C++の宿題 年月日を表示します

date.cpp

#include <iostream>
#include <iomanip>
#include <time.h>

using namespace std;

class Date {
  private:
    int year, month, day;
  public:
    Date(void);
    Date(int y, int m = 1, int d = 1); 

    int Year(void)  const { return year; }
    int Month(void) const { return month; }
    int Day(void)   const { return day; }
};


Date::Date(void)
{
  time_t current;
  struct tm* local;

  time(&current);
  local = localtime(&current);
  year  = local->tm_year + 1900;
  month = local->tm_mon + 1;
  day   = local->tm_mday;
}

Date::Date(int y, int m, int d)
{
  year = y; month = m; day = d;
}

ostream& operator<<(ostream& s, const Date& x)
{
  return (s << setfill('0')
            << setw(4) << x.Year()  << "年"
            << setw(2) << x.Month() << "月"
            << setw(2) << x.Day()   << "日");
}

int main(void)
{
  Date MyBirthday(1992, 1, 4); 

  cout << "MyBirthday = " << MyBirthday << '\n';

  return 0;
}