15 files changed, 315 insertions, 144 deletions
diff --git a/src/Makefile.am b/src/Makefile.am
index ac41979d..a0c325dc 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -930,7 +930,7 @@ no_warning_test_LDADD = $(PTHREAD_LIBS) libprotobuf.la      \
                         ../gmock/gtest/lib/libgtest_main.la
 no_warning_test_CPPFLAGS = -I$(srcdir)/../gmock/gtest/include
 no_warning_test_CXXFLAGS = $(PTHREAD_CFLAGS) $(PTHREAD_DEF) $(ZLIB_DEF) \
-                           -Wall -Werror -Wno-invalid-offsetof -Werror=missing-declarations
+                           -Wall -Werror -Werror=missing-declarations
 nodist_no_warning_test_SOURCES = no_warning_test.cc $(protoc_outputs)
 
 TESTS = protobuf-test protobuf-lazy-descriptor-test protobuf-lite-test \
diff --git a/src/google/protobuf/any.pb.cc b/src/google/protobuf/any.pb.cc
index 1bd6cbe2..ace79986 100644
--- a/src/google/protobuf/any.pb.cc
+++ b/src/google/protobuf/any.pb.cc
@@ -19,7 +19,10 @@
 
 namespace google {
 namespace protobuf {
-class AnyDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<Any> {
+class AnyDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<Any>
+     _instance;
 } _Any_default_instance_;
 
 namespace protobuf_google_2fprotobuf_2fany_2eproto {
@@ -88,7 +91,7 @@ void TableStruct::InitDefaultsImpl() {
   GOOGLE_PROTOBUF_VERIFY_VERSION;
 
   ::google::protobuf::internal::InitProtobufDefaults();
-  _Any_default_instance_.DefaultConstruct();
+  _Any_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
       &_Any_default_instance_);}
 
diff --git a/src/google/protobuf/api.pb.cc b/src/google/protobuf/api.pb.cc
index 903fd93b..830fffbb 100644
--- a/src/google/protobuf/api.pb.cc
+++ b/src/google/protobuf/api.pb.cc
@@ -19,11 +19,20 @@
 
 namespace google {
 namespace protobuf {
-class ApiDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<Api> {
+class ApiDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<Api>
+     _instance;
 } _Api_default_instance_;
-class MethodDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<Method> {
+class MethodDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<Method>
+     _instance;
 } _Method_default_instance_;
-class MixinDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<Mixin> {
+class MixinDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<Mixin>
+     _instance;
 } _Mixin_default_instance_;
 
 namespace protobuf_google_2fprotobuf_2fapi_2eproto {
@@ -124,13 +133,13 @@ void TableStruct::InitDefaultsImpl() {
   ::google::protobuf::internal::InitProtobufDefaults();
   ::google::protobuf::protobuf_google_2fprotobuf_2fsource_5fcontext_2eproto::InitDefaults();
   ::google::protobuf::protobuf_google_2fprotobuf_2ftype_2eproto::InitDefaults();
-  _Api_default_instance_.DefaultConstruct();
+  _Api_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
-      &_Api_default_instance_);_Method_default_instance_.DefaultConstruct();
+      &_Api_default_instance_);_Method_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
-      &_Method_default_instance_);_Mixin_default_instance_.DefaultConstruct();
+      &_Method_default_instance_);_Mixin_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
-      &_Mixin_default_instance_);_Api_default_instance_.get_mutable()->source_context_ = const_cast< ::google::protobuf::SourceContext*>(
+      &_Mixin_default_instance_);_Api_default_instance_._instance.get_mutable()->source_context_ = const_cast< ::google::protobuf::SourceContext*>(
       ::google::protobuf::SourceContext::internal_default_instance());
 }
 
