class Introducer {
public:// 析构函数要virtual，否则在动态绑定时容易引起内存泄漏virtual ~Introducer() {// do nothing.};virtual void selfIntroduce() = 0;  // 接口函数
};

void introduce(Introducer &person) {person.selfIntroduce();
}

class Lucky: public Introducer {
public:Lucky(){};virtual void selfIntroduce() {printf("Hi, I'm lucky.\n");};
};

#include <cstdio>
#include <cstring>class Introducer {
public:virtual ~Introducer() {// do nothing.};virtual void selfIntroduce() = 0;
};class Lucky: public Introducer {
public:Lucky(){};virtual void selfIntroduce() {printf("Hi, I'm lucky.\n");};
};class Jacky: public Introducer {
public:Jacky() {};virtual void selfIntroduce() {printf("Hi, I'm jacky, Nice to meet you.\n");};
};class Penny: public Introducer {
public:Penny() {};virtual void selfIntroduce() {printf("Just call me penny, I like football.\n");};
};void introduce(Introducer &person) {person.selfIntroduce();
}int main(void) {Lucky lucky;introduce(lucky);Jacky jacky;introduce(jacky);Introducer *intr = new Penny();introduce(*intr);delete intr;intr = NULL;return 0;
}

5. 编译和结果输出
lucky@lucky-macbook:cplusplus_callback_function$ g++ class_callback.cpp -o class_callback
lucky@lucky-macbook:cplusplus_callback_function$ ./class_callback
Hi, I'm lucky.
Hi, I'm jacky, Nice to meet you.
Just call me penny, I like football.

#define TEXT_LEN 128void introduce(void (*pfun)(char *, size_t)) {char szText[TEXT_LEN] = {0};(*pfun)(szText, TEXT_LEN);printf("%s", szText);
}

2） 编写lambda程式实现回调接口并调用

auto fun1 = [] (char *outName, size_t len) -> void {strncpy(outName, "Hi, I'm jacky, Nice to meet you.\n", len);};
introduce(fun1);

3. 完整代码

#include <cstdio>
#include <cstring>
#include <functional>#define TEXT_LEN 128void introduce(void (*pfun)(char *, size_t)) {char szText[TEXT_LEN] = {0};(*pfun)(szText, TEXT_LEN);printf("%s", szText);
}// 定义函数指针
typedef void (*FUN_CALL)(char *, size_t);int main(void) {// 将lambda赋值给函数指针，一般不推荐这么做，推荐使用auto关键词FUN_CALL fun =  [] (char *outName, size_t len) -> void {strncpy(outName, "Hi, I'm lucky.\n", len);};introduce(fun);// 使用auto关键词定义函数变量，auto关键词是C++ 2011使用的。推荐使用auto fun1 = [] (char *outName, size_t len) -> void {strncpy(outName, "Hi, I'm jacky, Nice to meet you.\n", len);};introduce(fun1);// lambda程式直接作为参数传送，推荐使用，显得比较简洁introduce([](char *outName, size_t len) -> void {strncpy(outName, "Just call me penny, I like football.\n", len);});return 0;
}