Bug 1659909 - ToResultInvoke should also work with RefPtr/nsCOMPtr on win32; r=dom-workers-and-storage-reviewers,sg

Differential Revision: https://phabricator.services.mozilla.com/D87556

mfbt/ResultExtensions.h

@@ -242,14 +242,16 @@ auto ToResultInvoke(const SmartPtr<const T>& aObj,
 }
 
 #if defined(XP_WIN) && !defined(_WIN64)
-template <typename T, typename U, typename... XArgs, typename... Args>
+template <typename T, typename U, typename... XArgs, typename... Args,
+          typename = std::enable_if_t<std::is_base_of_v<U, T>>>
 auto ToResultInvoke(T& aObj, nsresult (__stdcall U::*aFunc)(XArgs...),
                     Args&&... aArgs) {
   return detail::ToResultInvokeMemberFunction<detail::select_last_t<XArgs...>>(
       aObj, aFunc, std::forward<Args>(aArgs)...);
 }
 
-template <typename T, typename U, typename... XArgs, typename... Args>
+template <typename T, typename U, typename... XArgs, typename... Args,
+          typename = std::enable_if_t<std::is_base_of_v<U, T>>>
 auto ToResultInvoke(const T& aObj,
                     nsresult (__stdcall U::*aFunc)(XArgs...) const,
                     Args&&... aArgs) {
@@ -269,6 +271,25 @@ auto ToResultInvoke(const T* const aObj,
                     Args&&... aArgs) {
   return ToResultInvoke(*aObj, aFunc, std::forward<Args>(aArgs)...);
 }
+
+template <template <class> class SmartPtr, typename T, typename U,
+          typename... XArgs, typename... Args,
+          typename = std::enable_if_t<std::is_base_of_v<U, T>>,
+          typename = decltype(*std::declval<const SmartPtr<T>>())>
+auto ToResultInvoke(const SmartPtr<T>& aObj,
+                    nsresult (__stdcall U::*aFunc)(XArgs...), Args&&... aArgs) {
+  return ToResultInvoke(*aObj, aFunc, std::forward<Args>(aArgs)...);
+}
+
+template <template <class> class SmartPtr, typename T, typename U,
+          typename... XArgs, typename... Args,
+          typename = std::enable_if_t<std::is_base_of_v<U, T>>,
+          typename = decltype(*std::declval<const SmartPtr<T>>())>
+auto ToResultInvoke(const SmartPtr<const T>& aObj,
+                    nsresult (__stdcall U::*aFunc)(XArgs...) const,
+                    Args&&... aArgs) {
+  return ToResultInvoke(*aObj, aFunc, std::forward<Args>(aArgs)...);
+}
 #endif
 
 // Macro version of ToResultInvoke for member functions. The macro has the

mfbt/tests/gtest/TestResultExtensions.cpp

@@ -412,3 +412,9 @@ TEST(ResultExtensions_ToResultInvoke, RefPtr_MemberFunction_NoInput_Macro)
     ASSERT_EQ(NS_ERROR_FAILURE, valOrErr.unwrapErr());
   }
 }
+
+TEST(ResultExtensions_ToResultInvoke, nsCOMPtr_NS_IMETHOD_bool_Result)
+{
+  nsCOMPtr<nsIFile> file = MakeAndAddRef<nsLocalFile>();
+  ASSERT_TRUE(ToResultInvoke(file, &nsIFile::Equals, file).isOk());
+}