diff --git a/src/google/protobuf/compiler/cpp/cpp_file.cc b/src/google/protobuf/compiler/cpp/cpp_file.cc
index e54288de..a1c13cf5 100644
--- a/src/google/protobuf/compiler/cpp/cpp_file.cc
+++ b/src/google/protobuf/compiler/cpp/cpp_file.cc
@@ -351,9 +351,10 @@ void FileGenerator::GenerateSource(io::Printer* printer) {
                "::";
     }
     printer->Print(
-        "class $classname$DefaultTypeInternal : "
-        "public ::google::protobuf::internal::ExplicitlyConstructed<$parent$$classname$> "
-        "{\n",
+        "class $classname$DefaultTypeInternal {\n"
+        "public:\n"
+        " ::google::protobuf::internal::ExplicitlyConstructed<$parent$$classname$>\n"
+        "     _instance;\n",
         "parent", parent, "classname", message_generators_[i]->classname_);
     printer->Indent();
     message_generators_[i]->GenerateExtraDefaultFields(printer);
@@ -740,7 +741,7 @@ void FileGenerator::GenerateBuildDescriptors(io::Printer* printer) {
       printer->Print(
           "file_level_metadata[$index$].reflection = "
           "$parent$::$classname$::CreateReflection(file_level_metadata[$index$]"
-          ".descriptor, _$classname$_default_instance_.get_mutable());\n",
+          ".descriptor, _$classname$_default_instance_._instance.get_mutable());\n",
           "index", SimpleItoa(i), "parent",
           ClassName(message_generators_[i]->descriptor_->containing_type(),
                     false),
diff --git a/src/google/protobuf/compiler/cpp/cpp_message.cc b/src/google/protobuf/compiler/cpp/cpp_message.cc
index abb2e95a..36cbf5d7 100644
--- a/src/google/protobuf/compiler/cpp/cpp_message.cc
+++ b/src/google/protobuf/compiler/cpp/cpp_message.cc
@@ -1604,7 +1604,6 @@ GenerateExtraDefaultFields(io::Printer* printer) {
   // Generate oneof default instance and weak field instances for reflection
   // usage.
   if (descriptor_->oneof_decl_count() > 0 || num_weak_fields_ > 0) {
-    printer->Print("public:\n");
     for (int i = 0; i < descriptor_->oneof_decl_count(); i++) {
       for (int j = 0; j < descriptor_->oneof_decl(i)->field_count(); j++) {
         const FieldDescriptor* field = descriptor_->oneof_decl(i)->field(j);
@@ -1977,7 +1976,7 @@ GenerateDefaultInstanceAllocator(io::Printer* printer) {
   // Construct the default instance.  We can't call InitAsDefaultInstance() yet
   // because we need to make sure all default instances that this one might
   // depend on are constructed first.
-  printer->Print("_$classname$_default_instance_.DefaultConstruct();\n"
+  printer->Print("_$classname$_default_instance_._instance.DefaultConstruct();\n"
                  "::google::protobuf::internal::OnShutdownDestroyMessage(\n"
                  "    &_$classname$_default_instance_);",
                  "classname", classname_);
@@ -1987,9 +1986,9 @@ void MessageGenerator::
 GenerateDefaultInstanceInitializer(io::Printer* printer) {
   if (IsMapEntryMessage(descriptor_)) {
     printer->Print(
-        "_$classname$_default_instance_.get_mutable()->set_default_instance(_$"
-        "classname$_default_instance_.get_mutable());\n"
-        "_$classname$_default_instance_.get_mutable()->InitAsDefaultInstance();"
+        "_$classname$_default_instance_._instance.get_mutable()->set_default_instance(_$"
+        "classname$_default_instance_._instance.get_mutable());\n"
+        "_$classname$_default_instance_._instance.get_mutable()->InitAsDefaultInstance();"
         "\n",
         "classname", classname_);
     return;
@@ -2012,7 +2011,8 @@ GenerateDefaultInstanceInitializer(io::Printer* printer) {
       if (field->containing_oneof() || field->options().weak()) {
         name = "_" + classname_ + "_default_instance_.";
       } else {
-        name = "_" + classname_ + "_default_instance_.get_mutable()->";
+        name =
+            "_" + classname_ + "_default_instance_._instance.get_mutable()->";
       }
       name += FieldName(field);
       printer->Print(
diff --git a/src/google/protobuf/compiler/plugin.pb.cc b/src/google/protobuf/compiler/plugin.pb.cc
index 5d7dad98..ac6f59dc 100644
--- a/src/google/protobuf/compiler/plugin.pb.cc
+++ b/src/google/protobuf/compiler/plugin.pb.cc
@@ -20,13 +20,25 @@
 namespace google {
 namespace protobuf {
 namespace compiler {
-class VersionDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<Version> {
+class VersionDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<Version>
+     _instance;
 } _Version_default_instance_;
-class CodeGeneratorRequestDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<CodeGeneratorRequest> {
+class CodeGeneratorRequestDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<CodeGeneratorRequest>
+     _instance;
 } _CodeGeneratorRequest_default_instance_;
-class CodeGeneratorResponse_FileDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<CodeGeneratorResponse_File> {
+class CodeGeneratorResponse_FileDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<CodeGeneratorResponse_File>
+     _instance;
 } _CodeGeneratorResponse_File_default_instance_;
-class CodeGeneratorResponseDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<CodeGeneratorResponse> {
+class CodeGeneratorResponseDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<CodeGeneratorResponse>
+     _instance;
 } _CodeGeneratorResponse_default_instance_;
 
 namespace protobuf_google_2fprotobuf_2fcompiler_2fplugin_2eproto {
@@ -144,15 +156,15 @@ void TableStruct::InitDefaultsImpl() {
 
   ::google::protobuf::internal::InitProtobufDefaults();
   ::google::protobuf::protobuf_google_2fprotobuf_2fdescriptor_2eproto::InitDefaults();
-  _Version_default_instance_.DefaultConstruct();
+  _Version_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
-      &_Version_default_instance_);_CodeGeneratorRequest_default_instance_.DefaultConstruct();
+      &_Version_default_instance_);_CodeGeneratorRequest_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
-      &_CodeGeneratorRequest_default_instance_);_CodeGeneratorResponse_File_default_instance_.DefaultConstruct();
+      &_CodeGeneratorRequest_default_instance_);_CodeGeneratorResponse_File_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
-      &_CodeGeneratorResponse_File_default_instance_);_CodeGeneratorResponse_default_instance_.DefaultConstruct();
+      &_CodeGeneratorResponse_File_default_instance_);_CodeGeneratorResponse_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
-      &_CodeGeneratorResponse_default_instance_);_CodeGeneratorRequest_default_instance_.get_mutable()->compiler_version_ = const_cast< ::google::protobuf::compiler::Version*>(
+      &_CodeGeneratorResponse_default_instance_);_CodeGeneratorRequest_default_instance_._instance.get_mutable()->compiler_version_ = const_cast< ::google::protobuf::compiler::Version*>(
       ::google::protobuf::compiler::Version::internal_default_instance());
 }
 
