Instrument the student_info class to count how objects are created, copied, assi

Question

Instrument the student_info class to count how objects are created, copied, assigned, and destroied.

To do this add static variables to the Student_info class. (e.g. static int myVar = 0;) These variables are shared among all the objects created. You will need to create constructors, a copy constructor, an assignment operator, and a destructor that all increment the static variables.

Use this instrumented class to execute the student record programs from Section 6.2. Important note: You will find all of the source code from the text to be used as the basis for this project at: https://github.com/bitsai/book-exercises/tree/master/Accelerated%20C%2B%2B/chapter06

You will, of course, need to make changes to suit your system and to instrument the code.

Test data can be found at: https://github.com/bitsai/book-exercises/tree/master/Accelerated%20C%2B%2B/data

At the end of the program print out the static variable values. Since they are public you can get at them using the class name (e.g Student_info::myVar).

Explanation / Answer

Well, I see that Student_info is a struct here. Lets add a static variable to it. The headerfile will look as following when we add constructor, copy constructor,

assignment operator and destructors.

struct Student_info {
   std::string name;
   double midterm, final;
   std::vector<double> homework;
   static int myVar; //declaration is done here

   //Constructors
   Student_info();
   Student_info(std::string sname, double m, double f, std::vector<double> hw);

   //Copy Constructor
   Student_info(const Student_info &obj);

   //Assignment Operator
   Student_info& Student_info::operator=( const Student_info& other);

   //Destructor
   ~Student_info();
}

};

Now, all the implementation will go into the source file i.e. cc file. We initialize our static variable here as well as implement all the functions.

int Student_info::myVar = 0; //static variable initialization

//constructors

Student_info::Student_info() : name(""), midterm(0.0), final(0.0)
   { myVar++; }

Student_info::Student_info(std::string sname, double m, double f, std::vector<double> hw): name(sname), midterm(m), final(f), homework(hw)
   { myVar++; }

//Copy Constructor

Student_info::Student_info(const Student_info &obj)
   {
       name = obj.name;
       midterm = obj.midterm;
       final = obj.final;
       homework = obj.homework;
       myVar++;
   }

//Assignment operator

Student_info::Student_info& Student_info::operator=( const Student_info& other ) {
             name = other.name;
             midterm = other.midterm;
             final = other.final;
              homework = other.homework;
              myVar++;
             return *this;
   }

//Destructor

Student_info::~Student_info() {
       myVar++;
   }

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