X-Git-Url: https://git.chrismorgan.info/anymap/blobdiff_plain/c6480a91723804547a8cc99a2066f64436008abe..27eca551823bac40421ae7ee6e83e7541790b723:/src/lib.rs diff --git a/src/lib.rs b/src/lib.rs index e38670b..beef1bd 100644 --- a/src/lib.rs +++ b/src/lib.rs @@ -1,17 +1,52 @@ -//! This crate provides the `AnyMap` type, a safe and convenient store for one value of each type. +//! This crate provides a safe and convenient store for one value of each type. +//! +//! Your starting point is [`Map`]. It has an example. -#![feature(core, std_misc, convert)] -#![cfg_attr(test, feature(test))] #![warn(missing_docs, unused_results)] -#[cfg(test)] -extern crate test; +#![cfg_attr(not(feature = "std"), no_std)] + +use core::any::{Any, TypeId}; +use core::convert::TryInto; +use core::hash::{Hasher, BuildHasherDefault}; +use core::marker::PhantomData; + +#[cfg(not(any(feature = "std", feature = "hashbrown")))] +compile_error!("anymap: you must enable the 'std' feature or the 'hashbrown' feature"); -use std::any::TypeId; -use std::marker::PhantomData; +#[cfg(not(feature = "std"))] +extern crate alloc; -use raw::{RawAnyMap, Any}; -use unchecked_any::UncheckedAnyExt; +#[cfg(not(feature = "std"))] +use alloc::boxed::Box; + +use any::{UncheckedAnyExt, IntoBox}; +pub use any::CloneAny; + +#[cfg(all(feature = "std", not(feature = "hashbrown")))] +/// A re-export of [`std::collections::hash_map`] for raw access. +/// +/// If the `hashbrown` feature gets enabled, this will become an export of `hashbrown::hash_map`. +/// +/// As with [`RawMap`][crate::RawMap], this is exposed for compatibility reasons, since features +/// are supposed to be additive. This *is* imperfect, since the two modules are incompatible in a +/// few places (e.g. hashbrown’s entry types have an extra generic parameter), but it’s close, and +/// much too useful to give up the whole concept. +pub use std::collections::hash_map as raw_hash_map; + +#[cfg(feature = "hashbrown")] +/// A re-export of [`hashbrown::hash_map`] for raw access. +/// +/// If the `hashbrown` feature was disabled, this would become an export of +/// `std::collections::hash_map`. +/// +/// As with [`RawMap`][crate::RawMap], this is exposed for compatibility reasons, since features +/// are supposed to be additive. This *is* imperfect, since the two modules are incompatible in a +/// few places (e.g. hashbrown’s entry types have an extra generic parameter), but it’s close, and +/// much too useful to give up the whole concept. +pub use hashbrown::hash_map as raw_hash_map; + +use self::raw_hash_map::HashMap; macro_rules! impl_common_methods { ( @@ -19,10 +54,10 @@ macro_rules! impl_common_methods { new() => $new:expr; with_capacity($with_capacity_arg:ident) => $with_capacity:expr; ) => { - impl $t { + impl $t { /// Create an empty collection. #[inline] - pub fn new() -> $t { + pub fn new() -> $t { $t { $field: $new, } @@ -30,7 +65,7 @@ macro_rules! impl_common_methods { /// Creates an empty collection with the given initial capacity. #[inline] - pub fn with_capacity($with_capacity_arg: usize) -> $t { + pub fn with_capacity($with_capacity_arg: usize) -> $t { $t { $field: $with_capacity, } @@ -62,6 +97,10 @@ macro_rules! impl_common_methods { self.$field.shrink_to_fit() } + // Additional stable methods (as of 1.60.0-nightly) that could be added: + // try_reserve(&mut self, additional: usize) -> Result<(), TryReserveError> (1.57.0) + // shrink_to(&mut self, min_capacity: usize) (1.56.0) + /// Returns the number of items in the collection. #[inline] pub fn len(&self) -> usize { @@ -80,20 +119,56 @@ macro_rules! impl_common_methods { self.