diff --git a/src/google/protobuf/descriptor.pb.cc b/src/google/protobuf/descriptor.pb.cc
index d1918f3b..33e2f9b4 100644
--- a/src/google/protobuf/descriptor.pb.cc
+++ b/src/google/protobuf/descriptor.pb.cc
@@ -19,57 +19,135 @@
 
 namespace google {
 namespace protobuf {
-class FileDescriptorSetDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<FileDescriptorSet> {
+class FileDescriptorSetDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<FileDescriptorSet>
+     _instance;
 } _FileDescriptorSet_default_instance_;
-class FileDescriptorProtoDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<FileDescriptorProto> {
+class FileDescriptorProtoDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<FileDescriptorProto>
+     _instance;
 } _FileDescriptorProto_default_instance_;
-class DescriptorProto_ExtensionRangeDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<DescriptorProto_ExtensionRange> {
+class DescriptorProto_ExtensionRangeDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<DescriptorProto_ExtensionRange>
+     _instance;
 } _DescriptorProto_ExtensionRange_default_instance_;
-class DescriptorProto_ReservedRangeDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<DescriptorProto_ReservedRange> {
+class DescriptorProto_ReservedRangeDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<DescriptorProto_ReservedRange>
+     _instance;
 } _DescriptorProto_ReservedRange_default_instance_;
-class DescriptorProtoDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<DescriptorProto> {
+class DescriptorProtoDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<DescriptorProto>
+     _instance;
 } _DescriptorProto_default_instance_;
-class ExtensionRangeOptionsDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<ExtensionRangeOptions> {
+class ExtensionRangeOptionsDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<ExtensionRangeOptions>
+     _instance;
 } _ExtensionRangeOptions_default_instance_;
-class FieldDescriptorProtoDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<FieldDescriptorProto> {
+class FieldDescriptorProtoDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<FieldDescriptorProto>
+     _instance;
 } _FieldDescriptorProto_default_instance_;
-class OneofDescriptorProtoDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<OneofDescriptorProto> {
+class OneofDescriptorProtoDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<OneofDescriptorProto>
+     _instance;
 } _OneofDescriptorProto_default_instance_;
-class EnumDescriptorProtoDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<EnumDescriptorProto> {
+class EnumDescriptorProtoDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<EnumDescriptorProto>
+     _instance;
 } _EnumDescriptorProto_default_instance_;
-class EnumValueDescriptorProtoDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<EnumValueDescriptorProto> {
+class EnumValueDescriptorProtoDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<EnumValueDescriptorProto>
+     _instance;
 } _EnumValueDescriptorProto_default_instance_;
-class ServiceDescriptorProtoDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<ServiceDescriptorProto> {
+class ServiceDescriptorProtoDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<ServiceDescriptorProto>
+     _instance;
 } _ServiceDescriptorProto_default_instance_;
-class MethodDescriptorProtoDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<MethodDescriptorProto> {
+class MethodDescriptorProtoDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<MethodDescriptorProto>
+     _instance;
 } _MethodDescriptorProto_default_instance_;
-class FileOptionsDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<FileOptions> {
+class FileOptionsDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<FileOptions>
+     _instance;
 } _FileOptions_default_instance_;
-class MessageOptionsDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<MessageOptions> {
+class MessageOptionsDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<MessageOptions>
+     _instance;
 } _MessageOptions_default_instance_;
-class FieldOptionsDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<FieldOptions> {
+class FieldOptionsDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<FieldOptions>
+     _instance;
 } _FieldOptions_default_instance_;
-class OneofOptionsDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<OneofOptions> {
+class OneofOptionsDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<OneofOptions>
+     _instance;
 } _OneofOptions_default_instance_;
-class EnumOptionsDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<EnumOptions> {
+class EnumOptionsDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<EnumOptions>
+     _instance;
 } _EnumOptions_default_instance_;
-class EnumValueOptionsDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<EnumValueOptions> {
+class EnumValueOptionsDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<EnumValueOptions>
+     _instance;
 } _EnumValueOptions_default_instance_;
-class ServiceOptionsDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<ServiceOptions> {
+class ServiceOptionsDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<ServiceOptions>
+     _instance;
 } _ServiceOptions_default_instance_;
-class MethodOptionsDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<MethodOptions> {
+class MethodOptionsDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<MethodOptions>
+     _instance;
 } _MethodOptions_default_instance_;
-class UninterpretedOption_NamePartDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<UninterpretedOption_NamePart> {
+class UninterpretedOption_NamePartDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<UninterpretedOption_NamePart>
+     _instance;
 } _UninterpretedOption_NamePart_default_instance_;
-class UninterpretedOptionDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<UninterpretedOption> {
+class UninterpretedOptionDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<UninterpretedOption>
+     _instance;
 } _UninterpretedOption_default_instance_;
-class SourceCodeInfo_LocationDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<SourceCodeInfo_Location> {
+class SourceCodeInfo_LocationDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<SourceCodeInfo_Location>
+     _instance;
 } _SourceCodeInfo_Location_default_instance_;
-class SourceCodeInfoDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<SourceCodeInfo> {
+class SourceCodeInfoDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<SourceCodeInfo>
+     _instance;
 } _SourceCodeInfo_default_instance_;
-class GeneratedCodeInfo_AnnotationDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<GeneratedCodeInfo_Annotation> {
+class GeneratedCodeInfo_AnnotationDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<GeneratedCodeInfo_Annotation>
+     _instance;
 } _GeneratedCodeInfo_Annotation_default_instance_;
-class GeneratedCodeInfoDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<GeneratedCodeInfo> {
+class GeneratedCodeInfoDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<GeneratedCodeInfo>
+     _instance;
 } _GeneratedCodeInfo_default_instance_;
 
