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Substantial refactoring, exposing a raw interface.

Browse source 
This is not necessarily the final form, but I think it’s pretty good.
The only alteration to the public interface is the removal of the
iteration methods from `AnyMap`; they are now attached to `RawAnyMap`.

The diff appears considerably more scary than it is in actual fact due
to some comparatively unnecessary changes like the field name (from
`data` to `raw`). Really, it’s minimal.
This commit is contained in:
Chris Morgan 2015-03-24 13:42:01 +11:00
parent 9a3d4ae73b
commit 143ee06268
3 changed files with 471 additions and 273 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

402
src/lib.rs
View file

@ -10,99 +10,83 @@
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;
use std::collections::hash_state::HashState;
use std::mem::transmute;
use std::raw::TraitObject;
use std::marker::PhantomData;
struct TypeIdHasher {
value: u64,
}
use raw::RawAnyMap;
use unchecked_any::UncheckedAnyExt;
struct TypeIdState;
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: $new,
}
}
impl HashState for TypeIdState {
type Hasher = TypeIdHasher;
/// Creates an empty collection with the given initial capacity.
#[inline]
pub fn with_capacity($with_capacity_arg: usize) -> $t {
$t {
$field: $with_capacity,
}
}
fn hasher(&self) -> TypeIdHasher {
TypeIdHasher { value: 0 }
}
}
/// Returns the number of elements the collection can hold without reallocating.
#[inline]
pub fn capacity(&self) -> usize {
self.$field.capacity()
}
impl Hasher 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(&mut self.value, transmute(&bytes[0]), 1)
/// 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()
}
}
}
#[inline(always)]
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> {
#[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.
@ -129,98 +113,28 @@ impl UncheckedBoxAny for Box<Any> {
/// ```
///
/// Values containing non-static references are not permitted.
#[derive(Debug)]
pub struct AnyMap {
data: HashMap<TypeId, Box<Any>, TypeIdState>,
raw: RawAnyMap,
}
impl_common_methods! {
field: AnyMap.raw;
new() => RawAnyMap::new();
with_capacity(capacity) => RawAnyMap::with_capacity(capacity);
}
impl AnyMap {
/// Construct a new `AnyMap`.
#[inline]
pub fn new() -> AnyMap {
AnyMap {
data: HashMap::with_hash_state(TypeIdState),
}
}
/// Creates an empty AnyMap with the given initial capacity.
#[inline]
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]
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]
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]
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]
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]
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]
pub fn into_iter(self) -> IntoIter {
IntoIter {
inner: self.data.into_iter(),
}
}
/// Returns a reference to the value stored in the collection for the type `T`, if it exists.
pub fn get<T: Any>(&self) -> Option<&T> {
self.data.get(&TypeId::of::<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.
pub fn get_mut<T: Any>(&mut self) -> Option<&mut T> {
self.data.get_mut(&TypeId::of::<T>())
self.raw.get_mut(&TypeId::of::<T>())
.map(|any| unsafe { any.downcast_mut_unchecked::<T>() })
}
@ -228,80 +142,91 @@ impl AnyMap {
/// If the collection already had a value of type `T`, that value is returned.
/// Otherwise, `None` is returned.
pub fn insert<T: Any>(&mut self, value: T) -> Option<T> {
self.data.insert(TypeId::of::<T>(), Box::new(value))
.map(|any| *unsafe { any.downcast_unchecked::<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.
pub fn remove<T: Any>(&mut self) -> Option<T> {
self.data.remove(&TypeId::of::<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`.
