Pointer as reference

 no copy constructor

6-cia/src/geo2d-bb.cc

@@ -14,7 +14,8 @@ class Point
   Point(const Point& other); //copy constructor
   ~Point();                 //destructor never with parameters no return value
   static double distance(Point p,Point q);
-  double distance(Point other);    //non static instance method
+  double distance(Point* other);    //non static instance method
+                 //    |------------- pointer
  private:
   double xc;  //x-coordinate
   double yc;  //y-coordinate
@@ -36,13 +37,6 @@ Point::Point(const Point& other)
  std::cout<<"copy constructor Point "<<xc<<","<<yc<<"\n";
 }
 
-/* wrong copy constructor
-Point::Point(const Point& other)
-:xc(2*other.xc),yc(2*other.yc)
-{
- std::cout<<"copy constructor Point "<<xc<<","<<yc<<"\n";
-}
-*/
 
 Point::~Point()
 {
@@ -55,50 +49,36 @@ double Point::distance(Point p,Point q)
                  //  |----|----|----|----------------private
 }
 
-double Point::distance(Point other)  //copy constructor
+double Point::distance(Point* other)  
 {
- return std::hypot(other.xc - xc,
-                   other.yc - yc);
-} //destructor of other
-
+/* hack
+ other->xc=0;
+ other->yc=0;
+*/ 
+ return std::hypot((*other).xc - xc,
+                     other->yc - yc);
+/* other notation
+ (*other).yc <---> other->yc
+*/
+} 
 
-/*
-with self made copy constructor
-constructor Point 5,7
-constructor Point 8,11
-copy constructor Point 8,11
-destructor Point 8,11
-d=5
-destructor Point 8,11
-destructor Point 5,7
 
 
-without own copy constructor
+/*
 constructor Point 5,7
 constructor Point 8,11
-destructor Point 8,11   of instance other
 d=5
 destructor Point 8,11
 destructor Point 5,7
-
-with wrong copy constructor
-constructor Point 5,7
-constructor Point 8,11
-copy constructor Point 0,0
-destructor Point 0,0
-d=8.60233
-destructor Point 8,11
-destructor Point 5,7
-
-
-
 */
+
 //---------------------------  use case
 int main(int argc,char** args)
 {
  Point p(5, 7);
  Point q(8,11);
- auto d=p.distance(q);  //other = q copy constructor
+ auto d=p.distance(&q);  //other = pointer to q
+                //|---------------  address of
  std::cout<<"d="<<d<<"\n"; 
  return 0;
 }