add Object::get_identity_hash (#169)

src/binding.cc

@@ -610,6 +610,10 @@ v8::Isolate* v8__Object__GetIsolate(v8::Object& self) {
   return self.GetIsolate();
 }
 
+int v8__Object__GetIdentityHash(v8::Object& self) {
+  return self.GetIdentityHash();
+}
+
 v8::Array* v8__Array__New(v8::Isolate* isolate, int length) {
   return local_to_ptr(v8::Array::New(isolate, length));
 }

src/object.rs

@@ -47,6 +47,7 @@ extern "C" {
     key: *const Name,
     value: *const Value,
   ) -> MaybeBool;
+  fn v8__Object__GetIdentityHash(object: &Object) -> int;
 
   fn v8__Array__New(isolate: *mut Isolate, length: int) -> *mut Array;
 }
@@ -148,6 +149,15 @@ impl Object {
   pub fn get_isolate(&mut self) -> &Isolate {
     unsafe { v8__Object__GetIsolate(self) }
   }
+
+  /// Returns the identity hash for this object. The current implementation
+  /// uses a hidden property on the object to store the identity hash.
+  ///
+  /// The return value will never be 0. Also, it is not guaranteed to be
+  /// unique.
+  pub fn get_identity_hash(&self) -> int {
+    unsafe { v8__Object__GetIdentityHash(self) }
+  }
 }
 
 impl Array {

tests/test_api.rs

@@ -827,7 +827,8 @@ fn object() {
 
     let object_ = v8::Object::new(scope);
     assert!(!object_.is_null_or_undefined());
-
+    let id = object_.get_identity_hash();
+    assert_ne!(id, 0);
     context.exit();
   }
   drop(locker);