#[inline]
pub fn contains<T: Any>(&self) -> bool {
self.data.contains_key(&TypeId::of::<T>())
self.raw.contains_key(&TypeId::of::<T>())
}
/// Gets the entry for the given type in the collection for in-place manipulation
pub fn entry<T: Any>(&mut self) -> Entry<T> {
match self.data.entry(TypeId::of::<T>()) {
hash_map::Entry::Occupied(e) => Entry::Occupied(OccupiedEntry {
entry: e,
match self.raw.entry(TypeId::of::<T>()) {
raw::Entry::Occupied(e) => Entry::Occupied(OccupiedEntry {
inner: e,
type_: PhantomData,
}),
hash_map::Entry::Vacant(e) => Entry::Vacant(VacantEntry {
entry: e,
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]
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]
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]
pub fn drain(&mut self) -> Drain {
Drain {
inner: self.data.drain(),
pub fn into_raw(self) -> RawAnyMap {
self.raw
}
/// 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]
pub fn from_raw(raw: RawAnyMap) -> AnyMap {
AnyMap {
raw: raw,
}
}
/// Removes all items from the collection. Keeps the allocated memory for reuse.
#[inline]
pub fn clear(&mut self) {
self.data.clear()
}
}
/// A view into a single occupied location in an AnyMap
/// A view into a single occupied location in an `AnyMap`.
pub struct OccupiedEntry<'a, V: 'a> {
entry: hash_map::OccupiedEntry<'a, TypeId, Box<Any>>,
inner: raw::OccupiedEntry<'a>,
type_: PhantomData<V>,
}
/// A view into a single empty location in an AnyMap
/// A view into a single empty location in an `AnyMap`.
pub struct VacantEntry<'a, V: 'a> {
entry: hash_map::VacantEntry<'a, TypeId, Box<Any>>,
inner: raw::VacantEntry<'a>,
type_: PhantomData<V>,
}
/// A view into a single location in an AnyMap, which may be vacant or occupied
/// 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>),
@ -313,8 +238,8 @@ impl<'a, V: Any + Clone> Entry<'a, V> {
/// 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>> {
match self {
Entry::Occupied(entry) => Ok(entry.into_mut()),
Entry::Vacant(entry) => Err(entry),
Entry::Occupied(inner) => Ok(inner.into_mut()),
Entry::Vacant(inner) => Err(inner),
}
}
}
@ -322,28 +247,28 @@ impl<'a, V: Any + Clone> Entry<'a, V> {
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() }
}
/// 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() }
}
/// 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() }
}
/// 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)).downcast_unchecked() }
unsafe { *self.inner.insert(Box::new(value)).downcast_unchecked() }
}
/// 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() }
}
}
@ -351,79 +276,10 @@ 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)).downcast_mut_unchecked() }
unsafe { self.inner.insert(Box::new(value)).downcast_mut_unchecked() }
}
}
/// `AnyMap` iterator.
#[derive(Clone)]
pub struct Iter<'a> {
inner: hash_map::Iter<'a, TypeId, Box<Any>>,
}
/// `AnyMap` mutable references iterator.
pub struct IterMut<'a> {
inner: hash_map::IterMut<'a, TypeId, Box<Any>>,
}
/// `AnyMap` draining iterator.
pub struct Drain<'a> {
inner: hash_map::Drain<'a, TypeId, Box<Any>>,
}
/// `AnyMap` move iterator.
pub struct IntoIter {
inner: hash_map::IntoIter<TypeId, Box<Any>>,
}
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() }
}
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() }
}
impl<'a> Iterator for Drain<'a> {
type Item = Box<Any>;
#[inline]
fn next(&mut self) -> Option<Box<Any>> {
self.inner.next().map(|item| item.1)
}
#[inline]
fn size_hint(&self) -> (usize, Option<usize>) { self.inner.size_hint() }
}
impl Iterator for IntoIter {
type Item = Box<Any>;
#[inline]
fn next(&mut self) -> Option<Box<Any>> {
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(|| {

