#include "stdafx.h"

?

#include <iostream>

using namespace std;

?

class TestAction;

?

typedef void (*fp)(int);

?

void Drink(int i)

{

?????? cout<<"No. "<<i<<" drink..."<<endl;

}

?

void Eat(int i)

{

?????? cout<<"No. "<<i<<" eat..."<<endl;

}

?

class TestAction

{

public:

?????? fp testAct;

?

?????? void TestAct(int i)

?????? {

????????????? if (testAct != NULL)

????????????? {

???????????????????? testAct(i);

????????????? }

?????? }

};

?

int main(int argc, char* argv[])

{????

?????? TestAction doact;

?????? doact.testAct = &Drink;?????

?????? doact.TestAct(0);

?????? doact.TestAct(1);

?????? doact.TestAct(2);

?????? doact.testAct = &Eat;?

?????? doact.TestAct(0);

?????? doact.TestAct(1);

?????? doact.TestAct(2);

?????? return 0;

}

#include "stdafx.h"

?

#include <iostream>

using namespace std;

?

class Action;

class TestAction;

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// 函数指针类型为类 Action 的成员函数

typedef void (Action::*fp)(int);

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class Action

{

public:

?????? void Drink(int i)

?????? {

????????????? cout<<"No. "<<i<<" drink..."<<endl;

?????? }

?

?????? void Eat(int i)

?????? {

????????????? cout<<"No. "<<i<<" eat..."<<endl;

?????? }

};

?

class TestAction

{

public:

?????? // 定义一个函数指针

?????? fp testAct;

?????? //Action 对象实例 , 该指针用于记录被实例化的 Action 对象

?????? Action * pAction;

?

?????? void TestAct(int i)

?????? {

????????????? if ((pAction != NULL) && (testAct != NULL))

????????????? {

???????????????????? // 调用

????????????? ?????? (pAction->*testAct)(i);

????????????? }

?????? }

};

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int main(int argc, char* argv[])

{

?????? Action act;

?????? TestAction doact;

?????? doact.pAction = &act;

?????? doact.testAct = Action::Drink;??

?????? doact.TestAct(0);

?????? doact.TestAct(1);

?????? doact.TestAct(2);

?????? doact.testAct = Action::Eat;?????

?????? doact.TestAct(0);

?????? doact.TestAct(1);

?????? doact.TestAct(2);

?????? return 0;

}

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#include "stdafx.h"

?

#include <iostream>

#include <functional>

?

using namespace std;

?

class Action;

class Drink;

class Eat;

class TestAction;

?

class Action

{

public:???

?????? int operator()(int i)

?????? {

????????????? Act(i);

????????????? return i;

?????? }

?

?????? virtual void Act(int i) = 0;

};

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class Drink : public Action

{

?????? void Act(int i)

?????? {

????????????? cout<<"No. "<<i<<" drink..."<<endl;

?????? }

};

?

class Eat : public Action

{

?????? void Act(int i)

?????? {

????????????? cout<<"No. "<<i<<" eat..."<<endl;

?????? }????

};

?

class TestAction

{

public:

?????? void TestAct(int i, Action& testAct)

?????? {????

????????????? testAct(i);

?????? }

};

?

int main(int argc, char* argv[])

{???????????

?????? TestAction doact;??????????????

?????? doact.TestAct(0, Drink());

?????? doact.TestAct(1, Drink());

?????? doact.TestAct(2, Drink());??

?????? doact.TestAct(0, Eat());

?????? doact.TestAct(1, Eat());

?????? doact.TestAct(2, Eat());

?????? return 0;

}

#include "stdafx.h"

?

#include <iostream>

?

using namespace std;

?

class Negate

{

public:

?????? template<class T> T operator()(T t) const

?????? {

????????????? return -t;

?????? }

};

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void Callback(int n, const Negate& neg)? // 传递一个函数对象

{

?????? n = neg(n);? // 调用重载的 () 操作 来对 n 进行 negate 操作

?????? cout << n << endl;

}

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int main(int argc, char* argv[])

{

?????? // 调用方式一

?????? Callback(5, Negate());

?

?????? // 调用方式二

?????? Negate neg;

?????? cout << neg(9.99999) << endl;??????

?????? cout << neg(__int32(39999999)) << endl;

???

?????? return 0;

}