1 //! This crate provides the `AnyMap` type, a safe and convenient store for one value of each type.
3 #![cfg_attr(all(feature = "bench", test), feature(test))]
4 #![warn(missing_docs, unused_results)]
6 #[cfg(all(feature = "bench", test))]
10 use std
::marker
::PhantomData
;
13 use any
::{UncheckedAnyExt
, IntoBox
, Any
};
15 macro_rules
! impl_common_methods
{
17 field
: $t
:ident
.$field
:ident
;
19 with_capacity($with_capacity_arg
:ident
) => $with_capacity
:expr
;
21 impl<A
: ?Sized
+ UncheckedAnyExt
> $t
<A
> {
22 /// Create an empty collection.
24 pub fn new() -> $t
<A
> {
30 /// Creates an empty collection with the given initial capacity.
32 pub fn with_capacity($with_capacity_arg
: usize) -> $t
<A
> {
34 $field
: $with_capacity
,
38 /// Returns the number of elements the collection can hold without reallocating.
40 pub fn capacity(&self) -> usize {
41 self.$field
.capacity()
44 /// Reserves capacity for at least `additional` more elements to be inserted
45 /// in the collection. The collection may reserve more space to avoid
46 /// frequent reallocations.
50 /// Panics if the new allocation size overflows `usize`.
52 pub fn reserve(&mut self, additional
: usize) {
53 self.$field
.reserve(additional
)
56 /// Shrinks the capacity of the collection as much as possible. It will drop
57 /// down as much as possible while maintaining the internal rules
58 /// and possibly leaving some space in accordance with the resize policy.
60 pub fn shrink_to_fit(&mut self) {
61 self.$field
.shrink_to_fit()
64 /// Returns the number of items in the collection.
66 pub fn len(&self) -> usize {
70 /// Returns true if there are no items in the collection.
72 pub fn is_empty(&self) -> bool
{
73 self.$field
.is_empty()
76 /// Removes all items from the collection. Keeps the allocated memory for reuse.
78 pub fn clear(&mut self) {
88 /// A collection containing zero or one values for any given type and allowing convenient,
89 /// type-safe access to those values.
91 /// The type parameter `A` allows you to use a different value type; normally you will want it to
92 /// be `anymap::any::Any`, but there are other choices:
94 /// - If you want the entire map to be cloneable, use `CloneAny` instead of `Any`.
95 /// - You can add on `+ Send` and/or `+ Sync` (e.g. `Map<Any + Send>`) to add those bounds.
98 /// # use anymap::AnyMap;
99 /// let mut data = AnyMap::new();
100 /// assert_eq!(data.get(), None::<&i32>);
101 /// data.insert(42i32);
102 /// assert_eq!(data.get(), Some(&42i32));
103 /// data.remove::<i32>();
104 /// assert_eq!(data.get::<i32>(), None);
106 /// #[derive(Clone, PartialEq, Debug)]
111 /// assert_eq!(data.get::<Foo>(), None);
112 /// data.insert(Foo { str: format!("foo") });
113 /// assert_eq!(data.get(), Some(&Foo { str: format!("foo") }));
114 /// data.get_mut::<Foo>().map(|foo| foo.str.push('t'));
115 /// assert_eq!(&*data.get::<Foo>().unwrap().str, "foot");
118 /// Values containing non-static references are not permitted.
120 pub struct Map
<A
: ?Sized
+ UncheckedAnyExt
= Any
> {
124 // #[derive(Clone)] would want A to implement Clone, but in reality it’s only Box<A> that can.
125 impl<A
: ?Sized
+ UncheckedAnyExt
> Clone
for Map
<A
> where Box
<A
>: Clone
{
126 fn clone(&self) -> Map
<A
> {
128 raw
: self.raw
.clone(),
133 /// The most common type of `Map`: just using `Any`.
135 /// Why is this a separate type alias rather than a default value for `Map<A>`? `Map::new()`
136 /// doesn’t seem to be happy to infer that it should go with the default value.
137 /// It’s a bit sad, really. Ah well, I guess this approach will do.
138 pub type AnyMap
= Map
<Any
>;
140 impl_common_methods
! {
142 new() => RawMap
::new();
143 with_capacity(capacity
) => RawMap
::with_capacity(capacity
);
146 impl<A
: ?Sized
+ UncheckedAnyExt
> Map
<A
> {
147 /// Returns a reference to the value stored in the collection for the type `T`, if it exists.
