设计模式--原型模式（创建型）

//父类
class Resume
{
protected:
    char *name;
public:
    Resume() {}
    virtual ~Resume() {}
    virtual Resume* Clone() { return NULL; }
    virtual void Set(char *n) {}
    virtual void Show() {}
};

class ResumeA : public Resume
{
public:
    ResumeA(const char *str);  //构造函数
    ResumeA(const ResumeA &r); //拷贝构造函数
    ~ResumeA();                //析构函数
    ResumeA* Clone();          //克隆，关键所在
    void Show();               //显示内容
};
ResumeA::ResumeA(const char *str) 
{
    if(str == NULL) {
        name = new char[1]; 
        name[0] = ‘\0‘; 
    }
    else {
        name = new char[strlen(str)+1];
        strcpy(name, str);
    }
}
ResumeA::~ResumeA() { delete [] name;}
ResumeA::ResumeA(const ResumeA &r) {
    name = new char[strlen(r.name)+1];
    strcpy(name, r.name);
}
ResumeA* ResumeA::Clone() {
    return new ResumeA(*this);
}
void ResumeA::Show() {
    cout<<"ResumeA name : "<<name<<endl; 
}

int main()
{
    Resume *r1 = new ResumeA("A");
    Resume *r2 = new ResumeB("B");
    Resume *r3 = r1->Clone();
    Resume *r4 = r2->Clone();
    r1->Show(); r2->Show();
    //删除r1,r2
    delete r1; delete r2;    
    r1 = r2 = NULL;
    //深拷贝所以对r3,r4无影响
    r3->Show(); r4->Show();
    delete r3; delete r4;
    r3 = r4 = NULL;
}