AbsoluteC++中文第二版书上的源代码

				//This is the implementation file: dtime.cpp of the class DigitalTime.
				//The interface for the class DigitalTime is in the header file dtime.h.
				#include 
				#include 
				#include 
				using std::istream;
				using std::ostream;
				using std::cout;
				using std::cin;
				#include "dtime.h"
				
				namespace
				{
				    int digitToInt(char c)
				    {
				        return ( int(c) - int('0') );
				    }
				
				    //Uses iostream, cctype, and cstdlib:
				    void readMinute(int& theMinute)
				    {
				        char c1, c2;
				        cin >> c1 >> c2;
				
				        if (!(isdigit(c1) && isdigit(c2)))
				        {
				            cout 				            exit(1);
				        }
				
				        theMinute = digitToInt(c1)*10 + digitToInt(c2);
				
				        if (theMinute < 0 || theMinute > 59)
				        {
				            cout 				            exit(1);
				        }
				    }
				
				    //Uses iostream, cctype, and cstdlib:
				    void readHour(int& theHour)
				    {
				        char c1, c2;
				        cin >> c1 >> c2;
				        if ( !( isdigit(c1) && (isdigit(c2) || c2 == ':' ) ) )
				        {
				            cout 				            exit(1);
				        }
				
				        if (isdigit(c1) && c2 == ':')
				        {
				            theHour = digitToInt(c1);
				        }
				        else //(isdigit(c1) && isdigit(c2))
				        {
				            theHour = digitToInt(c1)*10 + digitToInt(c2);
				            cin >> c2; //discard ':'
				            if (c2 != ':')
				            {
				                cout 				                exit(1);
				            }
				        }
				
				        if (theHour == 24)
				            theHour = 0; //Standardize midnight as 0:00
				
				        if ( theHour < 0 || theHour > 23 )
				        {
				            cout 				            exit(1);
				        }
				    }
				} //unnamed namespace
				
				
				namespace DTimeSavitch
				{
				
				    //Uses iostream:
				    istream& operator >>(istream& ins, DigitalTime& theObject)
				    {
				        readHour(theObject.hour);
				        readMinute(theObject.minute);
				        return ins;
				    }
				 
				    ostream& operator 				    {
				        outs 				        if (theObject.minute < 10)
				            outs 				        outs 				        return outs;
				    }
				 
				    bool operator ==(const DigitalTime& time1, const DigitalTime& time2)
				    {
				        return (time1.hour == time2.hour && time1.minute == time2.minute);
				    }
				
				    DigitalTime::DigitalTime(int theHour, int theMinute)
				    {
				        if (theHour < 0 || theHour > 24 || theMinute < 0 || theMinute > 59)
				        {
				            cout 				            exit(1);
				        }
				        else
				        {
				            hour = theHour;
				            minute = theMinute;
				        }
				
				        if (hour == 24)
				            hour = 0; //standardize midnight as 0:00
				    }
				
				    DigitalTime::DigitalTime( )
				    {
				        hour = 0;
				        minute = 0;
				    }  
				
				    int DigitalTime::getHour( ) const
				    {
				        return hour;
				    }
				
				    int DigitalTime::getMinute( ) const
				    {
				        return minute;
				    }
				
				    void DigitalTime::advance(int minutesAdded)
				    {
				        int grossMinutes = minute + minutesAdded;
				        minute = grossMinutes%60;
				
				        int hourAdjustment = grossMinutes/60;
				        hour = (hour + hourAdjustment)%24;
				    }
				
				    void DigitalTime::advance(int hoursAdded, int minutesAdded)
				    {
				        hour = (hour + hoursAdded)%24;
				        advance(minutesAdded);
				    }
				
				
				} //DTimeSavitch