318
src/raw.rs Normal file
View file

@ -0,0 +1,318 @@
//! The raw form of an AnyMap, allowing untyped access.
//!
//! All relevant details are in the `RawAnyMap` struct.
use std::any::{Any, TypeId};
use std::borrow::Borrow;
use std::collections::hash_map::{self, HashMap};
use std::collections::hash_state::HashState;
use std::default::Default;
use std::hash::{Hash, Hasher};
use std::iter::IntoIterator;
use std::mem;
use std::ops::{Index, IndexMut};
use std::ptr;
struct TypeIdHasher {
value: u64,
}
struct TypeIdState;
impl HashState for TypeIdState {
type Hasher = TypeIdHasher;
fn hasher(&self) -> TypeIdHasher {
TypeIdHasher { value: 0 }
}
}
impl Hasher 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 {
ptr::copy_nonoverlapping(&mut self.value, mem::transmute(&bytes[0]), 1)
}
}
#[inline(always)]
fn finish(&self) -> u64 { self.value }
}
/// The raw, underlying form of an AnyMap.
///
/// At its essence, this is a wrapper around `HashMap<TypeId, Box<Any>>`, with the portions that
/// would be memory-unsafe removed or marked unsafe. Normal people are expected to use the safe
/// `AnyMap` interface instead, but there is the occasional use for this such as iteration over the
/// contents of an `AnyMap`. However, because you will then be dealing with `Any` trait objects, it
/// doesn’t tend to be so very useful. Still, if you need it, it’s here.
#[derive(Debug)]
pub struct RawAnyMap {
inner: HashMap<TypeId, Box<Any>, TypeIdState>,
}
impl Default for RawAnyMap {
fn default() -> RawAnyMap {
RawAnyMap::new()
}
}
impl_common_methods! {
field: RawAnyMap.inner;
new() => HashMap::with_hash_state(TypeIdState);
with_capacity(capacity) => HashMap::with_capacity_and_hash_state(capacity, TypeIdState);
}
/// RawAnyMap iterator.
#[derive(Clone)]
pub struct Iter<'a> {
inner: hash_map::Iter<'a, TypeId, Box<Any>>,
}
impl<'a> Iterator for Iter<'a> {
type Item = &'a Any;
#[inline] fn next(&mut self) -> Option<&'a Any> { self.inner.next().map(|x| &**x.1) }
#[inline] fn size_hint(&self) -> (usize, Option<usize>) { self.inner.size_hint() }
}
impl<'a> ExactSizeIterator for Iter<'a> {
#[inline] fn len(&self) -> usize { self.inner.len() }
}
/// RawAnyMap mutable iterator.
pub struct IterMut<'a> {
inner: hash_map::IterMut<'a, TypeId, Box<Any>>,
}
impl<'a> Iterator for IterMut<'a> {
type Item = &'a mut Any;
#[inline] fn next(&mut self) -> Option<&'a mut Any> { self.inner.next().map(|x| &mut **x.1) }
#[inline] fn size_hint(&self) -> (usize, Option<usize>) { self.inner.size_hint() }
}
impl<'a> ExactSizeIterator for IterMut<'a> {
#[inline] fn len(&self) -> usize { self.inner.len() }
}
/// RawAnyMap move iterator.
pub struct IntoIter {
inner: hash_map::IntoIter<TypeId, Box<Any>>,
}
impl Iterator for IntoIter {
type Item = Box<Any>;
#[inline] fn next(&mut self) -> Option<Box<Any>> { self.inner.next().map(|x| x.1) }
#[inline] fn size_hint(&self) -> (usize, Option<usize>) { self.inner.size_hint() }
}
impl ExactSizeIterator for IntoIter {
#[inline] fn len(&self) -> usize { self.inner.len() }
}
/// RawAnyMap drain iterator.
pub struct Drain<'a> {
inner: hash_map::Drain<'a, TypeId, Box<Any>>,
}
impl<'a> Iterator for Drain<'a> {
type Item = Box<Any>;
#[inline] fn next(&mut self) -> Option<Box<Any>> { self.inner.next().map(|x| x.1) }
#[inline] fn size_hint(&self) -> (usize, Option<usize>) { self.inner.size_hint() }
}
impl<'a> ExactSizeIterator for Drain<'a> {
#[inline] fn len(&self) -> usize { self.inner.len() }
}
impl RawAnyMap {
/// An iterator visiting all entries in arbitrary order.
///
/// Iterator element type is `&Any`.
#[inline]
pub fn iter(&self) -> Iter {
Iter {
inner: self.inner.iter(),
}
}
/// An iterator visiting all entries in arbitrary order.
///
/// Iterator element type is `&mut Any`.
#[inline]
pub fn iter_mut(&mut self) -> IterMut {
IterMut {
inner: self.inner.iter_mut(),
}
}
/// 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]
pub fn into_iter(self) -> IntoIter {
IntoIter {
inner: self.inner.into_iter(),
}
}
/// Clears the map, returning all items as an iterator.
///
/// Iterator element type is `Box<Any>`.
///
/// Keeps the allocated memory for reuse.
#[inline]
pub fn drain(&mut self) -> Drain {
Drain {
inner: self.inner.drain(),
}
}
/// Gets the entry for the given type in the collection for in-place manipulation.
pub fn entry(&mut self, key: TypeId) -> Entry {
match self.inner.entry(key) {
hash_map::Entry::Occupied(e) => Entry::Occupied(OccupiedEntry {
inner: e,
}),
hash_map::Entry::Vacant(e) => Entry::Vacant(VacantEntry {
inner: e,
}),
}
}
/// Returns a reference to the value corresponding to the key.
///
/// The key may be any borrowed form of the map's key type, but `Hash` and `Eq` on the borrowed
/// form *must* match those for the key type.
pub fn get<Q: ?Sized>(&self, k: &Q) -> Option<&Any>
where TypeId: Borrow<Q>, Q: Hash + Eq {
self.inner.get(k).map(|x| &**x)
}
