Date class.

#include <iostream>

typedef unsigned char uchar;
typedef unsigned int ulong;

//Создайте класс Data
//с операциями +(int), +=(int), =, ==, !=, >, < , >=, < =, ++ и --
//(int) - количество дней

class CData{
    uchar m_day;
    uchar m_month;
    ulong m_year;
    bool __isleab(){
        if(!(m_year % 400)) return true;
        else if (!(m_year % 100)) return false;
        else if(!(m_year % 4)) return true;
        return false;
    }

    uchar __daysinmonth(uchar month){
        uchar days[] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
        if(__isleab()) days[1] = 29;
        return days[month-1];
    }

    int __compare (CData b){
        if(m_year < b.m_year) return -1;
        else if(m_year == b.m_year){
            if(m_month < b.m_month) return -1;
            else if(m_month == b.m_month){
                if(m_day < b.m_day) return -1;
                else if(m_day == b.m_day) return 0;
            }
        }

        return 1;
    }

public:
    CData(uchar day, uchar month, ulong year){
        m_day = day; m_month = month; m_year = year;
    }

    CData operator += (int d){
        while(d){
            if(d + m_day <= __daysinmonth(m_month) && d + m_day > 0){ m_day += d; d = 0; }
            else{
                if(d + m_day > 0){
                    d -= __daysinmonth(m_month);
                    m_month++;
                    if(m_month == 13){m_month = 1; m_year++;}
                }
            }
        }
    }

    bool operator <= (CData b){ return __compare(b) <= 0;}
    bool operator >= (CData b){ return __compare(b) >= 0;}

    bool operator < (CData b){  return __compare(b) < 0;}
    bool operator > (CData b){  return __compare(b) > 0;}
    bool operator == (CData b){ return !__compare(b);   }
    bool operator != (CData b){ return __compare(b);    }

    CData operator ++ (){
        CData _r = *this;
        *this += 1;
        return _r;
    }

    CData operator -- (){
        CData _r = *this;
        *this += (-1);
        return _r;
    }
};

const CData operator + (CData a, int b){
    CData c = a; c += b;
    return c;
}

const CData operator + (int b, CData a){
    CData c = a; c += b;
    return c;
}