1 //! The raw form of an AnyMap, allowing untyped access.
3 //! All relevant details are in the `RawAnyMap` struct.
5 use std
::any
::{Any
, TypeId
};
6 use std
::borrow
::Borrow
;
7 use std
::collections
::hash_map
::{self, HashMap
};
8 use std
::collections
::hash_state
::HashState
;
9 use std
::default::Default
;
10 use std
::hash
::{Hash
, Hasher
};
11 use std
::iter
::IntoIterator
;
13 use std
::ops
::{Index
, IndexMut
};
22 impl HashState
for TypeIdState
{
23 type Hasher
= TypeIdHasher
;
25 fn hasher(&self) -> TypeIdHasher
{
26 TypeIdHasher
{ value
: 0 }
30 impl Hasher
for TypeIdHasher
{
32 fn write(&mut self, bytes
: &[u8]) {
33 // This expects to receive one and exactly one 64-bit value
34 debug_assert!(bytes
.len() == 8);
36 ptr
::copy_nonoverlapping(&mut self.value
, mem
::transmute(&bytes
[0]), 1)
41 fn finish(&self) -> u64 { self.value
}
45 /// The raw, underlying form of an AnyMap.
47 /// At its essence, this is a wrapper around `HashMap<TypeId, Box<Any>>`, with the portions that
48 /// would be memory-unsafe removed or marked unsafe. Normal people are expected to use the safe
49 /// `AnyMap` interface instead, but there is the occasional use for this such as iteration over the
50 /// contents of an `AnyMap`. However, because you will then be dealing with `Any` trait objects, it
51 /// doesn’t tend to be so very useful. Still, if you need it, it’s here.
53 pub struct RawAnyMap
{
54 inner
: HashMap
<TypeId
, Box
<Any
>, TypeIdState
>,
57 impl Default
for RawAnyMap
{
58 fn default() -> RawAnyMap
{
63 impl_common_methods
! {
64 field
: RawAnyMap
.inner
;
65 new() => HashMap
::with_hash_state(TypeIdState
);
66 with_capacity(capacity
) => HashMap
::with_capacity_and_hash_state(capacity
, TypeIdState
);
69 /// RawAnyMap iterator.
72 inner
: hash_map
::Iter
<'a
, TypeId
, Box
<Any
>>,
74 impl<'a
> Iterator
for Iter
<'a
> {
76 #[inline] fn next(&mut self) -> Option<&'a Any> { self.inner.next().map(|x| &**x.1) }
77 #[inline] fn size_hint(&self) -> (usize, Option<usize>) { self.inner.size_hint() }
79 impl<'a
> ExactSizeIterator
for Iter
<'a
> {
80 #[inline] fn len(&self) -> usize { self.inner.len() }
83 /// RawAnyMap mutable iterator.
84 pub struct IterMut
<'a
> {
85 inner
: hash_map
::IterMut
<'a
, TypeId
, Box
<Any
>>,
87 impl<'a
> Iterator
for IterMut
<'a
> {
88 type Item
= &'a
mut Any
;
89 #[inline] fn next(&mut self) -> Option<&'a mut Any> { self.inner.next().map(|x| &mut **x.1) }
90 #[inline] fn size_hint(&self) -> (usize, Option<usize>) { self.inner.size_hint() }
92 impl<'a
> ExactSizeIterator
for IterMut
<'a
> {
93 #[inline] fn len(&self) -> usize { self.inner.len() }
96 /// RawAnyMap move iterator.
98 inner
: hash_map
::IntoIter
<TypeId
, Box
<Any
>>,
100 impl Iterator
for IntoIter
{
101 type Item
= Box
<Any
>;
102 #[inline] fn next(&mut self) -> Option<Box<Any>> { self.inner.next().map(|x| x.1) }
103 #[inline] fn size_hint(&self) -> (usize, Option<usize>) { self.inner.size_hint() }
105 impl ExactSizeIterator
for IntoIter
{
106 #[inline] fn len(&self) -> usize { self.inner.len() }
109 /// RawAnyMap drain iterator.
