boost库 bind/function的使用

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Boost::Function 是对函数指针的对象化封装，在概念上与广义上的回调函数类似。相对于函数指针，function除了使用自由函数，还可以使用函数对象，甚至是类的成员函数，这个就很强大了哈

#include <boost/function.hpp>#include <boost/bind.hpp>#include <iostream> using namespace std;  class TestA{    public:        void method()        {            cout<<"TestA: method: no arguments"<<endl;        }         void method(int a, int b)        {            cout<<"TestA: method: with arguments"                <<"value of a is:"<<a                 <<"value of b is "<<b <<endl;        }};  void sum(int a, int b){    int sum = a + b;    cout<<"sum: "<<sum<<endl;}  int main(){    boost::function<void()> f;    TestA test;     f = boost::bind(&TestA::method, &test);    f();     f = boost::bind(&TestA::method, &test, 1, 2);    f();     f = boost::bind(&sum, 1, 2);    f();}

2. 应用：Thread封装

在实现自定义的线程类时，曾经这么干过：定义虚函数run()，用户自定义的CustomThread::Thread后，自己实现run()函数就OK了。当时觉得这么做也不错。
现在有了boost::function/boost::bind我们可以这么干：
定义一个线程类：
.h文件

#include <pthread.h>#include <string>#include <boost/function.hpp>#include <boost/bind.hpp> using namespace std;class Thread{    typedef boost::function<void()> ThreadFun;    public:        Thread(const ThreadFun& threadFun,const string& threadName = string());        pid_t     getThreadId();        string    getThreadName();        int       start();         private:        static void* startThread(void* thread);       private:        pthread_t   m_thread; //线程句柄        pid_t       m_tid;    //线程ID        string      m_strThreadName;    //线程名称        bool        m_bStarted;         //线程是否启动        ThreadFun   m_func;             //线程处理函数};

.cpp

#include "thread.h" Thread::Thread(const Thread::ThreadFun& threadFun, const string& threadName):m_func(threadFun), m_strThreadName(threadName){} int Thread::start(){    m_tid = pthread_create(&m_thread, NULL, &startThread, this);    return 0;} void* Thread::startThread(void* obj){  Thread* thread = static_cast<Thread*>(obj);  thread->m_func();  return NULL;} pid_t Thread::getThreadId(){    return m_tid;}; string  Thread::getThreadName(){    return m_strThreadName;}

void ThreadProcess(){    int count = 100;    for (int i = 0; i < count; i++)    {        if (i % 10 == 0)            cout<<"\n";        cout<<i<<"\t";    }} int main(){    boost::function<void()> f;    f = boost::bind(&ThreadProcess);            Thread thread(f, "ThreadTest");        thread.start();    sleep(1000*1000);    return 0;}

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