Add cpp_using_directive

src/cpp_entity_type.cpp

@@ -15,6 +15,7 @@ bool cppast::is_scope(cpp_entity_type type) noexcept
 
     case cpp_entity_type::file_t:
     case cpp_entity_type::namespace_alias_t:
+    case cpp_entity_type::using_directive_t:
         break;
     }
 

src/cpp_namespace.cpp

@@ -23,3 +23,8 @@ cpp_entity_type cpp_namespace_alias::do_get_entity_type() const noexcept
 {
     return cpp_entity_type::namespace_alias_t;
 }
+
+cpp_entity_type cpp_using_directive::do_get_entity_type() const noexcept
+{
+    return cpp_entity_type::using_directive_t;
+}