$field.clear() } } + + impl Default for $t { + #[inline] + fn default() -> $t { + $t::new() + } + } } } -mod unchecked_any; -pub mod raw; -#[cfg(feature = "clone")] -mod with_clone; +mod any; + +/// Raw access to the underlying `HashMap`. +/// +/// This is a public type alias because the underlying `HashMap` could be +/// `std::collections::HashMap` or `hashbrown::HashMap`, depending on the crate features enabled. +/// For that reason, you should refer to this type as `anymap::RawMap` rather than +/// `std::collections::HashMap` to avoid breakage if something else in your crate tree enables +/// hashbrown. +/// +/// See also [`raw_hash_map`], an export of the corresponding `hash_map` module. +pub type RawMap = HashMap, BuildHasherDefault>; /// A collection containing zero or one values for any given type and allowing convenient, /// type-safe access to those values. /// +/// The type parameter `A` allows you to use a different value type; normally you will want it to +/// be `core::any::Any` (also known as `std::any::Any`), but there are other choices: +/// +/// - If you want the entire map to be cloneable, use `CloneAny` instead of `Any`; with that, you +/// can only add types that implement `Clone` to the map. +/// - You can add on `+ Send` or `+ Send + Sync` (e.g. `Map`) to add those auto +/// traits. +/// +/// Cumulatively, there are thus six forms of map: +/// +/// - [Map]<dyn [core::any::Any]>, also spelled [`AnyMap`] for convenience. +/// - [Map]<dyn [core::any::Any] + Send> +/// - [Map]<dyn [core::any::Any] + Send + Sync> +/// - [Map]<dyn [CloneAny]> +/// - [Map]<dyn [CloneAny] + Send> +/// - [Map]<dyn [CloneAny] + Send + Sync> +/// +/// ## Example +/// +/// (Here using the [`AnyMap`] convenience alias; the first line could use +/// [anymap::Map][Map]::<[core::any::Any]>::new() instead if desired.) +/// /// ```rust -/// # use anymap::AnyMap; -/// let mut data = AnyMap::new(); +/// let mut data = anymap::AnyMap::new(); /// assert_eq!(data.get(), None::<&i32>); /// data.insert(42i32); /// assert_eq!(data.get(), Some(&42i32)); @@ -114,27 +189,45 @@ mod with_clone; /// /// Values containing non-static references are not permitted. #[derive(Debug)] -#[cfg_attr(feature = "clone", derive(Clone))] -pub struct AnyMap { - raw: RawAnyMap, +pub struct Map { + raw: RawMap, } +// #[derive(Clone)] would want A to implement Clone, but in reality it’s only Box that can. +impl Clone for Map where Box: Clone { + #[inline] + fn clone(&self) -> Map { + Map { + raw: self.raw.clone(), + } + } +} + +/// The most common type of `Map`: just using `Any`; [Map]<dyn [Any]>. +/// +/// Why is this a separate type alias rather than a default value for `Map`? `Map::new()` +/// doesn’t seem to be happy to infer that it should go with the default value. +/// It’s a bit sad, really. Ah well, I guess this approach will do. +pub type AnyMap = Map; + impl_common_methods! { - field: AnyMap.raw; - new() => RawAnyMap::new(); - with_capacity(capacity) => RawAnyMap::with_capacity(capacity); + field: Map.raw; + new() => RawMap::with_hasher(Default::default()); + with_capacity(capacity) => RawMap::with_capacity_and_hasher(capacity, Default::default()); } -impl AnyMap { +impl Map { /// Returns a reference to the value stored in the collection for the type `T`, if it exists. - pub fn get(&self) -> Option<&T> { + #[inline] + pub fn get>(&self) -> Option<&T> { self.raw.get(&TypeId::of::()) .map(|any| unsafe { any.downcast_ref_unchecked::() }) } /// Returns a mutable reference to the value stored in the collection for the type `T`, /// if it exists. - pub fn get_mut(&mut self) -> Option<&mut T> { + #[inline] + pub fn get_mut>(&mut self) -> Option<&mut T> { self.raw.get_mut(&TypeId::of::()) .map(|any| unsafe { any.downcast_mut_unchecked::() }) } @@ -142,82 +235,164 @@ impl AnyMap { /// 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. - pub fn insert(&mut self, value: T) -> Option { + #[inline] + pub fn insert>(&mut self, value: T) -> Option { unsafe { - self.raw.insert(TypeId::of::(), Box::new(value)) + self.raw.insert(TypeId::of::(), value.into_box()) .map(|any| *any.downcast_unchecked::()) } } + // rustc 1.60.0-nightly has another method try_insert that