110 pub struct Drain
<'a
> {
111 inner
: hash_map
::Drain
<'a
, TypeId
, Box
<Any
>>,
113 impl<'a
> Iterator
for Drain
<'a
> {
114 type Item
= Box
<Any
>;
115 #[inline] fn next(&mut self) -> Option<Box<Any>> { self.inner.next().map(|x| x.1) }
116 #[inline] fn size_hint(&self) -> (usize, Option<usize>) { self.inner.size_hint() }
118 impl<'a
> ExactSizeIterator
for Drain
<'a
> {
119 #[inline] fn len(&self) -> usize { self.inner.len() }
123 /// An iterator visiting all entries in arbitrary order.
125 /// Iterator element type is `&Any`.
127 pub fn iter(&self) -> Iter
{
129 inner
: self.inner
.iter(),
133 /// An iterator visiting all entries in arbitrary order.
135 /// Iterator element type is `&mut Any`.
137 pub fn iter_mut(&mut self) -> IterMut
{
139 inner
: self.inner
.iter_mut(),
143 /// Creates a consuming iterator, that is, one that moves each item
144 /// out of the map in arbitrary order. The map cannot be used after
147 /// Iterator element type is `Box<Any>`.
149 pub fn into_iter(self) -> IntoIter
{
151 inner
: self.inner
.into_iter(),
155 /// Clears the map, returning all items as an iterator.
157 /// Iterator element type is `Box<Any>`.
159 /// Keeps the allocated memory for reuse.
161 pub fn drain(&mut self) -> Drain
{
163 inner
: self.inner
.drain(),
167 /// Gets the entry for the given type in the collection for in-place manipulation.
168 pub fn entry(&mut self, key
: TypeId
) -> Entry
{
169 match self.inner
.entry(key
) {
170 hash_map
::Entry
::Occupied(e
) => Entry
::Occupied(OccupiedEntry
{
173 hash_map
::Entry
::Vacant(e
) => Entry
::Vacant(VacantEntry
{
179 /// Returns a reference to the value corresponding to the key.
181 /// The key may be any borrowed form of the map's key type, but `Hash` and `Eq` on the borrowed
182 /// form *must* match those for the key type.
183 pub fn get
<Q
: ?Sized
>(&self, k
: &Q
) -> Option
<&Any
>
184 where TypeId
: Borrow
<Q
>, Q
: Hash
+ Eq
{
185 self.inner
.get(k
).map(|x
| &**x
)
188 /// Returns true if the map contains a value for the specified key.
190 /// The key may be any borrowed form of the map's key type, but `Hash` and `Eq` on the borrowed
191 /// form *must* match those for the key type.
192 pub fn contains_key
<Q
: ?Sized
>(&self, k
: &Q
) -> bool
193 where TypeId
: Borrow
<Q
>, Q
: Hash
+ Eq
{
194 self.inner
.contains_key(k
)
197 /// Returns a mutable reference to the value corresponding to the key.
199 /// The key may be any borrowed form of the map's key type, but `Hash` and `Eq` on the borrowed
200 /// form *must* match those for the key type.
201 pub fn get_mut
<Q
: ?Sized
>(&mut self, k
: &Q
) -> Option
<&mut Any
>
202 where TypeId
: Borrow
<Q
>, Q
: Hash
+ Eq
{
203 self.inner
.get_mut(k
).map(|x
| &mut **x
)
206 /// Inserts a key-value pair from the map. If the key already had a value present in the map,
207 /// that value is returned. Otherwise, None is returned.
209 /// It is the caller’s responsibility to ensure that the key corresponds with the type ID of
210 /// the value. If they do not, memory safety may be violated.
211 pub unsafe fn insert(&mut self, key
: TypeId
, value
: Box
<Any
>) -> Option
<Box
<Any
>> {
212 self.inner
.insert(key
, value
)
215 /// Removes a key from the map, returning the value at the key if the key was previously in the
218 /// The key may be any borrowed form of the map's key type, but `Hash` and `Eq` on the borrowed
219 /// form *must* match those for the key type.
