coding base on UML diagram c++

Question

I have a Line class UML diagram which shows the following details

 - pOne: Point
 - pTwo: Point
 + Line (ptOne: Point, ptTwo: Point)
 + getPOne () : Point
 + getPTwo () : Point
 + setPOne (pOne: Point) 
 + setPTwo (pTwo: Point)

)

this is what I have done according to my interpretation of the UML diagram

Line.h

#ifndef __testing__Line__
#define __testing__Line__
#include <iostream>
#include "Point"

class Line  {

private:
   //pOne and pTwo are objects of Point 
   Point pOne;
   Point pTwo;

public:

    Line() {

    };//default Constructor

    // constructor of class Line to store objects of Point(pOne,pTwo)
    Line (Point pOne,Point pTwo);

    // get method for objects of Point(pOne,pTwo)
    Point getPOne();
    Point getPTwo();

    // set method for objects of a(one,two)
    void setPOne (Point pOne);
    void setPTwo (Point pTwo);

};
#endif /* defined(__testing__Line__) */

Line.cpp

#include "Line.h"

Line::Line (Point pOne, Point pTwo)  {
    setPOne(pOne);
    setPTwo(pTwo);
}

Point Line::getPOne()    {
    return pOne;
}

Point Line::getPTwo()    {
    return pTwo;
}

Line::setPOne (Point pOne)   {
     this-> pOne = pOne;
}

Line::setATwo (Point pTwo)   {
     this->pTwo = pTwo;
}

and in main cpp I tried to call the function getPOne()

main.cpp

#include "Point"
#include "Line"

int main() {
    Line outputMethod;
    //Invalid operands to binary expression
    std::cout << outputMethod.getPOne() << std::endl;
}

How should I call getPOne() from Line class given in the above situation?

---

operator overloading

//overload << operator
friend std::ostream& operator<<(std::ostream& os, Point&)
{
  return os;
}

Answer 1

There are 2 issues with your implementation:

1. You shouldn't derive your Line class from Point - it's wrong semantically ( Line isn't a kind of Point ) and according to the UML description as well.

2. You need to define a proprietary operator << for your Point class in order to use it with cout . If you don't do that, the compiler doesn't know how to print your data (it's your proprietary defined data, after all).