would be nice to add when stable. + /// Removes the `T` value from the collection, /// returning it if there was one or `None` if there was not. - pub fn remove(&mut self) -> Option { + #[inline] + pub fn remove>(&mut self) -> Option { self.raw.remove(&TypeId::of::()) .map(|any| *unsafe { any.downcast_unchecked::() }) } /// Returns true if the collection contains a value of type `T`. #[inline] - pub fn contains(&self) -> bool { + pub fn contains>(&self) -> bool { self.raw.contains_key(&TypeId::of::()) } /// Gets the entry for the given type in the collection for in-place manipulation - pub fn entry(&mut self) -> Entry { + #[inline] + pub fn entry>(&mut self) -> Entry { match self.raw.entry(TypeId::of::()) { - raw::Entry::Occupied(e) => Entry::Occupied(OccupiedEntry { + raw_hash_map::Entry::Occupied(e) => Entry::Occupied(OccupiedEntry { inner: e, type_: PhantomData, }), - raw::Entry::Vacant(e) => Entry::Vacant(VacantEntry { + raw_hash_map::Entry::Vacant(e) => Entry::Vacant(VacantEntry { inner: e, type_: PhantomData, }), } } -} -impl AsRef for AnyMap { - fn as_ref(&self) -> &RawAnyMap { + /// Get access to the raw hash map that backs this. + /// + /// This will seldom be useful, but it’s conceivable that you could wish to iterate over all + /// the items in the collection, and this lets you do that. + /// + /// To improve compatibility with Cargo features, interact with this map through the names + /// [`anymap::RawMap`][RawMap] and [`anymap::raw_hash_map`][raw_hash_map], rather than through + /// `std::collections::{HashMap, hash_map}` or `hashbrown::{HashMap, hash_map}`, for anything + /// beyond self methods. Otherwise, if you use std and another crate in the tree enables + /// hashbrown, your code will break. + #[inline] + pub fn as_raw(&self) -> &RawMap { &self.raw } -} -impl AsMut for AnyMap { - fn as_mut(&mut self) -> &mut RawAnyMap { + /// Get mutable access to the raw hash map that backs this. + /// + /// This will seldom be useful, but it’s conceivable that you could wish to iterate over all + /// the items in the collection mutably, or drain or something, or *possibly* even batch + /// insert, and this lets you do that. + /// + /// To improve compatibility with Cargo features, interact with this map through the names + /// [`anymap::RawMap`][RawMap] and [`anymap::raw_hash_map`][raw_hash_map], rather than through + /// `std::collections::{HashMap, hash_map}` or `hashbrown::{HashMap, hash_map}`, for anything + /// beyond self methods. Otherwise, if you use std and another crate in the tree enables + /// hashbrown, your code will break. + /// + /// # Safety + /// + /// If you insert any values to the raw map, the key (a `TypeId`) must match the value’s type, + /// or *undefined behaviour* will occur when you access those values. + /// + /// (*Removing* entries is perfectly safe.) + #[inline] + pub unsafe fn as_raw_mut(&mut self) -> &mut RawMap { &mut self.raw } -} -impl Into for AnyMap { - fn into(self) -> RawAnyMap { + /// Convert this into the raw hash map that backs this. + /// + /// This will seldom be useful, but it’s conceivable that you could wish to consume all the + /// items in the collection and do *something* with some or all of them, and this lets you do + /// that, without the `unsafe` that `.as_raw_mut().drain()` would require. + /// + /// To improve compatibility with Cargo features, interact with this map through the names + /// [`anymap::RawMap`][RawMap] and [`anymap::raw_hash_map`][raw_hash_map], rather than through + /// `std::collections::{HashMap, hash_map}` or `hashbrown::{HashMap, hash_map}`, for anything + /// beyond self methods. Otherwise, if you use std and another crate in the tree enables + /// hashbrown, your code will break. + #[inline] + pub fn into_raw(self) -> RawMap { self.raw } + + /// Construct a map from a collection of raw values. + /// + /// You know what? I can’t immediately think of