Basic Shape class and Circle Class : I have this homework assignment to do and I did most of the code, but I have an error in int main(). Here's what the assignment saids: 1. Define an abstract base class called BasicShape. The BasicShape class should have the following members: 
            
a)	Protected Member Variable: area (a double used to hold the shape’s area).

b)	Private Member Variable: name (a string to indicate the shape’s type)

c)	Constructor and Public Member Functions:
•	BasicShape(double a, string n): A constructor that sets value of member area with a and member name with n.
•	calcArea(): This public function should be a pure virtual function.
•	print(): A public virtual function that only prints the value of data member area
•	getName():A public function that returns the value of data member name

2.	Define a class named Circle. It should be derived from the BasicShape class.
      It should have the following members: 

a)	Private Member Variable: radius (a double used to hold the circle’s radius)

b)	Constructor and Public Member Functions:
•	Circle(double a, string n, double r): constructor that should call the base class constructor to initialize the member area with a and name with n. The constructor will also set the value of member radius with r 
•	calcArea(): Overridden function that calculates the area of the circle (area = 3.14159 * radius * radius) and stores the result in the inherited member area. 
•	print(): Overridden function that will print the radius, inherited member area and inherited member name. This function should use the base class’s print function to print the area.

3.	After you have created these classes, create a test program 
•	Write a function named poly whose only parameter is a BasicShape pointer. 
•	Function poly should use the BasicShape pointer to invoke calcArea function and print function. 
•	In main(): define a Circle object with initial area 0, name Round and radius 10. 
•	From main(), call the function poly such that it will polymorphically invoke calcArea function and print function of the Circle object.

And here's my code:

       Basic Shape.h

    #ifndef BASICSHAPE_H
    #define BASICSHAPE_H
    #include <string>
    class basicShape
    {
    public:
	basicShape(const std::string &, double &);
	double getArea() const;
		virtual double calcArea() const = 0;
		virtual void print()const;
		std::string getname()const;
    protected:
	const double area;
    private:
	const std::string name;
    };

    #endif

    Basic Shape.cpp

    #include <iostream>
    #include"Basic Shape.h"
    #include <string>
    using namespace std;
    basicShape::basicShape(const string &n, double &a)
	: area(a), name(n)
    {

     }
      void basicShape::print() const 
      {
	cout << "The area is: " << area;
    }

     string basicShape::getname() const
    {
	    return name;
    }

    Circle.h

    #ifndef CIRCLE_H
    #define CIRCLE_H
    #include <string>
    #include "Basic Shape.h"
    using namespace std;
    class Circle : public basicShape
    {
    public:
	Circle(const string & n, double & a, double & r);
	virtual double calcArea() const override;
		virtual void print() const override;
    private:
	double radius;
    };
       #endif

      Circle.cpp

      #include <iostream>
      #include "Circle.h"
    #include<string>
    using namespace std;

    Circle::Circle(const string &n, double &a,  double &r)
	:basicShape(n,a)
    {
	    radius = r;
	   calcArea();
    }
    double Circle::calcArea() const 
       {
	     double area;
	     area = 3.14159*radius*radius;
	    return area;
       }
       double basicShape::getArea() const
      {
	   return area;
      }
       void Circle::print() const
       {
	     cout << "radius:" << radius;
	     basicShape::print();
	    basicShape::getname();
       }

        Test.cpp

       #include <iostream>
       #include "Basic Shape.h"
       #include "Circle.h"
       #include <string>
        #include<vector>
        using namespace std;
      void poly(const basicShape * const);

       int main()
       { 
	    Circle circle("Round",0.0,10.0);
	   vector< basicShape * > shapes(1);
	    for (const basicShape *basicshapePtr : shapes)
		 poly(basicshapePtr);
       }
      void poly(const basicShape * const baseClassPtr)
    {
	   baseClassPtr->calcArea();
	   baseClassPtr->print();
     }