 namespace protobuf_google_2fprotobuf_2fdescriptor_2eproto {
@@ -573,77 +651,77 @@ void TableStruct::InitDefaultsImpl() {
   GOOGLE_PROTOBUF_VERIFY_VERSION;
 
   ::google::protobuf::internal::InitProtobufDefaults();
-  _FileDescriptorSet_default_instance_.DefaultConstruct();
+  _FileDescriptorSet_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
-      &_FileDescriptorSet_default_instance_);_FileDescriptorProto_default_instance_.DefaultConstruct();
+      &_FileDescriptorSet_default_instance_);_FileDescriptorProto_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
-      &_FileDescriptorProto_default_instance_);_DescriptorProto_ExtensionRange_default_instance_.DefaultConstruct();
+      &_FileDescriptorProto_default_instance_);_DescriptorProto_ExtensionRange_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
-      &_DescriptorProto_ExtensionRange_default_instance_);_DescriptorProto_ReservedRange_default_instance_.DefaultConstruct();
+      &_DescriptorProto_ExtensionRange_default_instance_);_DescriptorProto_ReservedRange_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
-      &_DescriptorProto_ReservedRange_default_instance_);_DescriptorProto_default_instance_.DefaultConstruct();
+      &_DescriptorProto_ReservedRange_default_instance_);_DescriptorProto_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
-      &_DescriptorProto_default_instance_);_ExtensionRangeOptions_default_instance_.DefaultConstruct();
+      &_DescriptorProto_default_instance_);_ExtensionRangeOptions_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
-      &_ExtensionRangeOptions_default_instance_);_FieldDescriptorProto_default_instance_.DefaultConstruct();
+      &_ExtensionRangeOptions_default_instance_);_FieldDescriptorProto_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
-      &_FieldDescriptorProto_default_instance_);_OneofDescriptorProto_default_instance_.DefaultConstruct();
+      &_FieldDescriptorProto_default_instance_);_OneofDescriptorProto_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
-      &_OneofDescriptorProto_default_instance_);_EnumDescriptorProto_default_instance_.DefaultConstruct();
+      &_OneofDescriptorProto_default_instance_);_EnumDescriptorProto_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
-      &_EnumDescriptorProto_default_instance_);_EnumValueDescriptorProto_default_instance_.DefaultConstruct();
+      &_EnumDescriptorProto_default_instance_);_EnumValueDescriptorProto_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
-      &_EnumValueDescriptorProto_default_instance_);_ServiceDescriptorProto_default_instance_.DefaultConstruct();
+      &_EnumValueDescriptorProto_default_instance_);_ServiceDescriptorProto_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
-      &_ServiceDescriptorProto_default_instance_);_MethodDescriptorProto_default_instance_.DefaultConstruct();
+      &_ServiceDescriptorProto_default_instance_);_MethodDescriptorProto_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
-      &_MethodDescriptorProto_default_instance_);_FileOptions_default_instance_.DefaultConstruct();
+      &_MethodDescriptorProto_default_instance_);_FileOptions_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
-      &_FileOptions_default_instance_);_MessageOptions_default_instance_.DefaultConstruct();
+      &_FileOptions_default_instance_);_MessageOptions_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
-      &_MessageOptions_default_instance_);_FieldOptions_default_instance_.DefaultConstruct();
+      &_MessageOptions_default_instance_);_FieldOptions_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
-      &_FieldOptions_default_instance_);_OneofOptions_default_instance_.DefaultConstruct();
+      &_FieldOptions_default_instance_);_OneofOptions_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
-      &_OneofOptions_default_instance_);_EnumOptions_default_instance_.DefaultConstruct();
+      &_OneofOptions_default_instance_);_EnumOptions_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
-      &_EnumOptions_default_instance_);_EnumValueOptions_default_instance_.DefaultConstruct();
+      &_EnumOptions_default_instance_);_EnumValueOptions_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
-      &_EnumValueOptions_default_instance_);_ServiceOptions_default_instance_.DefaultConstruct();
+      &_EnumValueOptions_default_instance_);_ServiceOptions_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
-      &_ServiceOptions_default_instance_);_MethodOptions_default_instance_.DefaultConstruct();
+      &_ServiceOptions_default_instance_);_MethodOptions_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
