c++ 대입연산자 관련

#include <iostream>
#include <string.h>
 
 
 
class CBankAccount
{
public:
    CBankAccount(){};
    ~CBankAccount(){};
 
    void SetBankName(const char * buf)
    {
        strcpy(m_BankName, buf);
    }
 
    char m_BankName[100];
    int m_Cash;
    int m_Interest;
    int * m_HistoryCash;
 
    CBankAccount& operator = ( CBankAccount & account1)
    {
    	SetBankName (account1.m_BankName);
    	m_Cash     = account1.m_Cash;
    	m_Interest = account1.m_Interest;
 
        if(m_HistoryCash != NULL)
        {
        	delete [] m_HistoryCash;
        }
    	m_HistoryCash = new int[12];
 
    	int temp;
    	for(int i = 0; i < 12; i++)
    	{
    		temp              = account1.m_HistoryCash[i];
    		m_HistoryCash[i]  = temp;
    	}
 
        account1.m_Cash = 100;
    	return *this;
 
    }
 
};
 
 
class A
{
public:
    A(){};
    ~A(){};
 
    int a;
};
 
 
int main(int argc, char** argv)
{
 
    CBankAccount b1;
    CBankAccount b2;
 
    strcpy(b2.m_BankName, "BankName");
    b2.m_Cash           = 10;
    b2.m_HistoryCash    = new int[12];
    b2.m_Interest       = 30;
    printf("b2.m_Cash    %d\n", b2.m_Cash);
 
    b1 = b2;
 
    printf("b1.m_Cash    %d\n", b1.m_Cash);
    printf("b2.m_Cash    %d\n", b2.m_Cash);
    delete [] b2.m_HistoryCash;
 
 
    //    
    A a;
    A b;
    a = b;
 
 
	return 0;
}