/// Returns true if the map contains a value for the specified key.
///
/// The key may be any borrowed form of the map's key type, but `Hash` and `Eq` on the borrowed
/// form *must* match those for the key type.
pub fn contains_key<Q: ?Sized>(&self, k: &Q) -> bool
where TypeId: Borrow<Q>, Q: Hash + Eq {
self.inner.contains_key(k)
}
/// Returns a mutable reference to the value corresponding to the key.
///
/// The key may be any borrowed form of the map's key type, but `Hash` and `Eq` on the borrowed
/// form *must* match those for the key type.
pub fn get_mut<Q: ?Sized>(&mut self, k: &Q) -> Option<&mut Any>
where TypeId: Borrow<Q>, Q: Hash + Eq {
self.inner.get_mut(k).map(|x| &mut **x)
}
/// Inserts a key-value pair from the map. If the key already had a value present in the map,
/// that value is returned. Otherwise, None is returned.
///
/// It is the caller’s responsibility to ensure that the key corresponds with the type ID of
/// the value. If they do not, memory safety may be violated.
pub unsafe fn insert(&mut self, key: TypeId, value: Box<Any>) -> Option<Box<Any>> {
self.inner.insert(key, value)
}
/// Removes a key from the map, returning the value at the key if the key was previously in the
/// map.
///
/// The key may be any borrowed form of the map's key type, but `Hash` and `Eq` on the borrowed
/// form *must* match those for the key type.
pub fn remove<Q: ?Sized>(&mut self, k: &Q) -> Option<Box<Any>>
where TypeId: Borrow<Q>, Q: Hash + Eq {
self.inner.remove(k)
}
}
impl<Q: ?Sized> Index<Q> for RawAnyMap where TypeId: Borrow<Q>, Q: Eq + Hash {
type Output = Any;
fn index<'a>(&'a self, index: &Q) -> &'a Any {
self.get(index).expect("no entry found for key")
}
}
impl<Q: ?Sized> IndexMut<Q> for RawAnyMap where TypeId: Borrow<Q>, Q: Eq + Hash {
fn index_mut<'a>(&'a mut self, index: &Q) -> &'a mut Any {
self.get_mut(index).expect("no entry found for key")
}
}
impl IntoIterator for RawAnyMap {
type Item = Box<Any>;
type IntoIter = IntoIter;
fn into_iter(self) -> IntoIter {
self.into_iter()
}
}
/// A view into a single occupied location in a `RawAnyMap`.
pub struct OccupiedEntry<'a> {
inner: hash_map::OccupiedEntry<'a, TypeId, Box<Any>>,
}
/// A view into a single empty location in a `RawAnyMap`.
pub struct VacantEntry<'a> {
inner: hash_map::VacantEntry<'a, TypeId, Box<Any>>,
}
/// A view into a single location in an AnyMap, which may be vacant or occupied.
pub enum Entry<'a> {
/// An occupied Entry
Occupied(OccupiedEntry<'a>),
/// A vacant Entry
Vacant(VacantEntry<'a>),
}
impl<'a> Entry<'a> {
/// Returns a mutable reference to the entry if occupied, or the VacantEntry if vacant.
pub fn get(self) -> Result<&'a mut Any, VacantEntry<'a>> {
match self {
Entry::Occupied(inner) => Ok(inner.into_mut()),
Entry::Vacant(inner) => Err(inner),
}
}
}
impl<'a> OccupiedEntry<'a> {
/// Gets a reference to the value in the entry.
pub fn get(&self) -> &Any {
&**self.inner.get()
}
/// Gets a mutable reference to the value in the entry.
pub fn get_mut(&mut self) -> &mut Any {
&mut **self.inner.get_mut()
}
/// 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 Any {
&mut **self.inner.into_mut()
}
/// Sets the value of the entry, and returns the entry's old value.
///
/// It is the caller’s responsibility to ensure that the key of the entry corresponds with
/// the type ID of `value`. If they do not, memory safety may be violated.
pub unsafe fn insert(&mut self, value: Box<Any>) -> Box<Any> {
self.inner.insert(value)
}
/// Takes the value out of the entry, and returns it.
pub fn remove(self) -> Box<Any> {
self.inner.remove()
}
}
impl<'a> VacantEntry<'a> {
/// Sets the value of the entry with the VacantEntry's key,
/// and returns a mutable reference to it
///
/// It is the caller’s responsibility to ensure that the key of the entry corresponds with
/// the type ID of `value`. If they do not, memory safety may be violated.
pub unsafe fn insert(self, value: Box<Any>) -> &'a mut Any {
&mut **self.inner.insert(value)
}
}

24
src/unchecked_any.rs Normal file
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use std::any::Any;
use std::mem;
use std::raw::TraitObject;
#[allow(missing_docs)] // Bogus warning (it’s not public outside the crate), ☹
pub trait UncheckedAnyExt {
unsafe fn downcast_ref_unchecked<T: 'static>(&self) -> &T;
unsafe fn downcast_mut_unchecked<T: 'static>(&mut self) -> &mut T;
unsafe fn downcast_unchecked<T: 'static>(self: Box<Self>) -> Box<T>;
}
impl UncheckedAnyExt for Any {
unsafe fn downcast_ref_unchecked<T: 'static>(&self) -> &T {
mem::transmute(mem::transmute::<_, TraitObject>(self).data)
}
unsafe fn downcast_mut_unchecked<T: 'static>(&mut self) -> &mut T {
mem::transmute(mem::transmute::<_, TraitObject>(self).data)
}
unsafe fn downcast_unchecked<T: 'static>(self: Box<Any>) -> Box<T> {
mem::transmute(mem::transmute::<_, TraitObject>(self).data)
}
}