-      &_MethodOptions_default_instance_);_UninterpretedOption_NamePart_default_instance_.DefaultConstruct();
+      &_MethodOptions_default_instance_);_UninterpretedOption_NamePart_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
-      &_UninterpretedOption_NamePart_default_instance_);_UninterpretedOption_default_instance_.DefaultConstruct();
+      &_UninterpretedOption_NamePart_default_instance_);_UninterpretedOption_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
-      &_UninterpretedOption_default_instance_);_SourceCodeInfo_Location_default_instance_.DefaultConstruct();
+      &_UninterpretedOption_default_instance_);_SourceCodeInfo_Location_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
-      &_SourceCodeInfo_Location_default_instance_);_SourceCodeInfo_default_instance_.DefaultConstruct();
+      &_SourceCodeInfo_Location_default_instance_);_SourceCodeInfo_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
-      &_SourceCodeInfo_default_instance_);_GeneratedCodeInfo_Annotation_default_instance_.DefaultConstruct();
+      &_SourceCodeInfo_default_instance_);_GeneratedCodeInfo_Annotation_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
-      &_GeneratedCodeInfo_Annotation_default_instance_);_GeneratedCodeInfo_default_instance_.DefaultConstruct();
+      &_GeneratedCodeInfo_Annotation_default_instance_);_GeneratedCodeInfo_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
-      &_GeneratedCodeInfo_default_instance_);_FileDescriptorProto_default_instance_.get_mutable()->options_ = const_cast< ::google::protobuf::FileOptions*>(
+      &_GeneratedCodeInfo_default_instance_);_FileDescriptorProto_default_instance_._instance.get_mutable()->options_ = const_cast< ::google::protobuf::FileOptions*>(
       ::google::protobuf::FileOptions::internal_default_instance());
-  _FileDescriptorProto_default_instance_.get_mutable()->source_code_info_ = const_cast< ::google::protobuf::SourceCodeInfo*>(
+  _FileDescriptorProto_default_instance_._instance.get_mutable()->source_code_info_ = const_cast< ::google::protobuf::SourceCodeInfo*>(
       ::google::protobuf::SourceCodeInfo::internal_default_instance());
-  _DescriptorProto_ExtensionRange_default_instance_.get_mutable()->options_ = const_cast< ::google::protobuf::ExtensionRangeOptions*>(
+  _DescriptorProto_ExtensionRange_default_instance_._instance.get_mutable()->options_ = const_cast< ::google::protobuf::ExtensionRangeOptions*>(
       ::google::protobuf::ExtensionRangeOptions::internal_default_instance());
-  _DescriptorProto_default_instance_.get_mutable()->options_ = const_cast< ::google::protobuf::MessageOptions*>(
+  _DescriptorProto_default_instance_._instance.get_mutable()->options_ = const_cast< ::google::protobuf::MessageOptions*>(
       ::google::protobuf::MessageOptions::internal_default_instance());
-  _FieldDescriptorProto_default_instance_.get_mutable()->options_ = const_cast< ::google::protobuf::FieldOptions*>(
+  _FieldDescriptorProto_default_instance_._instance.get_mutable()->options_ = const_cast< ::google::protobuf::FieldOptions*>(
       ::google::protobuf::FieldOptions::internal_default_instance());
-  _OneofDescriptorProto_default_instance_.get_mutable()->options_ = const_cast< ::google::protobuf::OneofOptions*>(
+  _OneofDescriptorProto_default_instance_._instance.get_mutable()->options_ = const_cast< ::google::protobuf::OneofOptions*>(
       ::google::protobuf::OneofOptions::internal_default_instance());
-  _EnumDescriptorProto_default_instance_.get_mutable()->options_ = const_cast< ::google::protobuf::EnumOptions*>(
+  _EnumDescriptorProto_default_instance_._instance.get_mutable()->options_ = const_cast< ::google::protobuf::EnumOptions*>(
       ::google::protobuf::EnumOptions::internal_default_instance());
-  _EnumValueDescriptorProto_default_instance_.get_mutable()->options_ = const_cast< ::google::protobuf::EnumValueOptions*>(
+  _EnumValueDescriptorProto_default_instance_._instance.get_mutable()->options_ = const_cast< ::google::protobuf::EnumValueOptions*>(
       ::google::protobuf::EnumValueOptions::internal_default_instance());
-  _ServiceDescriptorProto_default_instance_.get_mutable()->options_ = const_cast< ::google::protobuf::ServiceOptions*>(
+  _ServiceDescriptorProto_default_instance_._instance.get_mutable()->options_ = const_cast< ::google::protobuf::ServiceOptions*>(
       ::google::protobuf::ServiceOptions::internal_default_instance());
-  _MethodDescriptorProto_default_instance_.get_mutable()->options_ = const_cast< ::google::protobuf::MethodOptions*>(
+  _MethodDescriptorProto_default_instance_._instance.get_mutable()->options_ = const_cast< ::google::protobuf::MethodOptions*>(
       ::google::protobuf::MethodOptions::internal_default_instance());
 }
 
