一个日期处理类（日期自增）

[c++]代码库

#include <iostream>

class CDate {
private:
	int m_nDay; // Range: 1 - 30 (lets assume all months have 30 days!
	int m_nMonth; // Range: 1 - 12
	int m_nYear;

	void AddDays(int nDaysToAdd) {
		m_nDay += nDaysToAdd;

		if (m_nDay > 30) {
			AddMonths(m_nDay / 30);

			m_nDay %= 30; // rollover 30th -> 1st
		}
	}

	void AddMonths(int nMonthsToAdd) {
		m_nMonth += nMonthsToAdd;

		if (m_nMonth > 12) {
			AddYears(m_nMonth / 12);

			m_nMonth %= 12; // rollover dec -> jan
		}
	}

	void AddYears(int m_nYearsToAdd) {
		m_nYear += m_nYearsToAdd;
	}

public:

	// Constructor that initializes the object to a day, month and year
	CDate(int nDay, int nMonth, int nYear) :
			m_nDay(nDay), m_nMonth(nMonth), m_nYear(nYear) {
	}
	;

	// Unary increment operator (prefix)
	CDate& operator ++() {
		AddDays(1);
		return *this;
	}

	// postfix operator: differs from prefix in return-type and parameters
	CDate operator ++(int) {
		// Create a copy of the current object, before incrementing day
		CDate mReturnDate(m_nDay, m_nMonth, m_nYear);

		AddDays(1);

		// Return the state before increment was performed
		return mReturnDate;
	}

	void DisplayDate() {
		std::cout << m_nDay << " / " << m_nMonth << " / " << m_nYear;
	}
};

int main() {
	// Instantiate and initialize a date object to 25 May 2008
	CDate mDate(26, 11, 2012);

	std::cout << "The date object is initialized to: ";

	// Display initial date
	mDate.DisplayDate();
	std::cout << std::endl;

	// Applying the prefix increment operator
	++mDate;

	std::cout << "Date after prefix-increment is: ";

	// Display date after incrementing
	mDate.DisplayDate();
	std::cout << std::endl;

	return 0;
}