any legitimate use for this, especially because + /// of the requirement of the `BuildHasherDefault` generic in the map. + /// + /// Perhaps this will be most practical as `unsafe { Map::from_raw(iter.collect()) }`, iter + /// being an iterator over `(TypeId, Box)` pairs. Eh, this method provides symmetry with + /// `into_raw`, so I don’t care if literally no one ever uses it. I’m not even going to write a + /// test for it, it’s so trivial. + /// + /// To improve compatibility with Cargo features, interact with this map through the names + /// [`anymap::RawMap`][RawMap] and [`anymap::raw_hash_map`][raw_hash_map], rather than through + /// `std::collections::{HashMap, hash_map}` or `hashbrown::{HashMap, hash_map}`, for anything + /// beyond self methods. Otherwise, if you use std and another crate in the tree enables + /// hashbrown, your code will break. + /// + /// # Safety + /// + /// For all entries in the raw map, the key (a `TypeId`) must match the value’s type, + /// or *undefined behaviour* will occur when you access that entry. + #[inline] + pub unsafe fn from_raw(raw: RawMap) -> Map { + Self { raw } + } } -/// A view into a single occupied location in an `AnyMap`. -pub struct OccupiedEntry<'a, V: 'a> { - inner: raw::OccupiedEntry<'a>, +impl Extend> for Map { + #[inline] + fn extend>>(&mut self, iter: T) { + for item in iter { + let _ = self.raw.insert(item.type_id(), item); + } + } +} + +/// A view into a single occupied location in an `Map`. +pub struct OccupiedEntry<'a, A: ?Sized + UncheckedAnyExt, V: 'a> { + #[cfg(all(feature = "std", not(feature = "hashbrown")))] + inner: raw_hash_map::OccupiedEntry<'a, TypeId, Box>, + #[cfg(feature = "hashbrown")] + inner: raw_hash_map::OccupiedEntry<'a, TypeId, Box, BuildHasherDefault>, type_: PhantomData, } -/// A view into a single empty location in an `AnyMap`. -pub struct VacantEntry<'a, V: 'a> { - inner: raw::VacantEntry<'a>, +/// A view into a single empty location in an `Map`. +pub struct VacantEntry<'a, A: ?Sized + UncheckedAnyExt, V: 'a> { + #[cfg(all(feature = "std", not(feature = "hashbrown")))] + inner: raw_hash_map::VacantEntry<'a, TypeId, Box>, + #[cfg(feature = "hashbrown")] + inner: raw_hash_map::VacantEntry<'a, TypeId, Box, BuildHasherDefault>, type_: PhantomData, } -/// A view into a single location in an `AnyMap`, which may be vacant or occupied. -pub enum Entry<'a, V: 'a> { +/// A view into a single location in an `Map`, which may be vacant or occupied. +pub enum Entry<'a, A: ?Sized + UncheckedAnyExt, V: 'a> { /// An occupied Entry - Occupied(OccupiedEntry<'a, V>), + Occupied(OccupiedEntry<'a, A, V>), /// A vacant Entry - Vacant(VacantEntry<'a, V>), + Vacant(VacantEntry<'a, A, V>), } -impl<'a, V: Any + Clone> Entry<'a, V> { +impl<'a, A: ?Sized + UncheckedAnyExt, V: IntoBox> Entry<'a, 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. + #[inline] pub fn or_insert(self, default: V) -> &'a mut V { match self { Entry::Occupied(inner) => inner.into_mut(), @@ -227,6 +402,7 @@ impl<'a, V: Any + Clone> Entry<'a, V> { /// 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. + #[inline] pub fn or_insert_with V>(self, default: F) -> &'a mut V { match self { Entry::Occupied(inner) => inner.into_mut(), @@ -235,77 +411,80 @@ impl<'a, V: Any + Clone> Entry<'a, V> { } } -impl<'a, V: Any> OccupiedEntry<'a, V> { +impl<'a, A: ?Sized + UncheckedAnyExt, V: IntoBox> OccupiedEntry<'a, A, V> { /// Gets a reference to the value in the entry + #[inline] pub fn get(&self) -> &V { unsafe { self.inner.get().downcast_ref_unchecked() } } /// Gets a mutable reference to the value in the entry + #[inline] pub fn get_mut(&mut self) -> &mut V { 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 + #[inline] pub fn into_mut(self) -> &'a mut V { unsafe { self.inner.into_mut().downcast_mut_unchecked() } } /// Sets the value of the entry, and returns the entry's old value + #[inline] pub fn