fix shape_predictor dlib::searialize and dlib::desearialize error (#156)

* fix shape_predictor dlib::searialize and dlib::desearialize error

* declare shape_predictor searialize and desearialize inline

* fix inline declare issue: declare inline before implement

dlib/image_processing/shape_predictor.h

@@ -398,7 +398,18 @@ namespace dlib
             return full_object_detection(rect, parts);
         }
 
-        friend void serialize (const shape_predictor& item, std::ostream& out)
+        friend void serialize (const shape_predictor& item, std::ostream& out);
+
+        friend void deserialize (shape_predictor& item, std::istream& in);
+
+    private:
+        matrix<float,0,1> initial_shape;
+        std::vector<std::vector<impl::regression_tree> > forests;
+        std::vector<std::vector<unsigned long> > anchor_idx; 
+        std::vector<std::vector<dlib::vector<float,2> > > deltas;
+    };
+
+    inline void serialize (const shape_predictor& item, std::ostream& out)
     {
         int version = 1;
         dlib::serialize(version, out);
@@ -407,7 +418,8 @@ namespace dlib
         dlib::serialize(item.anchor_idx, out);
         dlib::serialize(item.deltas, out);
     }
-        friend void deserialize (shape_predictor& item, std::istream& in)
+
+    inline void deserialize (shape_predictor& item, std::istream& in)
     {
         int version = 0;
         dlib::deserialize(version, in);
@@ -418,14 +430,6 @@ namespace dlib
         dlib::deserialize(item.anchor_idx, in);
         dlib::deserialize(item.deltas, in);
     }
-
-    private:
-        matrix<float,0,1> initial_shape;
-        std::vector<std::vector<impl::regression_tree> > forests;
-        std::vector<std::vector<unsigned long> > anchor_idx; 
-        std::vector<std::vector<dlib::vector<float,2> > > deltas;
-    };
-
 // ----------------------------------------------------------------------------------------
 
     class shape_predictor_trainer