148 pub fn get
<T
: IntoBox
<A
>>(&self) -> Option
<&T
> {
149 self.raw
.get(&TypeId
::of
::<T
>())
150 .map(|any
| unsafe { any
.downcast_ref_unchecked
::<T
>() })
153 /// Returns a mutable reference to the value stored in the collection for the type `T`,
155 pub fn get_mut
<T
: IntoBox
<A
>>(&mut self) -> Option
<&mut T
> {
156 self.raw
.get_mut(&TypeId
::of
::<T
>())
157 .map(|any
| unsafe { any
.downcast_mut_unchecked
::<T
>() })
160 /// Sets the value stored in the collection for the type `T`.
161 /// If the collection already had a value of type `T`, that value is returned.
162 /// Otherwise, `None` is returned.
163 pub fn insert
<T
: IntoBox
<A
>>(&mut self, value
: T
) -> Option
<T
> {
165 self.raw
.insert(TypeId
::of
::<T
>(), value
.into_box())
166 .map(|any
| *any
.downcast_unchecked
::<T
>())
170 /// Removes the `T` value from the collection,
171 /// returning it if there was one or `None` if there was not.
172 pub fn remove
<T
: IntoBox
<A
>>(&mut self) -> Option
<T
> {
173 self.raw
.remove(&TypeId
::of
::<T
>())
174 .map(|any
| *unsafe { any
.downcast_unchecked
::<T
>() })
177 /// Returns true if the collection contains a value of type `T`.
179 pub fn contains
<T
: IntoBox
<A
>>(&self) -> bool
{
180 self.raw
.contains_key(&TypeId
::of
::<T
>())
183 /// Gets the entry for the given type in the collection for in-place manipulation
184 pub fn entry
<T
: IntoBox
<A
>>(&mut self) -> Entry
<A
, T
> {
185 match self.raw
.entry(TypeId
::of
::<T
>()) {
186 raw
::Entry
::Occupied(e
) => Entry
::Occupied(OccupiedEntry
{
190 raw
::Entry
::Vacant(e
) => Entry
::Vacant(VacantEntry
{
198 impl<A
: ?Sized
+ UncheckedAnyExt
> AsRef
<RawMap
<A
>> for Map
<A
> {
199 fn as_ref(&self) -> &RawMap
<A
> {
204 impl<A
: ?Sized
+ UncheckedAnyExt
> AsMut
<RawMap
<A
>> for Map
<A
> {
205 fn as_mut(&mut self) -> &mut RawMap
<A
> {
210 impl<A
: ?Sized
+ UncheckedAnyExt
> Into
<RawMap
<A
>> for Map
<A
> {
211 fn into(self) -> RawMap
<A
> {
216 /// A view into a single occupied location in an `Map`.
217 pub struct OccupiedEntry
<'a
, A
: ?Sized
+ UncheckedAnyExt
, V
: 'a
> {
218 inner
: raw
::OccupiedEntry
<'a
, A
>,
219 type_
: PhantomData
<V
>,
222 /// A view into a single empty location in an `Map`.
223 pub struct VacantEntry
<'a
, A
: ?Sized
+ UncheckedAnyExt
, V
: 'a
> {
224 inner
: raw
::VacantEntry
<'a
, A
>,
225 type_
: PhantomData
<V
>,
228 /// A view into a single location in an `Map`, which may be vacant or occupied.
229 pub enum Entry
<'a
, A
: ?Sized
+ UncheckedAnyExt
, V
: 'a
> {
230 /// An occupied Entry
231 Occupied(OccupiedEntry
<'a
, A
, V
>),
233 Vacant(VacantEntry
<'a
, A
, V
>),
236 impl<'a
, A
: ?Sized
+ UncheckedAnyExt
, V
: IntoBox
<A
> + Clone
> Entry
<'a
, A
, V
> {
237 /// Ensures a value is in the entry by inserting the default if empty, and returns
238 /// a mutable reference to the value in the entry.
239 pub fn or_insert(self, default: V
) -> &'a
mut V
{
241 Entry
::Occupied(inner
) => inner
.into_mut(),
242 Entry
::Vacant(inner
) => inner
.insert(default),
246 /// Ensures a value is in the entry by inserting the result of the default function if empty,
247 /// and returns a mutable reference to the value in the entry.
