Add Cc::ptr_eq, Weak::ptr_eq

src/cc.rs

@@ -377,6 +377,12 @@ impl<T: ?Sized, O: AbstractObjectSpace> RawCc<T, O> {
     pub fn strong_count(&self) -> usize {
         self.ref_count()
     }
+
+    /// Returns `true` if the two `Cc`s point to the same allocation
+    #[inline]
+    pub fn ptr_eq(this: &Self, other: &Self) -> bool {
+        this.0.as_ptr() == other.0.as_ptr()
+    }
 }
 
 impl<T: ?Sized, O: AbstractObjectSpace> RawWeak<T, O> {
@@ -412,6 +418,12 @@ impl<T: ?Sized, O: AbstractObjectSpace> RawWeak<T, O> {
     pub fn weak_count(&self) -> usize {
         self.inner().weak_count()
     }
+
+    /// Returns `true` if the two `Weak`s point to the same allocation
+    #[inline]
+    pub fn ptr_eq(this: &Self, other: &Self) -> bool {
+        this.0.as_ptr() == other.0.as_ptr()
+    }
 }
 
 impl<T: ?Sized, O: AbstractObjectSpace> RawCc<T, O> {

src/tests.rs

@@ -1,6 +1,6 @@
-use crate::debug;
 use crate::testutil::test_small_graph;
 use crate::{collect, Cc, Trace, Tracer};
+use crate::{debug, Weak};
 use std::cell::Cell;
 use std::cell::RefCell;
 use std::ops::Deref;
@@ -509,6 +509,27 @@ fn test_trace_impl_double_visits() {
     }
 }
 
+#[test]
+fn test_cc_ptr_eq() {
+    let a = Cc::new(1);
+    let b = a.clone();
+    let c = Cc::new(1);
+
+    assert!(Cc::ptr_eq(&a, &b));
+    assert!(!Cc::ptr_eq(&a, &c));
+}
+
+#[test]
+fn test_weak_ptr_eq() {
+    let a = Cc::new(1);
+    let b = a.downgrade();
+    let a = a.downgrade();
+    let c = Cc::new(1).downgrade();
+
+    assert!(Weak::ptr_eq(&a, &b));
+    assert!(!Weak::ptr_eq(&a, &c));
+}
+
 #[cfg(not(miri))]
 quickcheck::quickcheck! {
     fn test_quickcheck_16_vertex_graph(edges: Vec<u8>, atomic_bits: u16, collect_bits: u16) -> bool {