From d29b143bda80baad6fd3f5b523ed54f10eb0eea3 Mon Sep 17 00:00:00 2001
From: Abseil Team <absl-team@google.com>
Date: Wed, 12 Oct 2022 10:30:15 -0700
Subject: Workaround for Visual C++ error C2039 with std::tuple_element_t.
Fixes #3931
PiperOrigin-RevId: 480659507
Change-Id: I6fabef63b1285189a06375227273d9de2456e37a
---
googlemock/include/gmock/gmock-actions.h | 12 ++++++++----
googlemock/include/gmock/internal/gmock-internal-utils.h | 7 +++++++
2 files changed, 15 insertions(+), 4 deletions(-)
diff --git a/googlemock/include/gmock/gmock-actions.h b/googlemock/include/gmock/gmock-actions.h
index 7e78c09..aad07d5 100644
--- a/googlemock/include/gmock/gmock-actions.h
+++ b/googlemock/include/gmock/gmock-actions.h
@@ -1428,8 +1428,10 @@ struct WithArgsAction {
// MSVC complains about the I parameter pack not being
// expanded (error C3520) despite it being expanded in the
// type alias.
- OnceAction<R(typename std::tuple_element<
- I, std::tuple<Args...>>::type...)>>::value,
+ // TupleElement is also an MSVC workaround.
+ // See its definition for details.
+ OnceAction<R(internal::TupleElement<
+ I, std::tuple<Args...>>...)>>::value,
int>::type = 0>
operator OnceAction<R(Args...)>() && { // NOLINT
struct OA {
@@ -1453,8 +1455,10 @@ struct WithArgsAction {
// MSVC complains about the I parameter pack not being
// expanded (error C3520) despite it being expanded in the
// type alias.
- Action<R(typename std::tuple_element<
- I, std::tuple<Args...>>::type...)>>::value,
+ // TupleElement is also an MSVC workaround.
+ // See its definition for details.
+ Action<R(internal::TupleElement<
+ I, std::tuple<Args...>>...)>>::value,
int>::type = 0>
operator Action<R(Args...)>() const { // NOLINT
Action<InnerSignature<R, Args...>> converted(inner_action);
diff --git a/googlemock/include/gmock/internal/gmock-internal-utils.h b/googlemock/include/gmock/internal/gmock-internal-utils.h
index 92d8eb9..2678920 100644
--- a/googlemock/include/gmock/internal/gmock-internal-utils.h
+++ b/googlemock/include/gmock/internal/gmock-internal-utils.h
@@ -453,6 +453,13 @@ struct Function<R(Args...)> {
template <typename R, typename... Args>
constexpr size_t Function<R(Args...)>::ArgumentCount;
+// Workaround for MSVC error C2039: 'type': is not a member of 'std'
+// when std::tuple_element is used.
+// See: https://github.com/google/googletest/issues/3931
+// Can be replaced with std::tuple_element_t in C++14.
+template <size_t I, typename T>
+using TupleElement = typename std::tuple_element<I, T>::type;
+
bool Base64Unescape(const std::string& encoded, std::string* decoded);
#ifdef _MSC_VER
--
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