diff --git a/src/google/protobuf/duration.pb.cc b/src/google/protobuf/duration.pb.cc
index db0f9fd8..ec1aa271 100644
--- a/src/google/protobuf/duration.pb.cc
+++ b/src/google/protobuf/duration.pb.cc
@@ -19,7 +19,10 @@
 
 namespace google {
 namespace protobuf {
-class DurationDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<Duration> {
+class DurationDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<Duration>
+     _instance;
 } _Duration_default_instance_;
 
 namespace protobuf_google_2fprotobuf_2fduration_2eproto {
@@ -88,7 +91,7 @@ void TableStruct::InitDefaultsImpl() {
   GOOGLE_PROTOBUF_VERIFY_VERSION;
 
   ::google::protobuf::internal::InitProtobufDefaults();
-  _Duration_default_instance_.DefaultConstruct();
+  _Duration_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
       &_Duration_default_instance_);}
 
diff --git a/src/google/protobuf/empty.pb.cc b/src/google/protobuf/empty.pb.cc
index d418e67a..09ef019b 100644
--- a/src/google/protobuf/empty.pb.cc
+++ b/src/google/protobuf/empty.pb.cc
@@ -19,7 +19,10 @@
 
 namespace google {
 namespace protobuf {
-class EmptyDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<Empty> {
+class EmptyDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<Empty>
+     _instance;
 } _Empty_default_instance_;
 
 namespace protobuf_google_2fprotobuf_2fempty_2eproto {
@@ -86,7 +89,7 @@ void TableStruct::InitDefaultsImpl() {
   GOOGLE_PROTOBUF_VERIFY_VERSION;
 
   ::google::protobuf::internal::InitProtobufDefaults();
-  _Empty_default_instance_.DefaultConstruct();
+  _Empty_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
       &_Empty_default_instance_);}
 
diff --git a/src/google/protobuf/field_mask.pb.cc b/src/google/protobuf/field_mask.pb.cc
index 60e3056b..6e867037 100644
--- a/src/google/protobuf/field_mask.pb.cc
+++ b/src/google/protobuf/field_mask.pb.cc
@@ -19,7 +19,10 @@
 
 namespace google {
 namespace protobuf {
-class FieldMaskDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<FieldMask> {
+class FieldMaskDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<FieldMask>
+     _instance;
 } _FieldMask_default_instance_;
 
 namespace protobuf_google_2fprotobuf_2ffield_5fmask_2eproto {
@@ -87,7 +90,7 @@ void TableStruct::InitDefaultsImpl() {
   GOOGLE_PROTOBUF_VERIFY_VERSION;
 
   ::google::protobuf::internal::InitProtobufDefaults();
-  _FieldMask_default_instance_.DefaultConstruct();
+  _FieldMask_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
       &_FieldMask_default_instance_);}
 
diff --git a/src/google/protobuf/source_context.pb.cc b/src/google/protobuf/source_context.pb.cc
index effe0a43..5d990772 100644
--- a/src/google/protobuf/source_context.pb.cc
+++ b/src/google/protobuf/source_context.pb.cc
@@ -19,7 +19,10 @@
 
 namespace google {
 namespace protobuf {
-class SourceContextDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<SourceContext> {
+class SourceContextDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<SourceContext>
+     _instance;
 } _SourceContext_default_instance_;
 
 namespace protobuf_google_2fprotobuf_2fsource_5fcontext_2eproto {
@@ -87,7 +90,7 @@ void TableStruct::InitDefaultsImpl() {
   GOOGLE_PROTOBUF_VERIFY_VERSION;
 
   ::google::protobuf::internal::InitProtobufDefaults();
-  _SourceContext_default_instance_.DefaultConstruct();
+  _SourceContext_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
       &_SourceContext_default_instance_);}
 
diff --git a/src/google/protobuf/struct.pb.cc b/src/google/protobuf/struct.pb.cc
index 02f117fb..73c36bd7 100644
--- a/src/google/protobuf/struct.pb.cc
+++ b/src/google/protobuf/struct.pb.cc
@@ -19,12 +19,20 @@
 
 namespace google {
 namespace protobuf {
-class Struct_FieldsEntryDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<Struct::Struct_FieldsEntry> {
+class Struct_FieldsEntryDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<Struct::Struct_FieldsEntry>
+     _instance;
 } _Struct_FieldsEntry_default_instance_;
-class StructDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<Struct> {
+class StructDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<Struct>
+     _instance;
 } _Struct_default_instance_;
-class ValueDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<Value> {
-  public:
+class ValueDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<Value>
+     _instance;
   int null_value_;
   double number_value_;
   ::google::protobuf::internal::ArenaStringPtr string_value_;
@@ -32,7 +40,10 @@ class ValueDefaultTypeInternal : public ::google::protobuf::internal::Explicitly
   const ::google::protobuf::Struct* struct_value_;
   const ::google::protobuf::ListValue* list_value_;
 } _Value_default_instance_;
-class ListValueDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<ListValue> {
+class ListValueDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<ListValue>
+     _instance;
 } _ListValue_default_instance_;
 
