使用C++11 std::bind和std::function实现回调机制

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我是靠谱客的博主老实小甜瓜，最近开发中收集的这篇文章主要介绍使用C++11 std::bind和std::function实现回调机制，觉得挺不错的，现在分享给大家，希望可以做个参考。

概述

#include <functional>
#include <iostream>

#define MY_CALLBACK_0(__selector__,__target__,

) std::bind(&__selector__,__target__, ##__VA_ARGS__)
#define MY_CALLBACK_1(__selector__,__target__,

) std::bind(&__selector__,__target__, std::placeholders::_1, ##__VA_ARGS__)
#define MY_CALLBACK_2(__selector__,__target__,

) std::bind(&__selector__,__target__, std::placeholders::_1, std::placeholders::_2, ##__VA_ARGS__)
#define MY_CALLBACK_3(__selector__,__target__,

) std::bind(&__selector__,__target__, std::placeholders::_1, std::placeholders::_2, std::placeholders::_3, ##__VA_ARGS__)

typedef std::function< void ()> CALLBACK_FUNC;

class Sender
{
public :
    Sender() { callback = nullptr; }
     virtual ~Sender() {}

public :
     void emit()
    {
        std::cout << "I am A,I send a message." << std::endl;
         if (callback) callback();
    }

     void setTarget(CALLBACK_FUNC target)
    {
        callback = target;
    }

public :
    CALLBACK_FUNC callback;
};

struct foo
{
     void doSomething_MemberFunction() const
    {
        std::cout << "I am member function,I got a message!" << std::endl;
    }

     static void doSomething_StaticMemberFunction( int i)
    {
        std::cout << "I am static member function,I got a message! i=" << i << std::endl;
    }
};

void doSomething_GlobalFunction()
{
    std::cout << "I am global function,I got a message!" << std::endl;
}

class Functor
{
public :
     void operator ()()
    {
        std::cout << "I am a functor!" << std::endl;
    }
};

void testBindFunction()
{
    Sender sender;
    foo f;

     // 成员函数
    sender.setTarget(std::bind(&foo::doSomething_MemberFunction, &f));
     // sender.setTarget(MY_CALLBACK_0(foo::doSomething_MemberFunction, &f));
    sender.emit();

     // 全局函数
    sender.setTarget(doSomething_GlobalFunction);
    sender.emit();

     // 静态成员函数
    sender.setTarget(std::bind(foo::doSomething_StaticMemberFunction, 666));
    sender.emit();

     // Lambda表达式
    auto lambda = []() { std::cout << "I am Lambda!" << std::endl; };
    sender.setTarget(lambda);
    sender.emit();

     // 仿函数
    sender.setTarget(Functor());
    sender.emit();
}