diff --git a/ch17/ex17.3/textquery.cpp b/ch17/ex17.3/textquery.cpp
index 16b337f4..e255ea2b 100644
--- a/ch17/ex17.3/textquery.cpp
+++ b/ch17/ex17.3/textquery.cpp
@@ -81,10 +81,7 @@ TextQuery::query(const std::string &sought) const
 /**
  * @brief do a query opertion and return tuple.
  */
-std::tuple<std::string,
-           std::shared_ptr<std::set<TextQuery::index_Tp>>,
-           std::shared_ptr<std::vector<std::string>>>
-                TextQuery::query_return_tuple(const std::string &sought)
+result_tuple TextQuery::query_return_tuple(const std::string &sought)
 {
     //! dynamicaly allocated set used for the word does not appear.
     static std::shared_ptr<std::set<index_Tp>> noData(new std::set<index_Tp>);
@@ -93,15 +90,8 @@ std::tuple<std::string,
     //std::map<std::string, std::shared_ptr<std::set<index_Tp>>>::const_iterator
     auto iter = wm.find(sought);
     if(iter == wm.end())
-        return  std::tuple <std::string,
-                            std::shared_ptr<std::set<index_Tp>>,
-                            std::shared_ptr<std::vector<std::string>>>
-                                                                     (sought, noData, file);
+        return result_tuple(sought, noData, file);
     else
-        return  std::tuple <std::string,
-                            std::shared_ptr<std::set<index_Tp>>,
-                            std::shared_ptr<std::vector<std::string>>>
-                                                                     (sought, iter->second, file);
-
+        return result_tuple(sought, iter->second, file);
 }
 
diff --git a/ch17/ex17.3/textquery.h b/ch17/ex17.3/textquery.h
index 26dfba93..38f660b4 100644
--- a/ch17/ex17.3/textquery.h
+++ b/ch17/ex17.3/textquery.h
@@ -22,6 +22,9 @@ class TextQuery
 
 public:
     typedef std::vector<std::string>::size_type index_Tp;
+    typedef std::tuple <std::string,
+                        std::shared_ptr<std::set<index_Tp>>,
+                        std::shared_ptr<std::vector<std::string>>>  result_tuple;
 
     //! constructor
     TextQuery(std::ifstream&);
@@ -31,10 +34,7 @@ class TextQuery
     query(const std::string&) const;
 
     //! query operation returns tuple
-    std::tuple <std::string,
-                std::shared_ptr<std::set<index_Tp>>,
-                std::shared_ptr<std::vector<std::string>>>
-                           query_return_tuple(const std::string& sought);
+    result_tuple query_return_tuple(const std::string& sought);
 private:
     std::shared_ptr<std::vector<std::string>> file;
     std::map<std::string,