原型模式

#include <iostream>
using namespace std;

class IPrototype
{
public:
    virtual void ShowClass() = 0;
    virtual IPrototype* Copy() = 0;
};
class ClassA: public IPrototype
{
public:
    virtual void ShowClass() { cout << "ClassA" << endl; }
    virtual IPrototype* Copy() { return new ClassA; }
};
class ClassB : public IPrototype
{
public:
    virtual void ShowClass() { cout << "ClassB" << endl; }
    virtual IPrototype* Copy() { return new ClassB; }
};
class ClassC : public IPrototype
{
public:
    virtual void ShowClass() { cout << "ClassC" << endl; }
    virtual IPrototype* Copy() { return new ClassC; }
};

int main()
{
    IPrototype* calculate = NULL;
    IPrototype* copy = NULL;
    calculate = new ClassA;
    copy = calculate->Copy();
    calculate->ShowClass();
    copy->ShowClass();
    delete calculate;
    delete copy;
    calculate = new ClassB;
    copy = calculate->Copy();
    calculate->ShowClass();
    copy->ShowClass();
    delete calculate;
    delete copy;
    calculate = new ClassC;
    copy = calculate->Copy();
    calculate->ShowClass();
    copy->ShowClass();
    delete calculate;
    delete copy;
    calculate = NULL;
    copy = NULL;
    return 0;
}