Fix compiler error with brace initializer (conflicts with #8492)
diff --git a/src/google/protobuf/stubs/mutex.h b/src/google/protobuf/stubs/mutex.h
index bff9681..79c9f67 100644
--- a/src/google/protobuf/stubs/mutex.h
+++ b/src/google/protobuf/stubs/mutex.h
@@ -116,7 +116,11 @@
// mutexes.
class GOOGLE_PROTOBUF_CAPABILITY("mutex") PROTOBUF_EXPORT WrappedMutex {
public:
+#if defined(__QNX__)
+ constexpr WrappedMutex() = default;
+#else
constexpr WrappedMutex() {}
+#endif
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.
