c++策略模式headfirst鸭子

关于策略模式的具体内容大家可以看书，这里只贴我的实现代码。写的仓促，可能存在考虑不全面的地方，欢迎留言。

strategy.h

//strategy.h
#include<iostream>
using namespace std;

class FlyBehaviour {
public:
	virtual void fly() = 0;
};
class Fly :public FlyBehaviour {
public:
	void fly() override;
};
class NFly :public FlyBehaviour {
public:
	void fly() override;
};

class QuackBehaviour {
public:
	virtual void quack() = 0;
};
class Quack :public QuackBehaviour {
public:
	void quack() override;
};
class NQuack :public QuackBehaviour {
public:
	void quack() override;
};

class Duck {
private:
	FlyBehaviour* _flybehaviour;
	QuackBehaviour* _quackbehaviour;
public:
	void swim();
	void performfly();
	void performquack();
	void setflybehaviour(unsigned short);
	void setquackbehaviour(unsigned short);
	virtual void display()=0;
};

class MyDuck :public Duck {
private:
	string _name;
public:
	void display() override;
	MyDuck(string name) :_name(name) {}
};
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strategy.cpp

#include"stratage.h"

void Fly::fly() {
	cout << "can fly";
}
void NFly::fly() {
	cout << "can't fly";
}

void Quack::quack() {
	cout << "guagua";
}
void NQuack::quack() {
	cout << "gaga" ;
}

void Duck::swim(){
	cout << "can swim" ;
}
void Duck::performfly(){
	_flybehaviour->fly();
}
void Duck::performquack() {
	_quackbehaviour->quack();
}
void Duck::setflybehaviour(unsigned short ui = 0) {
	if (_flybehaviour) free(_flybehaviour);
	switch(ui) {
		case(1):
			_flybehaviour = new Fly();
			break;
		case(2):
			_flybehaviour = new NFly();
			break;
		default:
			_flybehaviour = new Fly();
			break;
	}
}
void Duck::setquackbehaviour(unsigned short ui = 0) {
	if (_quackbehaviour) free(_quackbehaviour);
	switch (ui) {
	case(1):
		_quackbehaviour = new Quack();
		break;
	case(2):
		_quackbehaviour = new NQuack();
		break;
	default:
		_quackbehaviour = new Quack();
		break;
	}
}

void MyDuck::display() {
	cout << _name<<' ';
	swim();
	cout << ", ";
	performfly();
	cout << ", backed with '";
	performquack();
	cout << "'." << endl;
}

void test1() {
	MyDuck myduck1("duck1");
	myduck1.setflybehaviour(1);
	myduck1.setquackbehaviour(1);
	myduck1.display();
	MyDuck myduck2("duck2");
	myduck2.setflybehaviour(1);
	myduck2.setquackbehaviour(2);
	myduck2.display();
	MyDuck myduck3("duck3");
	myduck3.setflybehaviour(2);
	myduck3.setquackbehaviour(1);
	myduck3.display();
	MyDuck myduck4("duck4");
	myduck4.setflybehaviour(2);
	myduck4.setquackbehaviour(2);
	myduck4.display();
}
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main.cpp

void test1();
int main(){
	test1();
	return 0;
}
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输出结果