Updated for c++98 compatibility

python/google/protobuf/pyext/extension_dict.h

@@ -47,8 +47,9 @@ namespace protobuf {
 class Message;
 class FieldDescriptor;
 
+#ifdef _SHARED_PTR_H
 using std::shared_ptr;
-using std::string;
+#endif
 
 namespace python {
 

python/google/protobuf/pyext/message.h

@@ -52,8 +52,10 @@ class Descriptor;
 class DescriptorPool;
 class MessageFactory;
 
+#ifdef _SHARED_PTR_H
 using std::shared_ptr;
 using std::string;
+#endif
 
 namespace python {
 

python/google/protobuf/pyext/message_map_container.h

@@ -45,8 +45,9 @@ namespace protobuf {
 
 class Message;
 
+#ifdef _SHARED_PTR_H
 using std::shared_ptr;
-using std::string;
+#endif
 
 namespace python {
 

python/google/protobuf/pyext/repeated_composite_container.h

@@ -49,8 +49,9 @@ namespace protobuf {
 class FieldDescriptor;
 class Message;
 
+#ifdef _SHARED_PTR_H
 using std::shared_ptr;
-using std::string;
+#endif
 
 namespace python {
 

python/google/protobuf/pyext/repeated_scalar_container.h

@@ -48,8 +48,9 @@ namespace protobuf {
 
 class Message;
 
+#ifdef _SHARED_PTR_H
 using std::shared_ptr;
-using std::string;
+#endif
 
 namespace python {
 

python/google/protobuf/pyext/scalar_map_container.h

@@ -45,8 +45,9 @@ namespace protobuf {
 
 class Message;
 
+#ifdef _SHARED_PTR_H
 using std::shared_ptr;
-using std::string;
+#endif
 
 namespace python {