Add Equivalence trait

Cargo.toml

@@ -12,6 +12,7 @@ keywords = ["concurrent", "hashmap", "atomic", "lock-free"]
 exclude = ["assets/*"]
 
 [dependencies]
+equivalent = "1"
 seize = "0.4"
 serde = { version = "1", optional = true }
 
@@ -34,7 +35,10 @@ inherits = "release"
 debug-assertions = true
 
 [lints.rust]
-unexpected_cfgs = { level = "warn", check-cfg = ['cfg(papaya_stress)', 'cfg(papaya_asan)'] }
+unexpected_cfgs = { level = "warn", check-cfg = [
+    'cfg(papaya_stress)',
+    'cfg(papaya_asan)',
+] }
 
 [[bench]]
 name = "single_thread"

src/lib.rs

@@ -229,6 +229,7 @@ mod set;
 #[cfg(feature = "serde")]
 mod serde_impls;
 
+pub use equivalent::Equivalent;
 pub use map::{
     Compute, HashMap, HashMapBuilder, HashMapRef, Iter, Keys, OccupiedError, Operation, ResizeMode,
     Values,

src/map.rs

@@ -1,4 +1,5 @@
 use crate::raw::{self, InsertResult};
+use crate::Equivalent;
 use seize::{Collector, Guard, LocalGuard, OwnedGuard};
 
 use std::borrow::Borrow;
@@ -417,8 +418,7 @@ where
     #[inline]
     pub fn contains_key<Q>(&self, key: &Q, guard: &impl Guard) -> bool
     where
-        K: Borrow<Q>,
-        Q: Hash + Eq + ?Sized,
+        Q: Equivalent<K> + Hash + ?Sized,
     {
         self.get(key, guard).is_some()
     }
@@ -445,8 +445,8 @@ where
     #[inline]
     pub fn get<'g, Q>(&self, key: &Q, guard: &'g impl Guard) -> Option<&'g V>
     where
-        K: Borrow<Q> + 'g,
-        Q: Hash + Eq + ?Sized,
+        K: 'g,
+        Q: Equivalent<K> + Hash + ?Sized,
     {
         self.raw.check_guard(guard);
 
@@ -479,8 +479,7 @@ where
     #[inline]
     pub fn get_key_value<'g, Q>(&self, key: &Q, guard: &'g impl Guard) -> Option<(&'g K, &'g V)>
     where
-        K: Borrow<Q>,
-        Q: Hash + Eq + ?Sized,
+        Q: Equivalent<K> + Hash + ?Sized,
     {
         self.raw.check_guard(guard);
 
@@ -815,8 +814,8 @@ where
     #[inline]
     pub fn remove<'g, Q>(&self, key: &Q, guard: &'g impl Guard) -> Option<&'g V>
     where
-        K: Borrow<Q> + 'g,
-        Q: Hash + Eq + ?Sized,
+        K: 'g,
+        Q: Equivalent<K> + Hash + ?Sized,
     {
         self.raw.check_guard(guard);
 
@@ -848,8 +847,8 @@ where
     #[inline]
     pub fn remove_entry<'g, Q>(&self, key: &Q, guard: &'g impl Guard) -> Option<(&'g K, &'g V)>
     where
-        K: Borrow<Q>,
-        Q: Hash + Eq + ?Sized,
+        K: 'g,
+        Q: Equivalent<K> + Hash + ?Sized,
     {
         self.raw.check_guard(guard);
 
@@ -1278,8 +1277,7 @@ where
     #[inline]
     pub fn contains_key<Q>(&self, key: &Q) -> bool
     where
-        K: Borrow<Q>,
-        Q: Hash + Eq + ?Sized,
+        Q: Equivalent<K> + Hash + ?Sized,
     {
         self.get(key).is_some()
     }
@@ -1290,8 +1288,7 @@ where
     #[inline]
     pub fn get<Q>(&self, key: &Q) -> Option<&V>
     where
-        K: Borrow<Q>,
-        Q: Hash + Eq + ?Sized,
+        Q: Equivalent<K> + Hash + ?Sized,
     {
         // Safety: `self.guard` was created from our map.
         match unsafe { self.map.raw.get(key, &self.guard) } {
@@ -1306,8 +1303,7 @@ where
     #[inline]
     pub fn get_key_value<Q>(&self, key: &Q) -> Option<(&K, &V)>
     where
-        K: Borrow<Q>,
-        Q: Hash + Eq + ?Sized,
+        Q: Equivalent<K> + Hash + ?Sized,
     {
         // Safety: `self.guard` was created from our map.
         unsafe { self.map.raw.get(key, &self.guard) }

src/raw/mod.rs

@@ -2,7 +2,6 @@ mod alloc;
 mod probe;
 mod utils;
 
