update solution of lab02

labs/debugging/point.h

@@ -1,6 +1,7 @@
+#ifndef _POINT_H_
+#define _POINT_H_
 #include <iostream>
 
-
 // A simple 3D point class.  In this simple world, we'll follow the
 // convention often used in Computer Graphics.  y is the vertical
 // axes, "pointing" up.  The x and z axes define the ground plane.
@@ -26,3 +27,5 @@ std::ostream& operator<< (std::ostream &ostr, const Point &p);
 
 // A helper function to compute the slope between two Points.
 double compute_slope(const Point &a, const Point &b);
+
+#endif