design pattern CHAIN of reponsibility

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#include<cstdio>
using namespace std;
namespace pattern{
	/// this pattern links all handler as a line, if previous handler can process a request, it wil not be
	/// send to next handler. For example, if someone requested changing programming style, 
	/// this decision will be made by a programmer. 
	/// He will change his programming style without noticing his lead. 
	/// But if someone request changing the requirements, the programmer can not make this decision. 
	/// He will noticing his lead, and make his lead decided.
	/// this is request class.
	#define STYLE 0
	#define REQIREMENT 1
	class Request{
		public:
			int type; // changing programming style or changing requirements?
	};
	/// this class for processing request.
	class Handler{
	private:
		Handler* parent;
	public:
		Handler(Handler* p):parent(p){}
		virtual bool DoHandle(Request& r)=0;
		void Process(Request& r);
		virtual ~Handler(){}
	};
	void Handler::Process(Request& r){
		if(!this->DoHandle(r) && NULL != parent){
			parent->Process(r);
		}
	}
	class Programmer: public Handler{
		public:
		Programmer(Handler* p):Handler(p){}
		virtual bool DoHandle(Request& r);
	};
	bool Programmer::DoHandle(Request& r){
		if(r.type == STYLE){
			printf("programmer: I can process changing programming style\n");
			return true;
		}else{
			printf("programmer: I can not process this request. I will report this to my lead!\n");
			return false;
		}
	}
	class Lead:public Handler{
		public:
		Lead(Handler* p):Handler(p){}
		virtual bool DoHandle(Request& r);
	};
	bool Lead::DoHandle(Request& r){
		if(r.type == REQIREMENT){
			printf("lead: I will process changing reqirements\n");
			return true;
		}
		return false;
	}
}
int main(){
	pattern::Lead lead((pattern::Handler*)NULL);
	pattern::Programmer programmer(&lead);
	pattern::Request r;
	r.type = STYLE;
	programmer.Process(r);
	r.type = REQIREMENT;
	programmer.Process(r);
	return 0;
}