没有命名的成员

这是头文件名monitor.h

class DSRAgent;
class Detector;
class ReputationSystem;
class Monitor {
public:
    Monitor();
    Monitor(DSRAgent* agent);
    void handleTap(const Packet* packet);
    void handlePublishInfo(nsaddr_t src, double identification, int count,rating* ratings);
    void handlePacketSent(Packet* packet);
    void publishInfo(map<nsaddr_t, rating*> ratings);
    void setNetID(nsaddr_t netid); 
    nsaddr_t getNetID();
    friend class PackTableTimer;
    void setReputationSystem(ReputationSystem* rep_system);
    bool isPACK(int uid);
    void Terminate();
    PackTableTimer* pack_table_timer;
private:
    void packTableCheck();
    map<nsaddr_t, double> published_ids;
    PackTable pack_t;
    DSRAgent* dsragent;
    Detector* detector;
    ReputationSystem* reputation_system;
    nsaddr_t net_id; 
};
class PackTableTimer : public TimerHandler {
public:
PackTableTimer(Monitor *a) : TimerHandler() { a_ = a;}
void expire(Event *e);
protected:
Monitor *a_;
};

另一个文件是monitor.cc

void PackTableTimer::expire(Event *e)
{
    a_->packTableCheck();
    resched(PACK_TIMEOUT + PACK_TIMEOUT * Random::uniform(1.0));
}
DSRAgent* dsragent;
Monitor::Monitor(DSRAgent* agent)
{ 
    this->dsragent = agent;
    this->detector = new Detector(this);
    pack_table_timer = new PackTableTimer(this);
    pack_table_timer->sched(PACK_TIMEOUT + PACK_TIMEOUT * Random::uniform(1.0));
}
void Monitor::handleTap(const Packet* packet)
{
    Behavior behavior;
    hdr_sr *srh = hdr_sr::access(packet);
    hdr_ip *iph = hdr_ip::access(packet);
    hdr_cmn *cmh = hdr_cmn::access(packet);
    ID cur_hop(srh->addrs()[srh->cur_addr()-1]);
    nsaddr_t cur_addr = cur_hop.getNSAddr_t();
    int uid = cmh->uid();
    map<int, PackData*>::iterator it;
    it = pack_t.find(uid);

我得到以下错误:

<>之前**monitor.h: error: ' PackTableTimer '没有指定类型班长。cc:在构造函数' Monitor::Monitor(DSRAgent*) '中班长。cc:错误:' class Monitor '没有名为' PackTableTimer '的成员班长。Cc:错误:' pack_table_timer '未在此范围内声明**

class PackTableTimer;