use using instead of typedef

Signed-off-by: Chen Lihui <lihui.chen@sony.com>

rclcpp/include/rclcpp/typesupport_helpers.hpp

@@ -52,25 +52,25 @@ struct typesupport_action_tag {};
 template<typename T>
 struct typesupport_traits
 {
-  typedef T type_tag;
+  using type_tag = T;
 };
 
 template<>
 struct typesupport_traits<rosidl_message_type_support_t>
 {
-  typedef typesupport_message_tag type_tag;
+  using type_tag = typesupport_message_tag;
 };
 
 template<>
 struct typesupport_traits<rosidl_service_type_support_t>
 {
-  typedef typesupport_service_tag type_tag;
+  using type_tag = typesupport_service_tag;
 };
 
 template<>
 struct typesupport_traits<rosidl_action_type_support_t>
 {
-  typedef typesupport_action_tag type_tag;
+  using type_tag = typesupport_action_tag;
 };
 
 using SymbolNameErrorFuncPair = std::pair<std::string, std::function<std::string()>>;
@@ -132,7 +132,6 @@ get_typesupport_handle(
   }
 }
 
-
 }  // namespace rclcpp
 
 #endif  // RCLCPP__TYPESUPPORT_HELPERS_HPP_