From 1a371f628c49bff7043e32f2060ebb3d25c2269e Mon Sep 17 00:00:00 2001
From: Przemyslaw Olejniczak <p.olejniczak@itwh.de>
Date: Wed, 14 Apr 2021 17:26:32 +0200
Subject: [PATCH] constexpr defaulted default constructor of WrappedMutex
 causes compile errors #8492

---
 src/google/protobuf/stubs/mutex.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/google/protobuf/stubs/mutex.h b/src/google/protobuf/stubs/mutex.h
index 82b62a66b05e..bff96814b441 100644
--- a/src/google/protobuf/stubs/mutex.h
+++ b/src/google/protobuf/stubs/mutex.h
@@ -116,7 +116,7 @@ class CallOnceInitializedMutex {
 // mutexes.
 class GOOGLE_PROTOBUF_CAPABILITY("mutex") PROTOBUF_EXPORT WrappedMutex {
  public:
-  constexpr WrappedMutex() = default;
+  constexpr WrappedMutex() {}
   void Lock() GOOGLE_PROTOBUF_ACQUIRE() { mu_.lock(); }
   void Unlock() GOOGLE_PROTOBUF_RELEASE() { mu_.unlock(); }
   // Crash if this Mutex is not held exclusively by this thread.