demo_copy_constructor_5.cpp

对于一个初涉VC＋＋的人来书

//***************************************************

# include <iostream.h>
# include <string.h>
# include <stdlib.h>

class Person
{
public:
	Person(char* pN);  //浅拷贝
	Person(Person& p); //深拷贝(这里没有深拷贝而只有浅拷贝时会出错)
	~Person();         //析构

protected:
	char* pName;
};

Person::Person(char* pN) //浅拷贝定义
{
	cout<<"Constructing "<<pN<<endl;
	pName=new char[strlen(pN)+1];
	if(pName==NULL)
	{
		cout<<"Can't allocate more memory,terminating.\n";
		exit(1);
	}
	strcpy(pName,pN);
}

Person::Person(Person& p) //深拷贝定义
{
	cout<<"Copying "<<p.pName<<" into its own block"<<endl;
	pName=new char[strlen(p.pName)+1];
	if(pName==NULL)
	{
		cout<<"Can't allocate more memory,terminating.\n";
		exit(1);
	}
	strcpy(pName,p.pName);
}

Person::~Person() //析构定义
{
	cout<<"Destructing "<<pName<<endl;
	pName[0]='\0';
	delete pName;
//	delete[] pName;
}

void main()
{
	Person p1("Jenny");
	Person p2(p1); //等价于: p2=p1
}