248 pub fn or_insert_with
<F
: FnOnce() -> V
>(self, default: F
) -> &'a
mut V
{
250 Entry
::Occupied(inner
) => inner
.into_mut(),
251 Entry
::Vacant(inner
) => inner
.insert(default()),
256 impl<'a
, A
: ?Sized
+ UncheckedAnyExt
, V
: IntoBox
<A
>> OccupiedEntry
<'a
, A
, V
> {
257 /// Gets a reference to the value in the entry
258 pub fn get(&self) -> &V
{
259 unsafe { self.inner
.get().downcast_ref_unchecked() }
262 /// Gets a mutable reference to the value in the entry
263 pub fn get_mut(&mut self) -> &mut V
{
264 unsafe { self.inner
.get_mut().downcast_mut_unchecked() }
267 /// Converts the OccupiedEntry into a mutable reference to the value in the entry
268 /// with a lifetime bound to the collection itself
269 pub fn into_mut(self) -> &'a
mut V
{
270 unsafe { self.inner
.into_mut().downcast_mut_unchecked() }
273 /// Sets the value of the entry, and returns the entry's old value
274 pub fn insert(&mut self, value
: V
) -> V
{
275 unsafe { *self.inner
.insert(value
.into_box()).downcast_unchecked() }
278 /// Takes the value out of the entry, and returns it
279 pub fn remove(self) -> V
{
280 unsafe { *self.inner
.remove().downcast_unchecked() }
284 impl<'a
, A
: ?Sized
+ UncheckedAnyExt
, V
: IntoBox
<A
>> VacantEntry
<'a
, A
, V
> {
285 /// Sets the value of the entry with the VacantEntry's key,
286 /// and returns a mutable reference to it
287 pub fn insert(self, value
: V
) -> &'a
mut V
{
288 unsafe { self.inner
.insert(value
.into_box()).downcast_mut_unchecked() }
292 #[cfg(feature = "bench")]
294 fn bench_insertion(b
: &mut ::test
::Bencher
) {
296 let mut data
= AnyMap
::new();
298 let _
= data
.insert(42);
303 #[cfg(feature = "bench")]
305 fn bench_get_missing(b
: &mut ::test
::Bencher
) {
307 let data
= AnyMap
::new();
309 assert_eq!(data
.get(), None
::<&i32>);
314 #[cfg(feature = "bench")]
316 fn bench_get_present(b
: &mut ::test
::Bencher
) {
318 let mut data
= AnyMap
::new();
319 let _
= data
.insert(42);
320 // These inner loops are a feeble attempt to drown the other factors.
322 assert_eq!(data
.get(), Some(&42));
329 use {Map
, AnyMap
, Entry
};
330 use any
::{Any
, CloneAny
};
332 #[derive(Clone, Debug, PartialEq)] struct A(i32);
333 #[derive(Clone, Debug, PartialEq)] struct B(i32);
334 #[derive(Clone, Debug, PartialEq)] struct C(i32);
335 #[derive(Clone, Debug, PartialEq)] struct D(i32);
336 #[derive(Clone, Debug, PartialEq)] struct E(i32);
337 #[derive(Clone, Debug, PartialEq)] struct F(i32);
338 #[derive(Clone, Debug, PartialEq)] struct J(i32);
342 let mut map
: AnyMap
= AnyMap
::new();
343 assert_eq!(map
.insert(A(10)), None
);
344 assert_eq!(map
.insert(B(20)), None
);
345 assert_eq!(map
.insert(C(30)), None
);
346 assert_eq!(map
.insert(D(40)), None
);
347 assert_eq!(map
.insert(E(50)), None
);
348 assert_eq!(map
.insert(F(60)), None
);
350 // Existing key (insert)
351 match map
.entry
::<A
>() {
352 Entry
::Vacant(_
) => unreachable!(),
353 Entry
::Occupied(mut view
) => {
354 assert_eq!(view
.get(), &A(10));
355 assert_eq!(view
