小编gar*_*erg的帖子

我试着理解双重调度的工作原理.我创建了一个例子,其中一个怪物和一个来自抽象类生物的战士可以战斗.类Creature有方法"fight",它是在派生类中定义的,并且在每个派生类中定义了如果战士与战士或怪物等战斗会发生什么.我写了下面的代码:

#include<iostream>
using namespace std;

class Monster;
class Warrior;

class Creature{
public:
    virtual void fight(Creature&) =0;
};

class Monster: public Creature{
    void fightwho(Warrior& w) {cout<<"Monster versus Warrior"<<endl; }
    void fightwho(Monster& m) {cout<<"Monster versus Monster"<<endl; }
public:
    void fight(Creature& c)  {c.fightwho(*this);}
};

class Warrior: public Creature{
    void fightwho(Warrior& w) {cout<<"Warrior versus Warrior"<<endl; }
    void fightwho(Monster& m) {cout<<"Monster versus Warrior"<<endl; }
public:
    void fight(Creature& c) {c.fightwho(*this);}
};

int main()
{
Warrior w;
Monster m;
w.fight(m);
}

这导致编译器错误,我预见到:

ex12_10.cpp:在成员函数'virtual void Monster :: fight(Creature&)':ex12_10.cpp:17:30:错误:'class …