Moved the definition of the serialization friend functions out of the

vector_normalizer class because apparently not defining them this way prevents
someone from being able to invoke them by saying dlib::serialize().

--HG--
extra : convert_revision : svn%3Afdd8eb12-d10e-0410-9acb-85c331704f74/trunk%403391

dlib/statistics/statistics.h

@@ -232,8 +232,46 @@ namespace dlib
             temp_out.swap(item.temp_out);
         }
 
+        template <typename mt>
         friend void deserialize (
-            vector_normalizer& item, 
+            vector_normalizer<mt>& item, 
+            std::istream& in
+        ); 
+
+        template <typename mt>
+        friend void serialize (
+            const vector_normalizer<mt>& item, 
+            std::ostream& out 
+        );
+
+    private:
+
+        // ------------------- private data members -------------------
+
+        matrix_type m, sd;
+
+        // This is just a temporary variable that doesn't contribute to the
+        // state of this object.
+        mutable matrix_type temp_out;
+    };
+
+// ----------------------------------------------------------------------------------------
+
+    template <
+        typename matrix_type
+        >
+    inline void swap (
+        vector_normalizer<matrix_type>& a, 
+        vector_normalizer<matrix_type>& b 
+    ) { a.swap(b); }   
+
+// ----------------------------------------------------------------------------------------
+
+    template <
+        typename matrix_type
+        >
+    void deserialize (
+        vector_normalizer<matrix_type>& item, 
         std::istream& in
     )   
     {
@@ -249,8 +287,13 @@ namespace dlib
                                         "a vector_normalizer object.");
     }
 
-        friend void serialize (
-            const vector_normalizer& item, 
+// ----------------------------------------------------------------------------------------
+
+    template <
+        typename matrix_type
+        >
+    void serialize (
+        const vector_normalizer<matrix_type>& item, 
         std::ostream& out 
     )
     {
@@ -261,25 +304,8 @@ namespace dlib
         serialize(pca, out);
     }
 
-    private:
-
-        // ------------------- private data members -------------------
-
-        matrix_type m, sd;
-
-        // This is just a temporary variable that doesn't contribute to the
-        // state of this object.
-        mutable matrix_type temp_out;
-    };
-
-    template <
-        typename matrix_type
-        >
-    inline void swap (
-        vector_normalizer<matrix_type>& a, 
-        vector_normalizer<matrix_type>& b 
-    ) { a.swap(b); }   
-
+// ----------------------------------------------------------------------------------------
+// ----------------------------------------------------------------------------------------
 // ----------------------------------------------------------------------------------------
 
     template <