that is, one that moves each item
- /// out of the map in arbitrary order. The map cannot be used after
- /// calling this.
- ///
- /// Iterator element type is `Box<Any>`.
- #[inline]
- #[stable]
- pub fn into_iter(self) -> IntoIter {
- IntoIter {
- inner: self.data.into_iter(),
- }
- }
+impl_common_methods! {
+ field: AnyMap.raw;
+ new() => RawAnyMap::new();
+ with_capacity(capacity) => RawAnyMap::with_capacity(capacity);
+}
+impl AnyMap {
/// Returns a reference to the value stored in the collection for the type `T`, if it exists.
- #[stable]
- pub fn get<T: Any + 'static>(&self) -> Option<&T> {
- self.data.get(&TypeId::of::<T>())
+ pub fn get<T: Any>(&self) -> Option<&T> {
+ self.raw.get(&TypeId::of::<T>())
.map(|any| unsafe { any.downcast_ref_unchecked::<T>() })
}
/// Returns a mutable reference to the value stored in the collection for the type `T`,
/// if it exists.
- #[stable]
- pub fn get_mut<T: Any + 'static>(&mut self) -> Option<&mut T> {
- self.data.get_mut(&TypeId::of::<T>())
+ pub fn get_mut<T: Any>(&mut self) -> Option<&mut T> {
+ self.raw.get_mut(&TypeId::of::<T>())
.map(|any| unsafe { any.downcast_mut_unchecked::<T>() })
}
/// Sets the value stored in the collection for the type `T`.
/// If the collection already had a value of type `T`, that value is returned.
/// Otherwise, `None` is returned.
- #[stable]
- pub fn insert<T: Any + 'static>(&mut self, value: T) -> Option<T> {
- self.data.insert(TypeId::of::<T>(), Box::new(value) as Box<Any>)
- .map(|any| *unsafe { any.downcast_unchecked::<T>() })
+ pub fn insert<T: Any>(&mut self, value: T) -> Option<T> {
+ unsafe {
+ self.raw.insert(TypeId::of::<T>(), Box::new(value))
+ .map(|any| *any.downcast_unchecked::<T>())
+ }
}
/// Removes the `T` value from the collection,
/// returning it if there was one or `None` if there was not.
- #[stable]
- pub fn remove<T: Any + 'static>(&mut self) -> Option<T> {
- self.data.remove(&TypeId::of::<T>())
+ pub fn remove<T: Any>(&mut self) -> Option<T> {
+ self.raw.remove(&TypeId::of::<T>())
.map(|any| *unsafe { any.downcast_unchecked::<T>() })
}
/// Returns true if the collection contains a value of type `T`.
- #[stable]
- pub fn contains<T: Any + 'static>(&self) -> bool {
- self.data.contains_key(&TypeId::of::<T>())
+ #[inline]
+ pub fn contains<T: Any>(&self) -> bool {
+ self.raw.contains_key(&TypeId::of::<T>())
}
/// Gets the entry for the given type in the collection for in-place manipulation
- #[stable]
- pub fn entry<T: Any + 'static>(&mut self) -> Entry<T> {
- match self.data.entry(TypeId::of::<T>()) {
- hash_map::Entry::Occupied(e) => Entry::Occupied(OccupiedEntry { entry: e }),
- hash_map::Entry::Vacant(e) => Entry::Vacant(VacantEntry { entry: e }),
+ pub fn entry<T: Any>(&mut self) -> Entry<T> {
+ match self.raw.entry(TypeId::of::<T>()) {
+ raw::Entry::Occupied(e) => Entry::Occupied(OccupiedEntry {
+ inner: e,
+ type_: PhantomData,
+ }),
+ raw::Entry::Vacant(e) => Entry::Vacant(VacantEntry {
+ inner: e,
+ type_: PhantomData,
+ }),
}
}
- /// Returns the number of items in the collection.
+ /// Get a reference to the raw untyped map underlying the `AnyMap`.
+ ///
+ /// Normal users will not need to use this, but generic libraries working with an `AnyMap` may
+ /// just find a use for it occasionally.
#[inline]
- #[stable]
- pub fn len(&self) -> usize {
- self.data.len()
+ pub fn as_raw(&self) -> &RawAnyMap {
+ &self.raw
}
- /// Returns true if there are no items in the collection.
+ /// Get a mutable reference to the raw untyped map underlying the `AnyMap`.
+ ///
+ /// Normal users will not need to use this, but generic libraries working with an `AnyMap` may
+ /// just find a use for it occasionally.
