From 0b7798b2fba340969a0cf83698e5c0a2e25b7dbc Mon Sep 17 00:00:00 2001
From: Dino Radakovic <dinor@google.com>
Date: Wed, 26 Jan 2022 08:38:44 -0800
Subject: [PATCH] Change `ReturnArg` to use perfect forwarding of arguments
 (#3733)

PiperOrigin-RevId: 424355706
Change-Id: I618e5574b4b2c56a343905c20d8cc6d2a70cbcd1
---
 googlemock/include/gmock/gmock-actions.h   | 6 +++---
 googlemock/test/gmock-more-actions_test.cc | 6 ++++++
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/googlemock/include/gmock/gmock-actions.h b/googlemock/include/gmock/gmock-actions.h
index 72663c85..70c325a4 100644
--- a/googlemock/include/gmock/gmock-actions.h
+++ b/googlemock/include/gmock/gmock-actions.h
@@ -1079,9 +1079,9 @@ struct ReturnNewAction {
 template <size_t k>
 struct ReturnArgAction {
   template <typename... Args>
-  auto operator()(const Args&... args) const ->
-      typename std::tuple_element<k, std::tuple<Args...>>::type {
-    return std::get<k>(std::tie(args...));
+  auto operator()(Args&&... args) const -> decltype(std::get<k>(
+      std::forward_as_tuple(std::forward<Args>(args)...))) {
+    return std::get<k>(std::forward_as_tuple(std::forward<Args>(args)...));
   }
 };
 
diff --git a/googlemock/test/gmock-more-actions_test.cc b/googlemock/test/gmock-more-actions_test.cc
index 53bb029f..fdc8c709 100644
--- a/googlemock/test/gmock-more-actions_test.cc
+++ b/googlemock/test/gmock-more-actions_test.cc
@@ -462,6 +462,12 @@ TEST(ReturnArgActionTest, WorksForMultiArgStringArg2) {
   EXPECT_EQ("seven", a.Perform(std::make_tuple(5, 6, std::string("seven"), 8)));
 }
 
+TEST(ReturnArgActionTest, WorksForNonConstRefArg0) {
+  const Action<std::string&(std::string&)> a = ReturnArg<0>();
+  std::string s = "12345";
+  EXPECT_EQ(&s, &a.Perform(std::forward_as_tuple(s)));
+}
+
 TEST(SaveArgActionTest, WorksForSameType) {
   int result = 0;
   const Action<void(int n)> a1 = SaveArg<0>(&result);