 namespace protobuf_google_2fprotobuf_2fstruct_2eproto {
@@ -109,7 +120,7 @@ void protobuf_AssignDescriptors() {
   AssignDescriptors(
       "google/protobuf/struct.proto", schemas, file_default_instances, TableStruct::offsets, factory,
       file_level_metadata, file_level_enum_descriptors, NULL);
-file_level_metadata[0].reflection = Struct::Struct_FieldsEntry::CreateReflection(file_level_metadata[0].descriptor, _Struct_FieldsEntry_default_instance_.get_mutable());
+file_level_metadata[0].reflection = Struct::Struct_FieldsEntry::CreateReflection(file_level_metadata[0].descriptor, _Struct_FieldsEntry_default_instance_._instance.get_mutable());
 }
 
 void protobuf_AssignDescriptorsOnce() {
@@ -128,16 +139,16 @@ void TableStruct::InitDefaultsImpl() {
   GOOGLE_PROTOBUF_VERIFY_VERSION;
 
   ::google::protobuf::internal::InitProtobufDefaults();
-  _Struct_FieldsEntry_default_instance_.DefaultConstruct();
+  _Struct_FieldsEntry_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
-      &_Struct_FieldsEntry_default_instance_);_Struct_default_instance_.DefaultConstruct();
+      &_Struct_FieldsEntry_default_instance_);_Struct_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
-      &_Struct_default_instance_);_Value_default_instance_.DefaultConstruct();
+      &_Struct_default_instance_);_Value_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
-      &_Value_default_instance_);_ListValue_default_instance_.DefaultConstruct();
+      &_Value_default_instance_);_ListValue_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
-      &_ListValue_default_instance_);_Struct_FieldsEntry_default_instance_.get_mutable()->set_default_instance(_Struct_FieldsEntry_default_instance_.get_mutable());
-  _Struct_FieldsEntry_default_instance_.get_mutable()->InitAsDefaultInstance();
+      &_ListValue_default_instance_);_Struct_FieldsEntry_default_instance_._instance.get_mutable()->set_default_instance(_Struct_FieldsEntry_default_instance_._instance.get_mutable());
+  _Struct_FieldsEntry_default_instance_._instance.get_mutable()->InitAsDefaultInstance();
   _Value_default_instance_.null_value_ = 0;
   _Value_default_instance_.number_value_ = 0;
   _Value_default_instance_.string_value_.UnsafeSetDefault(
diff --git a/src/google/protobuf/timestamp.pb.cc b/src/google/protobuf/timestamp.pb.cc
index 553fdef7..f01ff345 100644
--- a/src/google/protobuf/timestamp.pb.cc
+++ b/src/google/protobuf/timestamp.pb.cc
@@ -19,7 +19,10 @@
 
 namespace google {
 namespace protobuf {
-class TimestampDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<Timestamp> {
+class TimestampDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<Timestamp>
+     _instance;
 } _Timestamp_default_instance_;
 
 namespace protobuf_google_2fprotobuf_2ftimestamp_2eproto {
@@ -88,7 +91,7 @@ void TableStruct::InitDefaultsImpl() {
   GOOGLE_PROTOBUF_VERIFY_VERSION;
 
   ::google::protobuf::internal::InitProtobufDefaults();
-  _Timestamp_default_instance_.DefaultConstruct();
+  _Timestamp_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
       &_Timestamp_default_instance_);}
 
diff --git a/src/google/protobuf/type.pb.cc b/src/google/protobuf/type.pb.cc
index b9cc7a93..47d425f5 100644
--- a/src/google/protobuf/type.pb.cc
+++ b/src/google/protobuf/type.pb.cc
@@ -19,15 +19,30 @@
 
 namespace google {
 namespace protobuf {
-class TypeDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<Type> {
+class TypeDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<Type>
+     _instance;
 } _Type_default_instance_;
-class FieldDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<Field> {
+class FieldDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<Field>
+     _instance;
 } _Field_default_instance_;
-class EnumDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<Enum> {
+class EnumDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<Enum>
+     _instance;
 } _Enum_default_instance_;
-class EnumValueDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<EnumValue> {
+class EnumValueDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<EnumValue>
+     _instance;
 } _EnumValue_default_instance_;
-class OptionDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<Option> {
+class OptionDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<Option>
+     _instance;
 } _Option_default_instance_;
 