insert(&mut self, value: V) -> V { - unsafe { *self.inner.insert(Box::new(value)).downcast_unchecked() } + unsafe { *self.inner.insert(value.into_box()).downcast_unchecked() } } /// Takes the value out of the entry, and returns it + #[inline] pub fn remove(self) -> V { unsafe { *self.inner.remove().downcast_unchecked() } } } -impl<'a, V: Any> VacantEntry<'a, V> { +impl<'a, A: ?Sized + UncheckedAnyExt, V: IntoBox> VacantEntry<'a, A, V> { /// Sets the value of the entry with the VacantEntry's key, /// and returns a mutable reference to it + #[inline] pub fn insert(self, value: V) -> &'a mut V { - unsafe { self.inner.insert(Box::new(value)).downcast_mut_unchecked() } + unsafe { self.inner.insert(value.into_box()).downcast_mut_unchecked() } } } -#[bench] -fn bench_insertion(b: &mut ::test::Bencher) { - b.iter(|| { - let mut data = AnyMap::new(); - for _ in 0..100 { - let _ = data.insert(42); - } - }) +/// A hasher designed to eke a little more speed out, given `TypeId`’s known characteristics. +/// +/// Specifically, this is a no-op hasher that expects to be fed a u64’s worth of +/// randomly-distributed bits. It works well for `TypeId` (eliminating start-up time, so that my +/// get_missing benchmark is ~30ns rather than ~900ns, and being a good deal faster after that, so +/// that my insert_and_get_on_260_types benchmark is ~12μs instead of ~21.5μs), but will +/// panic in debug mode and always emit zeros in release mode for any other sorts of inputs, so +/// yeah, don’t use it! 😀 +#[derive(Default)] +pub struct TypeIdHasher { + value: u64, } -#[bench] -fn bench_get_missing(b: &mut ::test::Bencher) { - b.iter(|| { - let data = AnyMap::new(); - for _ in 0..100 { - assert_eq!(data.get(), None::<&i32>); - } - }) -} +impl Hasher for TypeIdHasher { + #[inline] + fn write(&mut self, bytes: &[u8]) { + // This expects to receive exactly one 64-bit value, and there’s no realistic chance of + // that changing, but I don’t want to depend on something that isn’t expressly part of the + // contract for safety. But I’m OK with release builds putting everything in one bucket + // if it *did* change (and debug builds panicking). + debug_assert_eq!(bytes.len(), 8); + let _ = bytes.try_into() + .map(|array| self.value = u64::from_ne_bytes(array)); + } -#[bench] -fn bench_get_present(b: &mut ::test::Bencher) { - b.iter(|| { - let mut data = AnyMap::new(); - let _ = data.insert(42); - // These inner loops are a feeble attempt to drown the other factors. - for _ in 0..100 { - assert_eq!(data.get(), Some(&42)); - } - }) + #[inline] + fn finish(&self) -> u64 { self.value } } #[cfg(test)] mod tests { - use {AnyMap, Entry}; + use super::*; #[derive(Clone, Debug, PartialEq)] struct A(i32); #[derive(Clone, Debug, PartialEq)] struct B(i32); @@ -315,77 +494,89 @@ mod tests { #[derive(Clone, Debug, PartialEq)] struct F(i32); #[derive(Clone, Debug, PartialEq)] struct J(i32); - #[test] - fn test_entry() { - let mut map: AnyMap = AnyMap::new(); - assert_eq!(map.insert(A(10)), None); - assert_eq!(map.insert(B(20)), None); - assert_eq!(map.insert(C(30)), None); - assert_eq!(map.insert(D(40)), None); - assert_eq!(map.insert(E(50)), None); - assert_eq!(map.insert(F(60)), None); - - // Existing key (insert) - match map.entry::() { - Entry::Vacant(_) => unreachable!(), - Entry::Occupied(mut view) => { - assert_eq!(view.get(), &A(10)); - assert_eq!(view.insert(A(100)), A(10)); - } - } - assert_eq!(map.get::().unwrap(), &A(100)); - assert_eq!(map.len(), 6); + macro_rules! test_entry { + ($name:ident, $init:ty) => { + #[test] + fn $name() { + let mut map = <$init>::new(); + assert_eq!(map.insert(A(10)), None); + assert_eq!(map.insert(B(20)), None); + assert_eq!(map.insert(C(30)), None); + assert_eq!(map.insert(D(40)), None); + assert_eq!(map.insert(E(50)), None); + assert_eq!(map.insert(F(60)), None); + + // Existing key (insert) + match map.entry::() { + Entry::Vacant(_) => unreachable!