//!
//! All relevant details are in the `RawMap` struct.
-use std::any::TypeId;
-use std::borrow::Borrow;
+use core::any::{Any, TypeId};
+use core::borrow::Borrow;
use std::collections::hash_map::{self, HashMap};
-use std::hash::Hash;
-use std::hash::{Hasher, BuildHasherDefault};
-use std::mem;
-use std::ops::{Index, IndexMut};
-use std::ptr;
+use core::convert::TryInto;
+use core::hash::Hash;
+use core::hash::{Hasher, BuildHasherDefault};
+use core::ops::{Index, IndexMut};
-use any::{Any, UncheckedAnyExt};
+use crate::any::UncheckedAnyExt;
#[derive(Default)]
struct TypeIdHasher {
impl Hasher for TypeIdHasher {
#[inline]
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(mem::transmute(&bytes[0]), &mut self.value, 1)
- }
+ // 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));
}
#[inline]
fn verify_hashing_with(type_id: TypeId) {
let mut hasher = TypeIdHasher::default();
type_id.hash(&mut hasher);
- assert_eq!(hasher.finish(), unsafe { mem::transmute::<TypeId, u64>(type_id) });
+ // SAFETY: u64 is valid for all bit patterns.
+ assert_eq!(hasher.finish(), unsafe { core::mem::transmute::<TypeId, u64>(type_id) });
}
// Pick a variety of types, just to demonstrate it’s all sane. Normal, zero-sized, unsized, &c.
verify_hashing_with(TypeId::of::<usize>());
/// contents of an `Map`. 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 RawMap<A: ?Sized + UncheckedAnyExt = Any> {
+pub struct RawMap<A: ?Sized + UncheckedAnyExt = dyn Any> {
inner: HashMap<TypeId, Box<A>, BuildHasherDefault<TypeIdHasher>>,
}
// #[derive(Clone)] would want A to implement Clone, but in reality it’s only Box<A> that can.
impl<A: ?Sized + UncheckedAnyExt> Clone for RawMap<A> where Box<A>: Clone {
+ #[inline]
fn clone(&self) -> RawMap<A> {
RawMap {
inner: self.inner.clone(),
}
}
-impl<A: ?Sized + UncheckedAnyExt> Default for RawMap<A> {
- fn default() -> RawMap<A> {
- RawMap::new()
- }
-}
-
impl_common_methods! {
field: RawMap.inner;
new() => HashMap::with_hasher(Default::default());
}
/// Gets the entry for the given type in the collection for in-place manipulation.
+ #[inline]
pub fn entry(&mut self, key: TypeId) -> Entry<A> {
match self.inner.entry(key) {
hash_map::Entry::Occupied(e) => Entry::Occupied(OccupiedEntry {
///
/// 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.
+ #[inline]
pub fn get<Q: ?Sized>(&self, k: &Q) -> Option<&A>
where TypeId: Borrow<Q>, Q: Hash + Eq {
self.inner.get(k).map(|x| &**x)
///
/// 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.
+ #[inline]
pub fn contains_key<Q: ?Sized>(&self, k: &Q) -> bool
where TypeId: Borrow<Q>, Q: Hash + Eq {
self.inner.contains_key(k)
///
/// 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.
+ #[inline]
pub fn get_mut<Q: ?Sized>(&mut self, k: &Q) -> Option<&mut A>
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.
+ /// 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.
+ /// # Safety
+ ///
+ /// `key` and the type ID of `value` must match, or *undefined behaviour* occurs.
+ #[inline]
pub unsafe fn insert(&mut self, key: TypeId, value: Box<A>) -> Option<Box<A>> {
self.inner.insert(key, value)
}
///
/// 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.
+ #[inline]
pub fn remove<Q: ?Sized>(&mut self, k: &Q) -> Option<Box<A>>
where TypeId: Borrow<Q>, Q: Hash + Eq {
self.inner.remove(k)
impl<A: ?Sized + UncheckedAnyExt, Q> Index<Q> for RawMap<A> where TypeId: Borrow<Q>, Q: Eq + Hash {
type Output = A;
+ #[inline]
fn index(&self, index: Q) -> &A {
self.get(&index).expect("no entry found for key")
}
}
impl<A: ?Sized + UncheckedAnyExt, Q> IndexMut<Q> for RawMap<A> where TypeId: Borrow<Q>, Q: Eq + Hash {
+ #[inline]
fn index_mut(&mut self, index: Q) -> &mut A {
self.get_mut(&index).expect("no entry found for key")
}
type Item = Box<A>;
type IntoIter = IntoIter<A>;
+ #[inline]
fn into_iter(self) -> IntoIter<A> {
IntoIter {
inner: self.inner.into_iter(),
/// Ensures a value is in the entry by inserting the default if empty, and returns
/// a mutable reference to the value in the entry.
///
- /// 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.
+ /// # Safety
+ ///
+ /// The type ID of `default` must match the entry’s key, or *undefined behaviour* occurs.
+ #[inline]
pub unsafe fn or_insert(self, default: Box<A>) -> &'a mut A {
match self {
Entry::Occupied(inner) => inner.into_mut(),
/// 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.
///
- /// 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.
+ /// # Safety
+ ///
+ /// The type ID of the value returned by `default` must match the entry’s key,
+ /// or *undefined behaviour* occurs.
+ #[inline]
pub unsafe fn or_insert_with<F: FnOnce() -> Box<A>>(self, default: F) -> &'a mut A {
match self {
Entry::Occupied(inner) => inner.into_mut(),
impl<'a, A: ?Sized + UncheckedAnyExt> OccupiedEntry<'a, A> {
/// Gets a reference to the value in the entry.
+ #[inline]
pub fn get(&self) -> &A {
&**self.inner.get()
}
/// Gets a mutable reference to the value in the entry.
+ #[inline]
pub fn get_mut(&mut self) -> &mut A {
&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.
+ #[inline]
pub fn into_mut(self) -> &'a mut A {
&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.
+ /// # Safety
+ ///
+ /// The type ID of `value` must match the entry’s key, or *undefined behaviour* occurs.
+ #[inline]
pub unsafe fn insert(&mut self, value: Box<A>) -> Box<A> {
self.inner.insert(value)
}
/// Takes the value out of the entry, and returns it.
+ #[inline]
pub fn remove(self) -> Box<A> {
self.inner.remove()
}
impl<'a, A: ?Sized + UncheckedAnyExt> VacantEntry<'a, A> {
/// Sets the value of the entry with the VacantEntry's key,
- /// and returns a mutable reference to it
+ /// and returns a mutable reference to it.
+ ///
+ /// # Safety
///
- /// 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.
+ /// The type ID of `value` must match the entry’s key, or *undefined behaviour* occurs.
+ #[inline]
pub unsafe fn insert(self, value: Box<A>) -> &'a mut A {
&mut **self.inner.insert(value)
}