 namespace protobuf_google_2fprotobuf_2ftype_2eproto {
@@ -155,21 +170,21 @@ void TableStruct::InitDefaultsImpl() {
   ::google::protobuf::internal::InitProtobufDefaults();
   ::google::protobuf::protobuf_google_2fprotobuf_2fany_2eproto::InitDefaults();
   ::google::protobuf::protobuf_google_2fprotobuf_2fsource_5fcontext_2eproto::InitDefaults();
-  _Type_default_instance_.DefaultConstruct();
+  _Type_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
-      &_Type_default_instance_);_Field_default_instance_.DefaultConstruct();
+      &_Type_default_instance_);_Field_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
-      &_Field_default_instance_);_Enum_default_instance_.DefaultConstruct();
+      &_Field_default_instance_);_Enum_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
-      &_Enum_default_instance_);_EnumValue_default_instance_.DefaultConstruct();
+      &_Enum_default_instance_);_EnumValue_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
-      &_EnumValue_default_instance_);_Option_default_instance_.DefaultConstruct();
+      &_EnumValue_default_instance_);_Option_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
-      &_Option_default_instance_);_Type_default_instance_.get_mutable()->source_context_ = const_cast< ::google::protobuf::SourceContext*>(
+      &_Option_default_instance_);_Type_default_instance_._instance.get_mutable()->source_context_ = const_cast< ::google::protobuf::SourceContext*>(
       ::google::protobuf::SourceContext::internal_default_instance());
-  _Enum_default_instance_.get_mutable()->source_context_ = const_cast< ::google::protobuf::SourceContext*>(
+  _Enum_default_instance_._instance.get_mutable()->source_context_ = const_cast< ::google::protobuf::SourceContext*>(
       ::google::protobuf::SourceContext::internal_default_instance());
-  _Option_default_instance_.get_mutable()->value_ = const_cast< ::google::protobuf::Any*>(
+  _Option_default_instance_._instance.get_mutable()->value_ = const_cast< ::google::protobuf::Any*>(
       ::google::protobuf::Any::internal_default_instance());
 }
 
diff --git a/src/google/protobuf/wrappers.pb.cc b/src/google/protobuf/wrappers.pb.cc
index f8f55842..6d1bd21c 100644
--- a/src/google/protobuf/wrappers.pb.cc
+++ b/src/google/protobuf/wrappers.pb.cc
@@ -19,23 +19,50 @@
 
 namespace google {
 namespace protobuf {
-class DoubleValueDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<DoubleValue> {
+class DoubleValueDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<DoubleValue>
+     _instance;
 } _DoubleValue_default_instance_;
-class FloatValueDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<FloatValue> {
+class FloatValueDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<FloatValue>
+     _instance;
 } _FloatValue_default_instance_;
-class Int64ValueDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<Int64Value> {
+class Int64ValueDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<Int64Value>
+     _instance;
 } _Int64Value_default_instance_;
-class UInt64ValueDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<UInt64Value> {
+class UInt64ValueDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<UInt64Value>
+     _instance;
 } _UInt64Value_default_instance_;
-class Int32ValueDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<Int32Value> {
+class Int32ValueDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<Int32Value>
+     _instance;
 } _Int32Value_default_instance_;
-class UInt32ValueDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<UInt32Value> {
+class UInt32ValueDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<UInt32Value>
+     _instance;
 } _UInt32Value_default_instance_;
-class BoolValueDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<BoolValue> {
+class BoolValueDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<BoolValue>
+     _instance;
 } _BoolValue_default_instance_;
-class StringValueDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<StringValue> {
+class StringValueDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<StringValue>
+     _instance;
 } _StringValue_default_instance_;
-class BytesValueDefaultTypeInternal : public ::google::protobuf::internal::ExplicitlyConstructed<BytesValue> {
+class BytesValueDefaultTypeInternal {
+public:
+ ::google::protobuf::internal::ExplicitlyConstructed<BytesValue>
+     _instance;
 } _BytesValue_default_instance_;
 
 namespace protobuf_google_2fprotobuf_2fwrappers_2eproto {
@@ -175,23 +202,23 @@ void TableStruct::InitDefaultsImpl() {
   GOOGLE_PROTOBUF_VERIFY_VERSION;
 
   ::google::protobuf::internal::InitProtobufDefaults();
-  _DoubleValue_default_instance_.DefaultConstruct();
+  _DoubleValue_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
-      &_DoubleValue_default_instance_);_FloatValue_default_instance_.DefaultConstruct();
+      &_DoubleValue_default_instance_);_FloatValue_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
-      &_FloatValue_default_instance_);_Int64Value_default_instance_.DefaultConstruct();
+      &_FloatValue_default_instance_);_Int64Value_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
-      &_Int64Value_default_instance_);_UInt64Value_default_instance_.DefaultConstruct();
+      &_Int64Value_default_instance_);_UInt64Value_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
-      &_UInt64Value_default_instance_);_Int32Value_default_instance_.DefaultConstruct();
+      &_UInt64Value_default_instance_);_Int32Value_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
-      &_Int32Value_default_instance_);_UInt32Value_default_instance_.DefaultConstruct();
+      &_Int32Value_default_instance_);_UInt32Value_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
-      &_UInt32Value_default_instance_);_BoolValue_default_instance_.DefaultConstruct();
+      &_UInt32Value_default_instance_);_BoolValue_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
-      &_BoolValue_default_instance_);_StringValue_default_instance_.DefaultConstruct();
+      &_BoolValue_default_instance_);_StringValue_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
-      &_StringValue_default_instance_);_BytesValue_default_instance_.DefaultConstruct();
+      &_StringValue_default_instance_);_BytesValue_default_instance_._instance.DefaultConstruct();
   ::google::protobuf::internal::OnShutdownDestroyMessage(
       &_BytesValue_default_instance_);}