-use std::borrow::Borrow;
 use std::hash::{BuildHasher, Hash};
 use std::mem::MaybeUninit;
 use std::sync::atomic::{fence, AtomicPtr, AtomicU8, AtomicUsize, Ordering};
@@ -13,6 +12,7 @@ use self::alloc::{RawTable, Table};
 use self::probe::Probe;
 use self::utils::{untagged, AtomicPtrFetchOps, Counter, Parker, Shared, StrictProvenance, Tagged};
 use crate::map::{Compute, Operation, ResizeMode};
+use crate::Equivalent;
 
 use seize::{AsLink, Collector, Guard, Link};
 
@@ -286,8 +286,7 @@ where
     #[inline]
     pub unsafe fn get<'g, Q>(&self, key: &Q, guard: &'g impl Guard) -> Option<(&'g K, &'g V)>
     where
-        K: Borrow<Q>,
-        Q: Hash + Eq + ?Sized,
+        Q: Equivalent<K> + Hash + ?Sized,
     {
         let mut table = self.root(guard);
 
@@ -319,7 +318,7 @@ where
                     }
 
                     // Check for a full match.
-                    if unsafe { (*entry.ptr).key.borrow() } == key {
+                    if key.equivalent(unsafe { &(*entry.ptr).key }) {
                         // The entry was copied to the new table.
                         //
                         // In blocking resize mode we do not need to perform self check as all writes block
@@ -607,14 +606,9 @@ where
     //
     // The guard must be valid to use with this map.
     #[inline]
-    pub unsafe fn remove<'g, Q: ?Sized>(
-        &self,
-        key: &Q,
-        guard: &'g impl Guard,
-    ) -> Option<(&'g K, &'g V)>
+    pub unsafe fn remove<'g, Q>(&self, key: &Q, guard: &'g impl Guard) -> Option<(&'g K, &'g V)>
     where
-        K: Borrow<Q>,
-        Q: Hash + Eq,
+        Q: Equivalent<K> + Hash + ?Sized,
     {
         let mut table = self.root(guard);
 
@@ -661,7 +655,7 @@ where
                 }
 
                 // Check for a full match.
-                if unsafe { (*entry.ptr).key.borrow() != key } {
+                if !key.equivalent(unsafe { &(*entry.ptr).key }) {
                     probe.next(table.mask);
                     continue 'probe;
                 }

src/set.rs

@@ -1,4 +1,5 @@
 use crate::raw::{self, InsertResult};
+use crate::Equivalent;
 use seize::{Collector, Guard, LocalGuard, OwnedGuard};
 
 use crate::map::ResizeMode;
@@ -366,8 +367,7 @@ where
     #[inline]
     pub fn contains<Q>(&self, key: &Q, guard: &impl Guard) -> bool
     where
-        K: Borrow<Q>,
-        Q: Hash + Eq + ?Sized,
+        Q: Equivalent<K> + Hash + ?Sized,
     {
         self.get(key, guard).is_some()
     }
@@ -394,8 +394,7 @@ where
     #[inline]
     pub fn get<'g, Q>(&self, key: &Q, guard: &'g impl Guard) -> Option<&'g K>
     where
-        K: Borrow<Q> + 'g,
-        Q: Hash + Eq + ?Sized,
+        Q: Equivalent<K> + Hash + ?Sized,
     {
         self.raw.check_guard(guard);
 
@@ -459,10 +458,9 @@ where
     /// assert_eq!(set.pin().remove(&1), false);
     /// ```
     #[inline]
-    pub fn remove<'g, Q>(&self, key: &Q, guard: &'g impl Guard) -> bool
+    pub fn remove<Q>(&self, key: &Q, guard: &impl Guard) -> bool
     where
-        K: Borrow<Q> + 'g,
-        Q: Hash + Eq + ?Sized,
+        Q: Equivalent<K> + Hash + ?Sized,
     {
         self.raw.check_guard(guard);
 
@@ -772,8 +770,7 @@ where
     #[inline]
     pub fn contains<Q>(&self, key: &Q) -> bool
     where
-        K: Borrow<Q>,
-        Q: Hash + Eq + ?Sized,
+        Q: Equivalent<K> + Hash + ?Sized,
     {
         self.get(key).is_some()
     }
@@ -784,8 +781,7 @@ where
     #[inline]
     pub fn get<Q>(&self, key: &Q) -> Option<&K>
     where
-        K: Borrow<Q>,
-        Q: Hash + Eq + ?Sized,
+        Q: Equivalent<K> + Hash + ?Sized,
     {
         // Safety: `self.guard` was created from our map.
         match unsafe { self.set.raw.get(key, &self.guard) } {