C++保存成员函数指针

成员函数指针保存：

char mf_addr_[16];

void (DestT::*memfun)(int)；

memcpy(&mf_addr_,&memfun,sizeof(memfun));

 

 

DEMO:

class Signal1{
public:
    template <class DestT>
    void connect(DestT* dest,void (DestT::*memfun)(int)){
        inst_ = (void*)dest;
        assert(sizeof(memfun)<=sizeof(mf_addr_));
        memcpy(&mf_addr_,&memfun,sizeof(memfun));
        call_fun_ = &call_mf<DestT>;
    }
    
    void emit(int arg) const{
        call_fun_(inst_,mf_addr_,arg);
    }
private:
    void *inst_;
    char mf_addr_[16];
    void (*call_fun_)(void *,const char* ,int);





    template <class DestT> static void call_mf(void *inst,const char* memfun,int arg){
        void (DestT::*mf)(int);
        memcpy(&mf,memfun,sizeof(mf));
        ((static_cast<DestT*>(inst))->*mf)(arg);
    }
};

class Sender{
public:
    Signal1 s_;
    void doSignal(int i){
        s_.emit(i);
    }
};




class Receiver{
public:
    void onSignal(int i){
        cout<<"signal with "<<i<<endl;
    }
};







int main(int argc,char* argv[]){
    Sender sender;
    Receiver receiver;
    sender.s_.connect(&receiver, &Receiver::onSignal);
    sender.doSignal(5);
    return 0;
}