#[inline]
- #[stable]
- pub fn is_empty(&self) -> bool {
- self.data.is_empty()
+ pub fn as_raw_mut(&mut self) -> &mut RawAnyMap {
+ &mut self.raw
}
- /// Clears the map, returning all items as an iterator.
+ /// Convert the `AnyMap` into the raw untyped map that underlyies it.
///
- /// Iterator element type is `Box<Any>`.
- ///
- /// Keeps the allocated memory for reuse.
+ /// Normal users will not need to use this, but generic libraries working with an `AnyMap` may
+ /// just find a use for it occasionally.
#[inline]
- #[unstable = "matches collection reform specification, waiting for dust to settle"]
- pub fn drain(&mut self) -> Drain {
- Drain {
- inner: self.data.drain(),
- }
+ pub fn into_raw(self) -> RawAnyMap {
+ self.raw
}
- /// Removes all items from the collection. Keeps the allocated memory for reuse.
+ /// Convert a raw untyped map into an `AnyMap`.
+ ///
+ /// Normal users will not need to use this, but generic libraries working with an `AnyMap` may
+ /// just find a use for it occasionally.
#[inline]
- #[stable]
- pub fn clear(&mut self) {
- self.data.clear();
+ pub fn from_raw(raw: RawAnyMap) -> AnyMap {
+ AnyMap {
+ raw: raw,
+ }
}
}
-/// A view into a single occupied location in an AnyMap
-#[stable]
+/// A view into a single occupied location in an `AnyMap`.
pub struct OccupiedEntry<'a, V: 'a> {
- entry: hash_map::OccupiedEntry<'a, TypeId, Box<Any + 'static>>,
+ inner: raw::OccupiedEntry<'a>,
+ type_: PhantomData<V>,
}
-/// A view into a single empty location in an AnyMap
-#[stable]
+/// A view into a single empty location in an `AnyMap`.
pub struct VacantEntry<'a, V: 'a> {
- entry: hash_map::VacantEntry<'a, TypeId, Box<Any + 'static>>,
+ inner: raw::VacantEntry<'a>,
+ type_: PhantomData<V>,
}
-/// A view into a single location in an AnyMap, which may be vacant or occupied
-#[stable]
+/// A view into a single location in an `AnyMap`, which may be vacant or occupied.
pub enum Entry<'a, V: 'a> {
/// An occupied Entry
Occupied(OccupiedEntry<'a, V>),
Vacant(VacantEntry<'a, V>),
}
-impl<'a, V: 'static + Clone> Entry<'a, V> {
- #[unstable = "matches collection reform v2 specification, waiting for dust to settle"]
- /// Returns a mutable reference to the entry if occupied, or the VacantEntry if vacant
- pub fn get(self) -> Result<&'a mut V, VacantEntry<'a, V>> {
+impl<'a, V: Any + Clone> Entry<'a, V> {
+ /// Ensures a value is in the entry by inserting the default if empty, and returns
+ /// a mutable reference to the value in the entry.
+ pub fn or_insert(self, default: V) -> &'a mut V {
match self {
- Entry::Occupied(entry) => Ok(entry.into_mut()),
- Entry::Vacant(entry) => Err(entry),
+ Entry::Occupied(inner) => inner.into_mut(),
+ Entry::Vacant(inner) => inner.insert(default),
+ }
+ }
+
+ /// Ensures a value is in the entry by inserting the result of the default function if empty,
+ /// and returns a mutable reference to the value in the entry.
