Offer_1

#include <iostream>
#include <cstring>
using namespace std;

class CMyString
{
public:
	CMyString(char *m_pData=NULL);
	CMyString(const CMyString& str);
	~CMyString(void);

	CMyString& operator=(const CMyString& str);

	void print();
private:
	char *m_pData;
};

CMyString::CMyString(char *m_pData)
{
	if(m_pData!=NULL)
	{
		this->m_pData = new char[strlen(m_pData)+1];
		strcpy(this->m_pData, m_pData);
	}else{
		this->m_pData = NULL;
	}
}

CMyString::CMyString(const CMyString& str)
{
	new (this) CMyString(str.m_pData);
	//this->m_pData = new char[strlen(str.m_pData)+1];
	//strcpy(this->m_pData, str.m_pData);
}

CMyString::~CMyString()
{
	if(m_pData!=NULL)
	{
		delete []  m_pData;
		m_pData = NULL;
	}
}

CMyString& CMyString::operator=(const CMyString& str)
{
	if(this!=&str)
	{
		CMyString strTemp(str);
		char * pTemp = strTemp.m_pData;
		strTemp.m_pData = m_pData;
		m_pData = pTemp;
	}
	return *this;
}

void CMyString::print()
{
	if(m_pData!=NULL)
		cout<<m_pData<<endl;
}

int main()
{
	CMyString str("I'm xxxx.");
	str.print();
	CMyString cpy1 = str;
	cpy1.print();
	CMyString cpy2 = "hello World";
	cpy2.print();
	CMyString cpy3;
	cpy3 = str;
	cpy3.print();
	CMyString cpy4, cpy5;
	cpy4 = cpy5;
	cpy4.print();
	CMyString cpy6(cpy5);
	return 0;
}