[C++]给C++封装一个多播委托

一来闲的蛋疼,二来我们代码里面有一些fastdelegate的代码,在clang下面实在编译不过去,所以打算重造一个轮子,至少标准一点(换个编译器能编译过去...)....

废话不说,上代码:

// C++版的多播委托,使用boost::function
// 为了在各个编译器下面都能编译
// author:egmkang

#ifndef __ZEVENT_T_H__
#define __ZEVENT_T_H__
#include <boost/function.hpp>
#include <list>

template<typename T>
class zEventBaseT
{
public:
    typedef T DelegateType;
    typedef std::list<DelegateType*> ContainerType;
    typedef typename ContainerType::iterator IterType;

    inline void add(DelegateType *p)
    {
        if(p && !contains(p))
        {
            _impl_list.push_back(p);
        }
    }
    inline void remove(DelegateType *p)
    {
        _impl_list.remove(p);
    }
    inline void operator +=(DelegateType *p)
    {
        add(p);
    }
    inline void operator -=(DelegateType *p)
    {
        remove(p);
    }
protected:
    zEventBaseT(){}
    virtual ~zEventBaseT()
    {
        _impl_list.clear();
    }
    inline bool contains(DelegateType *p)
    {
        for(IterType iter = _impl_list.begin();
            iter != _impl_list.end();
            ++iter)
        {
            if(*iter == p) return true;
        }
        return false;
    }
protected:
    ContainerType _impl_list;
};

template<typename T>
class zEventT;

#define EVENT_CALL(...)                           \
    {                                             \
        ContainerType& impl = this->_impl_list;   \
        for(IterType iter = impl.begin();         \
            iter != impl.end();                   \
            ++iter)                               \
        {                                         \
            (*(*iter))(__VA_ARGS__);              \
        }                                         \
    }

//FUNCTION_ARGS = 0
template<>
class zEventT<boost::function<void()> >:
    public zEventBaseT<boost::function<void()> >
{
public:
    void operator()()
    {
        EVENT_CALL();
    }
};

//FUNCTION_ARGS = 1
template<typename P1>
class zEventT<boost::function<void(P1)> >:
    public zEventBaseT<boost::function<void(P1)> >
{
public:
    typedef typename zEventBaseT<boost::function<void(P1)> >::ContainerType ContainerType;
    typedef typename zEventBaseT<boost::function<void(P1)> >::IterType IterType;
    void operator()(P1 p1)
    {
        EVENT_CALL(p1);
    }
};

//FUNCTION_ARGS = 2
template<typename P1,typename P2>
class zEventT<boost::function<void(P1,P2)> >:
    public zEventBaseT<boost::function<void(P1,P2)> >
{
public:
    typedef typename zEventBaseT<boost::function<void(P1,P2)> >::ContainerType ContainerType;
    typedef typename zEventBaseT<boost::function<void(P1,P2)> >::IterType IterType;
    void operator()(P1 p1,P2 p2)
    {
        EVENT_CALL(p1,p2);
    }
};

//FUNCTION_ARGS = 3
template<typename P1,typename P2,typename P3>
class zEventT<boost::function<void(P1,P2,P3)> >:
    public zEventBaseT<boost::function<void(P1,P2,P3)> >
{
public:
    typedef typename zEventBaseT<boost::function<void(P1,P2,P3)> >::ContainerType ContainerType;
    typedef typename zEventBaseT<boost::function<void(P1,P2,P3)> >::IterType IterType;
    void operator()(P1 p1,P2 p2,P3 p3)
    {
        EVENT_CALL(p1,p2,p3);
    }
};

//FUNCTION_ARGS = 4
template<typename P1,typename P2,typename P3,typename P4>
class zEventT<boost::function<void(P1,P2,P3,P4)> >:
    public zEventBaseT<boost::function<void(P1,P2,P3,P4)> >
{
public:
    typedef typename zEventBaseT<boost::function<void(P1,P2,P3,P4)> >::ContainerType ContainerType;
    typedef typename zEventBaseT<boost::function<void(P1,P2,P3,P4)> >::IterType IterType;
    void operator()(P1 p1,P2 p2,P3 p3,P4 p4)
    {
        EVENT_CALL(p1,p2,p3,p4);
    }
};

#endif//__ZEVENT_T_H__

这里最多支持函数有四个参数,如果想要支持多的话,自己添上去就行.

使用该类的代码:

#include "zEvent.hpp"
#include <boost/bind.hpp>
#include <iostream>
#include <stdlib.h>

void printA(int a,int b)
{
    std::cout << (a+b) << std::endl;
}
void printB(int a,int b)
{
    std::cout << (a + b) << std::endl;
}
int main()
{
    typedef zEventT<boost::function<void(int)> > PrintEvent;
    typedef PrintEvent::DelegateType DelegateType;

    PrintEvent _event;
    DelegateType delegate1 = boost::bind(&printA,10,_1);
    DelegateType delegate2 = boost::bind(&printB,12,_1);
    
    _event += &delegate1;
    _event += &delegate2;
    _event(18);

    std::cout << std::endl;
    _event -= &delegate1;
    _event(19);

    system("pause");
    return 0;
}

之所以委托链内存的是指针,原因有2:

1. 指针很容易比较

2. boost::function比较貌似有一点问题

用boost::function有一点好处,就是可以通过boost::bind完成一些复杂的功能:-),而且boost::function也是C++0x的内容之一

PS:

随手写了一个,至少兼容VC,GCC 4.4+,clang 2.8,有什么问题或者建议都可以留言,欢迎斧正.

clang真是一个好东西啊,准备把我们服务器的代码改的在clang下面可以编译过去,用clang做代码分析检查:-D

我自己对容器内存的顺序没要求,所以把容器换成set了哈,哈哈