c++ - forward declaration of 'const class LHContactInfo' error when try to access it property -

i have 2 c++ class bellow. want lhcontactinfo property lhscenesubclass can nothing.so how can this?

#ifndef __levelhelper_api_contact_info_h__  #define __levelhelper_api_contact_info_h__    #include "lhconfig.h"  #if lh_use_box2d    #include "cocos2d.h"    class b2contact;    using namespace cocos2d;    class lhcontactinfo  {  public:            lhcontactinfo();      virtual ~lhcontactinfo();            node*       nodea;      node*       nodeb;      std::string nodeashapename;      std::string nodebshapename;      int         nodeashapeid;      int         nodebshapeid;            point       contactpoint;      float       impulse;            b2contact*  box2dcontact;  };    #endif    #endif //__levelhelper_api_contact_info_h__      #include "lhcontactinfo.h"    #if lh_use_box2d    #include "box2d/box2d.h"    lhcontactinfo::lhcontactinfo(){      nodea = null;      nodeb = null;      box2dcontact = null;  }  lhcontactinfo::~lhcontactinfo(){      nodea = null;      nodeb = null;      box2dcontact = null;  }    #endif

#ifndef __lh_scene_subclass_h__  #define __lh_scene_subclass_h__    #include "cocos2d.h"  #include "levelhelper2api.h"    class lhcontactinfo;  class lhscenesubclass : public lhscene  {  public:      static cocos2d::scene* createscene();        lhscenesubclass();      virtual ~lhscenesubclass();            bool initwithcontentoffile(const std::string& plistlevelfile);      virtual bool shoulddisablecontactbetweennodes(node* nodea, node* nodeb);      virtual void didbegincontact(const lhcontactinfo& contact);      virtual void didendcontact(const lhcontactinfo& contact);  };    #endif // __lh_scene_subclass_h__      //file.cpp    void lhscenesubclass::didbegincontact(const lhcontactinfo& contact){  	if(contact.nodea->getname() == "box1"){// error invalid use of incomplete type 'const class    lhcontactinfo'    	}  }  void lhscenesubclass::didendcontact(const lhcontactinfo& contact){      cclog("didendcontact...\n");  }

i want contact.nodea lhcontactinfo in didbegincontact function compile error ->error invalid use of incomplete type 'const class lhcontactinfo'

note:: - compile android ndk 10c

the class lhcontactinfo declared (ie, know name), due forward declaration. however, compiler needs class definition. need include file containing class definition.