heap_data_member.cpp

the source of dev_c++ most of them for game development

//Heap Data Member
//Demonstrates an object with a dynamically allocated data member

#include <iostream>
#include <string>

using namespace std;

class Critter
{
public: 
    Critter(const string& name = "")
    {
        cout << "Constructor called\n";
        m_pName = new string(name);  
    }
    
    ~Critter()                        //destructor
    {
        cout << "Destructor called\n";
        delete m_pName;
    }
    
    Critter(const Critter& c)     //copy constructor
    {
        cout << "Copy Constructor called\n";
        m_pName = new string;
        *m_pName = c.GetName();
    }
    
    Critter& operator=(const Critter& c)  //overloaded assignment operator
    {
        cout << "Overloaded Assignment Operator called\n";
        
        if (this == &c)
        {
            return *this;
        }
        else
        {
            *m_pName = c.GetName();
            return *this;
        }
    }

    string GetName() const { return *m_pName; }
    void SetName(const string& name = "") { *m_pName = name; }  
    void SayHi() const { cout << "Hi, my name is " << GetName() << "\n"; }

private:
    string* m_pName;
};

void testDestructor();
void testCopyConstructor(Critter copy);
void testAssignmentOp();

int main()
{
    testDestructor();
    cout << endl;
    
    Critter crit("Poochie");
    crit.SayHi();
    testCopyConstructor(crit);
    cout << endl;
    
    testAssignmentOp();
 
    return 0;
}

void testDestructor()
{
    Critter crit("Rover");
    crit.SayHi();
}

//passing object by value invokes its copy constructor
void testCopyConstructor(Critter copy)  
{
    copy.SayHi();
}

void testAssignmentOp()
{
    Critter crit1("crit1");
    Critter crit2("crit2");
    crit1 = crit2;
    crit1.SayHi();  
    crit2.SayHi();
    
    cout << "Setting name of crit1 back to 'crit1'\n";
    crit1.SetName("crit1");
    crit1.SayHi();  
    crit2.SayHi();   
    
    Critter crit("crit");
    crit = crit;
}