src: add equality operators for BaseObjectPtr

PR-URL: #33772
Backport-PR-URL: #33965
Reviewed-By: Benjamin Gruenbaum <[email protected]>

Author: addaleax

src/base_object-inl.h

@@ -338,6 +338,20 @@ BaseObjectPtrImpl<T, kIsWeak>::operator bool() const {
   return get() != nullptr;
 }
 
+template <typename T, bool kIsWeak>
+template <typename U, bool kW>
+bool BaseObjectPtrImpl<T, kIsWeak>::operator ==(
+    const BaseObjectPtrImpl<U, kW>& other) const {
+  return get() == other.get();
+}
+
+template <typename T, bool kIsWeak>
+template <typename U, bool kW>
+bool BaseObjectPtrImpl<T, kIsWeak>::operator !=(
+    const BaseObjectPtrImpl<U, kW>& other) const {
+  return get() != other.get();
+}
+
 template <typename T, typename... Args>
 BaseObjectPtr<T> MakeBaseObject(Args&&... args) {
   return BaseObjectPtr<T>(new T(std::forward<Args>(args)...));

src/base_object.h

@@ -236,6 +236,11 @@ class BaseObjectPtrImpl final {
   inline T* operator->() const;
   inline operator bool() const;
 
+  template <typename U, bool kW>
+  inline bool operator ==(const BaseObjectPtrImpl<U, kW>& other) const;
+  template <typename U, bool kW>
+  inline bool operator !=(const BaseObjectPtrImpl<U, kW>& other) const;
+
  private:
   union {
     BaseObject* target;  // Used for strong pointers.