220 pub fn remove
<Q
: ?Sized
>(&mut self, k
: &Q
) -> Option
<Box
<Any
>>
221 where TypeId
: Borrow
<Q
>, Q
: Hash
+ Eq
{
227 impl<Q
> Index
<Q
> for RawAnyMap
where TypeId
: Borrow
<Q
>, Q
: Eq
+ Hash
{
230 fn index
<'a
>(&'a
self, index
: Q
) -> &'a Any
{
231 self.get(&index
).expect("no entry found for key")
235 impl<Q
> IndexMut
<Q
> for RawAnyMap
where TypeId
: Borrow
<Q
>, Q
: Eq
+ Hash
{
236 fn index_mut
<'a
>(&'a
mut self, index
: Q
) -> &'a
mut Any
{
237 self.get_mut(&index
).expect("no entry found for key")
241 impl IntoIterator
for RawAnyMap
{
242 type Item
= Box
<Any
>;
243 type IntoIter
= IntoIter
;
245 fn into_iter(self) -> IntoIter
{
250 /// A view into a single occupied location in a `RawAnyMap`.
251 pub struct OccupiedEntry
<'a
> {
252 inner
: hash_map
::OccupiedEntry
<'a
, TypeId
, Box
<Any
>>,
255 /// A view into a single empty location in a `RawAnyMap`.
256 pub struct VacantEntry
<'a
> {
257 inner
: hash_map
::VacantEntry
<'a
, TypeId
, Box
<Any
>>,
260 /// A view into a single location in an AnyMap, which may be vacant or occupied.
262 /// An occupied Entry
263 Occupied(OccupiedEntry
<'a
>),
265 Vacant(VacantEntry
<'a
>),
269 /// Ensures a value is in the entry by inserting the default if empty, and returns
270 /// a mutable reference to the value in the entry.
272 /// It is the caller’s responsibility to ensure that the key of the entry corresponds with
273 /// the type ID of `value`. If they do not, memory safety may be violated.
274 pub unsafe fn or_insert(self, default: Box
<Any
>) -> &'a
mut Any
{
276 Entry
::Occupied(inner
) => inner
.into_mut(),
277 Entry
::Vacant(inner
) => inner
.insert(default),
281 /// Ensures a value is in the entry by inserting the result of the default function if empty,
282 /// and returns a mutable reference to the value in the entry.
284 /// It is the caller’s responsibility to ensure that the key of the entry corresponds with
285 /// the type ID of `value`. If they do not, memory safety may be violated.
286 pub unsafe fn or_insert_with
<F
: FnOnce() -> Box
<Any
>>(self, default: F
) -> &'a
mut Any
{
288 Entry
::Occupied(inner
) => inner
.into_mut(),
289 Entry
::Vacant(inner
) => inner
.insert(default()),
294 impl<'a
> OccupiedEntry
<'a
> {
295 /// Gets a reference to the value in the entry.
296 pub fn get(&self) -> &Any
{
300 /// Gets a mutable reference to the value in the entry.
301 pub fn get_mut(&mut self) -> &mut Any
{
302 &mut **self.inner
.get_mut()
305 /// Converts the OccupiedEntry into a mutable reference to the value in the entry
306 /// with a lifetime bound to the collection itself.
307 pub fn into_mut(self) -> &'a
mut Any
{
308 &mut **self.inner
.into_mut()
311 /// Sets the value of the entry, and returns the entry's old value.
313 /// It is the caller’s responsibility to ensure that the key of the entry corresponds with
314 /// the type ID of `value`. If they do not, memory safety may be violated.
315 pub unsafe fn insert(&mut self, value
: Box
<Any
>) -> Box
<Any
> {
316 self.inner
.insert(value
)
319 /// Takes the value out of the entry, and returns it.
320 pub fn remove(self) -> Box
<Any
> {
325 impl<'a
> VacantEntry
<'a
> {
326 /// Sets the value of the entry with the VacantEntry's key,
327 /// and returns a mutable reference to it
329 /// It is the caller’s responsibility to ensure that the key of the entry corresponds with
330 /// the type ID of `value`. If they do not, memory safety may be violated.
331 pub unsafe fn insert(self, value
: Box
<Any
>) -> &'a
mut Any
{
332 &mut **self.inner
.insert(value
)