+ pub fn or_insert_with<F: FnOnce() -> V>(self, default: F) -> &'a mut V {
+ match self {
+ Entry::Occupied(inner) => inner.into_mut(),
+ Entry::Vacant(inner) => inner.insert(default()),
}
}
}
-impl<'a, V: 'static> OccupiedEntry<'a, V> {
- #[stable]
+impl<'a, V: Any> OccupiedEntry<'a, V> {
/// Gets a reference to the value in the entry
pub fn get(&self) -> &V {
- unsafe { self.entry.get().downcast_ref_unchecked() }
+ unsafe { self.inner.get().downcast_ref_unchecked() }
}
- #[stable]
/// Gets a mutable reference to the value in the entry
pub fn get_mut(&mut self) -> &mut V {
- unsafe { self.entry.get_mut().downcast_mut_unchecked() }
+ unsafe { self.inner.get_mut().downcast_mut_unchecked() }
}
- #[stable]
/// Converts the OccupiedEntry into a mutable reference to the value in the entry
/// with a lifetime bound to the collection itself
pub fn into_mut(self) -> &'a mut V {
- unsafe { self.entry.into_mut().downcast_mut_unchecked() }
+ unsafe { self.inner.into_mut().downcast_mut_unchecked() }
}
- #[stable]
/// Sets the value of the entry, and returns the entry's old value
pub fn insert(&mut self, value: V) -> V {
- unsafe { *self.entry.insert(Box::new(value) as Box<Any + 'static>).downcast_unchecked() }
+ unsafe { *self.inner.insert(Box::new(value)).downcast_unchecked() }
}
- #[stable]
/// Takes the value out of the entry, and returns it
pub fn remove(self) -> V {
- unsafe { *self.entry.remove().downcast_unchecked() }
+ unsafe { *self.inner.remove().downcast_unchecked() }
}
}
-impl<'a, V: 'static> VacantEntry<'a, V> {
- #[stable]
+impl<'a, V: Any> VacantEntry<'a, V> {
/// Sets the value of the entry with the VacantEntry's key,
/// and returns a mutable reference to it
pub fn insert(self, value: V) -> &'a mut V {
- unsafe { self.entry.insert(Box::new(value) as Box<Any + 'static>).downcast_mut_unchecked() }
+ unsafe { self.inner.insert(Box::new(value)).downcast_mut_unchecked() }
}
}
-/// `AnyMap` iterator.
-#[stable]
-#[derive(Clone)]
-pub struct Iter<'a> {
- inner: hash_map::Iter<'a, TypeId, Box<Any + 'static>>,
-}
-
-/// `AnyMap` mutable references iterator.
-#[stable]
-pub struct IterMut<'a> {
- inner: hash_map::IterMut<'a, TypeId, Box<Any + 'static>>,
-}
-
-/// `AnyMap` draining iterator.
-#[unstable = "matches collection reform specification, waiting for dust to settle"]
-pub struct Drain<'a> {
- inner: hash_map::Drain<'a, TypeId, Box<Any + 'static>>,
-}
-
-/// `AnyMap` move iterator.
-#[stable]
-pub struct IntoIter {
- inner: hash_map::IntoIter<TypeId, Box<Any + 'static>>,
-}
-
-#[stable]
-impl<'a> Iterator for Iter<'a> {
- type Item = &'a Any;
-
- #[inline]
- fn next(&mut self) -> Option<&'a Any> {
- self.inner.next().map(|item| &**item.1)
- }
-
- #[inline]
- fn size_hint(&self) -> (usize, Option<usize>) { self.inner.size_hint() }
-}
-
-#[stable]
-impl<'a> Iterator for IterMut<'a> {
- type Item = &'a mut Any;
-
- #[inline]
- fn next(&mut self) -> Option<&'a mut Any> {
- self.inner.next().map(|item| &mut **item.1)
- }
-
- #[inline]
- fn size_hint(&self) -> (usize, Option<usize>) { self.inner.size_hint() }
-}
-
-#[stable]
-impl<'a> Iterator for Drain<'a> {
- type Item = Box<Any + 'static>;
-
- #[inline]
- fn next(&mut self) -> Option<Box<Any + 'static>> {
- self.inner.next().map(|item| item.1)
- }
-
- #[inline]
- fn size_hint(&self) -> (usize, Option<usize>) { self.inner.size_hint() }
-}
-
-#[stable]
-impl Iterator for IntoIter {
- type Item = Box<Any + 'static>;
-
- #[inline]
- fn next(&mut self) -> Option<Box<Any + 'static>> {
- self.inner.next().map(|item| item.1)
- }
-
- #[inline]
- fn size_hint(&self) -> (usize, Option<usize>) { self.inner.size_hint() }
-}
-
#[bench]
fn bench_insertion(b: &mut ::test::Bencher) {
b.iter(|| {
let mut data = AnyMap::new();
- for _ in range(0, 100) {
- let _ = data.insert(42i32);
+ for _ in 0..100 {
+ let _ = data.insert(42);
}
})
}
fn bench_get_missing(b: &mut ::test::Bencher) {
b.iter(|| {
let data = AnyMap::new();
- for _ in range(0, 100) {
+ for _ in 0..100 {
assert_eq!(data.get(), None::<&i32>);
}
})
fn bench_get_present(b: &mut ::test::Bencher) {
b.iter(|| {
let mut data = AnyMap::new();
- let _ = data.insert(42i32);
+ let _ = data.insert(42);
// These inner loops are a feeble attempt to drown the other factors.
- for _ in range(0, 100) {
- assert_eq!(data.get(), Some(&42i32));
+ for _ in 0..100 {
+ assert_eq!(data.get(), Some(&42));
}
})
}