(), + Entry::Occupied(mut view) => { + assert_eq!(view.get(), &A(10)); + assert_eq!(view.insert(A(100)), A(10)); + } + } + assert_eq!(map.get::().unwrap(), &A(100)); + assert_eq!(map.len(), 6); + + + // Existing key (update) + match map.entry::() { + Entry::Vacant(_) => unreachable!(), + Entry::Occupied(mut view) => { + let v = view.get_mut(); + let new_v = B(v.0 * 10); + *v = new_v; + } + } + assert_eq!(map.get::().unwrap(), &B(200)); + assert_eq!(map.len(), 6); - // Existing key (update) - match map.entry::() { - Entry::Vacant(_) => unreachable!(), - Entry::Occupied(mut view) => { - let v = view.get_mut(); - let new_v = B(v.0 * 10); - *v = new_v; - } - } - assert_eq!(map.get().unwrap(), &B(200)); - assert_eq!(map.len(), 6); + // Existing key (remove) + match map.entry::() { + Entry::Vacant(_) => unreachable!(), + Entry::Occupied(view) => { + assert_eq!(view.remove(), C(30)); + } + } + assert_eq!(map.get::(), None); + assert_eq!(map.len(), 5); - // Existing key (remove) - match map.entry::() { - Entry::Vacant(_) => unreachable!(), - Entry::Occupied(view) => { - assert_eq!(view.remove(), C(30)); + // Inexistent key (insert) + match map.entry::() { + Entry::Occupied(_) => unreachable!(), + Entry::Vacant(view) => { + assert_eq!(*view.insert(J(1000)), J(1000)); + } + } + assert_eq!(map.get::().unwrap(), &J(1000)); + assert_eq!(map.len(), 6); + + // Entry.or_insert on existing key + map.entry::().or_insert(B(71)).0 += 1; + assert_eq!(map.get::().unwrap(), &B(201)); + assert_eq!(map.len(), 6); + + // Entry.or_insert on nonexisting key + map.entry::().or_insert(C(300)).0 += 1; + assert_eq!(map.get::().unwrap(), &C(301)); + assert_eq!(map.len(), 7); } } - assert_eq!(map.get::(), None); - assert_eq!(map.len(), 5); + } + test_entry!(test_entry_any, AnyMap); + test_entry!(test_entry_cloneany, Map); - // Inexistent key (insert) - match map.entry::() { - Entry::Occupied(_) => unreachable!(), - Entry::Vacant(view) => { - assert_eq!(*view.insert(J(1000)), J(1000)); - } - } - assert_eq!(map.get::().unwrap(), &J(1000)); - assert_eq!(map.len(), 6); - - // Entry.or_insert on existing key - map.entry::().or_insert(B(71)).0 += 1; - assert_eq!(map.get::().unwrap(), &B(201)); - assert_eq!(map.len(), 6); - - // Entry.or_insert on nonexisting key - map.entry::().or_insert(C(300)).0 += 1; - assert_eq!(map.get::().unwrap(), &C(301)); - assert_eq!(map.len(), 7); + #[test] + fn test_default() { + let map: AnyMap = Default::default(); + assert_eq!(map.len(), 0); } - #[cfg(feature = "clone")] #[test] fn test_clone() { - let mut map = AnyMap::new(); + let mut map: Map = Map::new(); let _ = map.insert(A(1)); let _ = map.insert(B(2)); let _ = map.insert(D(3)); @@ -402,4 +593,46 @@ mod tests { assert_eq!(map2.get::(), Some(&F(5))); assert_eq!(map2.get::(), Some(&J(6))); } + + #[test] + fn test_varieties() { + fn assert_send() { } + fn assert_sync() { } + fn assert_clone() { } + fn assert_debug() { } + assert_send::>(); + assert_send::>(); + assert_sync::>(); + assert_debug::>(); + assert_debug::>(); + assert_debug::>(); + assert_send::>(); + assert_send::>(); + assert_sync::>(); + assert_clone::>(); + assert_clone::>(); + assert_clone::>(); + assert_debug::>(); + assert_debug::>(); + assert_debug::>(); + } + + #[test] + fn type_id_hasher() { + #[cfg(not(feature = "std"))] + use alloc::vec::Vec; + use core::hash::Hash; + fn verify_hashing_with(type_id: TypeId) { + let mut hasher = TypeIdHasher::default(); + type_id.hash(&mut hasher); + // SAFETY: u64 is valid for all bit patterns. + assert_eq!(hasher.finish(), unsafe { core::mem::transmute::(type_id) }); + } + // Pick a variety of types, just to demonstrate it’s all sane. Normal, zero-sized, unsized, &c. + verify_hashing_with(TypeId::of::()); + verify_hashing_with(TypeId::of::<()>()); + verify_hashing_with(TypeId::of::()); + verify_hashing_with(TypeId::of::<&str>()); + verify_hashing_with(TypeId::of::>()); + } }