//DemoAssign - demonstrate the assignment operator
#include <stdio.h>
#include <string.h>
#include <iostream.h>

// Name - a generic class used to demonstrate
//        the assignment and copy constructor
//        operators
class Name
{
  public:
    Name(char *pszN = 0)
    {
        copyName(pszN);
    }
    Name(Name& s)
    {
        copyName(s.pszName);
    }
    ~Name()
    {
        deleteName();
    }
    //assignment operator
    Name& operator=(Name& s)
    {
        //delete existing stuff...
        deleteName();
        //...before replacing with new stuff
        copyName(s.pszName);
        //return reference to existing object
        return *this;
    }

    // display - output the current object
    //           the default output object
    void display()
    {
        cout << pszName;
    }

  protected:
    void copyName(char *pszN);
    void deleteName();
    char *pszName;
};

//copyName() - allocate heap memory to store name
void Name::copyName(char *pszName)
{
    this->pszName = 0;
    if (pszName)
    {
        this->pszName = new char[strlen(pszName) + 1];
        strcpy(this->pszName, pszName);
    }
}

//deleteName() - return heap memory
void Name::deleteName()
{
    if (pszName)
    {
        delete pszName;
        pszName = 0;
    }
}

// displayNames - output function to reduce the
//                number of lines in main()
void displayNames(Name& pszN1, char* pszMiddle,
                  Name& pszN2, char* pszEnd)
{
    pszN1.display();
    cout << pszMiddle;
    pszN2.display();
    cout << pszEnd;
}

int main(int nArg, char* pszArgs[])
{
    // create two objects
    Name n1("Claudette");
    Name n2("Greg");
    displayNames(n1, " and ", 
                 n2, " are newly created objects\n");

    // now make a copy of an object
    Name n3(n1);
    displayNames(n3, " is a copy of ", 
                 n1, "\n");

    // make a copy of the object from the
    // address
    Name* pN = &n2;
    Name n4(*pN);
    displayNames(n4, " is a copy using the address of ", 
                 n2, "\n"); 

    // overwrite n2 with n1
    n2 = n1;
    displayNames(n1, " was assigned to ", 
                 n2, "\n");
    return 0;
}