//這個程序在本書所帶軟盤中。文件名為FAX.CPP
//這個程序在基類中忽略了關鍵字virtual，使程序不再具有多態性。

#include <iostream.h>
#include <string.h>
#include <stdlib.h>

class Fax {
	public:
		Fax(int);				//構造函數用來對機器中的紙數進行初始化
		void process(int);		//關鍵字virtual被忽略，程序不再具有多態性
	protected:
		char phone_num[32];
		int num_paper;

};

Fax::Fax(int paper)
{
	num_paper = paper;
}

void Fax::process(int pages)
{
	cout << "總紙數: " << pages << endl;
	cout << "這是虛擬處理.." << endl;
}

class Fax_machine: public Fax{
	public:
		Fax_machine(char* phone, int paper) : Fax(paper)
		{
			strcpy(phone_num, phone); 
		}
		void process(int);
};

void Fax_machine::process(int paper)
{
	if (paper > num_paper)
	{
		cout << "不能完成傳真!" << endl;
		cout << "紙張已用完。還需要至少加入 " << (paper-num_paper) 
			 << " 頁紙才可完成傳真。謝謝！" << endl;
	  	exit(1);
	}
	else {
		cout <<"完成傳真! " << endl;
		cout << "傳真發至: " << phone_num << endl;
		cout << "傳真發出頁數: " << paper << endl;
	}
}

class Printer: public Fax{
	public:
		Printer(int paper) : Fax(paper) { };
		void process(int);
};

void Printer::process(int paper)
{
	if (paper > num_paper)
	{
		cout << "不能完成打印!" << endl;
	  	cout << "紙張已用完! 請至少加入 " << (paper-num_paper) 
			 << " 頁紙才可完成打印。 謝謝！" << endl;
	  	exit(1);
	}
	else {
		cout << "完成打印! " << endl;
		cout << "打印總頁數為: " << paper << endl;
	}
}

void main(void)
{
	Fax_machine fax("324-8890", 100);
	Printer printer(30);

	Fax* use;

	use = &fax;
	use->process(9);
	cout << endl;

	use = &printer;
	use->process(40);
}

/*這個程序運行后將顯示如下輸出結果：
總紙數: 9
這是虛擬處理..

總紙數: 40
這是虛擬處理..
*/