.insert(A(100)), A(10));
358 assert_eq!(map
.get
::<A
>().unwrap(), &A(100));
359 assert_eq!(map
.len(), 6);
362 // Existing key (update)
363 match map
.entry
::<B
>() {
364 Entry
::Vacant(_
) => unreachable!(),
365 Entry
::Occupied(mut view
) => {
366 let v
= view
.get_mut();
367 let new_v
= B(v
.0 * 10);
371 assert_eq!(map
.get
::<B
>().unwrap(), &B(200));
372 assert_eq!(map
.len(), 6);
375 // Existing key (remove)
376 match map
.entry
::<C
>() {
377 Entry
::Vacant(_
) => unreachable!(),
378 Entry
::Occupied(view
) => {
379 assert_eq!(view
.remove(), C(30));
382 assert_eq!(map
.get
::<C
>(), None
);
383 assert_eq!(map
.len(), 5);
386 // Inexistent key (insert)
387 match map
.entry
::<J
>() {
388 Entry
::Occupied(_
) => unreachable!(),
389 Entry
::Vacant(view
) => {
390 assert_eq!(*view
.insert(J(1000)), J(1000));
393 assert_eq!(map
.get
::<J
>().unwrap(), &J(1000));
394 assert_eq!(map
.len(), 6);
396 // Entry.or_insert on existing key
397 map
.entry
::<B
>().or_insert(B(71)).0 += 1;
398 assert_eq!(map
.get
::<B
>().unwrap(), &B(201));
399 assert_eq!(map
.len(), 6);
401 // Entry.or_insert on nonexisting key
402 map
.entry
::<C
>().or_insert(C(300)).0 += 1;
403 assert_eq!(map
.get
::<C
>().unwrap(), &C(301));
404 assert_eq!(map
.len(), 7);
409 let mut map
: Map
<CloneAny
> = Map
::new();
410 let _
= map
.insert(A(1));
411 let _
= map
.insert(B(2));
412 let _
= map
.insert(D(3));
413 let _
= map
.insert(E(4));
414 let _
= map
.insert(F(5));
415 let _
= map
.insert(J(6));
416 let map2
= map
.clone();
417 assert_eq!(map2
.len(), 6);
418 assert_eq!(map2
.get
::<A
>(), Some(&A(1)));
419 assert_eq!(map2
.get
::<B
>(), Some(&B(2)));
420 assert_eq!(map2
.get
::<C
>(), None
);
421 assert_eq!(map2
.get
::<D
>(), Some(&D(3)));
422 assert_eq!(map2
.get
::<E
>(), Some(&E(4)));
423 assert_eq!(map2
.get
::<F
>(), Some(&F(5)));
424 assert_eq!(map2
.get
::<J
>(), Some(&J(6)));
428 fn test_varieties() {
429 fn assert_send
<T
: Send
>() { }
430 fn assert_sync
<T
: Sync
>() { }
431 fn assert_clone
<T
: Clone
>() { }
432 fn assert_debug
<T
: ::std
::fmt
::Debug
>() { }
433 assert_send
::<Map
<Any
+ Send
>>();
434 assert_send
::<Map
<Any
+ Send
+ Sync
>>();
435 assert_sync
::<Map
<Any
+ Sync
>>();
436 assert_sync
::<Map
<Any
+ Send
+ Sync
>>();
437 assert_debug
::<Map
<Any
>>();
438 assert_debug
::<Map
<Any
+ Send
>>();
439 assert_debug
::<Map
<Any
+ Sync
>>();
440 assert_debug
::<Map
<Any
+ Send
+ Sync
>>();
441 assert_send
::<Map
<CloneAny
+ Send
>>();
442 assert_send
::<Map
<CloneAny
+ Send
+ Sync
>>();
443 assert_sync
::<Map
<CloneAny
+ Sync
>>();
444 assert_sync
::<Map
<CloneAny
+ Send
+ Sync
>>();
445 assert_clone
::<Map
<CloneAny
+ Send
>>();
446 assert_clone
::<Map
<CloneAny
+ Send
+ Sync
>>();
447 assert_clone
::<Map
<CloneAny
+ Sync
>>();
448 assert_clone
::<Map
<CloneAny
+ Send
+ Sync
>>();
449 assert_debug
::<Map
<CloneAny
>>();
450 assert_debug
::<Map
<CloneAny
+ Send
>>();
451 assert_debug
::<Map
<CloneAny
+ Sync
>>();
452 assert_debug
::<Map
<CloneAny
+ Send
+ Sync
>>();